Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K39/00—Medicinal preparations containing antigens or antibodies
  • A61K39/02—Bacterial antigens
  • A61K39/09—Lactobacillales, e.g. aerococcus, enterococcus, lactobacillus, lactococcus, streptococcus
  • A61K39/092—Streptococcus

Definitions

• This invention relates to oral immunization or administration of hosts, animals or humans, with pneumococcal antigens to stimulate an immunological response and preferably provide protection against pneumococcal infection, preferably against colonization, and more preferably against systematic and humoral infection; and, to compositions therefor.
• Streptococcus pneumoniae causes more fatal infections world-wide than almost any other pathogen (Anonymous, 1991; Fraser, 1982). In the U.S.A., deaths caused by S. pneumoniae rival in numbers those caused by AIDS (Anonymous, 1991). In the U.S.A., most fatal pneumococcal infections occur in individuals over 65 years of age, in whom S. pneumoniae is the most community-acquired pneumonia. In the developed world, most pneumococcal deaths occur in the elderly, or in immunodeficient patents including those with sickle cell disease.
• pneumococcal infection is one of the largest causes of death among children less than 5 years of age (Berman et al., 1985; Greenwood et al. , 1987; Spika et al. , 1989, Bale, 1990) .
• the increase in the frequency of multiple antibiotic resistance among pneumococci and the prohibitive cost of drug treatment in poor countries make the present prospects for control of pneumococcal disease problematical (Munoz et al. , 1992; Marton et al. , Klugman, 1990) .
• pneumococcal meningitis is less common than other infections caused by these bacteria, it is particularly devastating; some 10% of patients die and greater than 50% of the remainder have life-long neurological sequelae (Bohr et al. , 1985; Klein et al. , 1981) .
• the present 23-valent capsular polysaccharide vaccine is about 60% effective against invasive pneumococcal disease with strains of the capsular types included in the vaccine (Bolan et al. , 1986; Shapiro et al. , 1991) .
• the 23-valent vaccine is not effective in children less than 2 years of age because of their inability to elicit adequate responses to most polysaccharides (Cowan et al. , 1978; Gotschlich et al. , 1977).
• Improved vaccines that can protect children and adults against invasive infections with pneumococci would help reduce some of the most deleterious aspects of this disease.
• a vaccine that protected against disease but did not reduce pneumococcal carriage rates would not, however, be expected to control the disease in immunocompromised individuals (Shapiro et al. , 1991) and in unimmunized individuals. Such a vaccine would also not be expected to affect the rates of infection in immunized children prior to the development of an adequate antibody or immunological response.
• a strategy that could control infections in all of these individuals would be any form of immunization that prevented or greatly reduced carriage, and hence transmission of pneumococci.
• immunization of young children with Haemophilus influenzae group b polysaccharide-protein conjugates it has been observed that carriage is reduced from about 4% to less than 1%, (Barbour et al., 1993), a possible explanation of concomitant herd immunity (Chiu et al. , 1994). If a vaccine could prevent colonization by pneumococci, such a vaccine would be expected to prevent virtually all pneumococcal infections in the immunized patients.
• Mucosal S- IgA response are predominantly generated by the common mucosal immune system (CMIS) (Mestecky, 1987) , in which immunogens are taken up by specialized lympho-epithelial structures collectively referred to as musoca-associated lymphoid tissue (MALT) .
• CMIS common mucosal immune system
• MALT musoca-associated lymphoid tissue
• the term common mucosal immune system refers to the fact that immunization at any mucosal site can elicit an immune response at all other mucosal sites (Mestecky, 1987) .
• immunization in the gut can elicit mucosal immunity in the upper airways and visa versa.
• the best studied MALT structures are the intestinal Peyer's patches (Mestecky, 1987).
• oral immunization can induce an antigen-specific IgG response in the systemic compartment in addition to mucosal IgA antibodies (McGhee, J.R. and H. Kiyono 1993, “New perspectives in vaccine development: mucosal immunity to infections", Infectious Agents and Disease 2:55-73).
