Several studies have been devoted to clear functionalization of gold nanoparticles (AuNPs) in different fields such as cellular and molecular biology, microbiology, immunology and physiology. In line with the high diagnostic value of AuNPs, its therapeutic application has been intensively developed in tumour therapy, in recent years. One of the best clinical applications of AuNPs is its use in targeted delivery of anti-cancer drugs. Recent studies have focused on the application of AuNPs to treat melanoma - a malignant neoplasm sourced from melanocytes skin cells - with poor prognosis in advanced stages. Furthermore, early diagnosis can be successfully achieved through utilizing this technique even at early stages with localized distribution. Herein, this study details the previous researches focusing on the use of AuNPs as a novel diagnostic and therapeutic option in management of melanoma.

Adoptive transfer of T cells expressing chimeric antigen receptors (CARs) is considered to be a novel anticancer therapy. To date, in most cases, single-chain variable fragments (scFvs) of murine origin have been used in CARs. However, this structure has limitations relating to the potential immunogenicity of mouse antigens in humans and the relatively large size of scFvs. For the first time, we used camelid nanobody (VHH) to construct CAR T cells against prostate specific membrane antigen (PSMA). The nanobody against PSMA (NBP) was used to show the feasibility of CAR T cells against prostate cancer cells. T cells were transfected, and then the surface expression of the CAR T cells was confirmed. Then, the functions of VHH-CAR T cell were evaluated upon coculture with prostate cancer cells. At the end, the cytotoxicity potential of NBPII-CAR in T cells was approximated by determining the cell surface expression of CD107a after encountering PSMA.Our data show the specificity of VHH-CAR T cells against PSMA + cells (LNCaP), not only by increasing the interleukin 2 (IL-2) cytokine (about 400 pg/mL), but also the expression of CD69 by almost 38%. In addition, VHH-CAR T cells were proliferated by nearly 60% when cocultured with LNCaP, as compared with PSMA negative prostate cancer cell (DU-145), which led to the upregulation of CD107a in T cells upto 31%. These results clearly show the possibility of using VHH-based CAR T cells for targeted immunotherapy, which may be developed to target virtually any tumor-associated antigen for adoptive T-cell immunotherapy of solid tumors. K E Y W O R D S chimeric antigen receptor T-cell, immunotherapy, prostate cancer, prostate specific membrane antigen, single-domain antibody fragment

Solid tumors that are responsible for more than 85% of cancer death cases need angiogenesis for their growth and metastasis. Among antiangiogenic therapies, targeting the vascular endothelial growth factor receptor 2 (VEGFR2) that is over‐expressed on tumor vasculatures has been a promising strategy. In this study, we developed a second generation nanobody (VHH)‐based CAR T cell targeting VEGFR2‐expressing tumor cells. The CAR T cell was developed by linking the anti‐VEGFR2 VHH to a spacer, and signaling domains of CD28 and CD3 ζ. The T cells were activated with anti‐CD3 plus rIL‐2 and electroporated with a plasmid encoding the CAR construct. The expression of activation markers, CD69 and CD25, on CAR T cells upon coculturing with VEGFR2‐expressing cells were 41% and 48%, and the IL‐2 and IFN‐γ production were 470 pg/mL and 360 pg/mL, respectively. The expression of degranulation marker, CD107a, was 30% and the cytotoxic activity of the CAR T cells reached to more than 30% with E:T ratio of 9:1. The anti‐VEGFR2 CAR but not mock T cells mediated specific lysis of 293‐KDR cells expressing human VEGFR2 and might be considered as a candidate for adoptive T‐cell immunotherapy of solid tumors. © 2019 IUBMB Life, 71(9):1259–1267, 2019

Background: Recently, modification of T cells with CAR has been an attractive approach for adoptive immunotherapy of cancers. Typically, CARs contain a scFv. Most often, scfvs are derived from a monoclonal antibody of murine origin and may be a trigger for host immune system that leads to the T-cell clearance. Nanobody is a specific antigen-binding fragment derived from camelid that has great homology to human VH and low immunogenic potential. Therefore, in this study, nanobody was employed instead of scFv in CAR construct. Methods: In this study, a CAR was constructed based on a nanobody against PSMA (NBPII-CAR). At first, Jurkat cells were electroporated with NBPII-CAR, and then flow cytometry was performed for NBPII-CAR expression. For functional analysis, CAR T cells were co-cultured with prostate cancer cells and analyzed for IL-2 secretion, CD25 expression, and cell proliferation. Results: Flow cytometry results confirmed the expression of NBPII-CAR on the transfected Jurkat cells. Our data showed the specificity of engineered Jurkat cells against prostate cancer cells by not only increasing the IL-2 cytokine (about 370 pg/ml) but also expressing the T-cell activation marker CD25 (about 30%). In addition, proliferation of engineered Jurkat cells increased nearly 60% when co-cultured with LNCaP (PSMA +), as compared with DU145 (PSMA-). Conclusion: Here, we describe the ability of nanobody-based CAR to recognize PSMA that leads to the activation of Jurkat cells. This construct might be used as a promising candidate for clinical applications in prostate cancer therapy.