Testosterone-induced abrogation of self-healing of Plasmodium chabaudi malaria in B10 mice: mediation by spleen cells.
This study investigates the suppressive effect of testosterone (Te) on the self-healing of Plasmodium chabaudi malaria in female mice of the strain C57BL/10, and, in particular, the possible role of spleen cells in mediating this Te effect. Our data show the following. (i) About 80% of B10 mice infected with 10(6) P. chabaudi-infected erythrocytes are capable of self-healing the infections. This capability is progressively impaired and finally abrogated after pretreating the B10 mice with Te for 3 weeks. (ii) The spleen is Te responsive. This becomes evident in a reduction of total spleen cells from 1.05 x 10(8) to 0.54 x 10(8) on average after Te treatment for 3 weeks. Moreover, Te treatment causes an increase in the relative proportion of CD8+ cells by about 4% and a decrease of Ig+ cells by about 4.5%, as revealed by flow cytometry. (iii) Spleen cells mediate the suppressive Te effect as revealed by adoptive transfer experiments. The percentage of self-healing mice dramatically decreases to about 8% when they receive, just prior to infection, nucleated spleen cells isolated from mice treated with Te for 3 weeks. This suppressive effect can be transferred by T cells in particular but also by non-T cells, though to a lesser extent. (iv) The adoptively transferred cells mediate their suppressive effect on self-healing only if the recipient mice receive Te during infection. Our data suggest that spleen cells become functionally changed by the Te treatment for 3 weeks. Particularly T cells, but also non-T cells, gain P. chabaudi-specific suppressive activities, and the cells require a Te-induced factor(s) to mediate these activities.
Division of Parasitology, Heinrich-Heine University, Dusseldorf, Germany.
W P
WP
Benten
U
U
Bettenhaeuser
F
F
Wunderlich
E
E
Van Vliet
H
H
Mossmann
D000818:Animals; D005260:Female; D016219:Immunotherapy, Adoptive; D008288:Malaria / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D016788:Plasmodium chabaudi; D013154:Spleen / Q000187:drug effects* / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D013739:Testosterone / Q000494:pharmacology*
D013739:Testosterone