• CT cholera toxin
• CT is a powerful adjuvant which greatly enhances the mucosal immunogenicity of other soluble antigens co-administered with it (Elson, 1989; Lycke et al. , 1986; Wilson et al. , 1989). Although it remains somewhat controversial, pure or recombinant CTB probably does not have these properties when administered intragastrically (i.g.) as an adjuvant. Very small amounts ( ⁇ l ⁇ g) of intact CT, however, can act synergistically with CTB as a powerful oral adjuvant (Wilson et al. , 1990) .
• CT and CTB act as adjuvants are not fully understood, but are certainly complex, and appear to depend on several factors including 1) the toxic activity associated with the ADT- ribosylating property of the Al subunit (Abbas et al. , 1991) ; 2) increased permeability of mucosae (Abbas et al., 1991; Ziegler-Heitbrock et al. , 1992); 3) enhanced antigen-presenting cell function (with increased levels of IL-1) (Abbas et al. , 1991; Ziegler-Heitbroqk et al.
• any attempt to identify antigens for vaccines against carriage should include immunizations designed to elicit mucosal immune responses. Accordingly, the oral (including peroral, intragastric) immunization or administration with pneumococcal proteins, as in the present invention has not, it is believed, been heretofore disclosed or suggested or, in addition, the evaluation of adjuvants, as in the present disclosure, has not, it is believed, been heretofore taught or suggested.
• the present invention provides a method of protecting a host, preferably a human host, against pneumococci and/or systemic infection by oral or peroral administration to the host, preferably by administration into the gut (stomach, intestines, digestive tract; e.g., intragastrically) of the host, of an effective amount of at least one pneumococcal surface protein A (PspA) and/or an immunogenic fragment thereof containing at least one protection-eliciting epitope.
• PspA pneumococcal surface protein A
• the present invention provides a method of eliciting an immunological response in a host against pneumococci and/or systemic infection by oral or peroral administration to the host, preferably administration into the gut (stomach, intestines, digestic tract; e.g., intragastrically) of the host, of an effective amount of at least one PspA and/or an immunogenic fragment thereof containing at least one epitope. More preferably, the response is protective and the epitope is protection-eliciting.
• the PspA may be in the form of killed whole S. pneumoniae or a lysate of whole S. pneumoniae.
• the PspA may be in the form of purified isolated protein or a fragment thereof (individually and/or collectively, for purposes only of shorthand in this specification, "PspA”) may be obtained from bacterial isolates or may be formed recombinantly.
• the PspA can be from in vivo expression thereof by a suitable vector containing DNA coding for PspA by recombinant techniques.
• the PspA is preferably in a vaccine or immunogenic composition.
• Such a composition can include a pharmaceutically acceptable adjuvant and/or a pharmaceutically acceptable carrier.
• the PspA may be mixed with pharmaceutically acceptable excipients which are compatible with the PspA.
• excipients may include water, saline, dextrose, glycerol, ethanol, and combinations thereof.
• the immunogenic compositions and vaccines may further contain auxiliary substances, such as wetting or emulsifying agents, pH buffering agents, or adjuvants to enhance the effectiveness thereof.
• the PspA is administered with non-toxic amounts of cholera toxin as an adjuvant.
• the oral administration preferably is effected by delivery into the stomach or gut, i.e., intragastrically to provide protection to the host against infection, preferably colonization, and more preferably against systemic infection.
• the oral administration also can provide protection to the host against pulmonary infection as well as protection to the host against an infection starting as a pulmonary infection.
• the oral administration can also involve respiratory mucosa, gingival mucosa or alveolar mucosa, and the administration can be perlingual or sublingual or into the mouth or respiratory tract, especially if the composition is administered in a liquid form, e.g., as a syrup, elixir etc.
• intragastric administration is preferred.
• compositions of the invention especially for oral administration, are conveniently provided as liquid preparations, e.g., isotonic aqueous solutions, suspensions, emulsions, or viscous compositions which may be buffered to a select pH.
• compositions of the invention can be "solid” from the pills, tablets, capsules, caplets, and the like, including “solid” preparations which are time - release or which have a liquid filling, e.g., gelatin covered liquid, whereby the gelatin is dissolved in the stomach and/or small intestine for delivery into the gut and/or digestive system.
• a method of immunization of a host against Streptococcus pneumoniae which comprises orally or perorally administering to the host an immunizing amount of pneumococcal surface protein A (PspA) in the form of a killed whole pneumococci, a lysate of pneumococci or an isolated PspA or an immunogenic fragment thereof.
