EP1242579A2

EP1242579A2 - Th1 specific cd4 t cell lines and method for inducing them ex vivo

Info

Publication number: EP1242579A2
Application number: EP00993724A
Authority: EP
Inventors: Véronique Pancre; Hélène Gras-Masse; Ahmed Bouzidi; Eric Hachulla; Claude Auriault
Original assignee: Centre National de la Recherche Scientifique CNRS; Institut Pasteur de Lille; Institut National de la Sante et de la Recherche Medicale INSERM; SEDAC-Therapeutics
Current assignee: Centre National de la Recherche Scientifique CNRS; Institut Pasteur de Lille; Institut National de la Sante et de la Recherche Medicale INSERM; SEDAC-Therapeutics
Priority date: 1999-12-30
Filing date: 2000-12-28
Publication date: 2002-09-25
Also published as: AU2860901A; FR2803307A1; WO2001049821A3; US20030138409A1; WO2001049821A2

Abstract

A TH1 specific CD4 T cell line, inducing an efficient CD8 response against an infection caused by an infectious agent, is obtained by removing from a donor a biological sample containing T cells; isolating the CD4<+> T cells from said sample; simultaneously providing dendritic cells isolated from the same sample or another sample derived from the same donor; subjecting the previously isolated CD4<+> T cells to <i>in vitro</i> immunisation with a peptide of a protein of the infectious agent exhibiting at least a T epitope, in the presence of the previously obtained dendritic cells; performing at least a restimulation, in the same conditions as for immunisation, optionally substituting the dendritic cells with B cells from the same donor.

Description

Lines of specific CD4 T lymphocytes of the TH1 type and method for their ex vivo induction.

The invention relates to obtaining ex vivo specific CD4 T lymphocytes of the TH1 type.

It relates more particularly to such lymphocytes and a method for obtaining them by ex vivo induction of specific CD4 T lymphocyte lines of THl type for an immunoprophylactic or therapeutic purpose with regard to infections caused by an infectious agent such as 'a virus, bacteria or parasite.

The context in which the invention is situated is explained below with reference to the infection with the Human Immunodeficiency Virus (HIV) which has mobilized many researchers for fifteen years, which makes it possible to have available a large volume of data.

HIV infection is characterized by chronic overactivity of the immune system which contrasts with a deficiency in many of the cells of the immune system. Ideally, vaccination against HIV should make it possible to transform chronic infection into acute infection, this by amplifying and accelerating the natural immune response. To date, vaccine research on HIV has mainly focused on two axes: on the one hand, the induction of a humoral response mediated by antibodies neutralizing the virus and, on the other hand, the induction of cell-mediated immunity. Although neutralization experiments have made it possible to observe positive results in terms of protection, the exclusive use of neutralizing antibodies for vaccination purposes appears to be of little application due to important limitations such as the restriction to minority viral isolates as well that a very high required antibody concentration.

In contrast, information from research into the cellular components of anti-HIV immune responses are more encouraging. Indeed, the data relating to the cytotoxic activity mediated by the cytotoxic suppressor T8 lymphocytes which express the CD8 marker, hereinafter called CD8 T lymphocytes [cytotoxic T lymphocytes (Cytotoxic T Lymphocytes or CTL)] reveal a correlation between the appearance of this activity and control of viral infection. Cytotoxic T lymphocytes directed against sequences derived from viral proteins appear very rapidly during the im response triggered by viral infection. In general, they play an important role in eliminating cells infected with the virus in acute infections and in blocking viral replication during persistent infections. These cytotoxic responses, like the induction of neutralizing antibodies, are closely associated with the so-called T helper responses known under the name "T helper" (abbreviated TH) mediated by the T4 lymphocytes which express the CD4 marker, hereinafter called CD4 T cells. Thus, an increase in the TH response makes it possible to obtain an optimal CTL response. In particular, in individuals who control viremia in the absence of antiviral therapy, very strong proliferative responses of virus-specific CD4 T cells are observed. In all cases, it appears clearly established that a clear CD4 response is essential for obtaining an effective CD8 response. Thus, in the context of a vaccine approach, it is now important to specify the nature of the CD4 response obtained. A response of the THl type (IFN-γ, IL-2) or of the TH2 type (IL-4) does not have the same meaning because it is feared that in the second case, it is for example more harmful than useful for vaccination, and all of the work carried out to date clearly demonstrate the importance of the IFN-γ-producing TH1 cells in protective anti-HIV immunity. But the orientation towards one type or the other of response is very difficult to control after injection of an antigen to an individual, in function of the genetic polymorphism expressed by the latter.

