B and T lymphocyte attenuator (BTLA) is an inhibitory immune checkpoint, which typically interacts with herpesvirus entry mediator (HVEM) and plays a crucial role in regulating immune balance. BTLA interacts with its ligand HVEM in a cis manner on the surface of the same immune cell to maintain immune tolerance, while trans interactions on the surface of different immune cells mediate immunosuppressive effects. Dysregulation of the BTLA/HVEM axis can impair the functions of immune cells, particularly T lymphocytes, promoting immune escape of tumor cells and ultimately leading to tumor progression. Researchers have found that BTLA and HVEM are abnormally expressed in various tumors and are associated with prognosis, suggesting that they may be potential targets for tumor immunotherapy. This review summarizes the molecular structures of BTLA and HVEM, immunomodulatory mechanisms, recent advances in hematologic malignancies, potential inhibitors of BTLA/HVEM interaction, and their applications in immunotherapy for hematologic malignancies.
Humans ; Receptors, Tumor Necrosis Factor, Member 14/chemistry* ; Receptors, Immunologic/immunology* ; Hematologic Neoplasms/genetics* ; Immunotherapy/methods* ; Animals

OBJECTIVE: To investigate the expression of co-inhibitory molecules TIGIT/CD155 and PD-1 on CD4⁺T cells and Treg cells in peripheral blood of patients with chronic lymphocytic leukemia (CLL) and analyze their clinical significance. METHODS: The expression of PD-1 and TIGIT on CD4⁺T cells and Treg cells was detected by flow cytometry in 40 CLL patients and 20 healthy controls. Additionally, the expression of CD155 on peripheral blood B cells and DC cells of the enrolled subjects was detected. RESULTS: The proportions of PD-1⁺TIGIT⁺CD4⁺T cells, PD-1⁺TIGIT⁺Treg cells and CD155⁺DC cells in peripheral blood of CLL patients were significantly higher than those of healthy controls ( P < 0.05). The proportions of PD-1⁺TIGIT⁺CD4⁺T cells and PD-1⁺TIGIT⁺Treg cells in CLL patients were significantly higher than those of PD-1⁺TIGIT^-CD4⁺T cells and PD-1⁺TIGIT^-Treg cells, respectively ( P < 0.05). Both PD-1⁺TIGIT⁺CD4⁺T cells and PD-1⁺TIGIT⁺Treg cells were positively correlated with the level of CD155⁺DC cells (r =0.742, r =0.766). With the progression of Binet stage, the proportions of PD-1⁺TIGIT⁺CD4⁺T cells, PD-1⁺TIGIT⁺Treg cells, and CD155⁺DC cells gradually increased ( P < 0.05), and the aforementioned three types cells were all increased in patients with CD38≥30%, IGVH unmutated, or poor prognosis due to chromosomal abnormalities ( P < 0.05). CONCLUSION Co-inhibitory molecules PD-1 and TIGIT may be involved in immunodepletion in patients with advanced CLL, which has clinical prognostic value. Dual inhibitor molecular targeted therapy provides a new direction for the individualized treatment of CLL.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; Receptors, Immunologic/metabolism* ; Programmed Cell Death 1 Receptor/metabolism* ; T-Lymphocytes, Regulatory/metabolism* ; Receptors, Virus/metabolism* ; CD4-Positive T-Lymphocytes/metabolism* ; Male ; Female ; Middle Aged ; Flow Cytometry ; Clinical Relevance