• PspA pneumococcal surface protein A
• the present invention further provides a vaccine composition or immunogenic composition for oral or peroral administration to a host, preferably for administration into the gut (stomach, digestive tract; e.g., intragastrically) of a host to confer protection or elicit an immunological response, against S. pneumoniae.
• a vaccine composition or immunogenic composition for oral or peroral administration to a host, preferably for administration into the gut (stomach, digestive tract; e.g., intragastrically) of a host to confer protection or elicit an immunological response, against S. pneumoniae.
• a vaccine composition or immunogenic composition for oral or peroral administration to a host, preferably for administration into the gut (stomach, digestive tract; e.g., intragastrically) of a host to confer protection or elicit an immunological response, against S. pneumoniae.
• the present invention provides a compartmentalized kit comprising PspA or a fragment thereof, and a suitable carrier, diluent or excipient; and optionally, a pharmaceutically acceptable adjuvant; and further optionally, instructions for admixture and/or administration.
• Reciprocal Log2 ELISA enzyme linked immunoadsorbant assay
• FIG. 3 shows a time course of PspA-specific serum antibody responses in mice subcutaneously immunized with 0.5 ⁇ g of PspA and CFA (antibody titers were examined in pooled sera collected from 6 mice by ELISA) ;
• FIG. 4 shows the elucidation of PspA-specific antibody forming cells (AFCs) in spleen of mice simultaneously immunized with 0.5 ⁇ g of PspA and CFA (AFCs were assessed on 14 days after 2nd immunization by the ELISPOT assay) ;
• Figure 5 shows the kinetics of antigen-specific serum antibody responses in mice orally immunized with PspA ((a) mice were orally immunized with 7.5 ⁇ g of PspA and (b) 7.5 ⁇ g of PspA together with lO ⁇ g of CT. Antibody titers were examined in pooled sera collected from 6 mice by the ELISA) ;
• Figure 6 shows an analysis of antigen-specific fecal IgA responses in mice orally immunized with 7.5 ⁇ g of PspA together with lO ⁇ g of CT (antibody titers were examined in pooled fecal extracts collected from 6 mice by the ELISA) ;
• Figure 7 shows the time cource of PspA-specific IgG subclass in mice orally immunized with 7.5 ⁇ g of PspA plus lO ⁇ g of CT (antibody titers were examined in pooled sera collected from 6 mice by the ELISA) .
• S-IgA secretory IgA
• CMIS common mucosal immune system
• MALT mucosa-associated lymphoid tissues
• GALT gut-associated lymphoid tissues
• Other structurally and functionally similar lymphoid follicles occur at other mucosal surfaces, including those of the respiratory tract (Croitoru et al. , 1994).
• Bronchus-associated lymphoid tissue was described by Bienenstock (Bienenstock et al., 1973a,- Bienenstock et al. 1973b) in experimental animals, but is apparently not present in the noninfected human bronchial tree (Pabst, 1992) .
• the upper respiratory tract in humans is furnished with Waldeyer's ring of tonsils and adenoids.
• the functional 12 equivalent of these consists of nasal-associated lymphoid tissue (NALT) , a bilateral strip of lymphoid tissue with overlying M-like epithelial cells at the base of the nasal passages (Kuper et al. , 1992).
• a host can be effectively immunized by oral instillation (e.g., intragastric instillation) of bacterial protein immunogens, preferably PspA or a fragment thereof, preferably mixed with an adjuvant, more preferably cholera toxin (CT) .
• an adjuvant more preferably cholera toxin (CT) .
• CT cholera toxin
• the amount of cholera toxin used is non-toxic to the host.
• the ability of a vaccine to protect against pneumococcal colonization means that the active component may protect against disease not only in the immunized host but, by eliminating carriage among immunized individuals, the pathogen and hence any disease it causes may be eliminated from the population as a whole.
• Oral or peroral administration can also prevent sepsis resulting from administration of pneumococci, so that the vaccine can protect against both pneumococcal colonization and sepsis (systemic infection) .
• PspA is the preferred antigen.
• WO 92/14488 is incorporated herein by reference.
• published International patent application WO 92/14488 there are described the DNA sequences for the pspA gene from S. pneumoniae Rxl, the production of a truncated form of PspA by genetic engineering and the demonstration that such truncated form of PspA confers protection in mice to challenge with live pneumococci.
