Importance of Lyt 1+ T-cells in the antitumor activity of an immunomodulator, SSM, extracted from human-type Tubercle bacilli.
An arabinomannan lipid extracted from Mycobacterium tuberculosis strain Aoyama B (SSM) is an immunopotentiating agent with interferon-inducing and antitumor activities. In the present study, the possible role(s) of various immunocompetent cells on the antitumor effect of SSM was investigated in mice bearing syngeneic (RL male 1 leukemia) and allogeneic (Ehrlich carcinoma) ascites tumors. When Thy 1+ T-cells were depleted from tumor-bearing mice by the administration of monoclonal anti-Thy 1.2 antibody, the protective effect of SSM was eliminated. However, when macrophage (M phi) and natural killer (NK) cell activities were depleted by treatment with M phi blockers (trypan blue and carrageenan) or a blocker for NK cells (anti-asialo GM1 antiserum), no alteration of the antitumor activity of SSM was observed. Therefore, T-lymphocytes, but not M phi or NK cells, were required for the expression of the antitumor efficacy of SSM. The antitumor activity of SSM was also abrogated by Lyt 1+ T-cells being depleted by treatment with monoclonal anti-Lyt 1.2 antibody, whereas the administration of monoclonal anti-Lyt 2.2 antibody had no effect on the antitumor activity. Independent of M phi, NK cells, or Lyt 2+ T-cells, Lyt 1+ T-lymphocytes appear to play an important role in the expression of the antitumor effects of SSM.
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D000950:Antigens, Ly / Q000032:analysis*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001688:Biological Products / Q000494:pharmacology*; D002351:Carrageenan / Q000494:pharmacology; D005260:Female; D007518:Isoantibodies / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D008055:Lipids; D008264:Macrophages / Q000276:immunology; D008297:Male; D008351:Mannans; D051379:Mice; D008807:Mice, Inbred BALB C; D009169:Mycobacterium tuberculosis / Q000032:analysis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014343:Trypan Blue / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D000950:Antigens, Ly; D000970:Antineoplastic Agents; D001688:Biological Products; D007518:Isoantibodies; D008055:Lipids; C029805:Lyt antibodies; D008351:Mannans; C031208:specific substance maruyama; D002351:Carrageenan; D014343:Trypan Blue