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

BACKGROUND: T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domains (TIGIT), an inhibitory receptor expressed on T cells, plays a dysfunctional role in antiviral infection and antitumor activity. However, it is unknown whether TIGIT expression on T cells influences the immunological effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccines. METHODS: Forty-five people living with HIV (PLWH) on antiretroviral therapy (ART) for more than two years and 31 healthy controls (HCs), all received a third dose of a SARS-CoV-2 inactivated vaccine, were enrolled in this study. The amounts, activation, proportion of cell subsets, and magnitude of the SARS-CoV-2-specific immune response of TIGIT + CD4 + and TIGIT + CD8 + T cells were investigated before the third dose but 6 months after the second vaccine dose (0W), 4 weeks (4W) and 12 weeks (12W) after the third dose. RESULTS: Compared to that in HCs, the frequency of TIGIT + CD8 + T cells in the peripheral blood of PLWH increased at 12W after the third dose of the inactivated vaccine, and the immune activation of TIGIT + CD8 + T cells also increased. A decrease in the ratio of both T naïve (T N ) and central memory (T CM ) cells among TIGIT + CD8 + T cells and an increase in the ratio of the effector memory (T EM ) subpopulation were observed at 12W in PLWH. Interestingly, particularly at 12W, a higher proportion of TIGIT + CD8 + T cells expressing CD137 and CD69 simultaneously was observed in HCs than in PLWH based on the activation-induced marker assay. Compared with 0W, SARS-CoV-2-specific TIGIT + CD8 + T-cell responses in PLWH were not enhanced at 12W but were enhanced in HCs. Additionally, at all time points, the SARS-CoV-2-specific responses of TIGIT + CD8 + T cells in PLWH were significantly weaker than those of TIGIT - CD8 + T cells. However, in HCs, the difference in the SARS-CoV-2-specific responses induced between TIGIT + CD8 + T cells and TIGIT - CD8 + T cells was insignificant at 4W and 12W, except at 0W. CONCLUSIONS TIGIT expression on CD8 + T cells may hinder the T-cell immune response to a booster dose of an inactivated SARS-CoV-2 vaccine, suggesting weakened resistance to SARS-CoV-2 infection, especially in PLWH. Furthermore, TIGIT may be used as a potential target to increase the production of SARS-CoV-2-specific CD8 + T cells, thereby enhancing the effectiveness of vaccination.
Humans ; Antibodies, Viral ; CD8-Positive T-Lymphocytes ; COVID-19/complications* ; COVID-19 Vaccines/immunology* ; HIV Infections/complications* ; Receptors, Immunologic ; SARS-CoV-2

The activation mechanism of chimeric antigen receptor (CAR)-engineered T cells may differ substantially from T cells carrying native T cell receptor, but this difference remains poorly understood. We present the first comprehensive portrait of single-cell level transcriptional and cytokine signatures of anti-CD19/4-1BB/CD28/CD3ζ CAR-T cells upon antigen-specific stimulation. Both CD4 helper T (T) cells and CD8 cytotoxic CAR-T cells are equally effective in directly killing target tumor cells and their cytotoxic activity is associated with the elevation of a range of T1 and T2 signature cytokines, e.g., interferon γ, tumor necrotic factor α, interleukin 5 (IL5), and IL13, as confirmed by the expression of master transcription factor genes TBX21 and GATA3. However, rather than conforming to stringent T1 or T2 subtypes, single-cell analysis reveals that the predominant response is a highly mixed T1/T2 function in the same cell. The regulatory T cell activity, although observed in a small fraction of activated cells, emerges from this hybrid T1/T2 population. Granulocyte-macrophage colony stimulating factor (GM-CSF) is produced from the majority of cells regardless of the polarization states, further contrasting CAR-T to classic T cells. Surprisingly, the cytokine response is minimally associated with differentiation status, although all major differentiation subsets such as naïve, central memory, effector memory, and effector are detected. All these suggest that the activation of CAR-engineered T cells is a canonical process that leads to a highly mixed response combining both type 1 and type 2 cytokines together with GM-CSF, supporting the notion that polyfunctional CAR-T cells correlate with objective response of patients in clinical trials. This work provides new insights into the mechanism of CAR activation and implies the necessity for cellular function assays to characterize the quality of CAR-T infusion products and monitor therapeutic responses in patients.
Antigens ; metabolism ; CTLA-4 Antigen ; metabolism ; Cell Differentiation ; drug effects ; Cell Line ; Cytokines ; metabolism ; Cytotoxicity, Immunologic ; drug effects ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Lymphocyte Activation ; drug effects ; immunology ; Lymphocyte Subsets ; drug effects ; metabolism ; Phenotype ; Proteomics ; Receptors, Chimeric Antigen ; metabolism ; Single-Cell Analysis ; methods ; T-Lymphocytes, Regulatory ; drug effects ; metabolism ; Th1 Cells ; cytology ; drug effects ; Th2 Cells ; cytology ; drug effects ; Transcription, Genetic ; drug effects ; Up-Regulation ; drug effects

