Protective immunity to Listeria monocytogenes in neonatally thymectomized (NTx) mice: involvement of T cells distinct from those in sham-thymectomized mice.
Neonatally thymectomized (NTx) mice, whose ability to mount antigen-specific cell-mediated immunity is reported to be generally defective, were found to be capable of mounting a normal level of acquired cellular resistance (ACR) and delayed footpad reaction (DFR) to Listeria monocytogenes. The present study was done in order to determine the functional differences of T cells contributing to the protection against L. monocytogenes between NTx and sham-operated mice. In mice immunized with viable L. monocytogenes, the absolute number of splenic T cells was significantly lower in NTx mice compared with sham-operated mice. When the ability of immune T cells to transfer ACR and DFR was examined by passive transfer, lymphocytes from immune NTx mice conferred a higher level of ACR and DFR on naive recipient mice, despite the marked difference in total number of T cells compared with immune Sham mice. Antigen-specific proliferation and interleukin-2 (IL-2) production by splenic T cells from immune NTx mice were significantly lower than in those from immune Sham mice. The proliferative response of T cells to exogenous IL-2 was also lower in NTx group. These results suggest that the requirement for the IL-2-driven T-cell proliferation system is basically low in the generation of effector T cells specific for L. monocytogenes.
Watanabe
Y
Y
Department of Immunology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Mitsuyama
M
M
Koga
T
T
Handa
T
T
Yoshikai
Y
Y
Nomoto
K
K
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular; D007116:Immunization, Passive; D007376:Interleukin-2 / Q000096:biosynthesis; D007958:Leukocyte Count; D008088:Listeriosis / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D013934:Thymectomy; D013950:Thymus Gland / Q000276:immunology*
D007376:Interleukin-2