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.

SummaryThe effect of heavy metal intoxication on superoxide anion (O 2 -) production and larval burden during experimental Ascaris suum infection was studied. Mice were chronically intoxicated with lead (Pb), cadmium (Cd) or mercury (Hg) and subsequently infected with A. suum. The metabolic activity of peritoneal macrophages in mice intoxicated with Pb was suppressed and subsequent parasitic infection did not change this inhibition. Cd intoxication increased the superoxide production and also stimulated the activity of this oxygen radical after A. suum infection. Intoxication with Hg had a stimulative effect on the macrophage metabolic activity and subsequent A. suum infection moderately reduced this activity. Parasite burden was different depending on a type of heavy metal intoxication. Pb intoxication moderately increased the parasite burden in the liver and lungs of intoxicated mice. In contrast, Cd and Hg intoxication triggered a marked reduction of A. suum larvae in the liver and lungs of intoxicated mice, respectively. Monitored heavy metals differed in their immunomodulatory effect on metabolic activity of macrophages what also altered the intensity of the parasite infection in the hosts.