Protection against Chlamydia psittaci in mice conferred by Lyt-2+ T cells.
A murine model was used to study the respective roles of L3T4+ and Lyt-2+ T cells in protection against Chlamydia psittaci. Donor mice were intravenously (i.v.) infected with 1 x 10(5) plaque-forming units (PFU) per mice of live C. psittaci. One month after inoculation, splenic cells from donors were transferred into syngenic recipients (5 x 10(7) cells/mouse). As measured by splenic colonization on Day 6 after i.v. challenge (1 x 10(5) PFU/mouse), transfer with primed (untreated) cells conferred a 3 log protection in this model. In vitro treatment, before transfer, of splenic cells with anti-Lyt-2 monoclonal antibody (mAb) and complement, markedly impaired the protection in comparison with control mice transferred with primed untreated cells, whereas treatment with anti-L3T4 mAb did not reduce the transferred protection. Resistance to a reinfection with C. psittaci was also studied after selective in vivo depletion of L3T4+ and Lyt-2+ T cells. One month after primary infection, mice were treated with anti-L3T4 or anti-Lyt-2 mAb and challenged thereafter (i.v., 1 x 10(5) PFU). The splenic colonization on Day 6 after challenge demonstrated that treatment with anti-Lyt-2 mAb impaired resistance against a subsequent infection with C. psittaci. Treatment with anti-L3T4 mAb in vivo had no effect on protection, as previously described in vitro. The mechanisms by which Lyt-2+ T cells could participate in the elimination of bacteria were discussed.
Buzoni-Gatel
D
D
INRA Unité Génétique et Immunité, Laboratoire de Pathologie Infectieuse et Immunologie, Nouzilly, France.
Guilloteau
L
L
Bernard
F
F
Bernard
S
S
Chardès
T
T
Rocca
A
A
D000818:Animals; D000950:Antigens, Ly / Q000032:analysis*; D005260:Female; D007111:Immunity, Cellular; D007116:Immunization, Passive; D051379:Mice; D008815:Mice, Inbred Strains; D009956:Psittacosis / Q000276:immunology* / Q000517:prevention & control; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000950:Antigens, Ly