Activation of macrophages and expansion of specific T lymphocytes in the lungs of mice intratracheally inoculated with Cryptococcus neoformans.
A quantitative and qualitative change in inflammatory cells in the lungs of mice after intratracheal inoculation of heat-killed Cryptococcus neoformans was examined by direct analysis of the pulmonary intraparenchymal leucocytes. Macrophages and T and B lymphocytes increased, peaked at day 7, and then gradually decreased to the basal level. Macrophages were activated 7 days after the inoculation, as indicated by the enhanced expression of MHC class II, intercellular adhesion molecule-1 (ICAM-1) and Fc receptor (FcR), which have been known as their activation markers. T cells were also activated, as indicated by the induction of IL-2 receptor (IL-2R) and the enhanced expression of leucocyte function-associated molecule-1 (LFA-1) and ICAM-1, a pair of adhesion molecules which have also been regarded as T cell activation markers. CD4+ T cells preferentially accumulated in lungs, and proliferated in vitro by stimulation with heat-killed whole yeast cells, suggesting that at least some of the infiltrated T cells expand locally in response to the organisms. These results demonstrate that the activation of macrophages and T cells reactive to C. neoformans is induced in lungs after intratracheal inoculation of heat-killed organisms, and suggest that these cells interact to eliminate organisms more efficiently from the host.
Kawakami
K
K
First Department of Internal Medicine, School of Medicine, University of the Ryukyus, Okinawa, Japan.
Kohno
S
S
Morikawa
N
N
Kadota
J
J
Saito
A
A
Hara
K
K
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002678:Chimera; D003453:Cryptococcosis / Q000276:immunology*; D006183:H-2 Antigens / Q000235:genetics; D008168:Lung / Q000166:cytology / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008262:Macrophage Activation / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D006183:H-2 Antigens