Heat-labile antigens of Salmonella enteritidis. I. Extraction of antigens

Milne, Margaret (University of Adelaide, Adelaide, Australia), and F. M. Collins. Heat-labile antigens of Salmonella enteritidis. I. Extraction of antigens. J. Bacteriol. 92:543-548. 1966.-Salmonella enteritidis strains of high and low mouse virulence were grown in continuous culture. Cell walls were obtained from both strains by sonic disruption, and the washed walls were extracted at 4 C with sodium dodecyl sulfate or sodium deoxycholate. The extracts were eluted with a saline gradient from a diethylaminoethyl cellulose column, and the separated peaks were tested for precipitin activity against rabbit antisera prepared with heator ethyl alcohol-killed vaccines. The separated antigens reacted less intensely with the antiserum to heat-killed cells than they did to the antisera prepared against alcohol-killed vaccine. Little antigenic difference could be detected between the extracts prepared from the virulent and the avirulent organisms.     

Tumor-associated antigens of rat moloney sarcoma cells. II. Cytosol antigens.

Rat Moloney sarcoma cells (MST) were pulsed with 35S-L-methionine for 10 and 60 min and lysed by vortexing in 0.5% deoxycholate, 0.5% NP40, 0.02 M Tris, 0.05 M NaCl, pH 7.5, for 30 sec. The lysate was centrifuged at 16,300 X G for 10 min and the supernatant was co-precipitated with Ig fractions of normal BN serum, normal Lewis serum, BN antiserum to Moloney sarcoma cells (BNaMST), BN antiserum to tumor-associated antigens (BNaTAA), BN antiserum to murine leukemia virus (BNaMuLV), BN antiserum to p30 (BNap30), BN antiserum to gp70 (BNagp70), Lewis antiserum to BN (LeaBN), and BN antiserum to BC5 tumor (BNaBC5). With BNaTAA and BNaMST, a cytoplasmic TAA with m.w. 85,000 was detected. In addition, BNaTAA detected three other species of cytoplasmic TAA with m.w. 220,000, 170,000 and 39,000.     

Tumor-associated antigens of rat moloney sarcoma cells. I. Cell-surface antigens.

The dissociated cell surface membranes of a rat Moloney sarcoma (MST), derived from a BN rat, were extracted with 2 M KI, with 6 M guanidine thiocyanate, or by papain digestion. Extracts obtained with these three reagents were fractionated on columns of controlled-pore glass, 170 A pore size. A fraction was eluted from each preparation that contained tumor-associated antigens (TAA), viral, fetal, and histocompatibility antigens. With an antibody specific for TAA, the TAA, devoid of detectable viral, fetal, and histocompatibility antigens, were co-precipitated by addition of goat antibody to rat immunoglobulin. After electrophoresis, on slab gels, three bands were detected with estimated m.w. of 185,000, 150,000, and 70,000. No such bands were detected on slab gel electrophoresis with extracts of BC5, a chemically induced tumor, of normal BN lymphoid cells, of M-MuLV, or of fetuses, after incubation with anti-TAA antibody and goat antibody to rat immunoglobulin. TAA extracts prepared with 2 M KI, 6 M guanidine thiocyanate, or papain digestion showed immunologic reactivity. Cold TAA inhibited the co-precipitation of labeled TAA by rat antibody specific for TAA; they elicited antibody in guinea pigs but not in rats; and antibodies specific for TAA were cytotoxic to MST in the presence of C.     

Bacterial capsular antigens. Structural patterns of capsular antigens

Structural patterns of bacterial capsular antigens including capsular polysac charides and exoglycans are given in this review. In addition, the immunological activity of capsular antigens and their role in type specificity of bacteria are discussed. Published in Russian in Biokhimiya, 2006, Vol. 71, No. 9, pp. 115–1174.     

