Induction of splenic T cell proliferation by lipid A in mice immunized with sheep red blood cells.
The stimulatory effect of alkali-treated lipid A on the in vivo proliferation of splenic T lymphocytes was investigated by determining 3H-thymidine incorporation into DNA after cell separation by nylon wool adherence. Our experimental model was the primary immune response against SRBC antigen. Mice received a single i.v. injection of alkali-treated lipid A 2 days post-immunization. The splenocytic IgG-plaque response was enhanced but the IgM-plaque response was not. On the 4th day postimmunization, 2H-thymidine uptake by the B cell population was not amplified. However, the splenocytic DNA content was increased in immunized, adjuvant-treated mice, and the radioactivity count in T lymphocytes of lipid A-treated mice was approximately twice that of lipid-untreated animals. We conclude that alkali-treated lipid A enhances T cell proliferation in mice immunized with red blood cells.
D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology; D004912:Erythrocytes / Q000276:immunology; D006462:Hemolytic Plaque Technique; D007075:Immunoglobulin M / Q000096:biosynthesis; D008050:Lipid A / Q000276:immunology / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012756:Sheep; D013154:Spleen / Q000166:cytology*; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology
D007075:Immunoglobulin M; D008050:Lipid A; D008070:Lipopolysaccharides