Patent application WO 94/02156 (PCT / US93 / 06653) filed on July 15, 1993 and which claims priority from July 16, 1992, relates to methods using dendritic cells to activate T cells. These methods are based on knowledge which were available at that time with regard to the cellular components of the immune response, in particular anti-HIV. In this application, the authors propose a protocol for purifying dendritic cells for cell therapy purposes. These dendritic cells are directly drawn by an antigen, to activate and expand specific T cells (CD4 and CD8). This protocol requires several isolation steps to obtain a purity of 80 to 90% of the dendritic cells.

The authors report experiments of in vitro immunization of autologous T cells by dendritic cells "exposed" to KLH (Keyhole Limpet Hemocyanine: lamprey hemocyanin) or to SWM (Sper Whale Myoglobin: sperm whale yoglobin). They do not address the orientation of the CD4 T response induced in these experiments, nor the question of the donor HLA genotype. Cell activation is characterized only on the basis of an erative proliferative response and the authors seem to anticipate a long-term expansion (6 to 8 weeks) of CD4 T cells (or CD8 T cells) before using them in cell therapy.

In the specific case of HIV infection, the authors use a peptide of the HIV gag protein for in vitro immunizations of autologous T cells from seronegative donors. They are only interested in the induction of a specific CD8 response which they propose to use within the framework of an adoptive cell therapy:

- in the late stages of the disease, by transfer of CD8 T cells from healthy HLA compatible subjects, - in the early stages of the disease, by transfer of autologous CD8 T cells (after ex vivo reactivation) or healthy HLA compatible subjects.

In conclusion, patent application WO 94/02156, in the particular case of HIV infection, constitutes an approach for obtaining a CD8 response. However, it does not expose the means making it possible to induce a specific CD4 TH1 response (more particularly generating a production of IFN-γ), allowing protection against infectious disorders, regardless of the HLA genotype of the donor. In addition, the methods and protocols described or provided for in this application are tedious or long (purification of dendritic cells in several stages, expansion over 6 to 8 weeks of cultures of CD4 or CD8 cells).

The present invention overcomes these shortcomings and drawbacks.

According to a first aspect, it relates to a line of specific CD4 T lymphocytes of the TH1 type effectively inducing cytotoxic T lymphocytes, that is to say an effective CD8 response, against an infection caused by an infectious agent. such as a virus, bacteria or parasite.

According to another aspect, the subject of the invention is a method making it possible to induce ex vivo, in a standardized manner, such a line.

More specifically, the subject of the invention is also a method of ex vivo induction of a line of specific CD4 T lymphocytes of TH1 type as defined above, which method essentially comprises the steps consisting in: a) taking from a donor a biological sample containing T lymphocytes; b) isolating the CD4 T lymphocytes from the sample taken in step a); in parallel c) obtain dendritic cells isolated from the same sample or from another sample from from the same donor; d) subjecting the CD4 T lymphocytes isolated in step b) to an immunological reaction or in vitro immunization with a peptide of a protein of the infectious agent having at least one T epitope, preferably a T epitope and a B epitope , in the presence of the dendritic cells of step c); e) performing at least one restimulation, preferably from one to three restimulations, under the same conditions as the immunization, optionally replacing the dendritic cells with B cells from the same donor.

The expression “peptide of a protein of the infectious agent” is understood here to mean a peptide whose sequence is identical to that of the corresponding fraction of said protein or is modified by contribution of a lipid part or by induction of a controlled degeneration chemically, to an extent such that its function is maintained, or a mixture of at least two peptides as defined above.

According to this method, CD4 ⁺ T lymphocytes, isolated in a previous step, are subjected directly to an immunological reaction or immunization in vitro with a peptide of a protein of the infectious agent to be combated, in the presence of dendritic cells previously isolated.

This process can be implemented on any human or animal biological sample containing T lymphocytes. It presents, a priori, a particular interest in its applications to human beings. In this case, for obvious ethical and practical reasons, the biological sample used is preferably blood and, for applications of the immunoprophylactic or therapeutic type, it is autologous blood.

