The immune checkpoint molecule V-set Ig domain-containing 4 is an independent prognostic factor for multiple myeloma

Exploring the immune microenvironment of osteosarcoma through T cell exhaustion-associated gene expression: a study on prognosis prediction

Background

Osteosarcoma is a highly aggressive type of bone cancer with a poor prognosis. In the tumor immune microenvironment, T-cell exhaustion can occur due to various factors, leading to reduced tumor-killing ability. The purpose of this study was to construct a prognostic model based on T-cell exhaustion-associated genes in osteosarcoma.

Methods

Patient data for osteosarcoma were retrieved from the TARGET and GEO databases. Consensus clustering was employed to identify two novel molecular subgroups. The dissimilarities in the tumor immune microenvironment between these subgroups were evaluated using the "xCell" algorithm. GO and KEGG analyses were conducted to elucidate the underlying mechanisms of gene expression. Predictive risk models were constructed using the least absolute shrinkage and selection operator algorithm and Cox regression analysis. To validate the prognostic significance of the risk gene expression model at the protein level, immunohistochemistry assays were performed on osteosarcoma patient samples. Subsequently, functional analysis of the key risk gene was carried out through in vitro experimentation.

Results

Four gene expression signatures (PLEKHO2, GBP2, MPP1, and VSIG4) linked to osteosarcoma prognosis were identified within the TARGET-osteosarcoma cohort, categorizing patients into two subgroups. The resulting prognostic model showed strong predictive capability, with area under the receiver operating characteristic curve (AUC) values of 0.728/0.740, 0.781/0.658, and 0.788/0.642 for 1, 3, and 5-year survival in both training and validation datasets. Notably, patients in the low-risk group had significantly higher stromal, immune, and ESTIMATE scores compared to high-risk counterparts. Additionally, a nomogram was developed, exhibiting high accuracy in predicting the survival outcome of osteosarcoma patients. Immunohistochemistry, Kaplan-Meier, and time-dependent AUC analyses consistently supported the prognostic value of the risk model within our osteosarcoma patient cohort. In vitro experiments provided additional validation by demonstrating that the downregulation of GBP2 promoted the proliferation, migration, and invasion of osteosarcoma cells while inhibiting apoptosis.

Conclusion

The current study established a prognostic signature associated with TEX-related genes and elucidated the impact of the pivotal gene GBP2 on osteosarcoma cells via in vitro experiments. Consequently, it introduces a fresh outlook for clinical prognosis prediction and sets the groundwork for targeted therapy investigations in osteosarcoma.

The biology of VSIG4: Implications for the treatment of immune-mediated inflammatory diseases and cancer

V-set and immunoglobulin domain containing 4 (VSIG4), a type I transmembrane receptor exclusively expressed in a subset of tissue-resident macrophages, plays a pivotal role in clearing C3-opsonized pathogens and their byproducts from the circulation. VSIG4 maintains immune homeostasis by suppressing the activation of complement pathways or T cells and inducing regulatory T-cell differentiation, thereby inhibiting the development of immune-mediated inflammatory diseases but enhancing cancer progression. Consequently, VSIG4 exhibits a potential therapeutic effect for immune-mediated inflammatory diseases, but also is regarded as a novel target of immune checkpoint inhibition in cancer therapy. Recently, soluble VSIG4, the extracellular domain of VSIG4, shed from the surface of macrophages, has been found to be a biomarker to define macrophage activation-related diseases. This review mainly summarizes recent new findings of VSIG4 in macrophage phagocytosis and immune homeostasis, and discusses its potential diagnostic and therapeutic usage in infection, inflammation, and cancer.

Therapeutic modulation of V Set and Ig domain-containing 4 (VSIG4) signaling in immune and inflammatory diseases

Inflammation is the result of acute and chronic stresses, caused by emotional or physical trauma, or nutritional or environmental pollutants, and brings serious harm to human life and health. As an important cellular component of the innate immune barrier, the macrophage plays a key role in maintaining tissue homeostasis and promoting tissue repair by controlling infection and resolving inflammation. Several studies suggest that V Set and Ig domain-containing 4 is specifically expressed in tissue macrophages and is associated with a variety of inflammatory diseases. In this paper, we mainly summarize the recent research on V Set and Ig domain-containing 4 structures, functions, function and roles in acute and chronic inflammatory diseases, and provide a novel therapeutic avenue for the treatment of inflammatory diseases, including nervous system, urinary, respiratory and metabolic diseases.