• PspA proteins are variable in size (roughly 70kDa) .
• the C-terminal 37% of the molecule is largely composed of the 20-amino acid repeats which form a binding site that permits PspA to attach to the phosphchloine residues of the pneumococcal lipoteichoic acids.
• the central region of PspA is rich in prolines and is suspected to be the portion of the molecule that passes through the cell wall.
• the sequence of the N- terminal 80% of the molecule is largely ⁇ -helical and contains the region of PspA that can elicit antibodies that are protective against sepsis.
• PspA's are almost always at least slightly different from one another, there is enough cross-reactivity between them that antibodies or an immunological response to one PspA detect or is effective with respect to PspAs on all pneumococci. Moreover, immunization with one PspA can either protect against death or delay death with virtually all different challenge strains. Accordingly, a mixture of a small number of PspA's could effective immunity against most pneumococci.
• the immunoprotective truncated PspAs described in WO 92/14488 may be used in the present invention as the PspA fragments described above for oral or peroral administration.
• Numerous vector systems for in vitro and in vivo expression of recombinant proteins are known; e.g., bacterial systems such as E. coli; and virus systems such as bacterial viruses, poxvirus (vaccinia, avipox virus, e.g., canarypox virus, fowlpox virus), baculovirus, herpes virus; yeast; and the like; and, these systems may be used for producing recombinant PspA using the coding therefor or of WO 92/14488.
• Immunogenicity can be significantly improved if the antigen (PspA) is co-administered with an adjuvant, commonly used as .001% to 50% percent solution in phosphate buffered saline.
• Adjuvants enhance the immunogenicity of an antigen (PspA) but are not necessarily immunogenic themselves.
• Adjuvants may act by retaining the antigen locally near the site of administration to produce a depot effect facilitating a slow, sustained release of antigen to cells of the immune system.
• Adjuvants can also attract cells of the immune system.
• Adjuvants can also attract cells of the immune system to an antigen depot and stimulate such cells to elicit immune responses.
• Immunostimulatory agents or adjuvants have been used for many years to improve the host immune response to, for example, vaccines.
• Intrinsic adjuvants such as lipopolysaccarides, normally are the components of the killed or attenuated bacteria used as vaccines.
• Extrinsic adjuvants are immunomodulators which are typically non-covalently linked to antigens and are formulated to enhance the host immune response.
• Aluminum hydroxide and aluminum phosphate are routinely used as adjuvants in human and veterinary vaccines. The efficacy of alum in increasing antibody responses to diphtheria and tetanus toxoids is well established and, more recently, a HBsAg vaccine has been adjuvanted with alum.
• extrinsic adjuvants can provoke potent immune responses to antigens. These include saponins complexed to membrane protein antigens (immune stimulating complexes) , pluronic polymers with mineral oil, killed mycobacteria in mineral oil, Freund's complete adjuvant, bacterial products, such as muramyl dipeptide (MDP) and lipopolysaccharide (LPS) , as well as lipid A, and liposomes.
• MDP muramyl dipeptide
• LPS lipopolysaccharide
• immunogens are preferably emulsified in adjuvants.
• Desirable characteristics of ideal adjuvants include any or all of: (1) lack of toxicity;
• Lockhoff et al. (U.S. Patent No. 4,855,283) reported that N-glycolipids analogs displaying structural similarities to the naturally occurring glycolipids, such as glycosphingolipids and glycoglycerolipids, are capable of eliciting strong immune responses in both herpes simplex virus vaccine and pseudorabies virus vaccine.
• Some glycolipids have been synthesized from long chain alkylamines and fatty acids that are linked directly with the sugar through the anomeric carbon atom, to mimic the functions of the naturally occurring lipid residues.
• compositions of the invention are conveniently provided as liquid preparations, e.g., isotonic aqueous solutions, suspensions, emulsions or viscous compositions which may be buffered to a selected pH.
• compositions of the invention can be in the "solid” form of pills, tablets, capsules, caplets and the like, including "solid" preparations which are time- released or which have a liquid filling, e.g., gelatin covered liquid, whereby the gelatin is dissolved in the stomach and/or small intestine for delivery to the gut and/or digestive system.