The ability of this method to induce specific CD4 T lymphocyte lines of TH1 type necessary for the generation of CTL has, as shown in the examples described below, been verified on various pathogens. In the particular case of HIV, the specific CD1 T lymphocyte lines of TH1 type necessary for the generation of CTL can be reinjected into anti-HIV cell therapy protocols. The patients treated can in particular be seropositive patients in asymptomatic phase with CD4 T cell level still intact or patients undergoing cell renewal under high-efficiency antiviral therapy (Highly Active AntiRetroviral Therapy (HAART). if there is a clear and rapid decrease in viremia, the virus is not eradicated and despite a restoration of the CD4 T cell count and the overall immune response (fight against associated opportunistic infections), no reappearance of the specific TH1 response against HIV, which is necessary for the elimination of the latter. The specific CD4 T lymphocyte lines of THl type obtained ex vivo according to the invention can therefore be used in addition to a HAART, for example triple therapy, for restoring THl potential. It goes without saying that for infections caused by other infectious agents, the pro usage tocol may be different. The lines can in particular, in certain cases, be used alone, that is to say not serve as a complement to therapy, for example when it is a question of carrying out the vaccination of a healthy subject.

In all of these applications, the specific CD4 T lymphocytes of the TH1 type according to the invention are autologous cells whose transfer is capable of inducing an effective CD8 response in vivo, without supply of CD8 cells.

The following illustrative examples are intended to better explain the invention. Example 1 Preparation of a Line of Specific CD4 T Lymphocytes of Type TH1, Anti-HIV and Results

1- Preparation. In this example, the inducer is the peptide

56-68 of the 27 kDa Nef (Negative Factor) protein which is an HIV regulatory protein initially described as having an inhibitory effect on viral replication in vi tro. The Nef gene is located 3 'to the HIV Env gene. References: "The HIV Nef protein: facts and hypotheses", Guy, B. et al., Res. Virol. , Jan-Feb 1992, 143 (1), 34-37 and "Virological and cellular physiological roles of HIV Nef protein", Venkatesan, S., Res. Virol. Jan-Feb 1992, 143 (1), 38-42. The sequence of the Nef protein is described in:

"Complete nucleotide sequence of AIDS virus, HTLV-III", Ratner, L. et al. , Nature 1985, 313, 277-284.

The peptide 56-68 sequence of the HIV Nef protein is

Ac-AWLEAQEEEEVGF-CONH ₂

This peptide contains both a T epitope and a B epitope. References: "T helper cell epitopes of the human immunodeficiency virus (HIV-1) nef protein in rats and chimpanzees", Estaquier et al., Mol. Immunol. April 1992, 29 (4), 489-99, "Determination of B-cell epitopes of nef HIV-1 protein: immunogenicity related to their structure", Estaquier et al., Mol. Immunol. Nov 1992, 29 (11), 1337-45 and "Comprehensive delineation of antigenic and immunogenic properties of peptides derived from the nef HIV-1 regulatory protein", Estaquier et al., Vaccine 1993, 11 (11), 1083-93.

The biological medium used is peripheral human blood. The samples (100 to 150 ml) listed in the following table came from different donors typed for molecules of class II of the major complex histocompatibility (CMH), in particular HLA-DR.

Whole blood, diluted half in phosphate buffer (PBS) is deposited on a gradient solution, specific for the isolation of mononuclear cells from human peripheral blood, Ficoll-Paque ^® Amersham Pharmacia Biotech (Sweden), according to the recommendations of manufacturer and the ring of mononuclear cells is recovered after centrifugation (400 g, 20 min, 20 ° C).

CD14 ⁺ blood monocytes are isolated by positive selection (Macs system, Milteny Biotech, Germany). The dendritic cells are then obtained at a purity of at least 80 to 90%, in a single step, by in vi tro differentiation of these CD14 ⁺ cells placed in the presence of IL-4 (1000 U / ml) and GM- CSF (800 U / ml) for five days in complete medium at 10% fetal calf serum (SVF). The CD14 "cells are for their part stored in complete medium at 10% human serum of group AB ⁺ for also five days.

At the end of these five days, the CD4 ⁺ T lymphocytes are isolated by depletion or negative selection (Macs system, Milteny Biotech) from the CD14 ^~ cells obtained previously.