V-Set and immunoglobulin domain containing (VSIG) proteins as emerging immune checkpoint targets for cancer immunotherapy

The development of immune checkpoint inhibitors is becoming a promising approach to fight cancers. Antibodies targeting immune checkpoint proteins such as CTLA-4 and PD-1 can reinvigorate endogenous antitumor T-cell responses and bring durable advantages to several malignancies. However, only a small subset of patients benefit from these checkpoint inhibitors. Identification of new immune checkpoints with the aim of combination blockade of multiple immune inhibitory pathways is becoming necessary to improve efficiency. Recently, several B7 family-related proteins, TIGIT, VSIG4, and VSIG3, which belong to the VSIG family, have attracted substantial attention as coinhibitory receptors during T-cell activation. By interacting with their corresponding ligands, these VSIG proteins inhibit T-cell responses and maintain an immune suppressive microenvironment in tumors. These results indicated that VSIG family members are becoming putative immune checkpoints in cancer immunotherapy. In this review, we summarized the function of each VSIG protein in regulating immune responses and in tumor progression, thus providing an overview of our current understanding of VSIG family members.

B7 Family Molecule VSIG4 Regulates Intestinal Anti-Enterohemorrhagic Escherichia coli Immunity by Altering Gut Flora Diversity

As an essential member of the B7 family, V-set and immunoglobulin domain-containing 4 (VSIG4) is expressed explicitly in tissue-resident macrophages (TRMs) and plays an essential role in maintaining the homeostasis of the environmental immune system. Here, we demonstrate that gene-targeted VSIG4-deficient mice infected with Enterohemorrhagic Escherichia coli (EHEC) display reduced bacterial burden. To reveal the role of VSIG4 in the fight against EHEC infection, we collected mice feces and used high-throughput 16S rRNA gene amplicons to detect changes in the flora. A total of 657330 sequences were sequenced on the PacBio platform, with an average length of 1498 bp. We found that VSIG4 deficiency could alter the gut microbiota by increasing diversity and shifting community composition. In particular, G_Akkermansia and G_Oscillo spiraceae increased significantly. These findings expand upon a prior observation that VSIG4 deficiency reduced EHEC colonization by changing the gut microbiota diversity and shifting community composition.

Expression of the immune checkpoint molecule V-set immunoglobulin domain-containing 4 is associated with poor prognosis in patients with advanced gastric cancer

BACKGROUND

Recent clinical studies on immune checkpoint (IC) inhibitors in the context of advanced gastric cancer (AGC) have failed to show significant survival benefits but have suggested the possible role of IC inhibitors in anti-AGC immunity. Considering the low efficacy of targeted drugs in AGC, there is an urgent need for the discovery of new targets for the development of immunotherapeutics and prognostic markers for patient selection. This study aimed to investigate the expression of a new IC molecule, V-set Ig domain-containing 4 (VSIG4), and its clinical significance in AGC and other major cancers.

METHODS

We analyzed the expression of VSIG4 and its correlation with survival in various carcinomas, including 882 surgically resected samples from patients with stage II-III AGC (two academic hospitals).

RESULTS

VSIG4 positivity in AGC was significantly associated with overall survival (OS; Hazard ratio (HR) = 2.661, 95% confidence interval [CI] = 2.012-3.519, P < 0.001) and event-free survival (HR = 2.8, 95% CI = 2.18-3.72, P < 0.001). These findings were successfully validated in independent cohorts. VSIG4 expression was also significantly correlated with low intratumoral CD8 + T-cell infiltration (CD8i) (P = 0.029) and high Foxp3 + /CD8i ratio (P = 0.026), which is consistent with the previously reported immunological function of VSIG4. However, VSIG4 expression was not associated with survival in other cancers (colon, P = 0.459; lung, P = 0.275; kidney, P = 0.121; breast, P = 0.147).

CONCLUSION

Our results suggest that VSIG4 is an independent prognostic factor in AGC and also implies that VSIG4 is a second-tier IC molecule in AGC, thus, providing an important basis for the development of gastric cancer-specific immunotherapeutics.

