The mode of anti\tumor function of noncytolytic Lyt\2+ T cells from C3H/He mice hyperimmune to syngeneic MH134 hepatoma was investigated within a double diffusion chamber system which was recently established in our laboratory. in the other chamber to that obtained by unfractionated MH134\hyperimmune spleen cells. The induction in the Lyt\2+ T cell\made up of chamber of anti\tumor effect to be delivered into the other chamber was dependent on the Apigenin small molecule kinase inhibitor co\presence of la\positive adherent cells along with Lyt\2+ T cells. Although adherent cell\depleted Lyt\2+ T cells regained the inducibility of anti\tumor immunity when supplemented with splenic adherent cells, the addition of adherent cells pretreated with chloroquine failed to restore the ability of Lyt\2+ T cells to induce their anti\tumor effect. In addition, paraformaldehyde\treated MH134 tumor cells instead of untreated tumor cells were not capable of activating Lyt\2+ T cells. These results indicate that a portion of Lyt\2+ T cells exerts their anti\tumor effect by a mechanism distinct from direct tumor cell lysis and that their activation for mediation of this type of tumor immunity requires the recognition of tumor antigens processed and presented by la\positive adherent cells. immunity . J. Immunol. , 133 , 1671 C 1676 ( 1984. ). [PubMed] [Google Scholar] 6) Fukuzawa M. , Fujiwara H. , Yoshioka T. , Itoh K. and Hamaoka T.Tumor\specific Lyt\1+2? T cells can reject tumor cells without inducing cytotoxic T lymphocyte responses . Transplant, Proc. , 17 , 599 C 605 ( 1985. ). [Google Scholar] 7) Greenberg P. D. , Cheever M. A. and Fefer A.Eradication of disseminated murine leukemia by chemoimmunotherapy with cyclophosphamide and adoptively transferred immune syngeneic Lyt\1+2? lymphocytes . J. Exp. Med. , 154 , 952 C 963 ( 1982. ). [PMC free article] [PubMed] [Google Scholar] 8) Leveland B. E. , Hogarth P. M. , Geredig R. H. and Mckenzie I. F. C.Cells mediating graft rejection in the mouse. I. Lyt\1 cells mediate skin graft rejection . J. Exp. Med. , 153 , 1044 C 1057 ( 1981. ). [PMC free article] [PubMed] [Google Scholar] 9) Dallman M. J. and Mason D. W.Cellular mechanisms of skin allograft rejection in the rat . Transplant Proc. , 15 , 335 C 338 ( 1983. ). [Google Scholar] 10) Lowry R. P. , Gurley K. E. , Blackburn J. and Forbes R. D. C.Delayed type hypersensitivity and lymphocytotoxicity in cardiac allograft rejection . Transplant. Proc. , Apigenin small molecule kinase inhibitor 15 , 343 C 346 ( 1983. ). [Google Scholar] 11) Tilney N. L. , Kupiec\Weglinshi J. N. , Heidecke C. D. , Lear P. A. and Storm T. B.Systems of prolongation and rejection of vascularized body organ allografts . Immunol. Rev. , 77 , 185 C 216 ( 1984. ). [PubMed] [Google Scholar] 12) Mason D. W. and Morris P. J.Effector systems in allograft rejection . Ann. Rev. Immunol. , 4 , 119 C 145 ( 1986. ). [PubMed] [Google Scholar] 13) LeFrancois L. CD63 and Sevan M. J.A reexamination from the function of Lyt\2\positive T cells in murine epidermis graft Apigenin small molecule kinase inhibitor rejection . J. Exp. Med. , 159 , 57 C 67 ( 1984. ). [PMC free of charge content] [PubMed] [Google Scholar] 14) Yoshioka T. , Sato S. , Ogata M. , Sakamoto K. , Sano H. , Shima J. , Yamamoto H. , Fujiwara H. and Hamaoka T.Function of tumor\particular Lyt\ 2+ T cells in tumor development inhibition tumor\neutralizing activity by Lyt\2+ aswell seeing that L3T4+ T cell subsets . Jpn. J. Tumor Res. (Gann) , 79 , 91 C 98 ( 1988. ). [PMC free of charge content] [PubMed] [Google Scholar] 15) Sakamoto K. , Fujiwara H. , Nakajima H. , Yoshioka T. , Takai Y. and Hamaoka T.The system of tumor growth inhibition of tumor\specific Lyt\1+2? T cells. II. Requirements of adherent cells for activating Lyt\1+2? T celts aswell Apigenin small molecule kinase inhibitor as for working as antitumor effectors turned on by factor(s) from Lyt\l+2? T cells . Jpn. J. Malignancy Res. (Gann) , 77 , 1142 C 1152 ( 1986. ). [PubMed] [Google Scholar] 16) Dialynas D. P. , Quan Z. S. , Wall K. A..