No abstract

Programmed death-ligand 1 (PD-L1) has been reported to be expressed in many types of tumor cells, and bind to PD-1 on T lymphocytes to inhibit immune response. Immunologic checkpoint blockade with antibodies that target the PD1/PD-L1 pathway has demonstrated to have impressive antitumor effects on many malignancies. However, the significance of PD1/PD-L1 pathway in cervical cancer remains unclear. Here we studied PD-L1, PD-1, CD8 and HPV expression in cervical cancer and normal cervix by immunohistochemical staining. Our results showed that there was more frequently positive for PD-L1, PD-1 and CD8 in cervical cancer tissues compared to normal tissues, especially those strongly stained HPV. Additionally, PD-L1, PD-1 and CD8 were more frequently stained in tissues from advanced tumor and tumor with lymphoid nodes or vascular invasion respectively. Tissues from patients with chemotherapy history had over expression of PD-L1 in tumor cells and more PD-1 and CD8 in stromal mononuclear cells, which were identified as tumor infiltrated lymphocytes (TILs). These findings point to a key role of PD-L1 in immune escape of cervical cancer, and provide a rationale for therapeutic targeting of the PD-1/PD-L1 pathway.

No abstract

mel-18 is a mammalian homolog of Drosophila melanogaster Polycomb group genes. Mice lacking the mel-18 gene show a posterior transformation of the axial skeleton, severe combined immunodeficiency, and a food-passing disturbance in the lower intestine due to hypertrophy of the smooth muscle layer. In this study, the severe combined immunodeficiency observed in mel-18 mutant mice is correlated with the impaired mitotic response of lymphocyte precursors upon interleukin-7 stimulation. Strikingly, the axial skeleton and lymphoid phenotypes are identical in both mel-18 and bmi-1 mutants, indicating that the Mel-18 and Bmi-1 gene products might act in the same genetic cascade. These results suggest that mammalian Polycomb group gene products are involved in cell cycle progression in the immune system.