Immune checkpoint protein VSIG4 as a biomarker of aging in murine adipose tissue

Adipose tissue is recognized as a major source of systemic inflammation with age, driving age-related tissue dysfunction and pathogenesis. Macrophages (Mφ) are central to these changes yet adipose tissue Mφ (ATMs) from aged mice remain poorly characterized. To identify biomarkers underlying changes in aged adipose tissue, we performed an unbiased RNA-seq analysis of ATMs from young (8-week-old) and healthy aged (80-week-old) mice. One of the genes identified, V-set immunoglobulin-domain-containing 4 (VSIG4/CRIg), encodes a Mφ-associated complement receptor and B7 family-related immune checkpoint protein. Here, we demonstrate that Vsig4 expression is highly upregulated with age in perigonadal white adipose tissue (gWAT) in two mouse strains (inbred C57BL/6J and outbred NIH Swiss) independent of gender. The accumulation of VSIG4 was mainly attributed to a fourfold increase in the proportion of VSIG4+ ATMs (13%-52%). In a longitudinal study, VSIG4 expression in gWAT showed a strong correlation with age within a cohort of male and female mice and correlated strongly with physiological frailty index (PFI, a multi-parameter assessment of health) in male mice. Our results indicate that VSIG4 is a novel biomarker of aged murine ATMs. VSIG4 expression was also found to be elevated in other aging tissues (e.g., thymus) and was strongly induced in tumor-adjacent stroma in cases of spontaneous and xenograft lung cancer models. VSIG4 expression was recently associated with cancer and several inflammatory diseases with diagnostic and prognostic potential in both mice and humans. Further investigation is required to determine whether VSIG4-positive Mφ contribute to immunosenescence and/or systemic age-related deficits.

Deciphering Immune-Associated Genes to Predict Survival in Clear Cell Renal Cell Cancer

Background

To elucidate the correlations between tumor microenvironment and clinical characteristics as well as prognosis in clear cell renal cell cancer (ccRCC) and investigate the immune-associated genes by a comprehensive analysis of The Cancer Genome Atlas (TCGA) database.

Methods

We collected mRNA expression profiles of 537 ccRCC samples from the TCGA database. Immune scores and stromal scores were calculated by applying the ESTIMATE algorithm. We evaluated the correlation between immune/stromal scores and clinical characteristics as well as prognosis. The differentially expressed genes (DEGs) were screened between high immune/stromal score and low immune/stromal score groups by the cutoff of |log (fold change)| > 1, P value <0.05 by using package "limma" in R. Functional enrichment analysis was performed by DAVID, and the protein-protein interaction network of intersected DEGs between stromal score and immune score groups was conducted using the STRING database. The Kaplan-Meier method was used to explore DEGs with predictive values in overall survival, and the prognostic DEGs were further validated in a Gene Expression Omnibus (GEO) dataset GSE29609.

Results

A higher immune score was associated with T3/4 (vs. T1/2, P < 0.001), N1 (vs. N0, P=0.05), M1 (vs. M0, P=0.004), G3/4 (vs. G1/2, P < 0.001), advanced AJCC stage (P < 0.001), and shorter overall survival (P=0.04). Intersected DEGs between immune and stromal score groups were 48 upregulated and 47 downregulated genes, with 43 DEGs associated with overall survival in ccRCC. After validation by a cohort of 39 ccRCC cases with detailed follow-up information from GSE29609, six immune-associated DEGs including CASP5, HSD11B1, VSIG4, HMGCS2, HSD11B2, and OGDHL were demonstrated to be predictive of prognosis in ccRCC.

Conclusions

Our study elucidated tight associations between immune score and clinical characteristics as well as prognosis in ccRCC. Moreover, six DEGs were explored and validated to exert predictive values in overall survival of ccRCC.

