Central memory T (Tcm) cells are a crucial subset in T cell development, playing an important role in long-term immune responses. Tcm cells exhibit strong proliferative capacity, long-term survival characteristics, and re-activation potential, enabling them to rapidly differentiate into effector T cells (Teff) upon antigen re-exposure, thus providing robust immune protection. The function of Tcm cells is regulated by various factors, including antigen exposure, cytokines, and metabolic conditions. A deeper understanding of their metabolic and epigenetic mechanisms under different pathological conditions will contribute to the development of more precise and effective immunotherapeutic strategies. This review elaborates on the origin and characteristics of Tcm cells, as well as their roles in antiviral responses, tumor immunity, and immunotherapy.
Humans ; Memory T Cells/cytology* ; Animals ; Immunologic Memory ; Neoplasms/therapy* ; Immunotherapy

Cancer immunotherapy including immune checkpoint inhibitors and adoptive cell therapy has gained revolutionary success in the treatment of hematologic tumors; however, it only gains limited success in solid tumors. For example, chimeric antigen receptor T (CAR-T) cell therapy has shown significant effects and potential for curing patients with B-cell malignancies. In contrast, it remains a challenge for CAR-T cell therapy to gain similar success in solid tumors. The anti-tumor effect of endogenous or adoptively transferred tumor-specific T cells depends largely on their differentiation status. T cells at early differentiation stage show better anti-tumor therapeutic effects than fully differentiated effector T cells. In cancer patients, the persistence of tumor-specific T cells with the stem cell memory or precursor phenotype is significantly associated with improved therapeutic outcomes; therefore, adoptively transfered CAR-T cells with stem cell memory and/or central memory is expected to gain better anti-tumor effects. Herein we focused on the in vitro optimized culture and expansion system to obtain CAR-T cells with stem cell memory or central memory phenotype for the review.
Humans ; Immunotherapy, Adoptive/methods* ; Receptors, Chimeric Antigen/genetics* ; Neoplasms/immunology* ; Immunologic Memory ; T-Lymphocytes/immunology* ; Memory T Cells/immunology* ; Animals ; Stem Cells/cytology* ; Cell Differentiation

OBJECTIVETo investigate effect of tumor-specific T cell receptor gene transfection on memory T cell differentiation in vitro.

METHODSTCRVbeta7.1 gene was transferred into peripheral blood mononuclear cells (PBMCs) obtained from healthy adults, and the expression of Vbeta7.1 was detected by flow cytometry before and after the transfection. Memory T cell differentiation was induced by stimulation with the hepatocarcinoma cell line BEL-7402 in vitro. The expression of surface molecules CD45RO, CD45RA and CCR7 was analyzed by flow cytometry to identify the phenotype and subsets of the memory T cells. Fluorescence-activated cell sorting was performed to detect the apoptosis of the tumor cells, and enzyme-linked immunoabsorbent assay was used to determine the production of interferon-gamma (IFN-gamma) for assessing the immune function of the memory T cells.

RESULTSFlow cytometry showed that TCRVbeta7.1 gene was efficiently expressed after transfection. After stimulation by the tumor cells in vitro, the expression of CD45RO in TCRVbeta7.1 gene-modified T cells increased gradually, and analysis of the coexpression of CD45RA and CCR7 revealed that the effector memory T cells constituted the majority of the differentiated memory T cells. The apoptotic rate of the tumor cells induced by the T cells increased significantly with also obviously increased INF-gamma secretion in the memory T cells.

CONCLUSIONTumor-specific TCRVbeta7.1 gene transfection can promote the differentiation of the memory T cells, the majority of which belongs to effector memory T cells that perform immune functions by inducing apoptosis and cytokine secretion.

Adult ; Apoptosis ; Carcinoma, Hepatocellular ; genetics ; metabolism ; pathology ; Cell Differentiation ; Cell Line, Tumor ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Genes, T-Cell Receptor alpha ; genetics ; Humans ; Immunologic Memory ; immunology ; Interferon-gamma ; metabolism ; Leukocyte Common Antigens ; metabolism ; Liver Neoplasms ; genetics ; metabolism ; pathology ; T-Lymphocytes ; cytology ; immunology ; metabolism ; Transfection