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 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

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*

Myasthenia gravis (MG) is a prototypical antibody-mediated neurological autoimmune disease with the involvement of humoral immune responses in its pathogenesis. T follicular helper (Tfh) cells have been implicated in many autoimmune diseases. However, whether and how Tfh cells are involved in MG remain unclear. Here, we established and studied a widely-used and approved animal model of human MG, the rat model with acetylcholine receptor alpha (AChRα) subunit (R-AChR)-induced experimental autoimmune myasthenia gravis (EAMG). This model presented mild body-weight loss 10 days after the first immunization (representing the early stage of disease) and more obvious clinical manifestations and body-weight loss 7 days after the second immunization (representing the late stage of disease). AChR-specific pre-Tfh cells and mature Tfh cells were detected in these two stages, respectively. In co-cultures of Tfh cells and B cells, the number of IgG2b-secreting B cells and the level of anti-AChR antibodies in the supernatant were higher in the cultures containing EAMG-derived Tfh cells. In immunohistochemistry and immunofluorescence assays, a substantial number of CD4/Bcl-6 T cells and a greater number of larger germinal centers were observed in lymph node tissues resected from EAMG rats. Based on these results, we hypothesize that an AChR-specific Tfh cell-mediated humoral immune response contributes to the development of EAMG.
Animals ; B-Lymphocytes ; immunology ; Disease Models, Animal ; Female ; Immunity, Humoral ; Lymph Nodes ; immunology ; Myasthenia Gravis, Autoimmune, Experimental ; immunology ; Protein Subunits ; immunology ; Proto-Oncogene Proteins c-bcl-6 ; immunology ; Rats, Inbred Lew ; Receptor Cross-Talk ; Receptors, Cholinergic ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology

Progressive multifocal leukoencephalopathy (PML) is a rare and lethal central nervous demyelinating disease caused by JC polyomavirus (JCV), particularly in patients with impaired immune system. The variation of JCV plays an important role in the pathogenesis of PML, including the recombination of non-coding regulatory region (NCCR), which is closely related to binding sites of transcription factors and affect the level of gene transcription. Nucleotide mutations in VP1 region determine the antigenicity and receptor specificity of JCV, play an important role in cell adsorption, immune-mediation and pathogenicity. In addition, immune cells are also involved in the pathogenesis of PML. T lymphocytes can recognize virus antigens, clear JCV, which are directly related to the prognosis of PML. B lymphocytes can serve as latent sites of JCV, and participate in viral transmission, replication, and coordination of the expression of transcription factors. This paper summarizes the roles of JCV variation and immune cells in pathogenesis of PML.
B-Lymphocytes ; immunology ; virology ; Capsid Proteins ; genetics ; immunology ; Humans ; JC Virus ; immunology ; Leukoencephalopathy, Progressive Multifocal ; pathology ; virology ; Mutation ; T-Lymphocytes ; immunology ; virology

<b>OBJECTIVEb>Aging is associated with the development of diseases because of immunosuppression and altered functioning of the neuroendocrine system. The medicinal properties of Morinda citrifolia L. have been widely exploited for the treatment of age-associated diseases. This study aims to investigate the in vitro and in vivo effects of noni (M. citrifolia) fruit juice (NFJ) on neuro-immunomodulation in the lymph node lymphocytes of F344 rats.

<b>METHODSb>Lymphocytes isolated from axillary and inguinal lymph nodes of young (3-4 months) and old (18-21 months) rats were treated in vitro with different concentrations (0.0001%, 0.01%, and 1%) of NFJ for a period of 24 h. In the in vivo study, old (16-17 months) male F344 rats were treated with 5 mL/kg body weight of 5%, 10% and 20% of NFJ, twice a day, by oral gavage, and lymph node lymphocytes were isolated after 60 d. Concanavalin A (Con A)-induced lymphocyte proliferation, interleukin-2 (IL-2) and interferon-γ (IFN-γ) production and expression of intracellular markers, such as phospho-extracellular signal-regulated kinase (p-ERK1/2), phospho-cAMP response element-binding protein, phospho-protein kinase B (p-Akt), phospho-tyrosine hydroxylase (p-TH), phospho-nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor-α (p-IκB-α) and phospho-nuclear factor-κB (p-NF-κB p65 and p50) were examined in the lymphocytes of lymph nodes.

<b>RESULTSb>NFJ increased Con A-induced lymphocyte proliferation, IL-2 and IFN-γ production, and p-ERK1/2 expression both in vitro and in vivo. In in vivo NFJ-treated old rats, lymph node lymphocytes showed increased expression of p-TH and Akt, nitric oxide production and decreased expression of p-NF-κB p65 and p50.

<b>CONCLUSIONb>These results suggest that the immunostimulatory properties of NFJ are facilitated through intracellular signaling pathways involving ERK1/2, Akt and NF-κB.

Adjuvants, Immunologic ; metabolism ; Aging ; immunology ; metabolism ; Animals ; Cell Proliferation ; Fruit ; chemistry ; metabolism ; Fruit and Vegetable Juices ; analysis ; Humans ; Interleukin-2 ; immunology ; Lymph Nodes ; cytology ; immunology ; Lymphocytes ; cytology ; immunology ; Male ; Morinda ; chemistry ; metabolism ; NF-kappa B ; immunology ; Plant Preparations ; metabolism ; Rats ; Rats, Inbred F344 ; Transcription Factor RelA ; immunology