Hepatitis B virus (HBV)-specific CD8⁺ T cells play a central role in controlling HBV infection; however, their function is impaired during chronic HBV infection, manifesting as a state of dysfunction. Recent studies have revealed that CD8⁺ T cell dysfunction in chronic HBV infection differs from the classical exhaustion observed in other viral infections or tumors. In 2024, several pivotal studies further elucidated novel mechanisms underlying CD8⁺ T cell dysfunction in chronic HBV infection and identified new therapeutic targets, including 4-1BB and transforming growth factor-beta (TGF-β). This review, while elucidating the dysfunction of CD8⁺ T cells in chronic HBV infection and its underlying mechanisms, focuses on summarizing the key findings from these latest studies and explores their translational value and clinical significance.
Humans ; Hepatitis B, Chronic/virology* ; CD8-Positive T-Lymphocytes/immunology* ; Hepatitis B virus/physiology* ; Animals ; Transforming Growth Factor beta/immunology*

Objective To investigate the differences of type 2 innate lymphocytes (ILC2) and interlukin 9 (IL-9) between chronic lymphocytic leukemia (CLL) patients and healthy controls, and to understand the effects of ILC2 on the function of regulatory T cells (Tregs), CD8⁺ T cells and CLL cells through IL-9. Methods Flow cytometry was used to detect the levels of ILC2 and Tregs in the peripheral blood of 45 newly diagnosed CLL patients and 24 healthy controls, and the expressions of granzyme B and perforin in CD8⁺ T cells in the peripheral blood of 28 patients and 15 healthy controls; ELISA was used to detect the level of IL-9 in the serum. ILC2 of patients and healthy controls was sorted by immunomagnetic beads and cultured separately, and the level of IL-9 in the culture supernatant was measured by ELISA. ILC2 sorted from CLL patients and healthy control-derived peripheral blood mononuclear cells(PBMCs) were co-cultured with the B cell leukemia MEC-1 cells, one group was supplemented with IL-9 antibody and the other group was not. After 72 hours of culture, the ratio of Tregs, programmed death 1 (PD-1), T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT), cytotoxic T lymphocyte antigen 4 (CTLA-4) on Tregs, granzyme B and perforin in CD8⁺ T cells were measured by flow cytometry, IL-9 level of the culture supernatant was measured by ELISA, the apoptosis of MEC-1 cells was measured by Annexin V-PI. Results Compared with the healthy control group, the levels of ILC2, Tregs and IL-9 in the CLL group increased significantly. The levels of granzyme B and perforin in CD8⁺ T cells were positively correlated in the peripheral blood of CLL patients. Compared with the healthy control group, IL-9 levels in the supernatant of sorted ILC2 from CLL patients increased. In the anti-IL9 antibody group, the level of PD-1 and TIGIT on Tregs decreased, and the level of granzyme B in CD8⁺ T cells increased significantly. The level of IL-9 in the anti-IL9 antibody group decreased statistically. And MEC-1 cells showed increased early apoptotic rate in the anti-IL9 antibody group statistically. Conclusion In CLL, ILC2 affects CD8⁺ T cells and Tregs through IL-9, which weakens the anti-tumor effect of CD8⁺ T cells, enhances the immunosuppressive effect of Tregs, and plays a role in the occurrence and development of CLL disease.
Humans ; Leukemia, Lymphocytic, Chronic, B-Cell/immunology* ; CD8-Positive T-Lymphocytes/immunology* ; T-Lymphocytes, Regulatory/immunology* ; Middle Aged ; Male ; Female ; Interleukin-9/blood* ; Aged ; Granzymes/metabolism* ; Perforin/metabolism* ; Immunity, Innate ; Adult ; Lymphocytes/immunology*

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

OBJECTIVE: To investigate the correlation between the types and quantities of immune cells in the graft and early immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their influence on clinical prognosis. METHODS: The clinical data of 83 patients with hematological diseases who received allo-HSCT in Shanxi Bethune Hospital from September 2020 to June 2023 were retrospectively analyzed. The number of mononuclear cells (MNC), CD34⁺ cells and lymphocyte subsets (including CD3⁺T, CD3⁺CD4⁺T(Th), CD3⁺CD8⁺T(Ts), NK cells and B cells) infused into the recipients was counted, and the peripheral blood lymphocytes were detected before conditioning and on days 14, 30, 60 and 100 post-HSCT. RESULTS: Multivariate analysis showed that the number of MNC in the graft affected the recovery of CD4⁺T lymphocytes after HSCT, and the number of CD4⁺T lymphocytes in the graft affected the recovery of NK cells and B cells after HSCT. The patient age, donor sex, stem cell source, degree of HLA matching, use of ATG before HSCT, the occurrence of acute graft-versus-host disease (aGVHD) after HSCT, and viral infection all affect the early cellular immune reconstitution post-HSCT. The number of infused cells had no significant impact on the median engraftment time for neutrophils and platelets after HSCT. Patients with lower numbers of CD3⁺T, CD4⁺T and B cells in the graft were more prone to viral infection after HSCT. However, the cells in the graft had no significant effect on disease recurrence or mortality. CONCLUSION The recovery rate of lymphocyte count after allo-HSCT varies. The numbers of MNC and CD4⁺T cells in the graft may be related to the cellular immune reconstitution after HSCT, while the numbers of CD34⁺,CD3⁺T,CD8⁺T,NK and B cells have no significant effect on the cellular immune reconstruction. The numbers of CD3⁺T,CD4⁺T and B cells in the graft were negatively correlated with viral infection after HSCT, but the cellular components of the graft have no obvious influence on hematopoietic reconstitution, disease recurrence, death, recurrence-free survival(RFS) and overall survival(OS) after HSCT.
Humans ; Hematopoietic Stem Cell Transplantation ; Immune Reconstitution ; Transplantation, Homologous ; Retrospective Studies ; Graft vs Host Disease/immunology* ; Male ; Female ; Killer Cells, Natural/immunology* ; Adult ; Middle Aged ; B-Lymphocytes/immunology* ; Prognosis ; Lymphocyte Subsets/immunology* ; Adolescent

