Inhibition by aldobiouronates in the precipitation of pneumococcal type II and III systems

Hexasaccharide (HS) containing 3 U of cellobiuronic acid was isolated from Streptococcus pneumoniae type 3 capsular polysaccharide S3 and coupled to bovine serum albumin (BSA), keyhole limpet hemocyanin (KLH), or tetanus toxoid (TT). The immunogenicity of these HS-protein conjugates in BALB/c mice was studied by measuring the production of circulating antibodies and the induction of protective immunity to viable S. pneumoniae type 3. Immunization of BALB/c mice with 0.5 jig of S3 resulted in the induction of immunoglobulin M (IgM) antibodies and complete protection against 25 U of a mean lethal dose of S. pneumoniae type 3 for 19 weeks after immunization. BALB/c mice immunized with 100 ,ug of HSq-BSA (containing 12 ,ug of HS) were also protected due to circulating IgM antibodies. Repeated injections with either 100 ,ug of HSq-BSA (three immunizations) or 100 ,ug of HS6-KLH (two immunizations) resulted in high levels of circulating IgG antibodies. These HS-protein conjugates induced complete protection which lasted at least 14 (HS9-BSA), 23 (HS6-KLH), or 8 (HS16-TT) weeks after the last immunization. Protection against viable S. pneumoniae type 3 could be passively transferred to nonimmunized mice by antisera containing IgM or IgG antibodies or both. Sera containing both IgM and IgG antibodies gave better protection than sera containing only IgM antibodies. The specificity of the induced protection was confirmed by challenge with the non-cross-reacting S. pneumoniae type 11. Anti-capsular polysaccharide antibodies confer immunity to infections with Streptococcus pneumonia (10). These anti-polysaccharide antibodies exert their protective effect by opsonization. S. pneumoniae infections can be prevented by vaccination with purified capsular polysaccharides, and in 1977 a polyvalent pneumococcal polysaccharide was licensed for general use in the United States (1). Because vaccination aims at long-lasting protection against infectious

Section: Methodsmentioning

confidence: 99%

Immunogenic properties in mice of hexasaccharide from the capsular polysaccharide of Streptococcus pneumoniae type 3

Snippe¹,

Houte²,

Dam³

et al. 1983

“…Accordingly, there is no 1,4,6-linked Glc, as previously thought, nor is there GlcA in the main chain, so the discussion of the Pn2-Pn2O cross-reaction in reference 30 requires revision. The immunodominant group of S2 is the isomaltouronic side chain (29), making it possible that the phospho-a-D-glucosyl residue of S20 (52a), responsible for the acquisition of cross-precipitation in anti-Pn8: intact S4 does not precipitate. Reactivity of both forms in anti-Pnl4 probably occurs because the 1,3-linked N-acetyl-D-galactosamine of S4 (34) fits partially into antibody sites designed for 1,3-linked D-Gal.…”

Section: Resultsmentioning

confidence: 99%

Precipitating cross-reactions among pneumococcal types

Heidelberger¹

1983

Data accumulated over many years are brought together on cross-reactions of 46 among the more than 80 pneumococcal serological types, with the idea of correlating cross-reactions with the structures of the relevant type-specific capsular polysaccharides, insofar as these have been determined. The precipitin reaction was carried out with the polysaccharides and antibodies raised in horses, rabbits, and a mule. Quantitative values (micrograms of antibody nitrogen per milliliter of antiserum at 0 to PC) are given in many instances and discussed, together with arbitrary qualitative data, in terms of the known structures of the polysaccharides. Some precise relationships are uncovered, and an attempt is made to determine why some of the cross-reactions are reciprocal and why others are only unilateral. were placed in a cold bath at 0 to PC for 2 days to 2 weeks or longer, depending on the rapidity of precipitation. Qualitative data are given within parentheses 1234 on September 3, 2020 by guest http://iai.asm.org/ Downloaded from CROSS-REACTIONS OF PNEUMOCOCCAL TYPES 1235 when carried out in antisera which were negative or weakly positive in other tests. Quantitative figures within parentheses refer to single analyses instead of the usual mean of duplicates. The following abbreviations are used: S, specific capsular polysaccharide; Gal, galactose; Glc, glucose; Rham, rhamnose; Man, mannose; GalA, galacturonic acid; GlcA, glucuronic acid; GlcNAc, N-acetylglucosamine; dp, depyruvylated. Except as indicated, the antisera used had been raised in horses. All sugars are in the pyranose form unless indicated as furanoses by f, as in Galf.

