BACKGROUND: Peripheral helper T (T PH ) cells are uniquely positioned within pathologically inflamed non-lymphoid tissues to stimulate B-cell responses and antibody production. However, the phenotype, function, and clinical relevance of T PH cells in hepatocellular carcinoma (HCC) are currently unknown. METHODS: Blood, tumor, and peritumoral liver tissue samples from 39 HCC patients (Sep 2016-Aug 2017) and 101 HCC patients (Sep 2011-Dec 2012) at the Third Affiliated Hospital of Sun Yat-sen University were used. Flow cytometry was used to quantify the expression, phenotype, and function of T PH cells. Log-rank tests were performed to evaluate disease-free survival and overall survival in samples from 39 patients and 101 patients with HCC. T PH cells, CD19 + B cells, and T follicular helper (T FH ) cells were cultured separately in vitro or isolated from C57/B6L mice in vivo for functional assays. RESULTS: T PH cells highly infiltrated tumor tissues, which was correlated with tumor size, early recurrence, and shorter survival time. The tumor-infiltrated T PH cells showed a unique ICOS hi CXCL13 + IL-21 - MAF + BCL-6 - phenotype and triggered naïve B-cell differentiation into regulatory B cells. Triggering programmed cell death protein 1 (PD-1) induced the production of C-X-C motif chemokine ligand 13 (CXCL13) by T PH cells, which then suppressed tumor-specific immunity and promoted disease progression. CONCLUSION Our study reveals a novel regulatory mechanism of T PH cell-regulatory B-cell-mediated immunosuppression and provides an important perspective for determining the balance between the differentiation of protumorigenic T PH cells and that of antitumorigenic T FH cells in the HCC microenvironment.
Carcinoma, Hepatocellular/metabolism* ; Liver Neoplasms/metabolism* ; Humans ; T-Lymphocytes, Helper-Inducer/metabolism* ; Animals ; Mice ; Male ; Female ; Mice, Inbred C57BL ; Middle Aged ; B-Lymphocytes, Regulatory/metabolism* ; Flow Cytometry ; Interleukin-21 ; Aged ; Chemokine CXCL13/metabolism*

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 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

OBJECTIVES: To investigate the efficacy of Qihuang Jianpi Zishen Granules (QJZ) for inhibiting renal B cell differentiation in MRL/lpr mice and explore its underlying mechanism. METHODS: Thirty 8-week-old female MRL/lpr mice were randomly divided into model group, QJZ group, prednisone (Pred) group, QJZ+Pred group, and AIM2 inhibitor group (n=6), with 6 8-week-old female C57BL/6 mice as the normal control group. After treatments with normal saline, QJZ, Pred, or AIM2 inhibitor for 8 weeks, the mice were examined for urinary total protein-to-creatinine ratio (TPCR) and albumin-to-creatinine ratio (ACR), serum creatinine (Cr) and blood urea nitrogen (BUN) levels, and renal histopathology (with HE, Masson, and PAS staining) and ultrastructural changes (with electron microscopy). ELISA, immunohistochemistry, immunofluorescence staining and flow cytometry were used to detect blood levels of anti-dsDNA antibodies, cytokines and chemokines, renal deposition of complement components C3 and C4, renal expressions of AIM2, CD19, CD27 and CD138, and changes in splenic B lymphocyte subsets. The effect of QJZ on the AIM2/Blimp-1/Bcl-6 signaling axis was examined using Western blotting. RESULTS: QJZ treatment significantly improved Cr, BUN, TPCR and ACR in MRL/lpr mice, ameliorated renal pathologies, reduced the expressions of ds-DNA, BAFF, IL-21, CXCL12, CXCL13, C3 and C4, and increased IL-10 levels. QJZ significantly downregulated renal expressions of the key B-cell transcription factors Blimp-1 and XBP-1, upregulated Bcl-6 and PAX5 expressions, inhibited B-cell differentiation, and lowered the expressions of AIM2, CD27, CD138 and CD69. Inhibition of AIM2 similarly reduced renal Blimp-1 and XBP-1 expressions, increased Bcl-6 and PAX5 levels, suppressed B-cell differentiation, decreased IgG production, reduced C3 and C4 deposition, and alleviated renal pathology in MRL/lpr mice. CONCLUSIONS QJZ inhibits B cell differentiation and alleviates renal damage in systemic lupus erythematosus possibly by suppressing the AIM2/Blimp-1/Bcl-6 signaling pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Mice, Inbred MRL lpr ; Female ; Mice ; Mice, Inbred C57BL ; Cell Differentiation/drug effects* ; B-Lymphocytes/drug effects* ; Proto-Oncogene Proteins c-bcl-6/metabolism* ; Kidney/drug effects* ; DNA-Binding Proteins/metabolism* ; Signal Transduction ; Lupus Nephritis

