CD4+ T-LYMPHOCYTES ARE NOT REQUIRED FOR MURINE RESISTANCE TO THE HUMAN FILARIAL PARASITE, BRUGIA-MALAYI

Immunocompetent mice are nonpermissive for the development and maturation of the human filarial parasite, Brugia malayi. We and others have shown that the absence of T-lymphocytes, alone or in combination with B-lymphocytes, renders mice permissive to infection. In a previous study, we showed that mice lacking CD8(+) T-lymphocytes are also completely nonpermissive for B. malayi, indicating that CD8(+) T-lymphocytes are not an obligate requirement for resistance. In the present study, we have examined the role of CD4(+) T-lymphocytes in resistance to filarial infection using two experimental systems. In the first, we used an anti-CD4 monoclonal antibody to deplete CD4(+) T-cells in vivo in immunocompetent BALB/c mice. In the second system, we used mutant mice in which the gene encoding the CD4 antigen had been disrupted by homologous recombination, resulting in a lack of CD4(+) T-cells. Challenge of either the anti-CD4 antibody depleted BALB/c mice or CD4 knockout mice with B. malayi infective-stage larvae demonstrated that mice lacking CD4(+) T-lymphocytes were resistant to infection. These data indicate that CD4(+) T-cells are not an obligate requirement for murine resistance to B. malayi. (C) 1994 Academic Press, Inc.