Differences in cellular immune responses of mice BALB/c to low and high infective doses of Trichinella spiralis

The study was focused on a role of lymphocytes and macrophages in the immune response of mice to Trichinella spiralis infection with low (10) and high (400) infective doses of larvae. The light infection stimulated the proliferation of splenic T lymphocytes only during the intestinal phase of the infection, till day 15 post infection (p.i.), but the heavy infection activated T cells during the migration of newborn larvae (from day 20 to 30 p.i.). B cell proliferation was markedly stimulated after the heavy infection. The light infection increased the presence of helper CD4 cells till day 10 p.i. in contrast to the heavy infection, but subpopulation of CD8 T cells was not influenced by a different size of infective dose. Cytokine production of IL-5 and IFN-γ was not markedly affected by the light infection in contrast to the heavy infection that stimulated IL-5 synthesis during the whole experiment and IFN-Γ during the migration of newborn larvae. The light infection stimulated a metabolic activity of peritoneal macrophages already in the intestinal phase, but the heavy infection affected their activity only in the muscle phase of the infection.