Cytokine-activated T cells (CATs) can be easily expanded and are widely applied to cancer immunotherapy. However, the good efficacy of CATs is rarely reported in clinical applications because CATs have no or very low antigen specificity. The low-efficacy problem can be resolved using T cell antigen receptor-engineered CAT (TCR-CAT). Herein, we demonstrate that NY-ESO-1 HLA-A*02:01-specific high-affinity TCR (HAT)-transduced CATs can specifically kill cancer cells with good efficacy. With low micromolar range dissociation equilibrium constants, HAT-transduced CATs showed good specificity with no off-target killing. Furthermore, the high-affinity TCR-CATs delivered significantly better activation and cytotoxicity than the equivalent TCR-engineered T cells (TCR-Ts) in terms of interferon-γ and granzyme B production and in vitro cancer cell killing ability. TCR-CAT may be a very good alternative to the expensive TCR-T, which is considered an effective personalized cyto-immunotherapy.
Cell Line, Tumor ; Cytokines ; metabolism ; Cytotoxicity, Immunologic ; Genetic Engineering ; HLA-A2 Antigen ; metabolism ; Humans ; Immunotherapy, Adoptive ; methods ; Lymphocyte Activation ; Receptors, Antigen, T-Cell ; genetics ; immunology ; T-Lymphocytes ; immunology

Objective To investigate the expression and regulation of programmed cell death protein 1 (PD1), B lymphocyte and T lymphocyte attenuator (BTLA) in peripheral blood of patients with non-small cell lung cancer (NSCLC); to examine the correlation of the mRNA levels between PD and BTLA in NSCLC. Methods Flow cytometry was used to detect the expression of PD1 and BTLA on the surfaces of CD8⁺ T cells and γδ⁺ T cells in the peripheral blood samples collected from 32 in-patients with stage IV NSCLC and 30 healthy individuals. We compared the expression of PD1 and BTLA on the surfaces of γδ⁺ T cells in the NSCLC patients with bone metastasis before and after the treatment of zoledronic acid. The correlations of PD1 and BTLA, as well as their ligands were analyzed using Pearson correlation analysis with the cBioPortal data platform. Results The frequency of PD1 on the surfaces of CD8⁺ T cells was significantly higher than that of the γδT cells in both healthy controls (t=2.324, P=0.024) and NSCLC patients（t=2.498, P=0.015). The frequency of PD1 on CD8⁺ T cells, rather than on γδ⁺ T cells, was significantly upregulated in advanced NSCLC patients compared with that in healthy controls (t=4.829, P<0.001). The PD1⁺ BTLA⁺γδT cells of the healthy controls were significantly lower than that of the NSCLC patients (t=2.422, P=0.0185). No differences in percentage of PD1⁺γδ⁺ and BTLA⁺γδ⁺ T cells were observed in 7 NSCLC patients with bone metastasis before and after zoledronic acid treatment. PD1 was positively correlated with BTLA in both lung adenocarcinoma (r=0.54; P<0.05) and lung squamous cell carcinoma (r=0.78; P<0.05). Conclusions The upregulation of co-inhibitory molecules occurs on the surfaces of both CD8⁺ T cells and γδT cells in advanced NSCLC, suggesting that these molecules were involved in regulating the inactivation of CD8⁺ T cells and γδ⁺ T cells, immune escape and tumor invasion.
Bone Neoplasms/secondary* ; CD8-Positive T-Lymphocytes ; Carcinoma, Non-Small-Cell Lung/immunology* ; Case-Control Studies ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Ligands ; Lung Neoplasms/immunology* ; Lymphocyte Subsets/immunology* ; Male ; Middle Aged ; Programmed Cell Death 1 Receptor/metabolism* ; RNA, Messenger/metabolism* ; Receptors, Antigen, T-Cell, gamma-delta ; Receptors, Immunologic/metabolism*

