WO2023281021A1

WO2023281021A1 - Engineered extracellular vesicles for intracellular delivery

Info

Publication number: WO2023281021A1
Application number: PCT/EP2022/068998
Authority: WO
Inventors: Tingqing GUO; Ying Lyu; Qifeng HAN
Original assignee: Novo Nordisk A/S
Priority date: 2021-07-08
Filing date: 2022-07-07
Publication date: 2023-01-12

Abstract

The present invention relates to engineered extracellular vesicles. More specifically, the present invention relates to an isolated EV comprising a fusogenic protein, a binding moiety to a cell membrane protein, and a molecule of interest, wherein the fusogenic protein and the binding moiety are displayed on the EV separately. The EV disclosed in the present invention shows improved intracellular delivery efficiency. The present invention also relates to a pharmaceutical composition comprising the EV and a method of delivering a molecule of interest to a recipient cell.

Description

DESCRIPTION

TITLE: ENGINEERED EXTRACELLULAR VESICLES FOR INTRACELLULAR DELIVERY

TECHNICAL FIELD

The present invention relates to isolated or engineered extracellular vesicles (EVs) . The present invention also relates to a pharmaceutical composition comprising the extracellular vesicles and a method of delivering a molecule of interest to a recipient cell.

BACKGROUND

EVs are cell-derived membranous particles released by cells. EVs carry nucleic acids, proteins, lipids and other bioactive substances to play a role in the body’s physiological and pathological processes. Compared to synthetic carriers such as liposomes and nanoparticles, the endogeneity and heterogeneity of EVs give them extensive and unique advantages in the field of disease diagnosis and treatment.

A big challenge in the industry for intracellular delivery of cargos (protein, peptide, RNA or DNA, etc) is that, even when there’s successful cellular uptake of the cargo facilitated by any given delivery system, majority of the cargo will be trapped and degraded in the endosomes to lysosomes of the cells.

Although native EVs are expected to be able to enable functional intracellular delivery, it’s still desirable to further engineer EVs and improve the delivery efficiency, and as such reduce the clinical doses for patients, which is clinically meaningful from both efficacy and safety perspective.

SUMMARY

The present invention provides an isolated particle comprising: 1) a lipid membrane, 2) a fusogenic protein, 3) a binding moiety to a membrane protein and 4) a molecule of interest, wherein the fusogenic protein and the binding moiety are displayed on the EV separately. In some embodiments, the lipid membrane is a mono- or bi-layer lipid structure.

Specifically, the present invention provides a modified/engineered EV. More specifically, the present invention provides an EV comprising both a fusogenic protein and a binding moiety to a membrane protein. An EV comprising both a fusogenic protein and a binding moiety to a membrane protein surprisingly shows an unexpected benefit (i.e. significantly improved delivery efficiency) in delivery of a molecule of interest (e.g. a cargo) intracellularly.

In one aspect, the present invention relates to an isolated EV comprising: i) a fusogenic protein, ii) a binding moiety to a cell membrane protein, and iii) a molecule of interest, wherein the fusogenic protein and the binding moiety are displayed on the EV separately.

In one aspect, the present invention further relates to a cell capable of heterologously expressing a fusogenic protein, a binding moiety to a cell membrane protein and a molecule of interest, wherein the fusogenic protein and the binding moiety are expressed separately in the cell.

In one aspect, the present invention further relates to a pharmaceutical composition comprising the EV of the present invention, and a pharmaceutically acceptable excipient.

In one aspect, the present invention further relates to a method of delivering a molecule of interest to a recipient cell, which comprises contacting the recipient cell with an effective amount of the EV of the present invention.

In one aspect, the present invention further relates to a cell comprising one or more vectors, wherein the vectors comprise a nucleic acid sequence encoding a fusogenic protein, a nucleic acid sequence encoding a binding moiety to a cell membrane protein, and a nucleic acid sequence encoding a molecule of interest, and wherein the nucleic acid sequence encoding the fusogenic protein and the nucleic acid sequence encoding the binding moiety are located in separate gene constructs.

In one aspect, the present invention further relates to a preparation method of the EV of the present invention, comprising: a) culturing eukaryotic cells in a medium, wherein said eukaryotic cells overexpress: 1) the fusogenic protein; 2) the binding moiety to a cell membrane protein; and 3) the molecule of interest, wherein the fusogenic protein and the binding moiety are expressed separately, and wherein said eukaryotic cells release EV by secreting said EV into the medium, and b) isolating the secreted EV.

In one aspect, the present invention further relates to the EV of the present invention, the pharmaceutical composition of the present invention, or the cell of the present invention, for use as a medicament. In one aspect, the present invention further relates to use of the EV of the present invention, the pharmaceutical composition of the present invention, or the cell of the present invention in the manufacture of a medicament.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 shows the isolation and characterization of EVs. (A) Schematic diagram of isolation processes. (B) Representative transmission electron microscopy (TEM) image of isolated EVs. Scale bar: 100 nm (C) Size distribution of EVs analysed by NanoFCM. (D) Representative dot-blot using Exoray.

Fig. 2 shows the schematic diagrams of engineered EVs. (A) Display of a fusogenic protein in EVs. (B) Display of a binding moiety to a cell membrane protein in EVs. (C) Co display of a fusogenic protein with a binding moiety to a cell membrane protein in EVs.

Fig. 3 shows the intracellular delivery of EVs by display of VSVG or VSVG mutant in EVs (A) and by display of VSVG with inhibiting LDLR binding (B).

Fig. 4 shows that display of Syncytin-1 on EVs didn’t demonstrate significant intracellular delivery in cells and increasing EV binding to cells by overexpressing SLC1 A5 didn’t improve intracellular delivery efficiency either.

Fig. 5 shows that the co-display of a fusogenic protein with a TFRC affibody (TFRafb) in EVs showed a synergistic effect on intracellular delivery.(A) Co-display of TFRafb and Syncytin-1. (B) Co-display of TFRafb and VSVG_K47Q_R354A.

Fig. 6 shows that the intracellular delivery efficiency could be inhibited by TFRC affibody or TF in a dose-dependent way in EVs with co-display of a fusogenic protein with a TFRC affibody.

Fig. 7 shows that directly fusing the binding moiety of a membrane protein to a fusion protein significantly decreased the intracellular delivery efficiency of EVs. (A) fusing TFRafb to VSVG. (B) fusing TFRafb to Syncytin-1.

Fig. 8 shows that the co-display of Syncytin-1 with HER2 affibody (HER2afb) in EVs showed a synergistic effect on intracellular delivery.

DESCRIPTION

The present invention provides an isolated particle comprising: 1) a lipid membrane, 2) a fusogenic protein, 3) a binding moiety to a membrane protein and 4) a molecule of interest, wherein the fusogenic protein and the binding moiety are displayed on the EV separately. In some embodiments, the lipid membrane is a mono- or bi-layer lipid structure. Specifically, the present invention provides a modified/engineered EV with improved delivery efficiency. More specifically, the present invention provides an EV comprising both a fusogenic protein and a binding moiety to a membrane protein, which shows a synergistic effect on intracellular delivery of a molecule of interest (e.g., a cargo).

In another aspect, the present invention has demonstrated that EVs displaying a binding moiety to a membrane protein (e.g. TFRC affibody) alone shows a very low efficiency in delivering a cargo into a recipient cell containing the membrane protein, however, codisplay of the binding moiety and a fusogenic protein on EVs can improve the delivery efficiency in a synergistic way.

In another aspect, the inventors of the present invention have surprisingly found that some endogenous fusogenic proteins (e.g. syncytin-1), despite showing poor intracellular delivery effect when used alone in EVs, could improve intercellular delivery dramatically in combination with a binding moiety to a membrane protein. Compared with an exogenous viral fusogenic protein (e.g., VSVG), an endogenous fusogenic protein is expected to generate lower immunogenicity in mammal.

In one aspect, the present invention further relates to a cell capable of heterologously expressing a fusogenic protein, a binding moiety to a cell membrane protein and a molecule of interest, wherein the fusogenic protein and the binding moiety are expressed separately.

In some embodiments, the binding moiety and an EV’s transmembrane moiety are expressed as a fusion molecule.

In some embodiments, the EV’s transmembrane moiety is Lamp2b.

In one aspect, the present invention further relates to a method of delivering a molecule of interest to a recipient cell, which comprises contacting the recipient cell with an effective amount of the EVs of the present invention. In some embodiments, the recipient cell is in vitro.

In some embodiments, the recipient cell is in vivo.

In some embodiment, the recipient cell contains the membrane protein in its cell membrane.

In some embodiments, the nucleic acid sequence encoding a fusogenic protein and the nucleic acid sequence encoding a binding moiety to a cell membrane protein exist in two vectors.

In some embodiments, the nucleic acid sequence encoding a binding moiety is operable linked to a nucleic acid sequence of an EV’s transmembrane moiety in one vector.

In some embodiments, the EV’s transmembrane moiety is Lamp2b.

In one aspect, the present invention further relates to a preparation method of the EV of the present invention, comprising: c) culturing cells in a medium, wherein said cells overexpress: 1) the fusogenic protein; 2) the binding moiety to a cell membrane protein; and 3) the molecule of interest, wherein the fusogenic protein and the binding moiety are expressed separately, and wherein the cells release EV by secreting said EV into the medium, and d) isolating the secreted EV.

