Specific suppressor T cells for delayed-type hypersensitivity in susceptible mice immunized against cutaneous leishmaniasis

Publisher Website
Google Scholar
Abstract
BALB/c mice injected i.v. with .gtoreq. 106 doses of formaldehyde-fixed promastigotes (ffp) of Leishmania major developed significantly lower levels of delayed-type hypersensitivity (DTH) compared with uninjected control mice when they were subsequently immunized intradermally with ffp. The suppression of DTH was antigen specific and was also inducible with lethally irradiated promastigotes or soluble parasite antigens. The suppressive effect was adoptively transferable with splenic T cells which express the Lyt-1+2+ and L3T4+ phenotypes. These specific suppressor T cells were active against both the inductive and expressive phases of DTH. They were sensitive to 200 rad of .gamma.-irradiation in vitro and appeared to manifest the suppressive activity via soluble factors. In spite of this profound suppression of DTH, BALB/c mice injected i.v. with 4 .times. 107 ffp were substantially protected against a challenge infection with L. major promastigotes. The possible relationship between the suppressor T cells for DTH and prophytactic immunization against fatal cutaneous leishmanial infection in susceptible BALB/c mice is discussed.

This publication has 20 references indexed in Scilit: