The Aberrant Expression Of PD-l2in Human Cervical Carcinomas And Its Immune Regulatory Effect On Active Human Peripheral Blood T Lymphocytes

Objective：To investigate the expression of co-stimulation moleculesPD-L2in human cervical carcinomas and its association with clinical andpathologic characteristics of these patients.Further to study the immuneregulatory effect of recombinant human PD-L2protein on active humanperipheral blood T lymphocytes in vitro.Methods：The expression of PD-L2in30cases of normal humancervical tissue,30cases of CINII-III, and67cases of cervical carcinomaswas detected by immunohistochemistry PV-6000staining， and therelationship of PD-L2expression with the clinical and pathologiccharacteristics of these cervical carcinoma patients was evaluated.Peripheral blood T lymphocytes were obtained from healthy volunteersand were divided into blank group and PD-L2group; respectively. Afterthese T lymphocytes were cultured72h, their proliferation was determinedby MTT；their apoptotic rates and cell-cycle was detected by FCM；IFN-γand IL-4concentration in their cultureal supernatant was tested by ELISA.Results： PD-L2weakly expressed in basal epithelium of normalcervical tissue; faintly expressed in epithelium of CIN II-III; and positively expressed in51%（34/67）cervical carcinomas. PD-L2expression incervical carcinomas associated with lymph node metastasis of cervicalcarcinomas（P<0.05）. In vitro, the apoptotic rates of CD4+T lymphocyte（14.01％）and CD8+Tlymphocyt（e14.40％）ofPD-L2groupwashigherthan that of blank group(7.79%and8.63%), however there was nodifference in T cells’ cycle and proliferation between PD-L2group withblank group. In superlatant,IFN-γ concentration of PD-L2group was2395.85±106.15pg/ml,its higher than that of blank group（P<0.05）, butIL-4concentration of PD-L2group was327.13±17.76pg/ml, lower thanthat of blank group（P<0.05）.Conclusions： PD-L2aberrantly expresses in cervical cancers and isassociated with their lymph node metastasis of cervical cancers.In vitro,recombinant human PD-L2protein promotes the apoptosis of peripheralblood CD4+and CD8+T lymphocytes and changes the secretions ofIFN-γ and IL-4. PD-L2may be a potential immunotherapy target ofcervical cancer.