OBJECTIVE: To explore the role of semaphorin 4D (Sema4D) in immunoglobulin A (IgA) -mediated immune abnormalities in B lymphocytes of pediatric Henoch-Schonlein purpura (HSP). METHODS: One hundred HSP children admitted to Hengshui People's Hospital from January 2022 to January 2023 were selected as HSP group, and one hundred healthy children as control group. Sema4D expression was detected, and the relationship between Sema4D expression in children's serum and skin lesions and clinical characteristics of children was analyzed. Sema4D expression on the surface of lymphocytes of HSP children was detected. Different concentrations of human recombinant Sema4D protein was used to stimulate peripheral blood mononuclear cells in HSP children in vitro. The expression level of IgA in the supernatant was detected to verify whether Sema4D mediates immune abnormalities through IgA secreted by B lymphocytes. RESULTS: The Sema4D level in the HSP group was significantly higher than that in the control group (P <0.001). Sema4D level in HSP children with severe, renal involvement, and joint involvement was higher than those with mild to moderate disease, and no renal or joint involvement (all P <0.001). Compared with control group, IgA level, CD8 ⁺ T lymphocyte proportion, and CD19 ⁺ B lymphocyte proportion in the HSP group were significantly higher but CD4 ⁺ T lymphocyte proportion was lower (all P <0.001). The expression levels of Sema4D on the surface of CD4 ⁺ T lymphocytes, CD8 ⁺ T lymphocytes, and CD19 ⁺ B lymphocytes in the HSP group were significantly higher than those in the control group (all P <0.001). With the increase of human recombinant Sema4D protein concentration, the level of IgA expression in HSP children gradually increased (P <0.05). Correlation analysis showed that Sema4D was significantly positively correlated with IgA (r =0.667). CONCLUSION HSP children show high expression of Sema4D, especially on the surface of T and B lymphocytes. The shedding of Sema4D from membrane surface may stimulate B lymphocytes to secrete IgA by binding to CD72, leading to immune abnormalities.
Humans ; IgA Vasculitis/immunology* ; Semaphorins/metabolism* ; B-Lymphocytes/metabolism* ; Immunoglobulin A/immunology* ; Child ; Antigens, CD/metabolism* ; Male ; Female ; Child, Preschool

B lymphocytes (B cells) play a complex and paradoxical role in tumorigenesis. They can recognize tumor-associated antigens, present these antigens to T cells, and produce antibodies that directly target and eliminate tumor cells. This makes B cells a potentially powerful ally in combating cancer. However, B cells also exhibit immunosuppressive functions, secreting cytokines like IL-10 or generating tumor-promoting antibodies that dampen the anti-tumor immune response, and some tumor cells have even been shown to exploit B cells to promote their growth and metastasis. This dual nature of B cells presents both opportunities and challenges for tumor immunotherapy. In this review, we summarize the mechanisms underlying the multifaceted functions of B cells and their current applications in cancer immunotherapy. Furthermore, we also explore the key issues and future directions in this field, emphasizing the need for further research to fully harness the anti-tumor potential of B cells in the fight against cancer.
Humans ; B-Lymphocytes/immunology* ; Neoplasms/therapy* ; Carcinogenesis/immunology* ; Immunotherapy/methods* ; Animals