In some embodiments, the cells are also named as “producer cells” or “donor cells”.

In some embodiments, the cells are prokaryotic or eukaryotic cells.

In some embodiments, the fusogenic protein and the binding moiety are expressed separately in the eukaryotic cells.

In some embodiments, the EV’s transmembrane moiety is Lamp2b. In one aspect, the present invention further relates to the EV of the present invention, the pharmaceutical composition of the present invention, or the cell of the present invention, for use as a medicament.

In one aspect, the present invention further relates to use of the EV of the present invention, the pharmaceutical composition of the present invention, or the cell of the present invention in the manufacture of a medicament.

In some embodiments, the EV is selected from the group consisting of an exosome, a microvesicle, an ectosome, a virosome, a microparticle and an oncosome.

In some embodiments, the fusogenic protein is an exogenous viral fusogenic protein.

In some embodiments, wherein the exogenous viral fusugenic protein is a viral fusogenic glycoprotein.

In some embodiments, the exogenous viral fusogenic protein is from an enveloped virus belonging to the families of Orthomyxoviridae, Paramyxoviridae, Retroviridae,

Filoviridae or Coronaviridae.

In some embodiments, the exogenous viral fusogenic protein is vesicular stomatitis virus glycoprotein (VSV-G) or the envelope glycoprotein of Lymphocytic choriomeningitis virus (LCMV_Gp), or the mutant thereof.

In some embodiments, the fusogenic protein is an endogenous fusogenic protein.

In some embodiments, the fusogenic protein is an endogenous viral fusogenic protein.

In some embodiments, the endogenous viral fusogenic protein is derived from a human retrovirus.

In some embodiments, the endogenous viral fusogenic protein is syncytin-1 or the mutant thereof.

In some embodiments, the membrane protein is a membrane receptor.

In some embodiments, the membrane receptor is a membrane receptor internalized by endocytosis.

In some embodiments, the membrane receptor is selected from the group consisting of a transferrin receptor (TFR), a low density lipoprotein receptor (LDLR), a neonatal Fc receptor (FcRn), an epidermal growth factor receptor (EGFR), a human epidermal growth factor receptor 2 (HER2), an asialoglycoprotein receptor (ASGPR), chemokine receptor, and riboflavin transporters (RFVT) . In some embodiments, the binding moiety is protein, peptide, antibody or the antigen binding fragment thereof, affibody, nanobody, aptamer, DNA, RNA, lipid, or carbohydrate.

In some embodiments, the fusogenic protein is capable of being incorporated into the membrane of an EV.

In some embodiments, the binding moiety is displayed on the surface of the EV.

In some embodiments, the binding moiety is displayed on the external surface of the EV.

In some embodiments, the binding moiety is displayed on the external surface of the EV through an EV’s transmembrane moiety, e.g. Lamp2b.

In some embodiments, the fusogenic protein and the binding moiety are displayed separately on the surface of the EV.

In some embodiments, the EV is a surface-engineered EV.

In some embodiments, the producer cells or donor cells or recipient cells are HEK293 cells, e.g. HEK293-6E cells.

In some embodiments, the molecule of interest is a biologically active molecule.

In some embodiments, the molecule of interest is protein.

In some embodiments, the molecule of interest is delivered into an EV through an adaptor protein. In some embodiments, the molecule of interest is associated with an EV through an adaptor protein. In some embodiments, the molecule of interest and an adaptor protein are present in a fusion protein. In some embodiments, the adaptor protein is arrestin domain-containing protein 1 (ARRDC1). In some embodiments, the adaptor protein is human arrestin domain-containing protein 1 (hARRDCI).

In some embodiments, the molecule of interest is cyclization recombination enzyme

(CRE).

Definitions

Unless otherwise specified, “a” or “an” means “one or more”. As such, the terms "a" (or "an"), "one or more," and "at least one" can be used interchangeably herein.

As used herein, the terms "extracellular vesicle," "EV," and grammatical variants thereof, are used interchangeably and refer to a cell-derived vesicle comprising a membrane that encloses an internal space. Extracellular vesicles comprise all membrane-bound vesicles (e.g, exosomes, microvesicles) that have a smaller diameter than the cell from which they are derived. In some aspects, extracellular vesicles range in diameter from 20 nm to 1000 nm, and can comprise various macromolecular payload/cargo either within the internal space (i.e., lumen), displayed on the external surface of the extracellular vesicle, and/or spanning the membrane. In some aspects, the payload/cargo can comprise adeno- associated virus (AAV), nucleic acids (e.g., DNA or RNA, such as antisense oligonucleotides, siRNA, shRNA, or mRNA), morpholinos, proteins, carbohydrates, lipids, small molecules, antigens, vaccines, vaccine adjuvants, and/or combinations thereof. In some aspects, the term extracellular vesicle or EV refers to a population of extracellular vesicles (EVs). In certain aspects, an extracellular vehicle comprises a scaffold/transmembrane moiety. By way of example and without limitation, extracellular vesicles include apoptotic bodies, fragments of cells, vesicles derived from cells by direct or indirect manipulation (e.g, by serial extrusion or treatment with alkaline solutions), vesiculated organelles, and vesicles produced by living cells (e.g, by direct plasma membrane budding or fusion of the late endosome with the plasma membrane). Extracellular vesicles can be derived from a living or dead organism, explanted tissues or organs, prokaryotic or eukaryotic cells, and/or cultured cells. In some aspects, the extracellular vesicles are produced by cells that express one or more transgene products.

As used herein, the term "exosome" refers to an extracellular vesicle with a diameter between 20-300 nm (e.g, between 40-200 nm, 40-150nm). Exosomes comprise a membrane that encloses an internal space (i.e., lumen), and, in some instance, can be generated from a cell (e.g, producer cell) by direct plasma membrane budding or by fusion of the late endosome with the plasma membrane. In certain instances, an exosome comprises a scaffold/transmembrane moiety. As described infra, exosome can be derived from a producer cell, and isolated from the producer cell based on its size, density, biochemical parameters, or a combination thereof. In some instance, the exosomes of the present disclosure are produced by cells that express one or more transgene products. In some instance, the term exosome refers to a population of exosomes.

In some instances, the EVs, e.g, exosomes or microvesicles, of the present disclosure can comprise various macromolecular payloads either within the internal space (i.e., lumen), displayed on the external (exterior) surface or internal (luminal) surface of the EV, and/or spanning the membrane. In some instances, the payload can comprise, e.g, nucleic acids, proteins, carbohydrates, lipids, small molecules, and/or combinations thereof.

In certain instances, an EV, e.g, an exosome, comprises a scaffold/transmembrane moiety, e.g, a scaffold protein or a fragment thereof. In some instances, the EVs of the present disclosure are without limitation nanovesicles, microsomes, microvesicles, extracellular bodies, apoptotic bodies, ectosomes, virosomes, microparticls or oncosomes. EVs, e.g. exosomes or microvesicles, produced from cells can be collected from the culture medium by any suitable method. Typically, a preparation of exosomes can be prepared from cell culture or tissue supernatant by centrifugation, filtration or combinations of these methods. For example, EVs, e.g. exosomes or microvesicles, can be prepared by differential centrifugation, that is low speed (<20000 g) centrifugation to pellet larger particles followed by high speed (>100000 g) centrifugation to pellet EVs, e.g. exosomes or microvesicles, size filtration with appropriate filters (for example, 0.22 pm filter), gradient ultracentrifugation (for example, with sucrose gradient) or a combination of these methods. In accordance with the present invention, the EVs, e.g. exosomes or microvesicles, are loaded with exogenous protein and/or peptide. In particular, in accordance with the present invention, the protein or peptide can be loaded in the EVs, e.g. exosomes or microvesicles, by overexpression of the protein or peptide in the cell which is used to produce the EVs, e.g. exosomes or microvesicles, so that the EVs, e.g. exosomes or microvesicles, can be loaded with the peptide or protein. In another aspect, EVs, e.g. exosomes or microvesicles, are prepared and then loaded with the desired protein and/or peptide for delivery. Exogenous refers to a protein with which the EV, e.g. exosome or microvesicle is not normally associated. Extracellular vesicles may be obtained from so-called extracellular vesicle (EV) producer cells. Extracellular vesicles may be taken up by so-called extracellular vesicle (EV) recipient cells. As used herein, the term “recipient cell” may be interchangeably with the term “target cell.”

As used herein, the term “fusogenic protein”, also named as “fusogen”, refers to a protein that induces a fusion between cells or membrane vesicles surrounded by a plasma membrane. The representative fusogenic protein as such may include vesicular stomatitis virus glycoprotein (VSV-G), and may additionally include tat protein of HIV, herpesvirus glycoprotein B (gB) such as HSV-1 gB, EBV gB, thogoto virus G protein, baculovirus gp64 such as AcMNPV gp64, Borna disease virus glycoprotein (BDV G), LCMV-gp, etc.

In some embodiments, the fusogenic protein is a viral fusogenic protein, e.g., HA, HIV-1 ENV, gp120, or VSV-G. In some embodiments, the fusogenic protein is a endogenous viral fusogenic protein, such as syncytin-1. In some embodiments, the fusogenic protein is a endogenous human fusogenic protein, such as myomaker, myomixer, myomerger, ADAM 12, ADAM2, IZUM01 or IZUM01R.

