title: Spontaneous rejection of intradermally transplanted non-engineered tumor cells by neutrophils and macrophages from syngeneic strains of mice.
abstract: It is not surprising that tumors arising spontaneously are rarely rejected by T cells, because in general they lack molecules to elicit a primary T-cell response. In fact, cytokine-engineered tumors can induce granulocyte infiltration leading to tumor rejection. In the present study, we i.d. injected seven kinds of non-engineered tumor cells into syngeneic strains of mice. Three of them (i.e. B16, KLN205, and 3LL cells) continued to grow, whereas four of them (i.e. Meth A, I-10, CL-S1, and FM3A cells) were spontaneously rejected after transient growth or without growth. In contrast to the i.d. injection of B16 cells into C57BL/6 mice, which induces infiltration of TAMs into the tumors, the i.d. injection of Meth A cells into BALB/c mice induced the invasion of cytotoxic inflammatory cells, but not of TAMs, into or around the tumors leading to an IFN-γ-dependent rejection. On day 5, the cytotoxic activity against the tumor cells reached a peak; and the effector cells were found to be neutrophils and macrophages. The i.d. Meth A or I-10 cell-immunized, but not non-immunized, mice rejected i.p.- or i.m.-transplanted Meth A or I-10 cells without growth, respectively. The main effector cells were CTLs; and there was no cross-sensitization between these two kinds of tumor cells, suggesting specific rejection of tumor cells by CTLs from i.d. immunized mice. These results indicate that infiltration of cytotoxic myeloid cells (i.e. neutrophils and macrophages, but not TAMs) into or around tumors is essential for their IFN-γ-dependent spontaneous rejection.
authors.affiliation: Department of Physiology, Osaka Medical College, Takatsuki 569-8686, Japan.
authors.forename: Minenori
authors.initials: M
authors.lastname: Ibata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takahashi
authors.forename: Tetsunosuke
authors.initials: T
authors.lastname: Shimizu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Inoue
authors.forename: Shogo
authors.initials: S
authors.lastname: Maeda
authors.forename: Junko
authors.initials: J
authors.lastname: Tashiro-Yamaji
authors.forename: Masashi
authors.initials: M
authors.lastname: Okada
authors.forename: Koichi
authors.initials: K
authors.lastname: Ueda
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kubota
authors.forename: Ryotaro
authors.initials: R
authors.lastname: Yoshida
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006084:Graft Rejection; D006801:Humans; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000235:genetics / Q000276:immunology*; D020556:Neutrophil Infiltration; D009504:Neutrophils / Q000276:immunology*