“…The isolated TS and OS were analyzed immunochemically by testing the inhibition of the antigen-antibody complex formation in the K11PS-anti-KllPS antibody system. Quantitative precipitations were carried out as described by Heidelberger et al (16). A 60-jig amount of OS inhibited the precipitin reaction by 50%.…”

mentioning

confidence: 99%

Immunogenic properties of octasaccharide-protein conjugates derived from Klebsiella serotype 11 capsular polysaccharide

Zigterman¹,

Dam²,

Snippe³

et al. 1985

The tetrasaccharide repeating unit of the capsular polysaccharide of Kkebsiella serotype 11, K11PS, comprises the following sequence: [-*3)-I8-D-GlcpA-(1--.3)-a-D-Galp-(1--3)-4-D-Glcp-(l--I with a 4,6-0-(1carboxyethylidene)-a-D-galactopyranosyl residue linked to 0-4 of the glucuronic acid residue. Octasaccharide (OS) derived from K11PS by bacteriophage +11-associated glycanase, was coupled to bovine serum albumin and to keyhole limpet hemocyanin. The immunogenicity of various antigens after intraperitoneal immunization was studied by measuring the levels of circulating antibodies. Injection of BALB/c mice with K11PS resulted in induction of 2-mercaptoethanol-sensitive immunoglobulin M antibodies. The responses observed in BALB/c nulnu mice and in male (CBA/N x C3H/HeN)Fl mice indicate that K11PS is a thymus-independent type 2 antigen. Immunization of BALB/c mice with either OS-bovine serum albumin or OS-keyhole limpet hemocyanin resulted in the induction of circulating 2-mercaptoethanol-resistant immunoglobulin G antibodies.Results in BALB/c nulnu mice indicate that the OS-protein conjugates are thymus-dependent antigens. Since the OS-keyhole limpet hemocyanin conjugate induced antibodies in both (CBA/N x C3H/HeN)Fl females and males, we propose to refer to this kind of antigen as a thymus-dependent type 1 antigen, whereas OS-bovine serum albumin, which evoked immunoglobulins in (CBA/N x C3H/HeN)Fl females only, can be referred to as a thymus-dependent type 2 antigen.Bacterial polysaccharides are generally considered to be thymus-independent (TI) antigens (4, 6) and are characterized by the induction of mainly immunoglobulin M (IgM) and IgG3 antibodies after primary immunization (17, 29), without the induction of immunological memory (35). Moreover, the immune response toward TI antigens is developed only at later stages of the ontogeny, which has important consequences for the vaccination of neonates (27,35).For vaccinations aiming at long-lasting protection against diseases, it would be desirable to immunize with thymus-dependent (TD) antigens (35). TD antigens are supposed to induce immunological memory and thus to provoke a state of prolonged resistance to infections (36). Furthermore, the development of TD forms of a particular TI antigen raises the possibility of immunizing young animals with more success than with the TI antigen itself.In earlier experiments with Streptococcus pneumoniae type 3 capsular polysaccharide (S3PS) and hexasaccharideprotein conjugates, we showed that the S3PS behaved as a TI antigen, whereas the hexasaccharide-protein conjugates behaved as TD antigens (35). To extend the results obtained with S3PS and hexasaccharide-protein conjugates of S. pneumoniae, we used the capsular polysaccharide of Klebsiella serotype 11, K11PS, as a novel model antigen. This polysaccharide was chosen because of the availability of bacteriophage +11-associated glycanase, which could be used to depolymerize K11PS. Enzymatic digestion of K11PS results in the cleavage of the ,(1-3-3) glycosidic linkage betw...