Malignant melanoma is one of the most aggressive forms of cancer and the leading cause of death from skin tumors. Given the increased incidence of melanoma diagnoses in recent years, it is essential to develop effective treatments to control this disease. In this regard, the use of cancer vaccines to enhance cell-mediated immunity is considered to be one of the most modern immunotherapy options for cancer treatment. The most recent cancer vaccine options are mRNA vaccines, with a focus on their usage as modern treatments. Advantages of mRNA cancer vaccines include their rapid production and low manufacturing costs. mRNA-based vaccines are also able to induce both humoral and cellular immune responses. In addition to the many advantages of mRNA vaccines for the treatment of cancer, their use is associated with a number of challenges. For this reason, before mRNA vaccines can be used for the treatment of cancer, comprehensive information about them is required and a large number of trials need to be conducted. Here, we reviewed the general features of mRNA vaccines, including their basis, stabilization, and delivery methods. We also covered clinical trials involving the use of mRNA vaccines in melanoma cancer and the challenges involved with this type of treatment. This review also emphasized the combination of treatment with mRNA vaccines with the use of immune-checkpoint blockers to enhance cell-mediated immunity.

In recent years, mesenchymal stem/stromal cells (MSCs) have widely been considered as therapeutic tools in basic researches and clinical trials. Accumulating evidence supports the idea that MSCs perform their therapeutic roles in paracrine manner especially through trophic factors and extracellular vesicles (EVs). Compared to cells, EVs have several advantages to be used as therapeutic agents, such as they lack self-replicating capabilities, dangers of ectopic differentiation, and tumor formation, genetic instability, and cellular rejection by the immune system. Since the MSC-derived EVs (MSC-EVs) appear to exert similar therapeutic effects of their parent cells, such as ability to arrive themselves to the site of injury and immunomodulatory properties, MSC-EVs have been widely studied in many animal models, including kidney, liver, cardiovascular, immunological, and neurological diseases. Regarding this, MSC-EVs look to be a novel and interesting approach to be studied in clinical trials of different inflammatory diseases. In this review, we summarize the properties and applications of MSC-EVs in different diseases.

One of the main issues in pathogenesis of MS is Th17/Treg imbalance. There are growing interests in nominating miRNAs involved in Th17 cell differentiation, suggesting them as new therapeutic agents that may reduce progression of different autoimmune diseases specially MS. We assessed transcript levels of miR-141 and miR-200a in MS patients, during relapsing and remitting phases. We also investigated possible role of miR-141, miR-200a in inducing differentiation to Th17 cells. Forty RR-MS patient samples including relapsing (n=20) and remitting (n=20) phases were chosen. Expression level of miR-141 and miR-200a were measured by RT-q PCR and compared to healthy control group (n=10). In-silico analyses on miR-141 and miR-200a targetome showed involvement of both miRNAs in T helper cell differentiation pathways including TGF-β, mTOR and JAK/STAT. We observed that percentage of RORγt⁺ CD4⁺ T cells increase in relapsing phase while FOXP3⁺ CD4⁺ increase in remitting phase of MS patients. Furthermore, both miR-141 and miR-200a show up-regulation in relapsing phase of MS patients compared to remitting and control groups. Interestingly, expression level of target genes of miR-141 and miR-200a, which were assessed through in-silico methods, show down-regulation in relapsing phase of MS patients. According to our results, miR-141 and miR-200a may be key miRNAs in progression of symptoms of MS through inducing differentiation of Th17 cells and inhibiting differentiation to Treg cells. Our data suggest that these miRNAs may probably inhibit negative regulators of Th17 cell differentiation, thus promoting its differentiation.

T cell immunoglobulin and mucin domain 3 (TIM-3) expression on malignant cells has been reported in some leukemias. In myelodysplastic syndrome (MDS), increased TIM-3 expression on TH1 cells, regulatory T cells, CD8+ T cells, and hematopoietic stem cells (HSCs), which play a role in the proliferation of blasts and induction of immune escape, has been reported. In AML, several studies have reported overexpression of TIM-3 on leukemia stem cells (LSCs) but not on healthy HSCs. Overexpression of TIM-3 on exhausted CD4+ and CD8+ T cells and leukemic cells in CML, ALL, and CLL patients could be a prognostic risk factor for poor therapeutic response and relapse in patients. Currently, several TIM-3 inhibitors are used in clinical trials for leukemias, and some have shown encouraging response rates for MDS and AML treatment. For AML immunotherapy, blockade TIM-3 may have dual effects: directly inhibiting AML cell proliferation and restoring T cell function. However, blockade of PD-1 and TIM-3 fails to restore the function of exhausted CD8+ T cells in the early clinical stages of CLL, indicating that the effects of TIM-3 blockade may be different in AML and other leukemias. Thus, further studies are required to evaluate the efficacy of TIM-3 inhibitors in different types and stages of leukemia. In this review, we summarize the biological functions of TIM-3 and its contribution as it relates to leukemias. We also discuss the effects of TIM-3 blockade in hematological malignancies and clinical trials of TIM-3 for leukemia therapy.