The humoral immune response of B cells is the key to the protection of specific immunity, and immune aging reshapes its production and function. The decreased B cell immune function is an indicator of immune senescence. The impaired humoral immune function mediated by antibody secreted by B cells leads to a decline in the response of elderly individuals to the vaccine. These people are therefore more susceptible to infection and deterioration, and have a higher incidence of tumors and metabolic diseases. Activation-induced cytidine deaminase (AID) is an enzyme that triggers immunoglobulin class conversion recombination (CSR) and somatic high frequency mutation (SHM). It decreases during immune senescence and is considered to be a biomarker of decreased B cell function in aging mice and humans. Understanding the inherent defects of B-cell immune senescence and the regulation mechanism of AID in the aging process can provide new research ideas for the susceptibility, prevention and treatment of diseases in the elderly.
Animals ; Humans ; Mice ; Aging/metabolism* ; B-Lymphocytes/metabolism* ; Cytidine Deaminase/metabolism* ; Somatic Hypermutation, Immunoglobulin

B cell receptor (BCR) is a key molecule involved in B cell specific recognition and the binding of antigens to produce adaptive humoral immune response. Gene rearrangement and high frequency mutation during B cell differentiation are the main mechanisms of BCR diversification. The enormous diversity and unique molecular structure of BCR determine the diversity and specificity of antigen recognition, shaping complex B cell repertoire with extensive collections of antigen specificities. Therefore, BCR antigen-specific information is vital to understanding the adaptive immune characteristics of different diseases. Our ability to connect BCR repertoire and antigen specificity has been enhanced with the development of B cell related research technologies, such as single cell sorting techniques, high-throughput sequencing (HTS), linking B cell receptor to antigen specificity through sequencing (LIBRA-seq). It could help researchers to better understand humoral immune responses, identify disease pathogenesis, monitor disease progression, design vaccines, and develop therapeutic antibodies and drugs. We summarizes recent studies on antigen-specific BCR of infections, vaccinations, autoimmune diseases and cancer. By analyzing autoantibody sequences of SLE as a case, the identification of autoantigens has become potentially possible due to this characterization.
Receptors, Antigen, B-Cell/metabolism* ; B-Lymphocytes/metabolism* ; Lymphocyte Activation ; High-Throughput Nucleotide Sequencing/methods*

Langerhans cell histiocytosis (LCH) is a rare proliferative disease dominated by the proliferation of Langerhans cells, which is inflammatory myeloid neoplasms. Its clinical manifestations are variable, occurring at any age and at any site, and it is rarer in adults than in children. The gold standard for diagnosis is histopathological biopsy. Due to the rarity of adult LCH and the heterogeneity of this disease, treatment of adult LCH should be developed according to the extent of the disease and risk stratification. With the discovery of MAPK, PI3K and c-KIT signaling pathway activation, especially BRAF V600E and MAP2K1 mutations, targeted therapy has become a hot spot for therapeutic research. Meanwhile, the discovery of high expression of M2-polarized macrophages and Foxp3⁺ regulatory T cells (Treg) in LCH has provided an important basis for the immunotherapy. In this article, we will focus on reviewing the latest research progress in the treatment of adult LCH in recent years, and provide a reference for clinical research on the treatment of adult LCH patients.
Adult ; Child ; Histiocytosis, Langerhans-Cell/therapy* ; Humans ; Mutation ; Proto-Oncogene Proteins B-raf/metabolism* ; Signal Transduction ; T-Lymphocytes, Regulatory/pathology*

