ROLE OF T-CELL SUBPOPULATIONS IN MICE INFECTED WITH ANGIOSTRONGYLUS-CANTONENSIS

When C57BL/6 mice were infected with Angiostrongylus cantonensis, the percentage of T helper (CD4+) cells and T supressor (CD8+) cells in pe ripheral blood increased weekly until the third and seventh week respe ctively, and then gradually decreased. C57BL/6 mice were depleted of C D4+ and CD8+ T cells by in vivo injection of anti-CD4 and anti-CD8 mon oclonal antibodies, respectively, and then infected with A. cantonensi s. There were significantly more and less worms recovered in the mice depleted of CD4+ and CD8+ T cells respectively than in undepleted mice . Discrete subpopulations of T cells from mice exposed to A. cantonens is for 3 weeks or 7 weeks were adoptively transferred to syngeneic rec ipients which were then given a challenge infection. Protection was me diated by a CD4+ T cell population present in mice after 3 weeks of in fection but was not demonstrable with cells taken 7 weeks after infect ion. When CD4+ T cells obtained from 3-week infected mice were mixed w ith 5% CD8+ T cells obtained from mice infected for 7 weeks, no signif icant transfer of resistance was observed. Thus, immune responses to A . cantonensis in mice were regulated by discrete subpopulations of T l ymphocytes.