Cell-mediated immunity in experimental murine dermatophytosis. I. TEMPORAL ASPECTS OF T-SUPPRESSOR ACTIVITY CAUSED BY <em>TRICHOPHYTON QUINCKEANUM</em>.

Cutaneous dermatophyte infections caused by Trichophyton quinckeanum were established in various strains of mice. All congenic BALB/B (H-2^b), BALB/c (H-2^d) and BALB/K(H-2^k) strains showed high susceptibility to dermatophyte infection. Susceptibility is independent of MHC phenotype, since other strains with corresponding H-2 haplotypes such as C57BL/6 (H-2^b), DBA/2 (H-2^d) and CBA (H-2^k) were resistant to the disease. During the acute phase of infection in BALB/c mice, the in vitro biastogenic responses of regional lymph node cells was suppressed. Suppression was observed for both the T cell mitogens concanavalin A and phytohaemagglutinin, and for the B cell mitogen lipopolysaccharide. A series of cell mixing experiments revealed that lymph node cells from infected mice were able to suppress the T cell and B cell mitogenic responses of lymph node cells from normal mice. Suppression was mediated by T cells and abrogated by treatment of lymph node ceils with either monoclonal anti-thy-1.2 or anti-Ly-2.2 and complement. In this report, we discuss the possibility that T-suppressor mechanism mediated by cells bearing the Ly-2⁺ phenotype and activated during dermatophyte infection may determine the course of the disease. [ABSTRACT FROM AUTHOR]