As used herein, the term "a viral fusogenic protein" or “a viral fusion protein” can refer to a viral glycoprotein that aids in driving the fusion process between the membranes of a virus and a target cell. In some instances, a viral fusogenic protein can include a fusion glycoprotein from an enveloped virus belonging to the families of Orthomyxoviridae, Paramyxoviridae, Retroviridae, Filoviridae or Coronaviridae. Other examples of viral fusion proteins are listed below.

As used herein, the term "exogenous viral fusogenic protein" can refer to viral fusogenic proteins that are derived from exogenous viruses. Such exogenous viruses are viruses that are not part of the human genome ("exogenous" to the genome) and existing ("circulating") in nature. Exogenous viral fusogenic proteins can therefore include any viral envelope glycoprotein from a virus that is found in nature and is able to mediate membrane fusion with cells (e.g., human cells).

As used herein, the term "endogenous viral fusogenic protein" can refer to viral fusogenic proteins derived from viruses that infected human ancestors millions of years ago and have integrated into the human genome ("endogenous" to the genome, i.e., within it). About 8 percent of human DNA is viral in origin. Most of that DNA has become inactivated, but there are a number of biologically active endogenous viral proteins that include functional endogenous viral fusogenic proteins.

In some embodiments, the viral fusogenic protein can be derived from a population of exogenous viral fusogenic proteins. Non-limiting examples of viral fusogenic proteins derived from a population of exogenous viral fusogenic proteins can include vesicular stomatitis virus glycoprotein (VSV-G), influenza hemagglutinin, HIV (e.g., gpl6, which is processed into gpl20 and gp41 subunits), Herpes simplex 1 (e.g., glycoprotein B (gB) and gH/gL), measles (e.g., hemagglutinin (H) and fusion (F) proteins), Ebola virus (e.g., glycoprotein (GP)), SARS (e.g., spike (S) protein, which is processed into SI and S2 subunits), SARS-CoV-2b (e.g., spike (S) protein, which is processed into SI and S2 subunits), MERS (e.g., spike (S) protein, which is processed into SI and S2 subunits),

Mokola virus (e.g., glycoprotein (G)), murine leukemia vims (e.g., surface (SU) and transmembrane (TM) proteins), Zika (e.g., prM-E), hepatitis C vims (e.g., glycoprotein El), varicella zoster virus (e.g., glycoprotein E (gE)), Epstein-Barr vims (e.g., glycoprotein B (gB) and gH/gL), and cytomegalovims (e.g., glycoprotein B (gB) and gH/gL).

In some embodiments, the viral fusion protein can be derived from a population of endogenous viral fusion proteins. Non-limiting examples of viral fusogenic protein derived from a population of endogenous viral fusogenic proteins can include Syncytin-I (also known as ERVWE-1) (e.g., surface (SU) and transmembrane (TM)), Syncytin-2 (e.g., surface (SU) and transmembrane (TM)), human endogenous retrovirus type K 108 (HERV-K 108) (e.g., surface (SU) and transmembrane (TM)), and EnvPbl (e.g., surface (SU) and transmembrane (TM)). The term “binding moiety” or “binding molecule” as used herein is any molecule, or portion or fragment thereof, that can bind specifically or selectively to a membrane protein, e.g., a cell membrane protein, and which includes proteins, nucleic acids, carbohydrates, lipids, low molecular weight compounds, and fragments thereof, each having the ability to bind to one or more of a soluble protein, a cell surface protein, a cell surface receptor protein, an intracellular protein, a carbohydrate, a nucleic acid, a hormone, or a low molecular weight compound (small molecule drug), or a fragment thereof. The binding moiety, in some instances, is a protein belonging to the immunoglobulin superfamily, or a nonimmunoglobulin binding molecule. In some instances, a binding moiety is an antibody, antibody fragment, bispecific antibody or other antibody-based molecule or compound. Other examples of binding moieties are known in the art and may be used, such as aptamers, avimers, receptor-binding ligands, nucleic acids, biotin-avidin binding pairs, binding peptides or proteins, etc.

The binding moiety is displayed on the surface of the EV, e.g. exosome or microvesicle, by displaying it as a fusion molecule with an EV’s transmembrane moiety, e.g. protein or lipid. A number of proteins are known to be associated with EVs, e.g. exosomes or microvesicles; that is they are incorporated into the EV, e.g. exosome or microvesicle, as it is formed. Examples of EV’s transmembrane moiety include but are not limited to Lamp-1 , Lamp-2, CD13, CD86, Flotillin, Syntaxin-3, CD2, CD36, CD40, CD40L, CD41a, CD44, CD45, ICAM-1 , Integrin alpha4, LiCAM, LFA-1 , Mac-1 alpha and beta, VtMA and B, CD3 epsilon and Zeta, CD9, CD18, CD37, CD53, CD63, CD81 , CD82, CXCR4, FcR, GluR2/3, HLA-DM (MHC II), immunoglobulins, MHC-I or MHC-II components, TCR beta and tetraspanins. In some embodiments, the binding moiety is expressed on the surface of the EV, e.g. exosome or microvesicle, by expressing it as a fusion protein with an EV’s transmembrane protein selected from the group consisting of Lamp-1 , Lamp-2, CD13, CD86, Flotillin and Syntaxin-3. In a particular embodiment the EV’s transmembrane protein is Lamp-2, e.g. Lamp-2b.

As used herein, that “the fusogenic protein and the binding moiety are displayed on the EV separately” means:

1) the fusogenic protein and the binding moiety are not fusing or conjugating with each other directly, or

2) the fusogenic protein and the binding moiety are not fusing or conjugating with each other with spacer or linker sequences, or

3) the fusogenic protein and the binding moiety are not located in the same fusion protein/molecule. Spacer or linker sequences may be provided between the binding moiety and the EV’s transmembrane protein for example to avoid interference from the binding moiety in the folding of the EV’s transmembrane protein. Suitable amino acids for incorporation in linkers include but are not limited to alanine, arginine, serine or glycine. In some embodiments, suitable linkers include Ala-Arg and Ser-Gly-Gly. In some embodiments, the linker comprises GGGGSGGGGSGGGGS.

The term “a membrane receptor”, also known as “a cell surface receptor” or “a transmembrane receptor” is a receptor that is embedded in the plasma membrane of cells. They act in cell signalling by receiving (binding to) extracellular molecules. In some instances, a membrane receptor refers to a receptor that can transport/uptake molecules (e.g., ions, small molecules, and macromolecules) or transmit signals into cells. In some instances, a membrane receptor refers to a receptor that can mediate endocytosis pathway in cells, which is also known as an endocytic membrane receptor or a membrane receptor internalized by endocytosis. Examples of membrane receptors include but are not limited to transferrin receptor (TfR), Low density lipoprotein receptor (LDLR), Epidermal growth factor receptor (EGFR), polymeric immunoglobulin receptor (p I g R) , neonatal Fc receptor (FcRn), G- protein coupled receptors (GPCR), asialoglycoprotein receptor (ASGPR), chemokine receptor, and riboflavin transporters (RFVT).

In some instances, the endocytic membrane receptor includes but is not limited to

1) G-protein coupled receptor (GPCR): Adrenoceptor b1-3 (ADRB1-3), chemokine C-C motif receptor 5 (CCR5), chemokine C-X-C motif 1-2/4 (CXCR1-2/4) or Coagulation factor II receptor (F2R), GLP-1 receptor (GLP1R),

2) tyrosine kinase receptors (RTK): Colony stimulating factor 1 receptor (CSF1R), Epidermal growth factor receptor (EGFR), Erb-b2 receptor tyrosine kinase 2-4 (ERBB2-4, HER2-4), Fibroblast growth factor receptor 1-4 (FGFR1-4), Fms-related tyrosine kinase 1/Vascular endothelial growth factor receptor 1 (FLT1 orVEGFRI), Insulin-like growth factor 1-2 receptor (IGF1-2R), Kinase insert domain receptor/Vascular endothelial growth factor receptor 2 (KDR orVEGFR2) , Tyrosine-protein kinase met (MET), Neurotrophic tyrosine kinase receptor type 1 (NTRK1), Platelet-derived growth factor a receptor (PDGFRA), Transforming growth factor b receptor 1-2 (TGFBR1-2), Insulin receptor (INSR), growth hormone receptor (GHR), or

3) transmembrane receptor (TRM): Folate receptor 1-3 (FOLR1-3), Low density lipoprotein receptor (LDLR) or Transferrin receptor (TFRC), Fc receptors (e.g. FcRn, FCGR2B), asialoglycoprotein receptor (ASGPR), Mannose Receptors (e.g. MRC1 , MRC2, M6PR). (Endocytosis and membrane receptor internalization: implication of F-BAR protein Carom. Front Biosci (Landmark Ed). 2017 Mar 1;22(9): 1439-1457.)

In some instances, the endocytosis process is dependent on clathrin, i.e. clathrin- dependent endocytosis (CDE). In some instances, the membrane receptors are internalized through CDE process. In some instances, the membrane receptors recycle back to the plasma membrane after cellular internalization. Receptors such as the transferrin receptor, LDL receptor, and HER2 continuously recycle back to the plasma membrane immediately after cellular internalization.