• compositions of the invention can contain pharmaceutically acceptable flavors and/or colors for rendering them more appealing.
• the viscous compositions may be in the form of gels, lotions, ointments, creams and the like and will typically contain a sufficient amount of a thickening agent so that the viscosity is from about 2500 to 6500 cps, although more viscous compositions, even up to 10,000 cps may be employed.
• Viscous compositions have a viscosity preferably of 2500 to 5000 cps, since above that range they become more difficult to administer. However, above that range, the compositions can approach solid or gelatin forms which are then easily administered as a swallowed pill for oral ingestion.
• Liquid preparations are normally easier to prepare than gels and other viscous compositions, and solid compositions. Additionally, liquid compositions are somewhat more convenient to administer, especially to animals, children, particularly small children, and others who may have difficulty swallowing a pill, tablet, capsule or the like, or in multi-dose situations. Viscous compositions, on the other hand can be formulated within the appropriate viscosity range to provide longer contact periods with mucosa, such as the lining of the stomach or intestine. Suitable nontoxic pharmaceutically acceptable carriers, and especially oral carriers, will be apparent to those skilled in the art of pharmaceutical and especially oral or peroral pharmaceutical formations.
• liquid dosage form e.g., whether the composition is to be formulated into a solution, a suspension, gel or another liquid form, or solid dosage form [e.g., whether the composition is to be formulated into a pill, tablet, capsule, caplet, time release form or liquid-filled form] .
• Solutions, suspensions and gels normally contain a major amount of water (preferably purified water) in addition to the antigen (PspA) .
• Minor amounts of other ingredients such as pH adjusters (e.g., a base such as NaOH) , emulsifiers or dispersing agents, buffering agents, preservatives, wetting agents, jelling agents, (e.g., methylcellulose) , colors and/or flavors may also be present.
• pH adjusters e.g., a base such as NaOH
• emulsifiers or dispersing agents e.g., a base such as NaOH
• buffering agents e.g., preservatives
• wetting agents e.g., methylcellulose
• jelling agents e.g., methylcellulose
• colors and/or flavors may also be present.
• the compositions can be isotonic, i.e., it can have the same osmotic pressure as blood and lacrimal fluid.
• compositions of this invention may be accomplished using sodium chloride, or other pharmaceutically acceptable agents such as dextrose, boric acid, sodium tartrate, propylene glycol or other inorganic or organic solutes.
• sodium chloride is preferred particularly for buffers containing sodium ions.
• Viscosity of the compositions may be maintained at the selected level using a pharmaceutically acceptable thickening agent.
• Methylcellulose is preferred because it is readily and economically available and is easy to work with.
• suitable thickening agents include, for 18 example, xanthan gum, carboxymethyl cellulose, hydroxypropyl cellulose, carbomer, and the like. The preferred concentration of the thickener will depend upon the agent selected. The important point is to use an amount which will achieve the selected viscosity.
• Viscous compositions are normally prepared from solutions by the addition of such thickening agents.
• a pharmaceutically acceptable preservative can be employed to increase the shelf-life of the compositions.
• Benzyl alcohol may be suitable, although a variety of preservatives including, for example, parabens, thimerosal, chlorobutanol, or benzalkonium chloride may also be employed.
• a suitable concentration of the preservative will be from 0.02% to 2% based on the total weight although there may be appreciable variation depending upon the agent selected.
• compositions must be selected to be chemically inert with respect to PspA. This will present no problem to those skilled in chemical and pharmaceutical principles, or problems can be readily avoided by reference to standard texts or by simple experiments (not involving undue experimentation) , from this disclosure.
• the immunologically effective compositions of this invention are prepared by mixing the ingredients following generally accepted procedures. For example the selected components may be simply mixed in a blender, or other standard device to produce a concentrated mixture which may then be adjusted to the final concentration and viscosity by the addition of water or thickening agent and possibly a buffer to control pH or an additional solute to control tonicity. Generally the pH may be from about 3 to 7.5.
• compositions can be administered in dosages and by techniques well known to those skilled in the medical and veterinary arts taking into consideration such factors as the age, sex, weight, and condition of the particular patient or animal, and the composition form used for administration (e.g., solid vs. liquid) .