Macrophage Ia antigens. I. macrophage populations differ in their expression of Ia antigens

By indirect immunofluorescence and microcytotoxicity it was demonstrated that different populations of murine macrophages bear different amounts of Ia antigens on their membranes. At least three subpopulations could be distinguished: those that lack Ia antigens and predominate in peritoneal exudate; cells bearing I-A antigens that are the majority of splenic macrophages and a minor population in the peritoneum; and cells bearing I-C antigens that are a minor population in both spleen and peritoneum. Internal radioisotope labeling studies confirmed that the I region molecules are synthesized by the macrophages. It is suggested that these different macrophage subpopulations may play distinct roles in the immune response.     

Serospecific antigens of Legionella pneumophila.

Serospecific antigens isolated by EDTA extraction from four serogroups of Legionella pneumophila were analyzed for their chemical composition, molecular heterogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological properties. The antigens were shown to be lipopolysaccharides and to differ from the lipopolysaccharides of other gram-negative bacteria. The serospecific antigens contained rhamnose, mannose, glucosamine, and two unidentified sugars together with 2-keto-3-deoxyoctonate, phosphate, and fatty acids. The fatty acid composition was predominantly branched-chain acids with smaller amounts of 3-hydroxymyristic acid. The antigens contain periodate-sensitive groups; mannosyl residues were completely cleaved by periodate oxidation. Hydrolysis of the total lipopolysaccharide by acetic acid resulted in the separation of a lipid A-like material that cross-reacted with the antiserum to lipid A from Salmonella minnesota but did not comigrate with it on sodium dodecyl sulfate gels. None of the four antigens contained heptose. All of the antigen preparations showed endotoxicity when tested by the Limulus amebocyte lysate assay. The results of this study indicate that the serogroup-specific antigens of L. pneumophila are lipopolysaccharides containing an unusual lipid A and core structure and different from those of other gram-negative bacteria.     

Specific antigens of Lactobacillus acidophilus.

Antigens specific for Lactobacillus acidophilus were investigated by double immunodiffusion in agar-gel. Antigenic materials were extracted from whole bacteria and some walls with cold trichloroacetic acid. Antisera were prepared by intravenous injection into rabbits of suspensions of whole organisms in solutions of bovine serum albumin, which had been heated and then washed. Four specific antigens were found as precipitinogens and denoted as antigens 11, 12, 13 and 14. Of 43 strains of L. acidophilus studied, 33 strains possessed antigen 11, six strains antigen 12, two strains antigen 13 and two strains antigen 14. Sugar compositions of wall preparations were analysed in an attempt to characterize the determinants of antigens 11 and 12. The walls contained glucose, galactose, hexosamine and sometimes glycerol, but no rhamnose was found. It was considered that alpha-glucopyranose was the major component of the determinant of antigen 11 since trehalose and maltose significantly inhibited the reaction between antibody 11 and its antigen; the determinant of antigen 12 was not clarified.     

Oncofoetal antigens of human trophoblast.

Rabbits immunized with human trophoblast cell membranes produced antibodies that were detected, by immunofluorescence, to react with normal human tissues, and, by complement-mediated cytotoxicity, with several transformed human cell lines. Absorption with trophoblast abolished all of these reactions, whereas multiple absorptions with lymphocytes, liver or kidney failed to remove reactivity with either trophoblast or certain transformed cells. To further identify the antigens responsible for these antibodies, rabbits were immunized with a chromatographed fraction of deoxycholate-solubilzed membranes prepared from KCl-extracted, ultracentrifuge-prepared trophoblast microvilli. The resultant IgG antibody reacted specifically with syncytiotrophoblastic membranes in sections of human placentae, in addition to recognizing the membranes of viable Chang liver, AV3, HEp-2, Sw/156 (kidney) and Sw/527 (breast) cells. That normal tissues, baboon or monkey placentae, and HeLa or Daudi cell lines did not react with this antibody, indicates the presence of species- and organ-specific antigens in human trophoblast, as well as the existence of trophoblast cross-reactive antigens on some transformed cells. The selective localization of these antigens at the interface of the materno-foetal graft suggests that they function biologically in the host-parasite relation of human pregnancy; their appearance on many transformed cells implies a similar function in the host-parasite relation of some human cancers.