Immunology: TREG cells in transplantation-a double-edged sword?

As a prognostic biomarker of clear cell renal cell carcinoma RUFY4 predicts immunotherapy responsiveness in a PDL1-related manner

Background

Clear cell renal cell carcinoma (ccRCC) is one of the most lethal malignancies in the urinary system and the existing immunotherapy has not achieved satisfactory outcomes. Therefore, this study aims at establishing a novel gene signature for immune infiltration and clinical outcome (overall survival and immunotherapy responsiveness) in ccRCC patients.

Methods

Based on RNA sequencing data and clinical information in The Cancer Genome Atlas (TCGA) database, we calculated proportions of immune cells in 611 samples using an online tool CIBERSORTx. Multivariate survival analysis was conducted to determine crucial survival-associated immune cells and immune-infiltration-related genes (IIRGs). Next, the clinical specimens and common renal cancer cell lines were applied to confirm IIRGs expression at protein and RNA levels. Finally, functional enrichment analyses and siRNA technology targeted to RUFY4 were implemented to verify its function of predicting immunotherapy response.

Results

Follicular helper T cells (TFHs) and Regulatory T cells (Tregs) were highly infiltrated in the tumor microenvironment (TME) and their relative proportions were independent prognostic factors for patients. Among IIRGs of TFHs and TREGs, RUFY4 was found to be highly activated in tumor microenvironment and its co-expression network was enriched in PDL1/PD1 checkpoint pathway in cancer. Additionally, knockdown of RUFY4 led to the decline of PDL1 and proliferation ability in ccRCC cell lines.

Conclusion

TFHs and Tregs were considered as prognostic biomarkers and RUFY4 was an immunotherapeutic predictor of ccRCC patients in a PDL1-Related manner.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02480-7.

Netrin-1 reduces lung ischemia-reperfusion injury by increasing the proportion of regulatory T cells

Objective

Inflammation is the primary mechanism of lung ischemia-reperfusion injury (LIRI) and neurologic factors can regulate inflammatory immune responses. Netrin-1 is an axonal guidance molecule, but whether Netrin-1 plays a role in LIRI remains unclear.

Methods

A mouse model of LIRI was established. Immunohistochemistry was used to detect expression of Netrin-1 and to enumerate macrophages and T cells in lung tissue. The proportion of regulatory T cells (Tregs) was assessed by flow cytometry. Levels of apoptosis were assessed by terminal deoxynucleotidyl transferase dUTP nick end staining.

Results

Numbers of macrophages and T cells in the lung tissues of mice with LIRI were elevated, while expression of netrin-1 was significantly decreased. Flow cytometry showed that the proportion of Tregs in mice with LIRI was significantly decreased. The proportion of Tregs among lymphocytes was positively correlated with netrin-1 expression. In vitro experiments showed that netrin-1 promoted an increase in Treg proportion through the A2b receptor. Animal experiments showed that netrin-1 could inhibit apoptosis and reduce T cell and macrophage infiltration by increasing the proportion of Tregs, ultimately reducing LIRI. Treg depletion using an anti-CD25 monoclonal antibody blocked the effects of netrin-1.

Conclusion

Netrin-1 reduced LIRI by increasing the proportion of Tregs.

Identifying hub genes of clear cell renal cell carcinoma associated with the proportion of regulatory T cells by weighted gene co-expression network analysis

BACKGROUND

Numerous patients with clear cell renal cell carcinoma (ccRCC) experience drug resistance after immunotherapy. Regulatory T (Treg) cells may work as a suppressor for anti-tumor immune response.

PURPOSE

We performed bioinformatics analysis to better understand the role of Treg cells in ccRCC.

RESULTS

Module 10 revealed the most relevance with Treg cells. Functional annotation showed that biological processes and pathways were mainly related to activation of the immune system and the processes of immunoreaction. Four hub genes were selected: LCK, MAP4K1, SLAMF6, and RHOH. Further validation showed that the four hub genes well-distinguished tumor and normal tissues and were good prognostic biomarkers for ccRCC.

CONCLUSION

The identified hub genes facilitate our knowledge of the underlying molecular mechanism of how Treg cells affect ccRCC in anti-tumor immune therapy.

METHODS

The CIBERSORT algorithm was performed to evaluate tumor-infiltrating immune cells based on the Cancer Genome Atlas cohort. Weighted gene co-expression network analysis was conducted to explore the modules related to Treg cells. Gene Ontology analysis and pathway enrichment analysis were performed for functional annotation and a protein-protein interaction network was built. Samples from the International Cancer Genomics Consortium database was used as a validation set.

Ratio of CD147high/CD147low in CD4+CD25+ T cells: A potential biomarker for early diagnosis and prediction of response to therapy for autoimmune diseases

Regulatory T cell (Treg cell) is an important immunosuppressive T cell subset and plays a dominant role in maintaining the immune balance in vivo. The function defects in Treg cells have been involved in the pathogenesis of many autoimmune diseases. The detection of Treg cell suppressive function is important for early diagnosis and prediction of response to treatment for autoimmune diseases. The traditional detection of Treg cell suppressive function needs at least 20 mL peripheral blood sample of patients and the results would be got in sixth day, therefore, it could not be widely applied in clinical. However, to find fast and simple detection method is very important. CD147 is a transmembrane protein and its expression is related to Treg cell suppressive function. Recent research has shown that the Treg cells with high CD147 expression have stronger suppressive function than which with low CD147 expression. In this work, we detected the ratio of CD147^high/CD147^low in CD4⁺CD25⁺ T cells in patients with active AS using fluorescence-activated cell sorter (FACS). The results show the ratio of CD147^high/CD147^low decreased obviously in patients with active AS compared with healthy controls, which reflects the suppressive function deficit of Treg cell. In the same time, the detection of the ratio of CD147^high/CD147^low needs only 150 μL peripheral blood sample and the result would be got in 4 h. We therefore hypothesize that the ratio of CD147^high/CD147^low is a good indicator for the Treg cell function, and it is especially suitable for early diagnosis and prediction of response to therapy targeted recovering Treg cell function in autoimmune diseases.