The expression of PD-L2 in human cervical carcinomas and the influence to peripheral blood T lymphocytes apoptosis / 重庆医学

ABSTRACT

Objective To determine PD-L2 expression in human cervical squamous cell carcinomas and analyze its association with the clinical and pathologic characteristics of these cases ;observe the role of recombinant PD-L2 protein on apoptosis of active peripheral blood T lymphocytes of cervical carcinoma patients .Methods PD-L2 expression in cervical squamous cell carcinomas was determined by immunohistochemistry staining ,and the association between PD-L2 expression with the clinical and pathologic characteristics of these cases was analyzed .In vitro ,the peripheral blood T lymphocytes of cervical carcinoma patients were divided into blank group ,PD-L2 group and PD-L2+anti-PD-1 group respectively .After these active T cells were cultured 72 h ,their apop-totic rates were detected by flow cytometry .Results PD-L2 expressed in 53 .3% (32/60)cervical squamous cell carcinomas ,and it′s expression associated with lymph node metastasis of these cases (P< 0 .05) .In vitro ,PD-L2 promoted apoptosis of CD4+ T and CD8+ T lymphocytes ,the apoptotic rates were 17 .0% and 22 .4% respectively ,which were higher than 9 .0% and 16 .2% of blank group;however ,the apoptotic rates dropped to 11 .1% and 17 .5% in PD-L2+anti-PD-1 group .Conclusion PD-L2 aberrantly ex-presses in cervical squamous cell carcinomas and is associated with their lymph node metastasis .PD-L2 promotes apoptosis of T lymphocytes and depresses the anti-tumor immunity of cervical microenvironment ,and promotes lymph node metastasis of these cancers .PD-L2/PD-1 pathway may be a potential immunotherapy target of cervical squamous cell carcinomas .