Cellular immune responses in mice immunized with Anisakis simplex larval antigens

Cellular immune responses to Anisakis simplex L3 antigens were investigated in BALB/c mice injected subcutaneously with a homologous crude extract (CE ). Popliteal lymph nodes (PLN) were found to be increased in size and weigh t after A. simplex CE footpad injection. The effects of A. simplex CE in vi tro proliferation were assayed with non-fractionated PLN cells or nylon-woo l purified T cells derived from pooled lymph node cells of mice subcutaneou sly injected with CE. Spleen cells from immunized animals (antigen alone, o r larva alone, or antigen plus larva) were studied by flow cytometry. The i mmunization induced a high proportion of CD4 + and TCR alpha beta + T cells . The number of B cells (CD45 + and TCR alpha beta-) in pre-immunized and i nfected mice was lower than that observed in animals subjected to infection only. The number of CD4 + T cells increased in the infected and in the pre -immunized and infected mice. In the latter, a decrease of CD8a + T cells w as noted. The greatest increase in CD8a+ and TCR alpha beta- T cells was fo und in mice that had been subjected to infection only. Histological analysi s showed that the most prominent lesions were gastric and intestinal in ani mals infected orally with one larva.