SLAM-family receptors come of age as a potential molecular target in cancer immunotherapy

The signaling lymphocytic activation molecule (SLAM) family receptors were discovered in immune cells for the first time. The SLAM-family receptors are a significant player in cytotoxicity, humoral immune responses, autoimmune diseases, lymphocyte development, cell survival, and cell adhesion. There is growing evidence that SLAM-family receptors have been involved in cancer progression and heralded as a novel immune checkpoint on T cells. Previous studies have reported the role of SLAMs in tumor immunity in various cancers, including chronic lymphocytic leukemia, lymphoma, multiple myeloma, acute myeloid leukemia, hepatocellular carcinoma, head and neck squamous cell carcinoma, pancreas, lung, and melanoma. Evidence has deciphered that the SLAM-family receptors may be targeted for cancer immunotherapy. However, our understanding in this regard is not complete. This review will discuss the role of SLAM-family receptors in cancer immunotherapy. It will also provide an update on recent advances in SLAM-based targeted immunotherapies.

Association of genetic polymorphisms in CD8+ T cell inhibitory genes and susceptibility to and progression of chronic HBV infection

BACKGROUND

Previous studies have shown that multiple inhibitory genes play an important role in HBV-specific CD8+ T cell exhaustion and dysfunction in the setting of chronic HBV infection. Polymorphic variants of these genes are thought to be predisposing factors for HBV susceptibility, clearance, and disease progression. The aim of this retrospective study was to identify variants affecting chronic HBV infection in a Chinese Han population.

METHODS

We chose 28 tgSNPs from HapMap data on 5 key genes. They were genotyped on a total of 858 chronic HBV patients, 429 patients who underwent spontaneous recovery, and 239 healthy controls. We evaluated the correlation between the polymorphisms and HBV susceptibility, spontaneous clearance, and disease progression.

RESULTS

The association of rs3827537 of BIM genotype TA and allele A was significantly different (P=0.016, OR=2.049; P=0.031, OR=1.925) between HBV patients and healthy controls. The rs36084323 of PD-1, as well as rs3766377, rs485618, rs4656942 of CD244 showed significant associations with the risk for HBV-related cirrhosis and hepatocellular carcinoma (HCC) (P=0.009, OR=0.482; P=0.009, OR=4.573; P=0.015, OR=0.580; P=0.028, OR=2.855). MDR analysis revealed that the four SNPs (rs36084323, rs3766377, rs485618, rs4656942) modulated the predisposition to cirrhosis and HCC in patients with chronic HBV infection (P=0.006). Using a luciferase reporter assay, we demonstrated that various alleles of rs3766377 had differential effects, and rs3766377 and rs485618 might have interactive effects.

CONCLUSIONS

The present study reveals genetic associations among PD-1 and CD244 variants that may be involved in the development of cirrhosis and HCC in patients with chronic HBV infection. The BIM variant was associated with HBV susceptibility.