title: Interleukin-12-anchored exosomes increase cytotoxicity of T lymphocytes by reversing the JAK/STAT pathway impaired by tumor-derived exosomes.
abstract: Tumor-derived exosomes express tumor antigens, leading to their promising utility as tumor vaccines, but they also can suppress T-cell signaling molecules and reduce cytotoxic effects. We investigated whether interleukin-12 (IL-12)-anchored exosomes (EXO/IL-12) reverse tumor exosome-mediated inhibition of T-cell activation and cytotoxicity was associated with inhibition of JAK3 and p-STAT5. A co-expression plasmid of pBudCE4.1/IL-12A/ IL-12B-GPI was constructed. EXO/IL-12 was identified by transmission electron microscopy and Western blotting, which induced proliferation and cytotoxicity of T-cells and were analyzed by CFSE-based flow cytometry. Expression of JAK2, JAK3 and p-STAT5 was detected by Western blotting. Our results showed that EXO/IL-12 was much more efficient in induction of the proliferation, release of IFN-gamma and cytotoxic effect of T lymphocytes than conventional exosomes in vitro. Exosomes inhibited the expression of JAK3 and phosphorylation of STAT5 in high doses in T-cells, but not JAK2, while EXO/IL-12 had much less attenuated reduction of the expression of p-STAT5. The enhanced cytotoxic effects of T lymphocytes might partly depend on EXO/IL-12 reversing the suppressed expression of p-Stat5 by Jak2/Stat5 pathway. These findings might provide an alternative approach for developing exosomes into tumor vaccines.
authors.affiliation: Department of Urology, The First Affiliated Hospital, Chongqing Medical University, Chongqing, PR China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiao-Hou
authors.initials: XH
authors.lastname: Wu
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Luo
authors.forename: Jia-Mo
authors.initials: JM
authors.lastname: Zhang
authors.forename: Bai-Cheng
authors.initials: BC
authors.lastname: He
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D055354:Exosomes / Q000276:immunology*; D006801:Humans; D018664:Interleukin-12 / Q000276:immunology*; D053616:Janus Kinase 3 / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000276:immunology; D009369:Neoplasms / Q000276:immunology / Q000473:pathology; D050799:STAT5 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: D000951:Antigens, Neoplasm; D050799:STAT5 Transcription Factor; D018664:Interleukin-12; D053616:Janus Kinase 3