The term “a molecule of interest” or "a biologically active molecule" or “a cargo” as use herein refers to any molecule that has a therapeutic or prophylactic effect in a subject in need thereof or be used for diagnostic purposes. Accordingly, by way of example, the term “a molecule of interest” or "a biologically active molecule" includes proteins (e.g, antibodies, polypeptides, proteins, and derivatives, fragments, and variants thereof), lipids and derivatives thereof, carbohydrates (e.g, glycan portions in glycoproteins), nucleic acids (e.g., siRNA, aptamers, short hairpin RNA, antisense oligonucleotides, ribozymes, microRNA mimics or DNA) or small molecules. The molecule of interest can be loaded into EVs of the present invention through known laboratory techniques.

Following is a non-limiting list of embodiments of the present invention.

EMBODIMENTS

1. An extracellular vesicle (EV) comprising: i) a fusogenic protein, ii) a binding moiety to a cell membrane protein, and, iii) a molecule of interest, wherein the fusogenic protein and the binding moiety are displayed on the EV separately.

2. The EV according to embodiment 1 , wherein the EV is an isolated EV.

3. The EV according to embodiment 1 or 2, which is selected from the group consisting of an exosome, a microvesicle, an ectosome, a virosome, a microparticle and an oncosome.

4. The EV according to any one of embodiments 1-3, wherein the fusogenic protein is an exogenous viral fusogenic protein. 5. The EV according to embodiment 4, wherein the exogenous viral fusogenic protein is a glycoprotein.

6. The EV according to embodiment 4 or 5, wherein the exogenous viral fusogenic protein is from an enveloped virus.

7. The EV according to embodiment 6, wherein the enveloped virus is selected from the group consisting of Orthomyxoviridae, Paramyxoviridae, Retroviridae, Filoviridae or Coronaviridae.

8. The EV according to any one of embodiments 4-7, wherein the exogenous viral fusogenic protein is a vesicular stomatitis virus glycoprotein (VSV-G) or an envelope glycoprotein of LCMV (LCMV_Gp), or a mutant thereof.

9. The EV according to embodiment 1 or 2, wherein the fusogenic protein is an endogenous fusogenic protein.

10. The EV according to embodiment 9, wherein the fusogenic protein is an endogenous viral fusogenic protein.

11. The EV according to embodiment 9 or 10, wherein the endogenous viral fusogenic protein is from a human retrovirus.

12. The EV according to any one of embodiments 9-11 , wherein the endogenous viral fusogenic protein is syncytin-1 or a mutant thereof.

13. The EV according to embodiment 1 or 2, wherein the membrane protein is a membrane receptor, e.g. a membrane receptor internalized by endocytosis.

14. The EV according to embodiment 13, wherein the membrane receptor is selected from the group consisting of a transferrin receptor (TFR), a low density lipoprotein receptor (LDLR), a neonatal Fc receptor (FcRn), an epidermal growth factor receptor (EGFR), a human epidermal growth factor receptor 2 (HER2), an asialoglycoprotein receptor (ASGPR), chemokine receptor, and riboflavin transporters (RFVT) .

15. The EV according to any one of the preceding embodiments, wherein the binding moiety is protein, peptide, antibody or an antigen binding fragment thereof, affibody, nanobody, aptamer, DNA, RNA, lipid, or carbohydrate.

16. The EV according to any one of the preceding embodiments, wherein the fusogenic protein is capable of being incorporated into the membrane of an EV.

17. The EV according to any one of the preceding embodiments, wherein the binding moiety is displayed on the surface of the EV.

18. The EV according to any one of the preceding embodiments, wherein the binding moiety is displayed on the surface of the EV through a transmembrane moiety of EV, e.g. Lamp2b. 19. The EV according to any one of the preceding embodiments, wherein the fusogenic protein and the binding moiety are displayed separately on the surface of the EV.

20. A pharmaceutical composition comprising an EV according to any one of the preceding embodiments, and a pharmaceutically acceptable excipient.

21. A method of delivering a molecule of interest to a recipient cell, the method comprising contacting the recipient cell with an effective amount of the EV vesicle according to any one of embodiments 1-19.

22. The method according to embodiment 21 , wherein the recipient cell is in vitro.

23. The method according to embodiment 21 , wherein the recipient cell is in vivo.

24. A preparation method of the EV according to any one of embodiments 1-19, comprising a) culturing eukaryotic cells in a medium, wherein said eukaryotic cells overexpress: 1) the fusogenic protein; 2) the binding moiety to a cell membrane protein; and 3) the molecule of interest, wherein the fusogenic protein and the binding moiety are expressed separately, and wherein said eukaryotic cells release EV by secreting said EV into the medium, and b) isolating the secreted EV.

25. The preparation method according to embodiment 24, wherein the fusogenic protein and the binding moiety are expressed separately in the eukaryotic cells.

26. The preparation method according to embodiment 24, wherein the binding moiety and a transmembrane moiety of EV are expressed as a fusion molecule.

27. The preparation method according to embodiment 26, wherein the transmembrane moiety of EV is Lamp2b.

28. A cell capable of heterologously expressing a fusogenic protein, a binding moiety to a cell membrane protein and a molecule of interest, wherein the fusogenic protein and the binding moiety are expressed separately.

29. The cell according to embodiment 28, wherein the fusogenic protein is an exogenous viral fusogenic protein.

30. The cell according to embodiment 29, wherein the exogenous viral fusogenic protein is a viral fusogenic glycoprotein.

31. The cell according to embodiment 29 or 30, wherein the exogenous viral fusogenic protein is from an enveloped virus belonging to the families of Orthomyxoviridae, Paramyxoviridae, Retroviridae, Filoviridae or Coronaviridae. 32. The cell according to any one of embodiments 29-31 , wherein the exogenous viral fusogenic protein is vesicular stomatitis virus glycoprotein (VSV-G) or the envelope glycoprotein of LCMV (LCMV_Gp), or the mutant thereof.

33. The cell according to embodiment 28, wherein the fusogenic protein is an endogenous fusogenic protein.

34. The cell according to embodiment 33, wherein the fusogenic protein is an endogenous viral fusogenic protein.

35. The cell according to embodiment 33 or 34, wherein the endogenous viral fusogenic protein is derived from a human retrovirus.

36. The cell according to any one of embodiments 33-35, wherein the endogenous viral fusogenic protein is syncytin-1 or the mutant thereof.

37. The cell according to embodiment 28, wherein the membrane protein is a membrane receptor, e.g. a membrane receptor internalized by endocytosis.

38. The cell according to embodiment 37, wherein the membrane receptor is selected from the group consisting of a transferrin receptor (TFR), a low density lipoprotein receptor (LDLR), a neonatal Fc receptor (FcRn), an epidermal growth factor receptor (EGFR), a human epidermal growth factor receptor 2 (HER2), an asialoglycoprotein receptor (ASGPR), chemokine receptor, and riboflavin transporters (RFVT) .

39. The cell according to any one of embodiments 28-38, wherein the binding moiety is protein, peptide, antibody or the antigen binding fragment thereof, affibody, nanobody, aptamer, DNA, RNA, lipid, or carbohydrate.

40. The cell according to any one of embodiments 28-39, wherein the fusogenic protein is capable of being incorporated into the membrane of an EV.

41. The cell according to any one of embodiments 28-40, wherein the binding moiety and a transmembrane moiety of EV are expressed as a fusion molecule.

42. The cell according to embodiment 41 , wherein the transmembrane moiety of EV is Lamp2b.

43. A cell comprising one or more vectors, wherein the one or more vectors comprise a nucleic acid sequence encoding a fusogenic protein, a nucleic acid sequence encoding a binding moiety to a cell membrane protein, and a nucleic acid sequence encoding a molecule of interest, and wherein the nucleic acid sequence encoding the fusogenic protein and the nucleic acid sequence encoding the binding moiety are located in separate gene constructs.

44. The cell according to embodiment 43, wherein the fusogenic protein is an exogenous viral fusogenic protein. 45. The cell according to embodiment 44, wherein the exogenous viral fusugenic protein is a viral fusogenic glycoprotein.

46. The cell according to embodiment 44 or 45, wherein the exogenous viral fusogenic protein is from an enveloped virus belonging to the families of Orthomyxoviridae, Paramyxoviridae, Retroviridae, Filoviridae or Coronaviridae.

47. The cell according to any one of embodiments 44-46, wherein the exogenous viral fusogenic protein is vesicular stomatitis virus glycoprotein (VSV-G) or the envelope glycoprotein of LCMV (LCMV_Gp), or the mutant thereof.

48. The cell according to embodiment 43, wherein the fusogenic protein is an endogenous fusogenic protein.

49. The cell according to embodiment 48, wherein the fusogenic protein is an endogenous viral fusogenic protein.

50. The cell according to embodiment 48 or 49, wherein the endogenous viral fusogenic protein is derived from a human retrovirus.

51. The cell according to any one of embodiments 48-50, wherein the endogenous viral fusogenic protein is syncytin-1 or a mutant thereof.

52. The cell according to embodiment 43, wherein the membrane protein is a membrane receptor, e.g. a membrane receptor internalized by endocytosis.

53. The cell according to embodiment 52, wherein the membrane receptor is selected from the group consisting of a transferrin receptor (TFR), a low density lipoprotein receptor (LDLR), a neonatal Fc receptor (FcRn), an epidermal growth factor receptor (EGFR), a human epidermal growth factor receptor 2 (HER2), an asialoglycoprotein receptor (ASGPR), chemokine receptor, and riboflavin transporters (RFVT) .