NIRF-Molecular Imaging with Synovial Macrophages-Targeting Vsig4 Nanobody for Disease Monitoring in a Mouse Model of Arthritis

Nanobody against V-set and Ig domain-containing 4 (Vsig4) on tissue macrophages, such as synovial macrophages, could visualize joint inflammation in multiple experimental arthritis models via single-photon emission computed tomography imaging. Here, we further addressed the specificity and assessed the potential for arthritis monitoring using near-infrared fluorescence (NIRF) Cy7-labeled Vsig4 nanobody (Cy7-Nb119). In vivo NIRF-imaging of collagen-induced arthritis (CIA) was performed using Cy7-Nb119. Signals obtained with Cy7-Nb119 or isotope control Cy7-NbBCII10 were compared in joints of naive mice versus CIA mice. In addition, pathological microscopy and fluorescence microscopy were used to validate the arthritis development in CIA. Cy7-Nb119 accumulated in inflamed joints of CIA mice, but not the naive mice. Development of symptoms in CIA was reflected in increased joint accumulation of Cy7-Nb119, which correlated with the conventional measurements of disease. Vsig4 is co-expressed with F4/80, indicating targeting of the increasing number of synovial macrophages associated with the severity of inflammation by the Vsig4 nanobody. NIRF imaging with Cy7-Nb119 allows specific assessment of inflammation in experimental arthritis and provides complementary information to clinical scoring for quantitative, non-invasive and economical monitoring of the pathological process. Nanobody labelled with fluorescence can also be used for ex vivo validation experiments using flow cytometry and fluorescence microscopy.

Low expression of VSIG4 is associated with poor prognosis in hepatocellular carcinoma patients with hepatitis B infection

Background

V-set and immunoglobulin domain containing protein 4 (VSIG4) was reported to play an important role in tumorigenesis. However, the expression and clinical relevance in hepatocellular carcinoma (HCC) remain unknown.

Materials and methods

First, the mRNA profiles of HCC were screened from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. VSIG4, a differentially expressed gene that has not been reported in HCC, was distinguished. Second, the correlation between VSIG4 expression and the prognosis of HCC patients from TCGA was analyzed. Third, VSIG4 mRNA level was detected in 36 pairs of HCC tissues and 4 HCC cell lines by PCR assay. And finally, prognosis analysis was assessed for 36 HCC patients with different expression levels of VSIG4.

Results

Bioinformatics analysis showed that VSIG4 expression was downregulated in HCC tissues, and the expression level of VSIG4 was negatively correlated with serum alpha fetal protein (AFP) level and tumor distant metastasis. Survival analysis of all HCC patients in TCGA indicated that the overall survival and disease-free survival were not significantly associated with VSIG4 expression. However, subgroup analysis showed that in the patients with hepatitis B virus-related HCC, both overall survival and disease-free survival were shorter in the low VSIG4 expression group. Our PCR results further showed that VSIG4 expression was significantly decreased in HCC tissues and HCC cell lines, and the disease-free survival in hepatitis B virus-related HCC patients with low VSIG4 expression was shorter than in those with high VSIG4 expression, which was consistent with the bioinformatics analysis results.

Conclusion

Our study suggests that VSIG4 is downregulated in HCC, and low expression of VSIG4 is associated with poor prognosis in hepatitis B virus-related HCC patients.

Immune Dysregulation in Cancer Patients Undergoing Immune Checkpoint Inhibitor Treatment and Potential Predictive Strategies for Future Clinical Practice

Realization of the full potential of immune checkpoint inhibitor-targeted onco-immunotherapy is largely dependent on overcoming the obstacles presented by the resistance of some cancers, as well as on reducing the high frequency of immune-related adverse events (IRAEs) associated with this type of immunotherapy. With the exception of combining therapeutic monoclonal antibodies, which target different types of immune checkpoint inhibitory molecules, progress in respect of improving therapeutic efficacy has been somewhat limited to date. Likewise, the identification of strategies to predict and monitor the development of IRAEs has also met with limited success due, at least in part, to lack of insight into mechanisms of immunopathogenesis. Accordingly, considerable effort is currently being devoted to the identification and evaluation of strategies which address both of these concerns and it is these issues which represent the major focus of the current review, particularly those which may be predictive of development of IRAEs. Following an introductory section, this review briefly covers those immune checkpoint inhibitors currently approved for clinical application, as well as more recently identified immune checkpoint inhibitory molecules, which may serve as future therapeutic targets. The remaining and more extensive sections represent overviews of: (i) putative strategies which may improve the therapeutic efficacy of immune checkpoint inhibitors; (ii) recent insights into the immunopathogenesis of IRAEs, most prominently enterocolitis; and (iii) strategies, mostly unexplored, which may be predictive of development of IRAEs.