title: Essential requirement of I-A region-identical host bone marrow or bone marrow-derived cells for tumor neutralization by primed L3T4+ T cells.
abstract: The antitumor activity of Meth A-hyperimmunized BALB/c mouse spleen cells (Meth A-Im-SPL) was assayed by the Winn test in H-2 incompatible bone marrow chimeras in closed colony CD-1 (nu/nu), inbred DDD/1(nu/nu) (H-2s), or inbred BALB/c(nu/nu) (H-2d) mice as recipients. We found that Meth A-Im-SPL suppressed Meth A growth in the chimera nude mice which were reconstituted with bone marrow cells of the H-2d haplotype (i.e., BALB/c, DBA/2 and B10.D2), but not in the chimeras which were reconstituted with bone marrow cells of the H-2a, H-2b, or H-2k haplotype (i.e., B10.A, B10, and B10.BR). These results suggested that H-2 restriction occurred between Meth A-Im-SPL and bone marrow or bone marrow-derived cells in tumor neutralization. Furthermore, Meth A-Im-SPL did not suppress Meth 1 tumors (antigenically distinct from Meth A tumors) in the presence or absence of mitomycin C-treated Meth A in a Winn assay. These results suggested that there is tumor specificity in the "effector phase" as well as in the "induction phase". The phenotype of the effectors in the Meth A-Im-SPL was Thy-1.2+ and L3T4+, because Meth A-Im-SPL lost their antitumor activity with pretreatment with anti-Thy-1.2 monoclonal antibody (mAb) and complement or anti-L3T4 mAb and complement, but not with anti-Lyt-2.2 mAb and complement or complement alone. Positively purified L3T4+ T cells from Meth A-Im-SPL (Meth A-Im-L3T4), obtained by the panning method, suppressed the tumor growth in the chimera nude mice which were reconstituted with bone marrow cells of B10.KEA2 mice (that were I-A region-identical with Meth A-Im-L3T4 cells but not others in H-2) as well as B10.D2 cells (that were fully identical with Meth A-Im-L3T4 cells in H-2). We conclude that Meth A-Im-SPL (L3T4+) neutralized the tumors in collaboration with I-A region-identical host bone marrow or bone marrow-derived cells, and the neutralization was not accompanied by the "bystander effect."
mesh_terms: D000818:Animals; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D016026:Bone Marrow Transplantation; D006183:H-2 Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains / Q000276:immunology; D008819:Mice, Nude / Q000276:immunology; D010641:Phenotype; D011828:Radiation Chimera; D012513:Sarcoma, Experimental / Q000276:immunology / Q000628:therapy*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000637:transplantation
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II