Gastric cancer patients display a distinctive population of IFNg+IL10+ double positive CD8 T cells, which persists longer during prolonged activation

Dysregulation of systemic immunity and its clinical application in gastric cancer

Immunotherapy has profoundly changed the treatment of gastric cancer, but only a minority of patients benefit from immunotherapy. Therefore, numerous studies have been devoted to clarifying the mechanisms underlying resistance to immunotherapy or developing biomarkers for patient stratification. However, previous studies have focused mainly on the tumor microenvironment. Systemic immune perturbations have long been observed in patients with gastric cancer, and the involvement of the peripheral immune system in effective anticancer responses has attracted much attention in recent years. Therefore, understanding the distinct types of systemic immune organization in gastric cancer will aid personalized treatment designed to pair with traditional therapies to alleviate their detrimental effects on systemic immunity or to directly activate the anticancer response of systemic immunity. Herein, this review aims to comprehensively summarize systemic immunity in gastric cancer, including perturbations in systemic immunity induced by cancer and traditional therapies, and the potential clinical applications of systemic immunity in the detection, prediction, prognosis and therapy of gastric cancer.

Human Umbilical Cord Mesenchymal Stem Cells Promote Anti-Inflammation and Angiogenesis by Targeting Macrophages in a Rat Uterine Scar Model

BACKGROUND

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have demonstrated efficacy in repairing uterine scars, although the underlying mechanisms remain unclear.

METHODS

Uterine injury was surgically induced in a rat model, followed by immediate transplantation of 5 × 10 ^ 5 hUC-MSCs to each side of the uterus. Uterine morphology was evaluated at days 14 and 30 using HE and Masson staining. Immunohistochemistry assessed macrophage polarization, angiogenesis and endometrial receptivity in the endometrium. Additionally, the regulatory effects of hUC-MSCs on macrophage polarization were explored through coculture. qRT-PCR quantified the expression of anti-inflammatory (IL10 and Arg1) and pro-inflammatory (iNOS and TNF-α) factors. Western blotting evaluated CD163 expression.

RESULTS

Transplantation of hUC-MSCs promoted the healing of uterine injuries and tissue regeneration while inhibiting tissue fibrosis. Immunohistochemistry at days 14 and 30 post-transplantation demonstrated the polarization of macrophages toward the M2 phenotype in the uterine injury area in the presence of hUC-MSCs. Furthermore, hUC-MSC transplantation improved angiogenesis and endometrial receptivity in the uterine injury rat model, associated with increased IL10 expression. hUC-MSC-induced angiogenesis can be resisted by depleted macrophages. In vitro coculture experiments further demonstrated that hUC-MSCs promoted IL10 expression in macrophages while suppressing TNF-α and iNOS expression. Western blotting showed enhanced CD163 expression in macrophages following hUC-MSC treatment.

CONCLUSIONS

hUC-MSCs contribute to the healing of uterine injuries by targeting macrophages to promote angiogenesis and the expression of anti-inflammatory factors.

Peripheral immune cell profiling of double-hit lymphoma by mass cytometry

BACKGROUND

Double-hit or Triple-hit lymphoma (DHL/THL) is a subset of high-grade B cell lymphoma harboring rearrangements of MYC and BCL2 and/or BCL6, and usually associate with aggressive profile, while current therapies tend to provide poor clinical outcomes and eventually relapsed. Further explorations of DHL at cellular and molecular levels are in demand to offer guidance for clinical activity.

METHODS

We collected the peripheral blood of DHL patients and diffused large B cell lymphoma (DLBCL) patients from single institute and converted them into PBMC samples. Mass cytometry was then performed to characterize these samples by 42 antibody markers with samples of healthy people as control. We divided the immune cell subtypes based on the expression profile of surface antigens, and the proportion of each cell subtype was also analyzed. By comparing the data of the DLBCL group and the healthy group, we figured out the distinguished immune cell subtypes of DHL patients according to their abundance and marker expression level. We further analyzed the heterogeneity of DHL samples by pairwise comparison based on clinical characteristics.

RESULTS

We found double-positive T cells (DPT) cells were in a significantly high percentage in DHL patients, whereas the ratio of double-negative T cells (DNT) was largely reduced in patients. Besides, CD38 was uniquely expressed at a high level on some naïve B cells of DHL patients, which could be a marker for the diagnosis of DHL (distinguishing from DLBCL), or even be a drug target for the treatment of DHL. In addition, we illustrated the heterogeneity of DHL patients in terms of immune cell landscape, and highlighted TP53 as a major factor that contributes to the heterogeneity of the T cells profile.

CONCLUSION

Our study demonstrated the distinct peripheral immune cell profile of DHL patients by contrast to DLBCL patients and healthy people, as well as the heterogeneity within the DHL group, which could provide valuable guidance for the diagnosis and treatment of DHL.

