Metastatic melanoma is the most aggressive and difficult to treat type of skin cancer, with a survival rate of less than 10%. Metastatic melanoma has conventionally been considered very difficult to treat; however, recent progress in understanding the cellular and molecular mechanisms involved in the tumorigenesis, metastasis and immune escape have led to the introduction of new therapies. These include targeted molecular therapy and novel immune-based approaches such as immune checkpoint blockade (ICB), tumor-infiltrating lymphocytes (TILs), and genetically engineered T-lymphocytes such as chimeric antigen receptor (CAR) T cells. Among these, CAR T cell therapy has recently made promising strides towards the treatment of advanced hematological and solid cancers. Although CAR T cell therapy might offer new hope for melanoma patients, it is not without its shortcomings, which include off-target toxicity, and the emergence of resistance to therapy (e.g., due to antigen loss), leading to eventual relapse. The present review will not only describe the basic steps of melanoma metastasis, but also discuss how CAR T cells could treat metastatic melanoma. We will outline specific strategies including combination approaches that could be used to overcome some limitations of CAR T cell therapy for metastatic melanoma.

Cell-based cancer therapies have led to a paradigm shift in the treatment of patients with various cancers. To date, a vast majority of cancer immunotherapies have used genetically engineered T cells to target tumors. Stimulation and ex vivo expansion of T cells, as one of the crucial starting materials for T cell manufacturing, have always been a critical part of adoptive T-cell therapy (ACT). Typically, anti-CD3 and anti-CD28 monoclonal antibodies (mAbs) along with interleukin-2 (IL-2), through transducing signals one, two, and three, respectively, are essential for in vitro T cell activation. Terminal differentiation and replicative senescence are the main barriers of the ACTs during the manufacturing of engineered T cells ex vivo. In this study, we aimed to compare the T cell activation protocol that we developed in our lab (soluble anti-CD3/28 mAbs) with a common T cell activation protocol (immobilized anti-CD3/soluble anti-CD28) in terms of T cell expansion, activation, immunophenotype, and cellular fate. We observed that T cells were equally expanded in both protocols. Notably, our modified protocol promoted the outgrowth of CD8+ T cells postactivation. Concerning the low concentrations of both soluble anti-CD3 and anti-CD28, the modified protocol could significantly enrich memory T cell subsets. In conclusion, our data demonstrated that the soluble CD3/28 mAbs protocol is cost-effective and more efficient for generating more potent T cells, thereby expecting a better therapeutic outcome.

Unraveling molecular interactions between viral proteins and host cells is key to understanding the pathogenesis of viral diseases. We hypothesized that potential sequence and structural similarities between SARS-CoV2 proteins and proteins of infected cells might influence host cell biology and antiviral defense. Comparing the proteins of SARS-CoV-2 with human and mammalian proteins revealed sequence and structural similarities between viral helicase with human UPF1. The latter is a protein that is involved in nonsense mediated RNA decay (NMD), an mRNA surveillance pathway which also acts as a cellular defense mechanism against viruses. Protein sequence similarities were also observed between viral nsp3 and human Poly ADP-ribose polymerase (PARP) family of proteins. Gene set enrichment analysis on transcriptomic data derived from SARS-CoV-2 positive samples illustrated the enrichment of genes belonging to the NMD pathway compared with control samples. Moreover, comparing transcriptomic data from SARS-CoV2-infected samples with transcriptomic data derived from UPF1 knockout cells demonstrated a significant overlap between datasets. These findings suggest that helicase/UPF1 sequence and structural similarity might have the ability to interfere with the NMD pathway with pathogenic and immunological implications.

Background: CAR T cells still face numerous obstacles in treating hematologic and solid malignancies. Although gene editing technologies have improved CAR T cell therapy, there are currently no systematic reviews to broadly address preclinical and clinical outcomes of gene-edited CAR T cells. Therefore, we aimed to systematically review the preclinical and clinical studies that evaluate the outcomes of knocked-out/knocked-down (KO/KD) CAR T cells. Methods: This study was submitted to international Prospective Register of Systematic Reviews (PROSPERO) with the ID CRD42022320541 and follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. We searched Five databases (PubMed, EMBASE, Cochrane Library, Web of Science, and Clinicaltrials.gov) up to March 19th, 2022 for the keywords of “CAR T cell” and “knock-out/knock-down”. The retrieved records then underwent a two-step screening process based on the inclusion criteria, first title/abstract and then full-text screenings, and their data were used for qualitative synthesis. Results: Our search results yielded 3780 records. Finally, a total of 241 records, including 193 animal and 52 human studies (four concurrent in both groups) that reported KO/KD genes for 105 proteins were included. The positive effects of these 105 KO/KD were categorized into five groups: (1) enabling allogeneic CAR production while limiting GVHD, (2) increasing the efficacy of CAR T cells, (3) Decreasing their side effects, (4) limiting CAR T cell fratricide, and (5) enabling the use of concurrent therapies. In the human section, solid tumors had fewer studies with less favorable outcomes compared to hematologic malignancies. Conclusions: This systematic review emphasized the various mechanisms by which CAR T cell effects could be boosted. Future researchers can choose their desired genes out of the 105 mentioned candidates. We also encourage the researchers to increase their efforts on solid tumors to compensate for the lack of increased efficacy in this group.

Circular RNAs (circRNAs) are endogenous non-coding RNA molecules that form covalently closed molecular loops. By regulating gene expression, circRNAs are known to play crucial roles in the development and progression of various diseases, including autoimmune, neoplastic, and neurological disorders. In this study, we examined the expression of circSnx5 in inflamed CNS tissue at different stages of experimental autoimmune encephalitis (EAE), an animal model for multiple sclerosis (MS), as well as in T cells that were activated and differentiated into different T helper phenotypes (Th1, Th17, Treg). EAE was induced and spinal cord tissues were isolated at different time points following disease induction. CD4+ T cells were isolated from mouse splenocytes and differentiated toward Th1, Th17, and Treg phenotypes, followed by the analysis of circSnx5 expression. Compared with control mice, enhanced expression of both circular and linear forms of Snx5 was detected in EAE lumbar spinal cords at the peak and post-peak phases of the disease. However, the ratio of the circular to linear forms (CLR) was decreased in EAE mice compared with controls. Expression of circSnx5 was highly correlated with the levels of inflammatory cytokines in the spinal cord tissue. Significant decreases were observed in circSnx5 expression levels following polyclonal activation of splenocytes. The expression of circSnx5 was also downregulated in differentiated T cells directed toward Th1, Th17, and Treg. Our findings suggest a potential role of circSnx5 in autoimmune neuroinflammation. The altered expression of circSnx5 during activation and differentiation may offer valuable insights into potential strategies for regulating inflammation in multiple sclerosis (MS).