title: Adoptive transfer of tumor-primed, in vitro-activated, CD4+ T effector cells (TEs) combined with CD8+ TEs provides intratumoral TE proliferation and synergistic antitumor response.
abstract: The importance of CD4+ Th1 cells during the effector phase of the antitumor response has been overshadowed by emphasis on CD8+ cytotoxic T lymphocytes (CTLs). To determine their respective functions, we purified antigen-primed T cells from tumor-draining lymph nodes and separately activated CD4+ and CD8+ subsets in vitro. Adoptive transfer of CD4+ T effector cells (T(E)s) combined with CD8+ T(E)s provided synergistic therapy for mice bearing subcutaneous, intracranial, or advanced pulmonary metastases. CD4+ T(E)s augmented IFN-gamma production by CD8+ T(E)s when cells were stimulated by tumor digest-containing antigen-presenting cells (APCs). CD4+ T(E)s infiltrated and proliferated extensively in pulmonary tumors, while also stimulating tumor antigen-specific CD8+ T cells. By contrast, CD8+ T(E)s showed minimal intratumoral proliferation in the absence of CD4+ cells or when systemically transferred CD4+ cells were prevented from infiltrating pulmonary tumors by pretreatment with pertussis toxin. Irradiation of CD4+ T cells immediately prior to adoptive transfer abrogated their intratumoral proliferation and direct antitumor efficacy but did not block their capacity to stimulate intratumoral CD8+ T(E) proliferation or tumor regression. These results highlight the importance of cross-presentation of tumor antigens during the effector phase of immunotherapy and suggest that approaches to stimulate CD4+ T(E) function and boost APC cross-presentation within tumors will augment cancer immunotherapy.
authors.affiliation: Center for Surgery Research, The Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Li-Xin
authors.initials: LX
authors.lastname: Wang
authors.forename: Suyu
authors.initials: S
authors.lastname: Shu
authors.forename: Mary L
authors.initials: ML
authors.lastname: Disis
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Plautz
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D002469:Cell Separation; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D007167:Immunotherapy / Q000379:methods*; D008175:Lung Neoplasms / Q000378:metabolism*; D008198:Lymph Nodes / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000970:Antineoplastic Agents