54. The cell according to any one of embodiments 43-53, wherein the binding moiety is protein, peptide, antibody or the antigen binding fragment thereof, affibody, nanobody, aptamer, DNA, RNA, lipid, or carbohydrate.

55. The cell according to any one of embodiments 43-54, wherein the fusogenic protein is capable of being incorporated into the membrane of an EV.

56. The cell according to any one of embodiments 43-55, wherein the nucleic acid sequence encoding a fusogenic protein and the nucleic acid sequence encoding a binding moiety to a cell membrane protein are present in two separate vectors.

57. The cell according to any one of embodiments 43-56, wherein the nucleic acid sequence encoding a binding moiety is operably linked to a nucleic acid sequence encoding a transmembrane moiety of EV in one vector. 58. The cell according to embodiment 57, wherein the transmembrane moiety of EV is Lamp2b.

59. Use of an EV according to any one of embodiments 1-19, a pharmaceutical composition according to embodiment 20, or a cell according to any one of embodiment of 28-58, in the manufacture of a medicament.

60. An EV according to any one of embodiments 1-19, a pharmaceutical composition according to embodiment 20, or a cell according to any one of embodiments of 28-58, for use as a medicament.

Examples

List of Abbreviations

EV is extracellular vesicle.

FBS is fetal bovine serum.

PS is penicillin/streptomycin.

PBS is phosphate buffered saline.

CRE is cyclization recombination enzyme.

ARRDC1 is arrestin domain-containing protein 1.

In this description, the Greek letter of m may be represented by "u", e.g. in pl=ul, in pM=uM or in pg=ug.

General Methods and Characterization

1. Plasmid transfection protocol used in Examples: (80 ml as an example)

• Passage the HEK293-6E cells on the day before transfection at 0.5~1 x10⁶ cells / ml.

• On the day of transfection, dilute the cells to 1.0 ^c 10⁶ cells / ml with culture medium (Freestyle 293 expression medium, Gibco, 12338-018) and transfer ~75 ml cell suspension in 250 ml shaker flask, place the shaker flask in a 37°C , 5% C0₂ incubator on an orbital shaker.

• Prepare lipid-DNA complexes as follows: o Dilute 80 pg of plasmid DNA (e.g. pJSV002 derived plasmids) in Opti-MEM I to a total volume of 2.6 ml. Mix gently. o Dilute 80 mI of 293fectin Transfection Reagent (Gibco) in Opti-MEM I to a total volume of 2.6 ml-. Mix gently and incubate for 5 minutes at room temperature. o After the 5 minutes incubation, add the diluted DNA to the diluted 293fectin Reagent to obtain a total volume of 5.2 ml. Mix gently o Incubate for 20 minutes at room temperature to allow the DNA-293fectin complexes to form.

• After incubation, add the 5.2 ml DNA-293fectin complexes to the 75 ml cell suspension. The flask should have a total volume of 80 ml, and contain approximately 1.0 *10⁶ viable cells per ml_.

• Incubate the cells in a 37°C incubator with a humidified atmosphere of 5% C0₂ in air on an orbital shaker rotating at 135 rpm, and harvest the cell culture supernatant after 48 h.

• Isolate and characterize EVs according to the following protocol.

2. Isolation and characterization of EVs

EVs were isolated using differential centrifugation. All the centrifugation steps were conducted at 4^°C. The cell culture supernatant was harvested at 48 h and centrifuged at 6,000g for 30 min to remove cell debris and large vesicles. After centrifugation, the supernatant was collected and subjected to 100,000g for 70 min. The pellet was suspended in PBS to obtain EVs (Fig.lA).

The isolated EVs were measured by Flow Nano Analyzer (N30E, NanoFCM Inc.) for the particle size distribution and concentration. The NanoFCM is a flow cytometry-based instrument with high sensitivity. To measure the particle size and concentration, the instrument is calibrated by the concentration standard and the size standard (S16M-Exo), purchased from NanoFCM. When measuring, the standard (silica nanoparticles) and the sample particles are detected under the same condition, and the wave length is 488nm. The calibration and measurement were operated according to the manufacture’s manual. The NanoFCM data indicated that the median size of the EVs is 62.75 nm and distributed from 45-150 nm (Fig.1C). Transmission electron microscopy (TEM) was utilized to analyse the morphology and the size of EVs. The samples were measured using Technai 120kV electron microscope. The EVs were negatively stained with 1 % uranyl acetate. Typical size of EVs in the TEM images are 40-150 nm (Fig.1 B). The TEM results are consistent with the observed size from the Flow Nano Analyzer. The isolated EVs were also detected by Exo-Check Exosome Antibody Array (EXORAY200B-8, System Biosciences). The array was incubated with 50 pg of EV proteins. Six EV markers (CD63, CD81 , FLOT1 , ICAM1 , ANXA5, and TSG101) were detected while cellular contamination marker GM130 was not detected, indicating that the isolated particles are EVs (Fig.1 D). 3. Quantification of CRE loading in EVs by a luminescence assay

CRE tagged with a C-terminal tag HiBiT was loaded into EV through fusing with an EV anchor protein(e.g. hARRDCI). HiBiT is an 11-amino-acid peptide tag that can bind tightly with LgBiT to form a luminescent enzyme. And the amount of HiBiT-tagged CRE in each EV sample can be determined by a luminescence assay with a commercial kit (Nano- Glo® HiBiT Lytic Detection System, Promega N3030) following the manual. Briefly, EV sample was lysed by a lytic detection reagent containing the IgBiT protein and the luciferase substrate furimazine. HiBiT bound tightly to LgBiT and promoted complex formation in the EV lysate to generate a bright, luminescent enzyme. The amount of HiBiT-tagged CRE in the EV lysate was proportional to the amount of luminescence and can be quantified from a standard curve of purified Halotag-HiBiT protein.

4. In vitro CRE editing color-switch assay.

Intracellular delivery efficiency of EVs was evaluated in a CRE reporter system. The CRE reporter cell line was derived from HEK293 cell, expressing “LoxP-GFP-stop-LoxP- RFP” cassette under CMV promoter. The cell line demonstrates strong GFP fluorescent signal in normal culture condition as the constitutive CMV promoter drives the high GFP expression. The downstream RFP ORF is not expressed because of the stop codon after the GFP ORF. Once the CRE protein is present in nucleus, the CRE excises / deletes the DNA fragment between two loxP sites, which removes the stop codon. As a result, the RFP ORF is then expressed under the CMV promoter, and the cell line switches to RFP fluorescent. Here the CRE protein was loaded into EV as a cargo and can be delivered into cells by EVs of the present invention. The percentage of RFP fluorescent cells can be used as an indicator of the intracellular delivery efficiency of different EVs.

The intracellular delivery efficiency of different EVs was evaluated in CRE reporter cells using CRE editing efficiency as an indicator. Different fusogenic proteins and the binding moiety were displayed on the surface of EVs and CRE protein was loaded into EVs through fusing with an EV anchor (e.g. ARRDC1). Reporter cells were seeded into PDL coated 96-well plate at 20,000 cells per well and cultured for 24-hr. Then cells were transfected with a plasmid encoding a cell membrane protein (e.g. TFRC, HER2 or SLC1A5) with Lipofectamine 3000 (Thermo Fisher). After 6-hr transfection, the medium was removed, and cells were treated with different EVs in DMEM medium plus 10% FBS and 1% PS for another 30-hr. Cells edited by CRE became RFP positive (red). Total cell number was measured through nucleus staining with Hoechst (blue) at 1 :50000. Fluorescent pictures of the whole well were taken by High-Content Analysis System (Operetta CLS, PerkinElmer) and the CRE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells. P value was calculated by Unpaired T Test.

Example 1: Plasmid preparation

Plasmids overexpressing TFRC, HER2 or SLC1 A5 were ordered from GenScript. DNA sequence of each receptor was cloned into standard mammalian expression cloning vector (pcDNA3.1+) by GenScript.

To modify EVs and load cargos into EVs, plasmids were constructed for the expression of CRE, fusogenic proteins, the binding moiety to transferrin receptor (TFRC/TFR), and/or the binding moiety to human epidermal growth factor receptor 2 (HER2).

The full-length coding region of hARRDC1-CRE-HiBit, including the ARRDC1 mature protein, the GS linker, the CRE-NLS protein, and the HiBit peptide, was inserted into the expression vector pJSV002 to obtain the plasmid pJSV-ARRDC1-CRE-HiBit. The plasmid pJSV-ARRDC1-CRE-HiBit (see Figure 2) has a size of around 6800 bp. The vector pJSV002 ( W02008009545 A1 , Figure 3B ) is a transient expression vector that can be used in combination with HEK2936E cells .

The coding region of hSyncytin-1 and its native signal peptide were inserted into pJSV002 to obtain the plasmid pJSV-hSyncytin-1.

The coding region of VSVG and its native signal peptide were inserted into pJSV002 to obtain the plasmid pJSV-VSVG.

The coding region of VSVG with K47Q and R354A mutations (VSVG_K47Q_R354A) to block LDL-R binding [Nature Communications 9: 1029 (2018)] and its native signal peptide were inserted into pJSV002 to obtain the plasmid pJSV-VSVG_K47Q_R354A.