The tumor immune-microenvironment in gastric cancer

AIMS AND BACKGROUND

The tumor microenvironment significantly influences malignant behavior and progression. Many components are involved in the tumor microenvironment, including extracellular matrix, stromal cells, immune and inflammatory cells, as well as cytokines that promote tumor development with complex interactions through the exchange of molecular information. It is now known that tumor immune escape may be influenced by the tumor microenvironment. The aim of this work is to conduct a review of the tumor immune-microenvironment in gastric cancer.

METHODS

We review the current knowledge of several immune cells involved in the gastric tumor microenvironment. In addition, a brief description of immunotherapy strategies for gastric cancer is also reviewed.

CONCLUSIONS

Among immune cell populations, lymphocytes, macrophages, dendritic cells and myeloid-derived suppressor cells are revealed to make the difference in promoting or suppressing gastric tumorigenesis, either directly or indirectly, via regulating the immune responses. Understanding these interactions in detail within the tumor immune-microenvironment will contribute to unraveling new therapeutic targets.

Poor clinical outcomes and immunoevasive contexture in CXCL13+CD8+ T cells enriched gastric cancer patients

As an adverse survival prognosticator, chemokine (C-X-C motif) ligand 13 (CXCL13) has been studied in several types of malignancies. The secretion and physiological roles of CXCL13 in follicular helper T cells (T_FH) cells have been well described, while the clinical significance of CD8⁺ tumor-infiltrating lymphocytes (TILs)-associated CXCL13 remains unknown. This study aims to investigate the clinical significance of CXCL13⁺CD8⁺ T cells in survival and chemotherapeutic responsiveness prediction in gastric cancer. In this study, 440 patients enrolled from Zhongshan Hospital with tumor microarray (TMA) specimens were randomly divided into testing set (n = 220) and validation set (n = 220) for analysis. CXCL13⁺CD8⁺ T cells were detected by multicolor immunohistochemistry. Fresh tumor tissue samples from another 60 gastric cancer patients were collected to detect CXCL13⁺CD8⁺ T cells functional status by flow cytometry (FCM). We found that high intratumoral CXCL13⁺CD8⁺ T cells infiltration predicted poor overall survival and inferior chemotherapeutic responsiveness in gastric cancer. CXCL13⁺CD8⁺T cells were associated with immunoevasive contexture with increased regulatory T (T_reg) cells and dysfunctional cytotoxic T lymphocytes (CTLs). Moreover, the combinational analysis of CXCL13⁺CD8⁺ T cells and CD8⁺ T cells infiltration stratified patients into distinct risk groups with different clinical outcomes and chemotherapeutic responsiveness. Conclusively, intratumoral CXCL13⁺CD8⁺ T cells infiltration could be an independent prognostic and predictive marker for gastric cancer patients. CXCL13⁺CD8⁺ T cells represented an exhausted CD8⁺ T cell subset, and might be a potential immunotherapeutic target in gastric cancer.

Adaptive immunity profiling associated with histological subtypes and postoperative survival in gastric cancer

Background

In gastric cancer (GC), abnormal adaptive immunity is correlated with chronic inflammatory disorders and poor prognosis. However, the global study of adaptive immunity involving genes expression is insufficient.

Methods

In this study, we investigated the transcriptional profile of adaptive immunity involving genes in GC from TCGA (The Cancer Genome Atlas). The relevance of adaptive immunity and the clinical features of patients with GC were assessed. Differences in gene expression between each feature and the correlation between gene expression and prognosis were elucidated.

Results

According to the expressional profile of adaptive immunity-related genes, 412 patients with GC were grouped into two primary classifications and three secondary classifications. There were no differences in prognosis detected between each subgroup. In the immune subgroups, the distributions of pathological type were obviously different. Additionally, histological types, AJCC (American Joint Committee on Cancer) stage features, grade, tumor stage, aneuploidy score, and fraction genome altered in different subgroups were significantly discrepant. There were 95 differently expressed genes (DEGs) detected between each histological type, which were represented by LAIR1, BTK and LAT2. According to identification of DEGs in the MSTAD (mucinous stomach adenocarcinoma) and SRCC (signet ring cell carcinoma) types, which were relevant to the best and worst prognosis types, respectively, we constructed a model combining seven genes to recognize the MSTAD type (AUC =0.91) and a model combining six genes to recognize the SRCC type (AUC =0.91). Moreover, the expression of FGL1 gene was notably contrasting among the different histological types, and the high-expression of FGL1 was correlated with a poor prognosis.

Conclusions

This study showed that the expressional patterns of adaptive immunity-related genes are closely related to the histological type of GC, and demonstrated that the expression of immune molecules is correlated to the prognosis. Our results are expected to promote immunological therapy for GC.