• dosesages for humans or other mammals can be determined without undue experimentation by the skilled artisan, from the Examples below (e.g., from the Examples involving mice) .
• CT is a potent mucosal immunogen (Elson et al. , 1984), probably because of the G H1 ganglioside-binding property of this binding subunit, CTB, that enables it to be taken up by the M cells of Peyer's patches and passed to the underlying immunocompetent cells.
• CT is a powerful adjuvant (Elson et al., 1989; Lycke et al., 1986; Wilson et al. , 1989) .
• CT greatly enhances immunogenicity of other soluble antigens co-administered with it.
• CTB is a strong adjuvant when given orally or perorally (e.g., intragastrically) in mice along with antigen, but CTB has no direct adjuvant effect, but can act synergistically with CT (Wilson et al., 1990).
• the mechanisms by which CT and CTB act as adjuvants are not fully understood, but are certainly complex, and appear to depend on several factors, including: l) the toxic activity associated with the ADP-ribosylating property of the Al subunit (Lycke et al., 1992; Abbas et al.
• CT can selectively inhibit CD8 + cells, and therefore tend to abrogate suppressive effects (Elson et al. , 1995) .
• carriage of pneumococci can be maintained for long periods in the very young and the elderly, it is generally not a permanent condition. Carriage is much less common in older children and young adults (Gray et al. , 1980; Gray et al. , 1981; Hendley et al., 1975; Brimblecombe et al. , 1958; Masters et al. , 1958) .
• Carriage is much less common in older children and young adults (Gray et al. , 1980; Gray et al. , 1981; Hendley et al., 1975; Brimblecombe et al. , 1958; Masters et al. , 1958) .
• One explanation for these findings is that carriage may be interfered with by immunity (possibly mucosal immunity) to pneumococci (Gray et al. , 1980; Gwaltney et al. , 1975) .
• Antibodies may be effective against carriage in two ways, namely: 1) they might act at the mucosal surface by opsonizing pneumococci, preventing attachment or surface invasion,- 2) they might act via opsonophagocytosis and killing. This latter mechanism could be especially important if carriage is dependent on minimal invasion of the nasal mucosal surface.
• the complement fixing antibodies could prevent the invasion and facilitate the killing of any pneumococci that invaded locally.
• complement fixing antibodies might be able to act and the mucosal surface if inflammation causes a sufficient release of complement, phagocytes, and possibly serum antibody.
• H. influenzae can be prevented by an intramuscular vaccine (Barbour et al. , 1993) . It has recently been reported that significant levels of H. influenzae polysaccharide-specific IgG and IgA are detected in secretions of children following immunization with the group b polysaccharide conjugate vaccine (Chiu et al. , 1994; Kauppi et al. , 1993) .
• Phagocytes are rare on the surface of normal nasopharyngeal tissue, and even if present, the phagocytes do not have the filtering action of the spleen and reticuloendothelial system to increase their chance of interactions with opsonized bacteria.
• Antibodies that block the virulence enhancing effects of pneumolysin and pneumococcal enzymes should be able to bind their antigens just as effectively whether phagocytes were present or not.
• results provided herein show that oral or peroral (e.g., i.g.) immunization with heat-killed pneumococci, and pneumococcal lysates, and purified PspA can protect mice against sepsis and therefore carriage too.
• oral or peroral (e.g., i.g.) immunization with heat-killed pneumococci, and pneumococcal lysates, and purified PspA can protect mice against sepsis and therefore carriage too.
• the ability of a vaccine to protect against disease not only in the immunized host, but, by eliminating carriage among immunized individuals, the pathogen and hence any disease it causes may be eliminated from the population as a whole.
• the vaccine or immunogenic composition which is administered orally, perorally or intragastrically as provided herein may be formulated in any convenient manner and in a dosage formulation consistent with the mode of administration and the elicitation of a protective response (see discussion above and Examples below) .
• the quantity of antigen to be administered depends on the subject to be immunized and the form of the antigen. Precise amounts and form of the antigen to be administered depend on the judgment of the practitioner. However, suitable dosage ranges are readily determinable by those skilled in the art from this disclosure, without undue experimentation, and may be of the order of micrograms to milligrams. Suitable 23 regimes for initial administration and booster doses also are variable, may include an initial administration followed by subsequent administrations; but nonetheless, may be ascertained by the skilled artisan, from this disclosure, without undue experimentation.
