CD40 is recognized as a member of tumor necrosis factor receptor super family. It is expressed by the immune and non-immune cells. Its interaction with CD40 ligand (CD154) brings about a regulatory effect on the cellular and humoral immunity. The pathway of CD40-CD154 is influential in various diseases. Investigations on such diseases have revealed dimensional mechanisms whereby this route intensifies host protection. Moreover, through these mechanisms, pathogens subvert the signaling of the CD40, conditions in which the CD40–CD154 pathway promotes disease and also through the relevant modulation for immunotherapy.This review focuses on the role of CD40–CD40L (CD154) interactions in dendritic cells (DCs) regulation, tolerogenic dendritic cells, role of CD40 in autoimmune disease, allograft rejection and induction of tolerance by down regulation of CD40. According to these roles, it is assumed that CD40 is a functional molecule in the pathologies of conditions like autoimmune diseases and allograft rejection caused by activated T and B cells.

Background: Type-1 diabetes (T1D) is an autoimmune disease in which T lymphocytes destroy insulin-producing β-cells. Control of self-reactive T lymphocytes and recovery of diabetic injury is the end point of T1D. Objective: To investigate generation of tolerogenic dendritic cells (tolDCs) as an innovative method of diabetes therapy. Methods: Lentivirus vector production was achieved by GIPZ mouse CD40 shRNA, psPAX2 and pMD2G plasmids DNA. Purified bone marrow derived DCs were treated with CD40 shRNA, and expression of CD40 and mRNA level were evaluated by flow cytometry and Real-Time PCR, respectively. CD40 knock-down DCs were injected into STZ-induced diabetic mice. Blood glucose; glucose tolerance test and weight were analyzed in different groups. Results: Mice treated with CD40 shRNA transfected DCs showed considerable differences in blood glucose, glucose tolerance, and weight compared to other groups. Also cytokine assays indicated an increase in IL-13 production in the CD40 shRNA group. Conclusion: In streptozotocin-induced diabetic mice model, administration of tolerogenic dendritic cells could improve diabetic parameters.

Background: One of the valuable tools for inhibiting the specific gene expression is antisense technique. To determine T cell responses, co-stimulatory molecule expression on the antigen presenting cells is important. In the present study, the effects of high affinity antisense against CD40 mRNA on the function and phenotype of DCs (dendritic cells) were investigated.Methods: The DCs were separated from the mice spleens and then cultured in vitro. By means of lipofectamine 2000, the antisense was delivered into the cells and the efficacy of transfection was estimated by flow cytometry.Also, the mRNA expression and protein synthesis were assessed by real time PCR and flow cytometry, respectively.The DCs were transfected with 6 mM antisense and 2 ml lipofectamine 2000.Results: The percentage of CD40 expression in DCs was 38%. The results showed that CD40 expression is reduced in DCs to 22% and 24%. By annexine V and propidium iodine staining, we could evaluate the viability of the transfected cells. The inhibition of CD40 gene expression was associated with the increase in IL-4 secretion.This shifted the DCs to stimulate Th2 cytokine production from the allogenic T cells. In addition, in the MLR, the DCs without CD40 expression showed poor allostimulatory effects. This finding is valuable in the study of the costimulatory molecules of DCs.Conclusion: These data demonstrate that direct interference of the cell surface expression of CD40 at transcriptional level by antisense confers tolerogenecity potential of DCs. This approach is a useful tool through which DCs become tolerogenic and can be studied as a potential therapeutic option for the autoimmune diseases and allograft rejection.

Background: Transformation and differentiation of activated B-cell to plasmacells and also memory cells depend on signaling from B-cell receptors. The signals from antigen and cytokine receptors on the surface of B cells lead to induce the expression of specific transcription factors, which finally determine the fate of B cells.Methods: Peripheral blood mononuclear cells (PBMC) were isolated via ficoll gradient and then purified B cells were separated using magnetic-activated cell sorting (MACS). Pure B cells were cultured in Roswell Park Memorial Institute 1640 (RPMI1640) culture media at the presence of purified anti-human CD40 antibody and anti-immunoglobulin M f (ab) ´2 or lipopolysaccharide (LPS) and anti-human CD40 antibody that induced B-cells differentiation to plasmablasts which was assessed with 3 markers (CD38+, CD27+, IgM-) and analyzed via flow cytometry. Findings: In stimulation of B cells with purified anti-human CD40 antibody and anti-IgM f (ab) ´2 or LPS through cross-linking B-cell receptor, the majority of B cells remained alive and differentiated to another lineage of B cells (plasmablast: CD38+, CD27+, IgM-). There was no significant statistical difference between expressions of plasmablast markers in two states of stimulation.Conclusion: B cells can be stimulated and differentiated to plasmablasts in vitro similar to in vivo condition. However, to achieve the best outcome in the differentiation of B cells, we should consider the nature of stimulator, the time of incubation, and the type of stimulators.

Blocking antibodies are valuable tools for inhibiting the specific receptor- ligand interactions. The interaction of co-stimulatory molecules on the antigen presenting cells with their ligands on T cells is an essential step for T cell activation. In the present study, the effect of blocking antibody against CD40 on its T cell stimulatory potential is investigated.The DCs (dendritic cells) were collected from the mice spleens and then cultured in vitro. We used purified rat anti-mice CD40 (Clone HM40-3) (BD USA) as a blocking antibody and the appropriate titer of the blocking antibody was determined by flow cytometry. The DCs were then treated by antibody and used in MLR assay.The results of these experiments showed that CD40 blockade were associated with the increase in the of IL-4 secretion, shifting the DCs to stimulate Th2 cytokine production by the allogenic T cells, while the secretion of IL-12 by DCs decreased. Similarly, the DCs with reduced CD40 expression poorly responded to alloantigen stimulation in the MLR.Collectively, these results emphasize the importance of CD40 pathway in tolerogenic DCs generation and also support the idea that downregulation of CD40 is effective in inhibiting the allostimulatory function.

Background. Breast cancer with a complex inheritance pattern is a major cause of cancer death among women worldwide. Single nucleotide polymorphisms (SNPs), the most common genetic variations, influence interindividual predisposition to disease and treatment outcomes with drugs. Evidence suggests that CD40 polymorphism contributes to pathogenesis of cancer. The co-stimulatory molecule CD40 plays a prominent role in immune regulation. This study aimed to test the association between polymorphisms in the CD40 gene and breast carcinogenesis in Arak, Iran. Methods. In this case-control study, three SNPs (rs1883832, rs4810485, rs3765459) were genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. We included 80 patients with breast cancer and 80 healthy controls. Statistical analysis was performed by SPSS (version 26) using Chi-Squared test at P˂ 0. 05. Results. Our data showed a statistically significant association between the two CD40 SNPs (1s1883832 and rs4810485) and breast cancer risk (P=0. 038 and P=0. 000, respectively). There was no significant association between rs3765459 and breast cancer risk (P=0. 190). Conclusion. We witnessed that CD40 gene polymorphisms (rs1883832 and rs4810485) contributed to breast cancer. So, they are associated with breast cancer risk. Practical Implications. The obtained data revealed a significant relationship between the rs1883832 and rs4810485 polymorphisms and the risk of breast cancer. Thus, these polymorphisms could be used as biomarkers to predict breast cancer.