Generation of a murine monoclonal antibody specific for N-glycolylneuraminic acid-containing gangliosides that also recognizes sulfated glycolipids.

The P3 murine monoclonal antibody (MAb) was generated by immunizing BALB/c mice with NeuGcGM3 included into liposomes. The specificity of this MAb was defined by an enzyme-linked immunosorbent assay and immunostaining on thin-layer chromatograms. P3 MAb binds to NeuGc-containing gangliosides and was shown also to react with sulfated glycolipids. A preliminary immunohistochemical study showed that the P3 MAb was able to recognize antigens expressed in human breast tumors.

Titres of class-specific antibodies against Shigella and Salmonella lipopolysaccharide antigens in colostrum and breast milk of Costa Rican, Swedish and Vietnamese mothers.

Enzyme immunoassays (EIA) were used to estimate titres of class-specific antibodies against purified and chemically defined phenol-water-extracted lipopolysaccharide (LPS) antigens of Salmonella serogroup B (BO), Shigella dysenteriae type I, Plesiomonas shigelloides (the same O-antigen as Shigella sonnei) and Shigella flexneri Y. Titres in colostrum and breast milk of Swedish, Vietnamese and Costa Rican mothers from various socioeconomic conditions were compared. The antibodies were mainly of the IgA isotype. IgM antibodies were also present, but only very low concentrations of IgG were found. In Costa Rican mothers, the IgA antibody titres were significantly higher (P less than 0.05) in women of low and middle socioeconomical conditions than were those in mothers of high socioeconomical level. The low titres in the last group were comparable to those found in Swedish mothers. The IgA antibody titres found in Vietnamese mothers were similar to those of Costa Rican mothers from the low and middle socioeconomic conditions, being highest against S. flexneri Y LPS. The IgM antibody titres were also highest in Vietnamese mothers, immediately followed by the Costa Rican mothers of low socioeconomic conditions. The low IgM titres in the Costa Rican women of high socioeconomic level were comparable to those seen in Swedish mothers. The results suggest that, in Costa Rica and Vietnam, S. flexneri is the most prevalent Shigella sp. causing infection and that Salmonella serogroup B infections are rare in all three countries. The results also show that the antibody repertoire in colostrum and breast milk varies. Furthermore, in addition to the prevalence of a specific micro-organism in a determined geographical area, such differences may be associated mainly with exposure to certain pathogens in particular socioeconomic conditions.

Novel isoglobo-neolacto-series hybrid glycolipid detected by a monoclonal antibody is a rat colon tumor-associated antigen.

Isoglobotetraosylceramide (GalNAc(beta 1-3)Gal(alpha 1-3)Gal(beta 1-4)Glc (beta 1-1)Cer), the major glycolipid species in dimethylhydrazine-induced rat tumors of colorectal origin, was not detected in epithelial cells of normal colon but was present in the non-epithelial stroma and could be extracted from each of nine tumors studied. Monoclonal antibodies produced against isoglobotetraosylceramide detected this and another novel rat tumor-associated glycolipid not present in epithelial cells nor in non-epithelial stroma of normal rat colon (Brodin, T., Thurin, J., Strömberg, N., Karlsson, K.-A. and Sjögren, H.O. (1985) Eur. J. Immunol. 16, 951-956). This novel glycolipid was present in 8/9 of the studied tumors and was also present in two in vitro cell clones. These were originally obtained from a W49/T4 colon tumor isograft. The novel glycolipid was characterized by mass spectrometry, 1H-NMR, and methylation analysis as a hybrid between the isoglobo- and neolacto-series, with the structure GalNAc(beta 1-3)Gal(alpha 1-3)Gal(beta 1-4)GlcNA(beta 1-3)Gal (beta 1-4)Glc(beta 1-1)Cer.