TFRafb is an affibody which can bind to transferrin receptor (TFRC). The full-length coding region of TFRafb-Lamp2b, including the native signal peptide of Lamp2b, the TFRafb, the (G4S)3 linker, and the Lamp2b protein, was inserted into pJSV002 to obtain the plasmid pJSV-TFRafb-Lamp2b.

The full-length coding region of TFRafb-VSVG, including the native signal peptide of VSVG, the TFRafb, the (G4S)3 linker, and the VSVG protein, was inserted into pJSV002 to obtain the plasmid pJSV-TFRafb-VSVG.

HER2afb is an affibody which can bind to lyq er$Ltrini q ¾$? B { xL¾egxs^eceptor 2 (HER2). The full-length coding region of HER2afb-Lamp2b, including the native signal peptide of Lamp2b, the HER2afb, the (G4S)3 linker, and the Lamp2b protein, was inserted into pJSV002 to obtain the plasmid pJSV-HER2afb-Lamp2b. The full-length coding region of TFRafb-hSyncytin-1 , including the native signal peptide of human syncytin-1 , the TFRafb, (G4S)3 linker, and human syncytin-1 protein, was inserted into pJSV002 to obtain the plasmid pJSV-TFRafb-hSyncytin-1.

The coding region of LCMV-gp and its native signal peptide were inserted into pJSV002 to obtain the plasmid pJSV-LCMV-gp.

The amino acid sequence of the hARRDCI protein is as shown in SEQ ID NO: 1.

MGRVQLFEISLSHGRWYSPGEPLAGTVRVRLGAPLPFRAIRVTCIGSCGVSNKAN DTAWWEEGYFNSSLSLADKGSLPAGEHSFPFQFLLPATAPTSFEGPFGKIVHQVRAAIHTP RFSKDHKCSLVFYILSPLNLNSIPDIEQPNVASATKKFSYKLVKTGSWLTASTDLRGYWGQ ALQLHADVENQSGKDTSPWASLLQKVSYKAKRWIHDVRTIAEVEGAGVKAWRRAQWHEQ ILVPALPQSALPGCSLIHIDYYLQVSLKAPEATVTLPVFIGNIAVNHAPVSPRPGLGLPPGAPP LWPSAPPQEEAEAEAAAGGPHFLDPVFLSTKSHSQRQPLLATLSSVPGAPEPCPQDGSPA SHPLHPPLCISTGATVPYFAEGSGGPVPTTSTLILPPEYSSWGYPYEAPPSYEQSCGGVEPS LTPES (SEQ ID NO: 1)

The amino acid sequence of the CRE-NLS protein is as shown in SEQ ID NO: 2.

SNLLTVHQNLPALPVDATSDEVRKNLMDMFRDRQAFSEHTWKMLQSVCRSWAA WCKLNNRKWFPAEPEDVRDYLLYLQARGLAVKTIQQHLGQLNMLHRRSGLPRPSDSNAVS LVMRRIRKENVDAGERAKQALAFERTDFDQVRSLMENSDRCQDIRNLAFLGIAYNTLLRIAEI ARIRVKDISRTDGGRMLIHIGRTKTLVSTAGVEKALSLGVTKLVERWISVSGVADDPNNYLFC RVRKNGVAAPSATSQLSTRALEGIFEATHRLIYGAKDDSGQRYLAWSGHSARVGAARDMA RAGVSIPEIMQAGGWTNVNIVMNYIRNLDSETGAMVRLLEDGDPKKKRKVEDPKKKRKVED PKKKRKV (SEQ ID NO: 2)

The amino acid sequence of the human Lamp2b protein and its signal peptide are as shown in SEQ ID NO: 3.

MVCFRLFPVPGSGLVLVCLVLGAVRSYALELNLTDSENATCLYAKWQMNFTVRYE TTNKTYKTVTISDHGTVTYNGSICGDDQNGPKIAVQFGPGFSWIANFTKAASTYSIDSVSFSY NTGDNTTFPDAEDKGILTVDELLAIRIPLNDLFRCNSLSTLEKNDWQHYWDVLVQAFVQNG TVSTNEFLCDKDKTSTVAPTIHTTVPSPTTTPTPKEKPEAGTYSVNNGNDTCLLATMGLQLNI TQDKVASVININPNTTHSTGSCRSHTALLRLNSSTIKYLDFVFAVKNENRFYLKEVNISMYLVN GSVFSIANNNLSYWDAPLGSSYMCNKEQTVSVSGAFQINTFDLRVQPFNVTQGKYSTAQEC SLDDDTILIPIIVGAGLSGLIIVIVIAYVIGRRKSYAGYQTL (SEQ ID NO: 3)

The amino acid sequence of the VSVG_K47Q_R354A protein and its signal peptide are as shown in SEQ ID NO: 4.

MKCLLYLAFLFIGVNCKFTIVFPHNQKGNWKNVPSNYHYCPSSSDLNWHNDLIGTA

LQVKMPQSHKAIQADGWMCHASKWVTTCDFRWYGPKYITHSIRSFTPSVEQCKESIEQTKQ GTWLNPGFPPQSCGYATVTDAEAVIVQVTPHHVLVDEYTGEWVDSQFINGKCSNYICPTVH

NSTTWHSDYKVKGLCDSNLISMDITFFSEDGELSSLGKEGTGFRSNYFAYETGGKACKMQY

CKHWGVRLPSGVWFEMADKDLFAAARFPECPEGSSISAPSQTSVDVSLIQDVERILDYSLC

QETWSKIRAGLPISPVDLSYLAPKNPGTGPAFTIINGTLKYFETRYIRVDIAAPILSRMVGMISG

TTTEAELWDDWAPYEDVEIGPNGVLRTSSGYKFPLYMIGHGMLDSDLHLSSKAQVFEHPHI

QDAASQLPDDESLFFGDTGLSKNPIELVEGWFSSWKSSIASFFFIIGLIIGLFLVLRVGIHLCIKL

KHTKKRQIYTDIEMNRLGK (SEQ ID NO: 4)

The amino acid sequence of the hSyncytin-1 protein and its signal peptide are as shown in SEQ ID NO: 5.

MALPYHIFLFTVLLPSFTLTAPPPCRCMTSSSPYQEFLWRMQRPGNIDAPSYRSLS KGTPTFTAHTHMPRNCYHSATLCMHANTHYWTGKMINPSCPGGLGVTVCWTYFTQTGMS DGGGVQDQAREKHVKEVISQLTRVHGTSSPYKGLDLSKLHETLRTHTRLVSLFNTTLTGLHE VSAQNPTNCWICLPLNFRPYVSIPVPEQWNNFSTEINTTSVLVGPLVSNLEITHTSNLTCVKF SNTTYTTNSQCIRWVTPPTQIVCLPSGIFFVCGTSAYRCLNGSSESMCFLSFLVPPMTIYTEQ DLYSYVISKPRNKRVPILPFVIGAGVLGALGTGIGGITTSTQFYYKLSQELNGDMERVADSLV TLQDQLNSLAAWLQNRRALDLLTAERGGTCLFLGEECCYYVNQSGIVTEKVKEIRDRIQRR AEELRNTGPWGLLSQWMPWILPFLGPLAAIILLLLFGPCIFNLLVNFVSSRIEAVKLQMEPKM QSKTKIYRRPLDRPASPRSDVNDIKGTPPEEISAAQPLLRPNSAGSS (SEQ ID NO: 5)

The amino acid sequence of TFRafb-(G4S)3-VSVG is as shown in SEQ ID NO:6. SVDNKFNKEAYDAEWEIWHLPNLNKSQATAFIMSLDDDPSQSANLLAEAKKLNDA QAPKGGGGSGGGGSGGGGSKFTIVFPHNQKGNWKNVPSNYHYCPSSSDLNWHNDLIGTA LQVKMPKSHKAIQADGWMCHASKWVTTCDFRWYGPKYITHSIRSFTPSVEQCKESIEQTKQ GTWLNPGFPPQSCGYATVTDAEAVIVQVTPHHVLVDEYTGEWVDSQFINGKCSNYICPTVH NSTTWHSDYKVKGLCDSNLISMDITFFSEDGELSSLGKEGTGFRSNYFAYETGGKACKMQY CKHWGVRLPSGVWFEMADKDLFAAARFPECPEGSSISAPSQTSVDVSLIQDVERILDYSLC QETWSKIRAGLPISPVDLSYLAPKNPGTGPAFTIINGTLKYFETRYIRVDIAAPILSRMVGMISG TTTERELWDDWAPYEDVEIGPNGVLRTSSGYKFPLYMIGHGMLDSDLHLSSKAQVFEHPHI QDAASQLPDDESLFFGDTGLSKNPIELVEGWFSSWKSSIASFFFIIGLIIGLFLVLRVGIHLCIKL KHTKKRQIYTDIEMNRLGK (SEQ ID NO:6)

The amino acid sequence of LCMV-gp and its signal peptide is as shown in SEQ ID

NO:7.

