Humoral antibody responses to the bacterial polysaccharide dextran B1355

Differential effect of interferon-gamma and interleukin-2 on the induction of IgA and IgM anti-dextran responses

Supernatants from T-cell lines and T-cell hybridomas can substitute for T cells in the induction of the anti-alpha(1,3) Dextran B1355 plaque-forming cell response in culture. The present study sought to define the lymphokines required for the induction of IgA and IgM anti-alpha (1,3) dextran responses. Recombinant Interferon-gamma (IFN-gamma) supported the induction of low levels of IgA anti-alpha(1,3) dextran plaque-forming cells in splenic B-cell cultures. IgA responses were substantially increased when cultures containing IFN-gamma were supplemented with an interleukin 2 (IL-2)-containing supernatant from the murine T-cell hybridoma BW.Mls, purified murine IL-2, or recombinant human IL-2. In striking contrast, IgM anti-alpha(1,3) dextran plaque-forming cells were not produced in cultures containing IFN-gamma alone or in combination with purified or recombinant IL-2. However, substantial IgM responses could be produced in cultures containing IFN-gamma and BW.Mls supernatant. This data indicates that there may be different lymphokine requirements for the induction of IgA and IgM anti-alpha(1,3) dextran B cells, or alternatively, such B cells may be in different stages of differentiation and therefore, not respond to the same lymphokines.

Dextran sulfate-induced peritoneal lysophospholipase activity varies among mouse strains

Lysophospholipase (LPL) activity resulting from the intraperitoneal injection of dextran sulfate (DS) was studied in different mouse strains. AKR/J and BALB/cByJ mouse strains showed decreased LPL levels when a low molecular weight DS was injected but increased LPL activity when high molecular weight DS was injected intraperitoneally. C57BL/6 mice had increased LPL activity with low molecular weight DS but decreased LPL activity with high molecular weight DS. All three mouse strains showed increased peritoneal-cell changes when injected with DS of a molecular weight of 79,000.

Coeliac disease: genetic, immunological and environmental factors in disease pathogenesis

Coeliac disease in humans is activated by the dietary ingestion of wheat gliadins and similar proteins in other grains. We have studied genetic, immunological and environmental factors that may play a role in the pathogenesis of disease. In mice, two genetic regions, the major histocompatibility complex (H-2) and the immunoglobulin heavy chain constant region, were shown to regulate the production of anti-gliadin antibody. In coeliac disease patients on a gluten-free diet, elevated levels of antigliadin antibody were associated with the immunoglobulin heavy chain allotype marker G2m(n). Studies of additional environmental factors involved in coeliac disease revealed a region of amino acid sequence homology and immunological crossreactivity between A-gliadin, a wheat gliadin component known to activate coeliac disease and the Elb early region protein of human adenovirus 12, an adenovirus serotype usually isolated from the human intestinal tract. Specific HLA markers may be associated with coeliac disease because they reflect the host's response to virus.