B7 Family Members in Pancreatic Ductal Adenocarcinoma: Attractive Targets for Cancer Immunotherapy

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with a five-year survival rate of approximately 5–10%. The immune checkpoint blockade represented by PD-1/PD-L1 inhibitors has been effective in a variety of solid tumors but has had little clinical response in pancreatic cancer patients. The unique suppressive immune microenvironment is the primary reason for this outcome, and it is essential to identify key targets to remodel the immune microenvironment. Some B7 family immune checkpoints, particularly PD-L1, PD-L2, B7-H3, B7-H4, VISTA and HHLA2, have been identified as playing a significant role in the control of tumor immune responses. This paper provides a comprehensive overview of the recent research progress of some members of the B7 family in pancreatic cancer, which revealed that they can be involved in tumor progression through immune-dependent and non-immune-dependent pathways, highlighting the mechanisms of their involvement in tumor immune escape and assessing the prospects of their clinical application. Targeting B7 family immune checkpoints is expected to result in novel immunotherapeutic treatments for patients with pancreatic cancer.

B7H4 Expression Is More Frequent in MSS Status Colorectal Cancer and Is Negatively Associated with Tumour Infiltrating Lymphocytes

“…There are a few reasons for this fact. Although the receptor for B7H4 remains unrecognized, B7H4, with the growing knowledge about its function, becomes an attractive therapeutic potential not only in the cancer field [ 28 ], but also in the autoimmune diseases field [ 2 ]. In normal tissues, human B7H4 mRNA is commonly expressed; however, B7H4 protein exhibits minimal or negative expression, e.g., in the intestine [ 29 ].…”