MGQIVTMFEALPHIIDEVINIVIIVLIVITGIKAVYNFATCGIFALISFLLLAGRSCGMYGL

KGPDIYKGVYQFKSVEFDMSHLNLTMPNACSANNSHHYISMGTSGLELTFTNDSIISHNFCN

LTSAFNKKTFDHTLMSIVSSLHLSIRGNSNYKAVSCDFNNGITIQYNLTFSDAQSAQSQCRTF

RGRVLDMFRTAFGGKYMRSGWGWTGSDGKTTWCSQTSYQYLIIQNRTWENHCTYAGPFG MSRILLSQEKTKFFTRRLAGTFTWTLSDSSGVENPGGYCLTKWMILAAELKCFGNTAVAKC NVNHDAEFCDMLRLIDYNKAALSKFKEDVESALHLFKTTVNSLISDQLLMRNHLRDLMGVPY CNYSKFWYLEHAKTGETSVPKCWLVTNGSYLNETHFSDQIEQEADNMITEMLRKDYIKRQG STPLALMDLLMFSTSAYLVSIFLHLVKIPTHRHIKGGSCPKPHRLTNKGICSCGAFKVPGVKT VWKRR (SEQ ID NO: 7)

The amino acid sequence of the TFRafb is as shown in SEQ ID NO: 8. SVDNKFNKEAYDAEWEIWHLPNLNKSQATAFIMSLDDDPSQSANLLAEAKKLNDA QAPK (SEQ ID NO: 8)

The amino acid sequence of the HiBit peptide is as shown in SEQ ID NO: 9. VSGWRLFKKIS (SEQ ID NO: 9)

The amino acid sequence of the HER2afb is as shown in SEQ ID NO: 10. VDNKFNKELRQAYWEIQALPNLNWTQSRAFIRSLYDDPSQSANLLAEAKKLNDAQ APK (SEQ ID NO: 10)

The amino acid sequence of HER2afb-(G4S)3-Lamp2b is as shown in SEQ ID NO:

11 (HER2afb-Lamp2b).

MVCFRLFPVPGSGLVLVCLVLGAVRSYAVDNKFNKELRQAYWEIQALPNLNWTQSR AFIRSLYDDPSQSANLLAEAKKLNDAQAPKGGGGSGGGGSGGGGSLELNLTDSENATCLY AKWQMNFTVRYETTNKTYKTVTISDHGTVTYNGSICGDDQNGPKIAVQFGPGFSWIANFTK AASTYSIDSVSFSYNTGDNTTFPDAEDKGILTVDELLAIRIPLNDLFRCNSLSTLEKNDWQHY WDVLVQAFVQNGTVSTNEFLCDKDKTSTVAPTIHTTVPSPTTTPTPKEKPEAGTYSVNNGN DTCLLATMGLQLNITQDKVASVININPNTTHSTGSCRSHTALLRLNSSTIKYLDFVFAVKNENR FYLKEVNISMYLVNGSVFSIANNNLSYWDAPLGSSYMCNKEQTVSVSGAFQINTFDLRVQPF NVTQGKYSTAQECSLDDDTILIPIIVGAGLSGLIIVIVIAYVIGRRKSYAGYQTL (SEQ ID NO:

11)

The amino acid sequence of TFRafb-(G4S)3-Lamp2b is as shown in SEQ ID NO:

12 (TFRafb- Lamp2b).

MVCFRLFPVPGSGLVLVCLVLGAVRSYASVDNKFNKEAYDAEWEIWHLPNLNKSQ ATAFIMSLDDDPSQSANLLAEAKKLNDAQAPKGGGGSGGGGSGGGGSLELNLTDSENATC LYAKWQMNFTVRYETTNKTYKTVTISDHGTVTYNGSICGDDQNGPKIAVQFGPGFSWIANF TKAASTYSIDSVSFSYNTGDNTTFPDAEDKGILTVDELLAIRIPLNDLFRCNSLSTLEKNDWQ HYWDVLVQAFVQNGTVSTNEFLCDKDKTSTVAPTIHTTVPSPTTTPTPKEKPEAGTYSVNN GNDTCLLATMGLQLNITQDKVASVININPNTTHSTGSCRSHTALLRLNSSTIKYLDFVFAVKN ENRFYLKEVNISMYLVNGSVFSIANNNLSYWDAPLGSSYMCNKEQTVSVSGAFQINTFDLRV QPFNVTQGKYSTAQECSLDDDTILIPIIVGAGLSGLIIVIVIAYVIGRRKSYAGYQTL (SEQ ID NO: 12) The amino acid sequence of TFRafb-(G4S)3-hSyncytin-1 is as shown in SEQ ID NO: 13 (TFRafb- hSyncytin-1).

MALPYHIFLFTVLLPSFTLTSVDNKFNKEAYDAEWEIWHLPNLNKSQATAFIMSLDDDPSQSA

NLLAEAKKLNDAQAPKGGGGSGGGGSGGGGSAPPPCRCMTSSSPYQEFLWRMQRPGNI

DAPSYRSLSKGTPTFTAHTHMPRNCYHSATLCMHANTHYWTGKMINPSCPGGLGVTVCWT

YFTQTGMSDGGGVQDQAREKHVKEVISQLTRVHGTSSPYKGLDLSKLHETLRTHTRLVSLF

NTTLTGLHEVSAQNPTNCWICLPLNFRPYVSIPVPEQWNNFSTEINTTSVLVGPLVSNLEITH

TSNLTCVKFSNTTYTTNSQCIRWVTPPTQIVCLPSGIFFVCGTSAYRCLNGSSESMCFLSFLV

PPMTIYTEQDLYSYVISKPRNKRVPILPFVIGAGVLGALGTGIGGITTSTQFYYKLSQELNGDM

ERVADSLVTLQDQLNSLAAWLQNRRALDLLTAERGGTCLFLGEECCYYVNQSGIVTEKVKE

IRDRIQRRAEELRNTGPWGLLSQWMPWILPFLGPLAAIILLLLFGPCIFNLLVNFVSSRIEAVKL

QMEPKMQSKTKIYRRPLDRPASPRSDVNDIKGTPPEEISAAQPLLRPNSAGSS(SEQ ID NO:

13)

Example 2: Intracellular delivery of exosomes by display of fusogenic protein in EVs 1) The fusogenic effects of VSVG exosomes are dependent on LDLR binding

ORE reporter cell line was incubated with each EV sample (displaying with VSVG or VSVG- K47Q_R354A) for 30 hours. The amount of EV sample added to the reporter cells were adjusted based on ORE quantification results. Cells delivered successfully with ORE became RFP positive (red) and all nucleus were stained with Hoechst (blue). The ORE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells.

EV displaying fusogenic protein VSVG showed high intracellular delivery efficiency (nearly 100% at 10000 pM, Table 1 and Fig. 3A). Low density lipoprotein receptor (LDLR) serves as a major entry receptor for VSVG. A VSVG mutant (VSVG-K47Q_R354A), which was reported to be defective in LDLR binding (Nat Commun. 2018 Mar 12;9(1):1029), showed decreased ORE editing efficiency (about 78%) at even higher ORE dose (40000 pM). (Table 1 and Fig. 3A, P<0.05).

ORE reporter cells were pretreated with PCSK9 for 18 hours at indicated dose to reduce LDLR expression and then incubated with 1000 pM VSVG EV sample for another 30 hours. Intracellular delivery of VSVG EVs was dose-dependently inhibited by PCSK9, which indicated the fusogenic effects of VSVG were dependent on LDLR binding. Data were demonstrated as mean ± SD (Table 2, Fig. 3B).

Table 1: The intracellular delivery of exosomes displayed with VSVG and VSVG mutant

Table 2: The intracellular delivery of exosomes displayed with VSVG by inhibiting LDLR binding

2) Overexpression of SLC1A5 does not improve the intracellular delivery of syncytin-1

CRE reporter cell line transfected with Syncytin-1 endogenous receptor SLC1 A5 (Q15758) was incubated with each EV sample for 30 hours. The amount of EV sample added to the reporter cells were adjusted based on CRE quantification results. Cells delivered successfully with CRE became RFP positive (red) and all nucleus were stained with Hoechst (blue). And the CRE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells. Data were demonstrated as mean ± SD (Table 3, and Fig. 4). Syncytin-1 is a human endogenous fusogenic protein with SLC1A5 as its reported receptor. SLC1A5 is reported to be a membrane channel for neutral amino acid transporting. CRE reporter cell line transfected with or without SLC1A5 was incubated with Syncytin-1 EV samples for 30 hours. Display of Syncytin-1 on EVs didn’t show significant intracellular delivery in Cre reporter cells (~ 1.1%). Moreover, increasing binding of Syncytin- 1 EV to cells by overexpressing its receptor SLC1 A5 in the receipt cells didn’t substantially improve intracellular delivery efficiency either (~1.7%) (Table 3, and Fig. 4, P>0.05). This result indicated increasing EV binding to receipt cells through a membrane protein/receptor didn’t necessarily achieve the improvement in the intracellular delivery. Table 3. The intracellular delivery of exosomes displayed with syncytin-1 by overexpressing endogenous receptor of syncytin-1 (SLC1A5) in the receipt cells

Example 3: A synergistic effect on intracellular delivery shown by co-display of a fusogenic protein with a binding moiety to TFRC in EVs.

1) To determine the delivery efficiency of various engineered EVs, one or two or three pJSV002 derived plasmids (80 pg of plasmid DNA in total) were co-transfected into HEK293-6E cells to produce EVs. The co-transfection protocols are listed in Table 4. Different fusogenic proteins and/or TFRafb were displayed on the surface of EVs, and CRE protein was loaded into EVs through fusing with hARRDCI . The schematic diagrams of EVs produced with different protocols are shown in Fig. 2.