Systemic lupus erythematosus (SLE) is a diffuse, systemic autoimmune disorder that can impact multiple organs and systems, with patients exhibiting abnormal levels of various autoantibodies and immune markers in their serum. It is currently understood that dysregulation of B cells activation plays a pivotal role in the pathogenesis of SLE, as aberrantly activated B cells produce autoantibodies that inflict damage on multiple organs through complement activation and antibody-dependent cell-mediated cyto-toxicity. Traditional therapies for SLE may prove ineffective for certain patients or lead to adverse reactions. In most instances, conventional treatment merely alleviates symptoms and necessitates lifelong immunotherapy. A limited number of clinical cases have explored chimeric antigen receptor T cells (CAR-T) therapy as a potential treatment for autoimmune diseases such as SLE. Research indicates that CAR-T can specifically target CD19 expressed on the surface of B cells and plasma cells, achieving profound depletion while minimizing drug-related side effects. This report details a female patient diagnosed with SLE and lupus nephritis who was successfully treated using dual-targeting B cells maturation antigen CAR-T by our research team; following treatment, she ceased steroid and immunomodulator use, attaining sustained remission without these medications. The patient was a 23-year-old female. Multiple examinations in other hospitals and in our hospital showed positive anti-double-stranded DNA (dsDNA) antibody and low complement C3. Renal biopsy in our hospital showed lupus nephritis Ⅳ-G (A/C), and National Institutes of Health (NIH) activity index (AI) score=4. She was diagnosed with "SLE, lupus nephritis (LN)". She was treated with hormones, immunosuppressants and Chinese medicine, but the effect was not good. After the CAR-T treatment, She stopped using hormones and immune agents and achieved continuous remission with zero hormones and zero immune agents. She became pregnant six months after CAR-T infusion, and gave birth to a healthy full-term, full-weight baby successfully. She is the first patient in China who successfully discontinued hormone, immune preparations and gave birth after CAR-T therapy. During the follow-up of the patient, we found that the immune indexes had basically returned to normal, and the safety was good. It indicates that CAR-T therapy may represent a promising and innovative therapeutic approach for the management of SLE. This offers hope and establishes a precedent for SLE women of childbearing age.
Female ; Humans ; Pregnancy ; B-Lymphocytes/immunology* ; Immunotherapy, Adoptive/methods* ; Lupus Erythematosus, Systemic/therapy* ; Lupus Nephritis/immunology* ; Receptors, Chimeric Antigen/therapeutic use* ; Young Adult

Hepatitis B is a global public health concern. Inducing hepatitis B surface antibody (HBsAb) through vaccination is a crucial preventive strategy. However, individuals show varying immune responses to the hepatitis B vaccine. Based on HBsAb levels, individuals can be categorized as high responders, low responders, or non-responders. T cells and their subsets play critical roles in modulating this response, and the composition of the T cell receptor (TCR) repertoire also influences immune responsiveness. Investigating the characteristics of T cells, their subsets, and TCR repertoires in individuals with differential responses post-vaccination may provide theoretical guidance for optimizing vaccine design and immunization strategies.
Humans ; Hepatitis B Vaccines/immunology* ; Hepatitis B/immunology* ; Vaccination ; Hepatitis B Antibodies/blood* ; T-Lymphocytes/immunology* ; Receptors, Antigen, T-Cell/immunology* ; Hepatitis B Surface Antigens/immunology* ; T-Lymphocyte Subsets/immunology*

Antibodies, Neutralizing ; Antibodies, Viral/isolation & purification* ; B-Lymphocytes/virology* ; COVID-19/virology* ; Humans ; Immunity/genetics* ; RNA, Viral/immunology* ; SARS-CoV-2/pathogenicity* ; Single-Cell Analysis

Multiple myeloma (MM), considered an incurable hematological malignancy, is characterized by its clonal evolution of malignant plasma cells. Although the application of autologous stem cell transplantation (ASCT) and the introduction of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs) have doubled the median overall survival to eight years, relapsed and refractory diseases are still frequent events in the course of MM. To achieve a durable and deep remission, immunotherapy modalities have been developed for relapsed/refractory multiple myeloma (RRMM). Among these approaches, chimeric antigen receptor (CAR) T-cell therapy is the most promising star, based on the results of previous success in B-cell neoplasms. In this immunotherapy, autologous T cells are engineered to express an artificial receptor which targets a tumor-associated antigen and initiates the T-cell killing procedure. Tisagenlecleucel and Axicabtagene, targeting the CD19 antigen, are the two pacesetters of CAR T-cell products. They were approved by the US Food and Drug Administration (FDA) in 2017 for the treatment of acute lymphocytic leukemia (ALL) and diffuse large B-cell lymphoma (DLBCL). Their development enabled unparalleled efficacy in combating hematopoietic neoplasms. In this review article, we summarize six promising candidate antigens in MM that can be targeted by CARs and discuss some noteworthy studies of the safety profile of current CAR T-cell therapy.
ADP-ribosyl Cyclase 1/immunology* ; B-Cell Maturation Antigen/immunology* ; Humans ; Immunotherapy, Adoptive/methods* ; Multiple Myeloma/therapy* ; Receptors, Chimeric Antigen/immunology* ; Receptors, G-Protein-Coupled/immunology* ; Signaling Lymphocytic Activation Molecule Family/immunology* ; Syndecan-1/immunology* ; T-Lymphocytes/immunology*