• kits wherein PspA or a fragment thereof is provided.
• the kit can include in a container separate from the PspA or fragment thereof, a suitable carrier, diluent or excipient.
• the kit can also include, in a container separate from the PspA or fragment thereof or from the carrier, diluent or excipient, or already in admixture with either of these components, an adjuvant, such as cholera toxin.
• the kit comprises: (i) PspA or fragment thereof, (ii) carrier, excipient or diluent, and optionally, (iii) adjuvant, wherein there are separate containers for (i) and (ii) , or for (i) , (ii) and (iii) , or for (i) and the combination of (ii) and (iii) , or for (ii) and the combination of (i) and (iii) .
• the kit can include instructions for mixing or combining ingredients and/or administration.
• mice Prior to oral immunization, mice were deprived of food for two hours and then given a solution of sodium bicarbonate to neutralize stomach acid. Thirty minutes later, mice were orally-immunized by gastric intubation with 7.5 ⁇ g of purified native PspA with or without CT. Oral immunizations were carried out on day 0, 7, 14, and 35. Serum and fecal extracts were collected prior to immunization on days 7, 14 and 35. Sera and fecal pellets were also collected on days 21, 28, 42 and 49. Sera and fecal extracts were obtained and assayed as 24 previously described (Jackson R.J., K. Fujihoski, J. Xu- Amano, H. Kiyono, CO.
• PspA was given orally with CT antigen specific IgM, IgG, and IgA responses were induced in the serum.
• PspA-specific IgG responses were elevated to Log2 19 after the 4th oral immunization with PspA plus CT;
• PspA-specific serum IgA responses of Log2 9 and 13 were detected on day 42 and
• mice were challenged intravenously with 3.6 x 10 3 colony forming units (CFU) of S. pneumoniae A66 two weeks following the 4th oral immunization with PspA alone or PspA plus CT.
• CFU colony forming units
• mice For systemic immunization of mice 0.5 ⁇ g of purified, native PspA with Complete Freund Adjuvant (CFA) was injected subcutaneously on days 0 and 14 (at a ratio of 1:1 CFA to PspA in PBS) .
• CFA Complete Freund Adjuvant
• mice were deprived of food for two hours, and then administered by gastric intubation a solution of sodium bicarbonate to neutralize stomach acid prior to the immunization. Thirty minutes later, mice were orally- immunized by gastric intubation with 7.5 ⁇ g of purified, native PspA, with or without mucosal adjuvant cholera toxin (CT) .
• CT mucosal adjuvant cholera toxin
• Oral immunizations were carried out on day 0, 7, 14 and 35. A total of six mice were used in each control and experimental group.
• Serum and fecal extracts were prepared as previously descrived (Jackson, R.J. et al, Infect. Immun. 1993) 61: 4272-79). Serum and fecal extracts were collected weekly intervals and assayed for PspA-specific IgM, IgG and IgA antibodies by ELISA. 96 well plates (Nunc Immuno Plate, Roskilde, Denmark) were coated with PspA in PBS for overnight at 4°C. After washing 3 times with PBS, wells were blocked for 1 hours with PBS containing 10% goat serum. Serial two-fold dilutions of samples were tested, starting at a dilution of 1:2 (fecal extract) and 1:32 (serum).
• the wells containing the aequorin derivatives were developed in a Dynatech ML-3000 luminometer by injection of 50mM Tris-HCl, pH 7.5, containing 20mM calcium acetate. Results were expressed as relative light unit (RLU) following subtraction of blank values. To determine endopoint titer for the luminometric assay, the straight line generated following background substraction was extrapolated (E titer) to a baseline 1000 relative light units above background.
• ELISPOT assay was performed as previously described (Jackson, R.J. et al. , Infect. Immun. (1993) £1: 4272-79) .
• Single cell suspensions were prepared from spleen by mechanical dissociation.
• Ninety- six well nitrocellulose plates (Millititer HA; Millipore Corp., Bedford, Mass.) were used for the assay.
• the plates were coated with 0.5 mg of purified, native PspA. After incubation overnight at 4°C plates were washed and blocked with 10% FCS-RPMI 1640.
