Semaforin Sema4D in the immune system in multiple sclerosis

Semaphorins in immune cell function, inflammatory and infectious diseases

The Semaphorin family is a group of proteins studied broadly for their functions in nervous systems. They consist of eight subfamilies ubiquitously expressed in vertebrates, invertebrates, and viruses and exist in membrane-bound or secreted forms. Emerging evidence indicates the relevance of semaphorins outside the nervous system, including angiogenesis, cardiogenesis, osteoclastogenesis, tumour progression, and, more recently, the immune system. This review provides a broad overview of current knowledge on the role of semaphorins in the immune system, particularly its involvement in inflammatory and infectious diseases, including chlamydial infections.

Construction of lncRNA and mRNA co-expression network associated with nasopharyngeal carcinoma progression

Nasopharyngeal carcinoma is a type of head and neck cancer with a high incidence in men. In the past decades, the survival rate of NPC has remained around 70%, but it often leads to treatment failure due to its distant metastasis or recurrence. The lncRNA-mRNA regulatory network has not been fully elucidated. We downloaded the NPC-related gene expression datasets GSE53819 and GSE12452 from the Gene Expression Omnibus database; GSE53819 included 18 NPC tissues and 18 normal tissues, and GSE12452 included 31 NPC tissues and 10 normal tissues. Weighted gene co-expression network analysis was performed on mRNA and lncRNA to screen out modules that were highly correlated with tumor progression. The two datasets were subjected to differential analysis after removing batch effects, and then Venn diagrams were used to screen for overlapping genes in the module genes and differential genes. The lncRNA-mRNA co-expression network was then constructed, and key mRNAs were identified by MCODE analysis and expression analysis. GSEA analysis and qRT-PCR were performed on key mRNAs. Through a series of analyses, we speculated that BTK, CD72, PTPN6, and VAV1 may be independent predictors of the prognosis of NPC patients.Taken together, our study provides potential candidate biomarkers for NPC diagnosis, prognosis, or precise treatment.

[Relapsing-remitting multiple sclerosis: clinical and immunological aspects of the pathology on the example of molecules Sema4D and CD72]

OBJECTIVE

To study the expression of Sema4D (CD100), receptor CD72 and a role of Sema4D-CD72-dependent signal in the control of the functions of immunocompetent cells in relapsing-remitting multiple sclerosis (RRMS).

MATERIAL AND METHODS

We studied 76 patients, including 52 with RRMS (41 in remission and 11 in exacerbation), 35 women (67.3%) and 17 men (32.7%) aged 18-55 years, who did not receive disease-modifying drugs, and 24 healthy donors. A controlled clinical and immunological examination of patients with RRMS was carried out proving the involvement of the Sema4D molecule and its CD72 receptor in pathological reactions in this autoimmune disease.

RESULTS AND CONCLUSION

The use of SemaD as a target in the treatment of RRMS is scientifically substantiated. In case of a positive decision on the use of anti-Sema4D drugs, it will be necessary to take into account the effects of semaphorin not only in the central nervous system, but also in the immune system of patients with RRMS.

A regulatory role for CD72 expression on B cells and increased soluble CD72 in primary Sjogren's syndrome

BACKGROUND

CD72, a co-receptor of B cell receptor (BCR), has been reported to have both positive and negative effects on B cell functions in several immunological diseases. The B cell plays an important role in the pathogenesis of primary Sjogren's syndrome (pSS). However, whether CD72 is involved in the process remains unknown. This study aimed to observe the possible role of CD72 in the pathogenesis of pSS.

RESULTS

A total of 60 cases who fulfilled the American-European Consensus Group (AECG) criteria for the diagnosis of pSS and 61 gender and age-matched healthy controls were recruited in this study. The percentage of CD72+ B cells was 85.31 ± 8.37% in pSS patients and 76.91 ± 8.50% in healthy controls(p < 0.001). The percentage of CD72+ B cells was correlated to serum IgG levels in patients [β = 0.018(0.001-0.036), p = 0.034]. The level of serum soluble CD72 was significantly higher in pSS patients than the one in healthy controls (0.41 (0.29) vs 0.07 (0.08) ng/mL, p < 0.001).

