Immune dysfunction expressed selectively on L3T4+ T cells in the tumor-bearing state.
Spleen cells from normal C3H/He or BALB/c mice generate cytotoxic T-lymphocyte (CTL) responses to both trinitrophenyl (TNP)-modified syngeneic cells (TNP-self) and allogeneic cells. In contrast, cells from these strains of mice bearing a syngeneic tumor failed to induce anti-TNP-self-CTL responses, although portions of the same responding cells generated comparable anti-allo-CTL responses to those induced by normal responding cells. Although anti-allo-CTL responses were inducible from only Lyt-2+ T-cell subset of responding cells from normal or tumor-bearing mice, induction of TNP-CTL responses required the participation of L3T4+ T-cell subset as well as Lyt-2+ CTL precursors. In addition, the fact that the addition of concanavalin A-stimulated culture supernatant to cultures of responding cells from tumor-bearing mice resulted in the induction of appreciable anti-TNP-self CTL responses demonstrated the defect of L3T4+ T-cell function in the tumor-bearing state. Such a functional defect was ascribed neither to the loss of L3T4+ T cells nor to the generation of suppressor cells in spleen cells of tumor-bearing mice. It was found on one hand that in vitro stimulation of antigen-presenting cell (APC)-depleted normal responding population with TNP-self prepared from cells of normal or tumor-bearing mice produced comparable anti-TNP CTL responses. On the other hand, APC-depleted responding cells from tumor-bearing mice were unable to induce anti-TNP CTL responses under conditions in which APC-depleted normal responding cells induced an effective TNP-CTL response. These results indicate that selective impairment of L3T4+ T cell-mediated immunity is induced in the tumor-bearing state and that such an impairment is ascribed to the dysfunction of L3T4+ T cells themselves, but not of APC required for the activation of L3T4+ T-cell subset.
Tada
T
T
Biomedical Research Center, Osaka University Medical School, Japan.
Sano
H
H
Sato
S
S
Shima
J
J
Fujiwara
H
H
Hamaoka
T
T
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000502:physiology; D002478:Cells, Cultured; D005260:Female; D007111:Immunity, Cellular; D007165:Immunosuppression Therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D009369:Neoplasms / Q000276:immunology*; D013154:Spleen / Q000166:cytology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000502:physiology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000502:physiology