• the blocking solution was discarded, and 100 ml of cells in 10% FCS-RPMI 1640 at various dilutions were added. Cell suspensions were incubated for 4 hours at 37°C in 5% C0 2 atmosphere. Plates were washed with PBS and PBS-0.05% Tween-20.
• the secondary antibody solution consisted of 100 ml of a 1:1,000 dilution of goat anti-mouse IgM, IgG and IgA conjugated to horseradish peroxidase (Southern Biotechnology Associates, Birmingham, AL) in PBS-0.05% Tween-20 containing 1% BSA.
• mice which were subcutaneously immunized with 0.5 ⁇ g of purified, native PspA with CFA were used in order to establish a base line for systemic immunization.
• PspA-specific IgG responses were detected by 14 days after the primary immunization and levels of antigen- specific titers were increased following secondary immunization. There PspA-specific IgG responses were 28 maintained for greater than 70 days (Fig. 3) .
• mice were sacrificed 4 days after secondary immunization. Splenic mononuclear cells were isolated and assayed for the detection of PspA-specific antibody producing cells by the ELISPOT assay.
• mice were protected from a lethal challenge with S. pneumoniae . Further, those responses were not enhanced following the booster oral immunization. Soluble proteins are generally not strong immunogens when given by the oral route. This result, however, suggests that small amounts of PspA are sufficient to induce serum responses by the oral route which are able to protect against challenge. Very small IgA response (1:32) were detected 3 weeks after 4th oral immunization on day 35. No antigen-specific IgM responses were detected during the analysis period following immunization (Fig. 5A) . In the case of fecal extracts, there was no detectable levels of antigen-specific immune responses.
• mucosal adjuvant CT with soluble protein antigen not only induces antigen-specific serum responses, but it also is an effective immunization regimen for the generation of antigen-specific antibody responses in mucosal sites.
• native 29 native 29
• PspA was given orally with lO ⁇ g CT on day 0, 7, 14 and 35, antigen-specific IgM, IgG and IgA responses were induced in the serum.
• PspA-specific IgM antibodies were induced (1:512) and shifted to secondary type responses where high levels of IgG responses (1:16,384) were elicited on day 21 (Fig. 5B) .
• These PspA-specific IgG responses were elevated up to 1:524,288 after 4th oral immunization with PspA plus CT.
• PspA-specific IgA serum responses were detected on day 42 and 49 (Fig. 5B) .
• antigen-specific IgA antibodies were detected in fecal extracts obtained from 2 weeks after the third oral immunization and the responses were increased following the 4th immunization (Fig. 6) .
• main response was noted as IgGl followed by IgG2b (Fig. 7) .
• IgA anti- spA appeared in the fecal extracts following the third immunization, and the response was increased after the fourth immunization.
• CT is known to selectively induce antigen- specific Th2 type response which promotes IgGl in serum as well as mucosal IgA responses when it was given orally together with protein antigen.
• mice were challenged intravenously with 3.6xl0 3 CFU of pneumococcal strain A66. The survival of mice was monitered for 21 days.
• mice orally-immunized with PspA plus CT showed antigen- specific serum IgG titer of 19 prior to the challenge (Table 2, below) .
• the levels of antigen-specific IgG response was low (serum titer of 6) .
• oral immunization with PspA and CT protected all the mice from the infection.
• oral immunization with PspA alone failed to provide complete protection, and three out of eight mice survived challenge (Table 2) .
• oral immunization with PspA vaccine can induce a protective, humoral immune response against S. pneumoniae infection.
• oral immuization with PspA plus CT could induce a protective level of systemic responses against different capsular serotypes of pneumococcal infection.
• Table 2 Oral immunization with PspA plus CT induces protective immunity to systemic challenge with capsular type 3 strain
• mice were challenged intravenously with 3.6xl0 3 CFU of A66. *P values shown above were calculated by the two tailed Wilcoxon two-sample tank test using, N.S: not significant, N.A: not applicable.
• the present invention provides a method of immunizing a host against pneumococci in a host and for protecting against systemic and humoral infection by pneumococci, by oral, particularly intragastric, administration of PspA in various forms.
• Greenwood, B.M., Greenwood A.M. Bradley, A.K., Tulloch, S., Hayes, R., Oldfield, F.S.J., Ann. Trop. Pediatr. 7:91-99 (1987) .

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