Intrinsic and extrinsic factors determining natural killer cell fate: Phenotype and function

Microbiota-Derived Short-Chain Fatty Acids Boost Antitumoral Natural Killer Cell Activity

Background: The intestinal microbiota can regulate numerous host functions, including the immune response. Through fermentation, the microbiota produces and releases microbial metabolites such as short-chain fatty acids (SCFAs), which can affect host homeostasis. There is growing evidence that the gut microbiome can have a major impact on cancer. Specific gut microbial composition and metabolites are associated with tumor status in the host. However, their effects on the antitumor response have scarcely been investigated. Natural killer (NK) cells play an important role in antitumor immunity due to their ability to directly identify and eliminate tumor cells. Methods: The aim of this study was to investigate the effects of SCFAs on antitumoral NK cell activity, using NK-92 cell line. Results: Here, we describe how SCFAs can boost antitumoral NK cell activity. The SCFAs induced the release of NK extracellular vesicles and reduced the secretion of the anti-inflammatory cytokine IL-10. The SCFAs also increased the cytotoxicity of the NK cells against multiple myeloma cells. Conclusions: Our results indicate, for the first time, the enormous potential of SCFAs in regulating antitumoral NK cell defense, where modulation of the SCFAs' production could play a fundamental role in cancer immunotherapy.

Sofosbuvir (+) daclatasvir (+) ribavirin in Egyptian patients with hepatitis C virus: Therapeutic outcomes and the prognostic role of natural killer cells

BACKGROUND

One of the prominent causes of chronic liver disease worldwide is the hepatitis C virus (HCV). HCV believed that innate immunity contributes to a sustained virological response (SVR) to the treatment of Sofosbuvir (SOF) (+) Daclatasvir (DCV) (+) Ribavirin (RBV). This study aimed to evaluate the impact of SOF (+) DCV (+) RBV therapy and persistent HCV infection on the subset of natural killer cells (NK) in HCV genotype four patients from Egypt.

MATERIALS AND METHODS

One hundred and ten patients with persistent HCV infections requiring SOF (+) DCV (+) RBV therapy were grouped, and a flow cytometry (FCM) study of the NK cell subset in peripheral blood was performed. The assessment was performed before and after three and/or six months of the cessation of viral suppression therapy when a patient had a long-term viral response (SVR). One hundred and ten volunteers from the National Liver Institute's (NLI) blood bank were selected as controls.

RESULTS

Patients with chronic HCV infection before therapy had considerably lower CD16+ and CD3- CD56+ cells than controls. Their levels increase during SOF (+) DCV (+) RBV therapy. In patients with SVR during treatment, CD16+ and CD3- CD56+ cells increased significantly compared to those who did not get SVR. Furthermore, CD56+ cells were significantly higher in patients with persistent infection before treatment than controls but diminished with the response to treatment.

CONCLUSION

NK cell activation following SOF (+) DCV (+) RBV therapy and polarization to cytotoxicity occurred early in HCV antiviral therapy and was elevated in the respondents. Our data illustrated that establishing an inhibitory cytotoxic NK profile is related to therapeutic outcomes.

HHLA2 is more significantly associated with poor prognosis in TSCC than PD-L1

BACKGROUND

The incidence and mortality of tongue squamous cell carcinoma have shown an alarming increase in recent years. This study aimed to investigate the potential of HHLA2 as an immune checkpoint in comparison to PD-L1.

METHODS

We obtained RNA-seq data from TCGA to study HHLA2 and PD-L1 expression across various tissues. Using the CIBERSORT package, we estimated cell type abundances within mixed populations based on gene expression profiles. Immunohistochemistry was performed to analyze HHLA2 and PD-L1 expression in Tongue squamous cell carcinoma. Prognostic evaluation was carried out with Kaplan-Meier curves and the log-rank test. To explore factors affecting HHLA2, univariate and multivariate Cox regression analyses were conducted with the COX regression model. Additionally, we used single-cell RNA sequencing data from the GEO database for gene set enrichment analysis with genes strongly correlated with HHLA2.

RESULTS

Our analysis of RNA-seq data unveiled a significant upregulation of HHLA2 and PD-L1 expression in primary tumors when compared with normal tissue. HHLA2 exhibited a positive expression rate of 36.9%, while PD-L1 had a positive expression rate of 24.6%. HHLA2 emerged as a noteworthy independent risk factor impacting the overall survival of Tongue squamous cell carcinoma patients. The analysis of scRNA-seq data shed light on the involvement of HHLA2 in key pathways related to cell cycle regulation and interferon alpha/beta signaling.

CONCLUSIONS

This study suggests that in the context of Tongue squamous cell carcinoma, HHLA2 may represent a more promising target for immunotherapy when compared with PD-L1.