OBJECTIVE: To identify differentially expressed genes in peripheral blood mononuclear cells between patients with continuous mild-to-moderate asthma and healthy controls using mRNA microarray in order to explore the underlying signaling pathways and clarify the roles of CD4+ T cells in the pathogenesis of asthma. METHODS: Global transcriptomic profiles of the CD4+ T cells were defined by using Agilent Sure Print G3 Human GE 8×60K microarray. Enrichment pathways were analyzed with Ingenuity Pathway Analysis (IPA) software. RESULTS: Compared with controls, 805 genes were up-regulated, 192 were down-regulated in asthma patients. Among these, the expression of 38 annotated genes have varied by 4 times or more. Expression of CD300A was inversely proportional to the absolute value of eosinophils (r=-0.89, P=0.02) as well as the proportion of eosinophils (r=-0.94, P=0.004), while CSF1R was inversely proportional to PD20 (r=-0.83, P=0.04) and AQLQ (r=-0.88, P=0.02) by correlation analysis. CONCLUSION Numerous pathophysiological pathways may be involved in the pathogenesis of asthma. Above findings have provided a basis for the delineation the pathogenesis of asthma.
Antigens, CD ; genetics ; Asthma ; immunology ; CD4-Positive T-Lymphocytes ; cytology ; Case-Control Studies ; Eosinophils ; Gene Expression Profiling ; Humans ; Leukocytes, Mononuclear ; Oligonucleotide Array Sequence Analysis ; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; Receptors, Immunologic ; genetics ; Transcriptome

Novel biologics that redirect cytotoxic T lymphocytes (CTLs) to kill tumor cells bearing a tumor associated antigen hold great promise in the clinic. However, the ability to safely and potently target CD3 on CTL toward tumor associated antigens (TAA) expressed on tumor cells remains a challenge of both technology and biology. Herein we describe the use of a Half DVD-Ig format that can redirect CTL to kill tumor cells. Notably, Half DVD-Ig molecules that are monovalent for each specificity demonstrated reduced non-specific CTL activation and conditional CTL activation upon binding to TAA compared to intact tetravalent DVD-Ig molecules that are bivalent for each specificity, while maintaining good drug like properties and appropriate PK properties.
Animals ; Antibodies, Bispecific ; immunology ; Antibodies, Monoclonal ; immunology ; pharmacokinetics ; CD3 Complex ; metabolism ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; ErbB Receptors ; metabolism ; Female ; Humans ; Lymphocyte Activation ; immunology ; Mice, SCID ; Neoplasms ; immunology ; pathology ; Rats, Sprague-Dawley ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo investigate the effect of triggering receptor expressed on myeloid cells 2 (TREM-2) overexpression on airway inflammation and remodeling in mice with asthma.

METHODSA total of 40 BALB/c mice were randomly divided into normal control, asthma, empty vector, and TREM-2 overexpression groups (n=10 each). Ovalbumin (OVA) sensitization and challenge were performed to establish the model of asthma. The mice in the control group were given normal saline, and those in the empty vector and TREM-2 overexpression groups were transfected with adenovirus vector and TREM-2 adenovirus, respectively. RT-PCR and Western blot were used to measure the expression of TREM-2, MMP-2, MMP-9, ADAM33, and ADAM8. Bronchoalveolar lavage fluid (BALF) was collected to perform cell counting and classification. ELISA was used to measure the total serum level of IgE and the levels of cytokines in BALF.

RESULTSCompared with the control group, the asthma group showed significant reductions in the mRNA and protein expression of TREM-2 (P<0.05), a significantly increased level of Th2 cytokine (P<0.05), and significantly increased numbers of total cells and classified cells. Compared with the asthma group, the TREM-2 overexpression group showed a significantly reduced level of Th2 cytokine (P<0.05), a significantly reduced level of IgE (P<0.05), and significantly reduced numbers of total cells and classified cells (P<0.05), as well as significantly downregulated expression of the inflammatory factors and growth factors MMP-2, MMP-9, TGF-β1, ADAM8, and ADAM33 (P<0.05).

CONCLUSIONSTREM-2 overexpression significantly alleviates airway inflammation and airway remodeling in mice with asthma and may become a potential target for the prevention and treatment of childhood asthma.

Airway Remodeling ; Animals ; Asthma ; etiology ; immunology ; Cytokines ; analysis ; Female ; Membrane Glycoproteins ; genetics ; physiology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; immunology ; RNA, Messenger ; analysis ; Receptors, Immunologic ; genetics ; physiology