Polysaccharide is among the main active components of Ganoderma lucidum for tumor prevention and treatment. Howe-ver, it remains unclear whether it has synergy with tumor immunotherapy. This study evaluated the effect of G. lucidum polysaccharides(GLP) on the infiltration of T lymphocytes into tumor and the underlying mechanism, in order to provide a reference for its application in tumor immunotherapy. GLP were prepared by water extraction and alcohol precipitation combined with Sevag method and then given(intraperitoneal injection) to the mice bearing B16-F10 cells at 25, 50 and 100 mg kg~(-1), respectively, to evaluate the effect on tumor growth. The infiltration of CD3~+ and CD8~+ T cells and the expression of intercellular cell adhesion molecule-1(ICAM-1) in tumor were detected by immunohistochemistry. EA.hy926 cells were treated with 50, 100 and 200 μg·mL~(-1) GLP, and the expression of ICAM-1 was determined by Western blot. The adhesion of EA.hy926 cells treated with GLP was measured with fluorescence-labeled Jurkat cells. To analyze the mechanism based on NF-κB pathway, this study determined the protein levels of nuclear factor kappa-B(NF-κB) p65, alpha inhibitor of NF-κB(IκBα), p-NF-κB p65 and p-IκBα by Western blot. The results showed that GLP can significantly inhibit the tumor growth in mice bearing B16-F10 cells, promote the infiltration of CD3~+ and CD8~+ T cells in tumor, and increase the expression of ICAM-1 in tumor. Meanwhile, GLP could also enhance the expression of ICAM-1 in EA.hy926 cells, thus strengthen the adhesion to Jurkat cells, induce phosphorylation and protein degradation of IκBα, and raise the expression and phosphorylation level of NF-κB p65. These results suggested that GLP could promote the expression of ICAM-1 through NF-κB pathway and further enhance the infiltration of T lymphocytes into tumor, thereby inhibiting tumor growth. This study lays a foundation for the further application of GLP in tumor immunotherapy.
Animals ; Endothelial Cells/metabolism* ; Intercellular Adhesion Molecule-1/genetics* ; Mice ; NF-kappa B/metabolism* ; Neoplasms ; Polysaccharides ; Reishi ; Signal Transduction ; T-Lymphocytes ; Tumor Necrosis Factor-alpha

OBJECTIVE: To study the correlation of the expression alteration of Tim-3 with the T cell and B cell dysfunction in peripheral blood of multiple myeloma (MM) patients. METHODS: 30 patients diagnosed as MM from October 2016 to October 2018 were selected and enrolled in MM group, and 30 healthy persons whose sex and age was matched with the MM patients were selected and enrolled in healthy control group (HC). The blood samples from MM patients and HC were collected, and the peripheral blood mononuclear cells (PBMNC) were separated by density gradient centrifugation, then the serum was kept for further study. The ratios of CD3CD4Tim-3T cells, CD3CD8Tim-3T cells and the CD19+CD20-CD38+B cells were analysed by flow cytometry (FCM)，and the concentration of T cell-related cytokines IFN-γ, TNF-αand B cell-related antibodies IgA, IgM and IgG were measured by ELISA. At the same time, the differences of the ratios of CCD3CD4Tim-3T, CD3CD8Tim-3T cells and plasmablast and the concentration of IFN-γ, TNF-α, IgA, IgM and IgG between the MM patient and HC were estimated, and the correlation of the ratio of CD3CD4Tim-3T, CD3CD8Tim-3T cells with the ratio of plasmablast and the concentration of IFN-γ, TNF-α, IgA, IgM and IgG in MM patients were analyzed. RESULTS: The ratio of CD3CD4Tim-3T, CD3CD8Tim-3T cells increased in MM patients, while the ratio of CD19+CD20- CD38+B cells and the concentration of IFN-γ, TNF-α, IgA, IgM and IgG decreased in MM patients. And there was a negative correlation of the ratio of CD3CD4Tim-3T cells with CD19+CD20-CD38+B cells and the concentration of IFN-γ, IgA, IgM and IgG in MM patients, while the ratio of CD3CD8Tim-3T cells just negatively correlated with the concentration of TNF-α. CONCLUSION Expression of Tim-3 on CD4 and CD8 cells elevates in the peripheral blood of MM patients, which also correlates with the function suppression of T and B cells.
B-Lymphocytes ; CD8-Positive T-Lymphocytes ; Hepatitis A Virus Cellular Receptor 2 ; metabolism ; Humans ; Leukocytes, Mononuclear ; Multiple Myeloma