The CD4 ⁺ T lymphocytes (1.10 ⁶ / ml) are then immunized in vitro by peptide 56-68 of the protein Nef (50 μg / ml) in the presence of the dendritic cells (DC) obtained in parallel (1.10 ⁶ / ml). '

The inventors having been able to show that freezing does not affect the functionality of the dendritic cells, the remaining dendritic cells are frozen and used for the first restimulation by the peptide Nef 56-68 which takes place fifteen days after the immunization.

For subsequent restimulations, the dendriditic cells are generally replaced, in particular beyond the second restimulation, by donor B cells, isolated from the same sample by depletion of CD4 ^~ cells into CD8 + cells (Macs system, Milteny Biotech). However, frozen dendritic cells can be used in all restimulations, as long as there are sufficient amounts.

Diagram 1 which follows summarizes the various stages of obtaining, from whole blood, the various cells used: dendritic cells, CD4 ⁺ T lymphocytes and B cells.

Diagram 1

VarioMACS

CD14 cells + CD14 "cells

+ IL-4 + GM-CSF

5 days

VarioMACS Cell.

Dendritics Cell, CD4 + Cell. CD4

VarioMACS

Cell. CD8 ⁺ Cell. CD8- = Cell. B

In the tests summarized in the table which follows, obtaining specific CD4 T lymphocytes of the TH1 type is summarized as follows: In vitro immunization (I) Cells CD4 ⁺ dendritic cells + peptide Culture: 15 days

1st Restimulation (1S)

CD4 + cells + dendritic cells + peptide Culture: 15 days

Second restimulation (2S) Cells CD4 ⁺ dendritic cells or B + peptide Culture: 15 days

Third restimulation (3S) Cells CD4 ⁺ cells + B + peptide Culture: 15 days

2- Results.

Cytokine production and anergy induction (non-response) were examined.

a) Production of cytokines.

The production of IFN-γ, IL-2, IL-4 and IL-5 was sought in culture supernatants of CD4 ⁺ T cells 24 h and 48 h after in vitro immunization ( I) and after successive restimulations (1S, 2S and

3S) by peptide 56-68 of the protein Nef, using an EL ISA method.

The results clearly show a TH 1 type orientation of the response obtained, with significant productions of IFN-γ and / or IL-2 but never of IL-4 or IL-5, and this whatever or the DR genotype of the sample.

b) Induction of anergy.

There is, as the case may be, from the second or third restimulation with the peptide, a sharp reduction, or more often than not, a disappearance of the production of IFN-γ and / or IL-2. It therefore seems that the optimal response is obtained after the second presentation of the peptide (1st restimulation) and that repeated restimulations tend to anergize the CD4 T lymphocytes prepared in this example.

Under these conditions, the reinjection of the cells to the patient must advantageously take place after the incubation which follows the 1st restimulation, ie approximately after one month of culture. The inventors have demonstrated that after in vitro immunization with peptide 56-68 of the protein Nef, CD4 ⁺ T cells very quickly (within 10 days) are generated having a phenotype of effector memory cells producing IFN-γ after restimulation with peptide 56-68 from Nef. This phenotype is given on the basis of a decrease in markers CD45RA (characterizing naive T cells) and CD62Ligand (T cell homing receptor) and an increase in marker CD45RO (characterizing memory T cells) which reaches 36% at D10. As in HIV infection, the appearance of CD4 memory cells specific for the virus is currently considered to be a factor of good prognosis in the course of the disease, this reinforces the advantage of using the immunization protocol in in vitro according to the invention, using peptide 56-68 of the protein Nef, for the purposes of cell therapy in infected subjects.

It goes without saying that for a given patient and a given protocol different factors can intervene in obtaining the optimal response sought, in particular as regards the moment when it intervenes. In vitro monitoring of the results is therefore recommended, even necessary in each case. RESULTS TABLE

t t

Example 2

The procedure is as in Example 1 using peptide 190-211 of Sm 28 GST, Glutathione S Transferase of 28 kDa from the parasite Schi s tosoma mans oni, called Sm 28 GST 190-211 whose sequence is:

NH ₂ -ENLLASSPRLAKYLSNRPATPF-C0OH

After immunization in vi tro and a restimulation, the CD4 T lymphocytes have a THl type orientation (with significant productions of IFN-γ and / or IL-2 but never of IL-4 or IL-5 ) of the response obtained, regardless of the DR genotype of the sample. Example 3 The procedure is as in Example 1 using the peptide 830-846 of the tetanus toxin. This peptide is called TT 830-846. Its sequence is:

Ac-QYIKANSKFIGITE KK-CONHs

After immunization in vi tro and a restimulation, the CD4 T lymphocytes have a THl type orientation (with significant productions of IFN-γ and / or IL-2 but never of IL-4 or IL-5 ) of the response obtained, regardless of the DR genotype of the sample. Example 4

The procedure is as in Example 1 using peptide 307-319 of 1 hemaglutinin of the Influenza virus. This peptide is called HA 307-319. Its sequence is:

Ac-PKYVKQNTLKLAT-CONH ₂

After immunization in vi tro and a restimulation, the CD4 T lymphocytes have a THl type orientation (with significant productions of IFN-γ and / or IL-2 but never of IL-4 or L-5 ) of the response obtained, regardless of the DR genotype of the sample. Examples 2 to 4 show that the method which has been described in detail with regard to HIV can be generalized to infections due to other viruses, bacteria and parasites. The inventors have demonstrated that despite this generalization of the method, the T repertoire (determined on the basis of the expression of the Vbeta regions of the T receptor) expressed by the induced CD4 T cell was specific for the peptide used for in vitro immunization. Thus, the T clones derived after in vitro immunization and a restimulation by the peptide 56-68 of the protein Nef all exhibit a TH1 response profile and a preferential expression of Vβ6.1. On the other hand, the clones derived, under the same conditions, with the peptide of Example 3 (peptide 830-846 of tetanus toxin) or of Example 4 (peptide 307-319 of 1 hemaglutinin of the Influenza virus), if they all have a Th1 response profile, express a different repertoire: respectively Vβ5 for example 3 and Vβ2 for example 4, which confirms the peptide-specific character of the induced response.

In general conclusion, the present invention makes it possible to generate very quickly CD4 TH1 cells, specific, producing IFN-γ, having a phenotype of memory cells and this whatever the HLA genotype of the donor.

Consequently, these cells can be used in cell therapy protocols, by adoptive transfer within 10 days of ex vivo immunization, in all pathologies where this type of cell has been described as protective and in particular in infection. by HIV (in particular by the generation of cells specific for peptide 56-68 of the protein Nef).

Claims

1.- Line of specific CD4 T lymphocytes of THl type effectively inducing cytotoxic T lymphocytes, that is to say an effective CD8 response, against an infection caused by an infectious agent such as a virus, a bacteria or parasite.

2. A method of ex vivo induction of a line of specific CD4 T lymphocytes of the TH1 type according to claim 1, which method essentially comprises the steps consisting in: a) taking a biological sample containing T lymphocytes from a donor; b) isolating the CD4 T lymphocytes from the sample taken in step a); in parallel c) obtain dendritic cells isolated from the same sample or from another sample from the same donor; d) subjecting the CD4 T lymphocytes isolated in step b) to an immunological reaction or in vitro immunization with a peptide of a protein of the infectious agent having at least one T epitope, preferably a T epitope and a B epitope , in the presence of the dendritic cells of step c); e) performing at least one restimulation, preferably from one to three restimulations, under the same conditions as the immunization, optionally replacing the dendritic cells with B cells from the same donor.

3.- Method according to claim 2, characterized in that the biological sample is a blood sample, preferably peripheral.

4.- Method according to claim 2 or 3, characterized in that the infectious agent is HIV.

5.- Method according to claim 4, characterized in that the protein is an HIV regulatory protein.

6.- Method according to claim 5, characterized in that the peptide is peptide 56-68 of the HIV regulatory protein Nef.

7.- Method according to any one of claims 2 to 6, characterized in that the CD4 T lymphocytes are cultured before the first restimulation and then between two successive restimulations for about fifteen days each time.

8.- Line of specific CD4 T lymphocytes of THl type obtained from the blood of a donor and effectively inducing cytotoxic T lymphocytes, that is to say an effective CD8 response, against an infection caused by an infectious agent such as a virus, a bacterium or a parasite, for the immunoprophylacic or therapeutic treatment of said donor.

9.- Line according to claim 8, characterized in that the infectious agent is HIV.