Table 4: Co-transfection protocol of pJSV002 derived plasmids

CRE reporter cell line transfected with TFRC (TFR1JHUMAN, P02786) was incubated with each EV sample for 30 hours . The amount of EV sample added to the reporter cells were adjusted based on CRE quantification results. Cells delivered successfully with CRE became RFP positive (red) and all nucleus were stained with Hoechst (blue). And the CRE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells. Data were demonstrated as mean ± SD (Table 5, 6 and Fig. 5).

Table 5. Synergistic effect on intracellular delivery from co-displaying Syncytin-1 and TfRafb on EV membrane

*: all EVs contained CRE as cargo.

**: CRE editing efficiency lower than 1% was considered as no meaningful delivery Note: the CRE editing efficiency data of No.1-4 EVs in Table 2 and Fig. 3 correspond to the transfection protocol of No.1-4 in Table 1 , respectively.

Table 6. Synergistic effect on intracellular delivery from co-displaying VSVG- K47Q R354A and TfRafb on EV membrane

*: all EVs contained CRE as cargo.

**: CRE editing efficiency lower than 1% was considered as no meaningful delivery Note: the CRE editing efficiency data of No.1-4 EVs in Table 3 and Fig. 3 correspond to the transfection protocol of No.1-2, 5-6 in Table 1 , respectively.

The data indicated that EVs without fusogenic protein didn’t show functional intracellular delivery of CRE. Display of a human endogenous fusogenic protein (e.g. Syncytin-1) or a binding moiety (e.g. affibody) to a cell membrane protein (e.g. TFRC) alone didn’t show significant improvement either. Co-display of TFRafb (TFRafb-Lamp2b) with Syncytin-1 showed a substantial increase in CRE editing. A VSVG mutant (VSVG- K47Q_R354A), which was reported to be defective in LDLR binding, showed compromised CRE editing efficiency (~78%) compared to WT VSVG (~100%, data shown in Fig. 3A). However, the editing efficiency returned to about 99% when the mutant was co-displayed with TFRafb on EV membrane. These results indicated that fusogenic proteins can work with a binding moiety (TFRafb) to cell membrane protein TFR in a synergistic way to increase EV intracellular delivery.

Example 4: The dose-dependent inhibition effect on EV’s delivery efficiency by adding free binding moiety to membrane protein.

CRE reporter cell line transfected with TFRC was incubated with each EV sample for 30 hours together with different concentration of TFRafb or Transferrin (TF). The amount of EV sample added to the reporter cells were adjusted based on CRE quantification results. Free TFRafb and Transferrin (TF) would compete with TFRafb on EV membrane to bind with TFRC. Cells delivered successfully with CRE became RFP positive (red) and all nucleus were stained with Hoechst (blue). The CRE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells. CRE delivery from all those TFRafb fusogenic EVs was dose-dependently inhibited by free TFRafb or Transferrin (TF). The co-transfection protocols are listed in Table 7. Data were demonstrated as mean ± SD (Table 8, Fig. 6).

Co-display of a fusogenic protein (such as VSVG mutant or Syncytin-1) together with TFRafb on EV membrane dramatically increased the in vitro CRE editing efficiency of EVs displayed with TFRafb alone (Table 8, Fig. 6). Moreover, the improved CRE delivery from all the TFRafb fusogenic EVs was dose-dependently inhibited by the addition of free binding moiety to TFRC (TFRafb or Transferrin (TF)), further demonstrating that the improved intracellular delivery of fusogenic EVs was dependent on the interaction between TFRC binding moiety (TFRafb) and TFRC.

Table 7: Co-transfection protocol of pJSV002 derived plasmids

Table 8. in vitro CRE editing efficiency of TFRafb fusogenic EVs

*: all EVs contained CRE as cargo.

Note: the CRE editing efficiency data of No.1-3 EVs in Table 8 and Fig. 6 correspond to the transfection protocol of No.1-3 in Table 7, respectively.

Example 5: Comparison of intracellular delivery efficiency between two different ways to co-display of a fusogenic protein with a TFRC affibody (TFRafb) on EVs CRE reporter cell line transfected with TFRC was incubated with each EV sample for 30 hours. The amount of EV sample added to the reporter cells were adjusted based on CRE quantification results. Cells delivered successfully with CRE became RFP positive (red) and all nucleus were stained with Hoechst (blue). And the CRE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells. Data were demonstrated as mean ± SD (Table 9 and Fig. 7).

There were two different approaches to co-display the binding moiety TFRafb and the fusogenic protein (VSVG or Syncytin-1) on EV membrane. One approach was directly fusing TFRafb to the fusogenic protein (TFRafb-VSVG, TFRafb-Syncytin-1), and the other approach was fusing TFRafb to another transmembrane protein (Lamp2b) on EV membrane in a separated construct (TFRafb-Lamp2b). Compared to fusing TFRafb to another transmembrane protein, directly fusing TFRafb to the fusogneic protein significantly decreased the intracellular delivery efficiency of EV samples, indicating TFRafb fusion could interfere with the normal fusogenic function of VSVG (P<0.01) and Syncytin-1 (P<0.01).

Table 9. The comparison of intracellular delivery between two different ways to codisplay of a fusogenic protein (VSVG) with a TFRC affibody (TFRafb) in EVs.

TFRafb- Lamp2b+ VSVG 86±0 1 :1 1000 pM

TFRafb-Lamp2b+Syncytin-1 38±2 1 :1 20000 pM

Example 5: A synergistic effect on intracellular delivery shown by co-display of syncytin-1 with a binding moiety to HER2 in EVs

CRE reporter cell line transfected with HER2 (ERBB2_HUMAN, P04626) was incubated with each EV sample for 30 hours. The amount of EV sample added to the reporter cells was adjusted based on CRE quantification results. Cells delivered successfully with CRE became RFP positive (red) and all nucleus were stained with Hoechst (blue). And the CRE editing efficiency was calculated as the percentage of red to blue cell number from 3 individual replicate wells. Data were demonstrated as mean ± SD (T able 10 and 11 , and Fig. 8).

The data indicated that EVs without fusogenic protein didn’t show functional intracellular delivery of CRE. Display of Syncytin-1 or a binding moiety (i.e. HER2afb) to a cell membrane protein (i.e. HER2) alone didn’t show significant improvement either. Codisplay of HER2afb (HER2-Lamp2b) with Syncytin-1 showed a substantial increase in CRE editing. This result indicated that Syncytin-1 can also work with a binding moiety to HER2 (HER2afb) in a synergistic way to increase EV intracellular delivery.

Table 10: Co-transfection protocol of pJSV002 derived plasmids

Table 11. Synergistic effect on intracellular delivery from the co-display of Syncytin-1 and a HER2 affibody (HER2afb) in EVs

I

While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. An isolated extracellular vesicle (EV) comprising: i) a fusogenic protein, ii) a binding moiety to a cell membrane protein, and, iii) a molecule of interest, wherein the fusogenic protein and the binding moiety are displayed on the EV separately.

2. The EV according to claim 1 , which is selected from the group consisting of an exosome, a microvesicle, an ectosome, a virosome, a microparticle and an oncosome.

3. The EV according to claim 1 , wherein the fusogenic protein is an exogenous viral fusogenic protein.

4. The EV according to claim 3, wherein the viral fusogenic protein is a vesicular stomatitis virus glycoprotein (VSVG) or an envelope glycoprotein of Lymphocytic choriomeningitis virus (LCMV_Gp), or a mutant thereof.

5. The EV according to claim 1 , wherein the fusogenic protein is an endogenous fusogenic protein.

6. The EV according to claim 5, wherein the fusogenic protein is an endogenous viral fusogenic protein.

7. The EV according to claim 5, wherein the endogenous viral fusogenic protein is syncytin- 1 or a mutant thereof.

8. The EV according to claim 1 , wherein the membrane protein is a membrane receptor, e.g. a membrane receptor internalized by endocytosis.

9. The EV according to claim 8, wherein the membrane receptor is selected from the group consisting of a transferrin receptor (TFR), a low density lipoprotein receptor (LDLR), a neonatal Fc receptor (FcRn), an epidermal growth factor receptor (EGFR), a human epidermal growth factor receptor 2 (HER2), an asialoglycoprotein receptor (ASGPR), chemokine receptor, and riboflavin transporters (RFVT) .

10. The EV according to any one of claims 1-9, wherein the binding moiety is protein, peptide, antibody or an antigen binding fragment thereof, affibody, nanobody, aptamer, DNA, RNA, lipid, or carbohydrate.

11. The EV according to any one of claims 1-9, wherein the binding moiety is displayed on the surface of the EV.

12. The EV according to claim 11 , wherein the binding moiety is displayed on the external surface of the EV through an EV’s transmembrane moiety, e.g. Lamp2b.

13. A pharmaceutical composition comprising an EV according to any one of claims 1-12, and a pharmaceutically acceptable excipient.

14. A method of delivering a molecule of interest to a recipient cell, the method comprising contacting the recipient cell with an effective amount of an EV according to any one of claims 1-12.

15. A cell capable of heterologously expressing a fusogenic protein, a binding moiety to a cell membrane protein and a molecule of interest.