CONCLUSIONS

The percentage of CD72+ B cells was upregulated in pSS patients and was correlated to the serum IgG level, which revealed the hyperactivity of B cells in this disease. The serum soluble CD72 level was also increased in pSS patients. These results indicated a potential role of CD72 in the pathogenesis of pSS.

[Relapsing-remitting multiple sclerosis: clinical and immunological aspects of the pathology on the example Sema4D and CD72]

AIM

To explore the expression of Sema4D, CD72 receptor and a role of Sema4D-CD72 signal in the control of immunocompetent cell function in remitting-relapsing multiple sclerosis (RRMS).

MATERIAL AND METHODS

Fifty-two patients with RRMS diagnosis according to 2010 revised McDonald's criteria were studied. The control group included 24 healthy people. A flow cytometry method was used to measure the expression of semaphorin Sema4D by T-lymphocytes of peripheral blood, expression of CD72 receptor by B-lymphocytes, percentage of cells containing pro- and anti-inflammatory cytokines. The level of soluble Sema4D (sSema4D) was evaluated by ELISA.

RESULTS

The level of Sema4D expression on T-lymphocytes (Mean Fluorescence Intensity - MFI) prevailed in cell subpopulations in patients with RRMS compared with the control group. Characteristics of membrane and sSema4D correlate with clinical presentations of the autoimmune disease. An increase in sSema4D level during cell cultivation was identified in RRMS patients. The results show the involvement of Sema4D in the hyperactivation of B-cell-mediated immunity through CD72 receptor and induction of proinflammatory cytokine synthesis.

CONCLUSION

RRMS is associated with elevated expression of Sema4D in the immune system. Membrane and sSema4D involved in the pathological process in RRMS. The authors suggest several mechanisms of the involvement of semaphorin and its receptor in the pathogenesis of RRMS: the direct damage of nervous tissues by sSema4D penetrated through the blood brain barrier disrupted in RRMS or by membrane Sema4D due to the infiltration of the central nervous system by T-lymphocytes and hyperactivation of B-cell-mediated immunity.

Semaphorins 4A and 4D in chronic inflammatory diseases

Long-term inflammatory processes directed at a particular endogenous or exogenous antigen, or sometimes of unknown etiology, form the pathogenetic basis for many debilitating conditions, such as cardiovascular, pulmonary, autoimmune, neurologic diseases, and cancer. Recent discoveries of neuroimmune semaphorins 4A and 4D (Sema4A and Sema4D, respectively) expression and function in the immune system and their key regulatory roles in fine tuning of inflammatory processes made them the molecules of interest for a potential immunotherapy. In this short review, we discuss the current knowledge in the Sema4A and Sema4D actions in chronic inflammation underlying the outlined above diseases.

The role of Sema4D/CD100 as a therapeutic target for tumor microenvironments and for autoimmune, neuroimmune and bone diseases

INTRODUCTION

Semaphorin 4D (Sema4D), also known as CD100, has been implicated in physiologic roles in the immune and nervous systems. However, the interaction of Sema4D with its high affinity receptor, Plexin-B1, reveals a novel role for Sema4D produced by the tumor microenvironment in tumor angiogenesis and metastasis.

AREAS COVERED

The ligation of Sema4D/CD100 with CD72 on immune and inflammatory cells is known to stimulate immune responses and regulation. Because CD100 and CD72 are expressed on lung immune and nonimmune cells, as well as on mast cells, the CD100/CD72 interaction plays another important role in allergic airway inflammation and mast cell functions. A better understanding of Sema4D-mediated cell signaling in physiological and pathological processes may be crucial for crafting new Sema4D-based therapeutics for human disease and tumor microenvironments. Strategies to achieve effective management through treatment with Sema4D include special siRNAs, neutralizing antibodies and knockdown.

EXPERT OPINION

This review focuses on the links between Sema4D and human diseases such as cancer, bone metabolism, immune responses and organ development. The current knowledge regarding the expression of Sema4D and its receptors and its functional roles is systemically reviewed to explore Sema4D as both a target and a therapeutic in human diseases.