[Effects of Sema3A derived from tumor cells on functions of dendritic cells].
To investigate the effects of tumor cell-derived Sema3A on the immunological functions of murine dendritic cells (DCs).



Lung adenocarcinoma A549 cells were transfected with small interference RNA, Si-Sema and Si-mut, and the interference efficiency was determined by real-time PCR and Western-blot. The concentrated supernatants from cultured tumor cells, Si-Sema and Si-mut-infected tumor cells were subjected to DCs respectively. The immunophenotypes of DCs were analyzed by flow cytometry, the production of IL-12P70 and the ability of DCs to stimulate DO11. 10 T cells secreting IFN-gamma and IL-2 were detected by enzyme linked immunosorbent assay (ELISA).



Knockdown with Si-Sema3A significantly decreased the secretion of Sema3A by A549 cells in comparison with the Si-mut cells. DCs exposed to supernatants from Si-Sema cells showed elevated levels of MHC, CD40 and CD80, more production of IL-12P70, and enhanced capability of activating antigen-specific T cells, as evidenced by the remarkably increased levels of IFN-gamma and IL-2.



A549 cells secrete Sema3A to inhibit the maturation and functions of DCs, which might be associated with the unidentified mechanism of immune evasion by tumor cells.
Zhou
Xie-lai
XL
Department of Basic Medicine, Hangzhou Normal University, Hangzhou 310036, China.
Huang
Yin
Y
Wang
Fang
F
Cai
Ling-fei
LF
Zhang
Li-huang
LH
Shi
Li-yun
LY
D000818:Animals; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D040121:Semaphorin-3A / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D014162:Transfection; D019139:Tumor Escape / Q000276:immunology*
C488217:Sema3a protein, mouse; D040121:Semaphorin-3A