Programmed death 1 (PD-1) and its ligand (PD-L1) serve as crucial targets in cancer immunotherapy, and their inhibitors have significantly improved the prognosis of many patients with malignant tumors. However, the issues of drug resistance and limited overall response rate associated with monotherapy remain prevalent. As a new generation of immune checkpoints, lymphocyte activation gene 3 (LAG-3) synergistically enhances the suppression of T cells alongside PD-1 in various cancers. Combining the blockade of both PD-1 and LAG-3 yields stronger anti-tumor immune effects compared to blocking either target alone, thereby reversing the immunosuppressive state of the tumor microenvironment and reducing the occurrence of resistance. This review covers the structural characteristics of LAG-3 and unveils its specific interactions with PD-1 across multiple cancers, providing a novel reference for overcoming the limitations of single-agent therapy.
Humans ; Neoplasms/immunology* ; Immunotherapy/methods* ; Programmed Cell Death 1 Receptor/metabolism* ; Lymphocyte Activation Gene 3 Protein ; Antigens, CD/metabolism* ; Animals ; Tumor Microenvironment/immunology* ; Immune Checkpoint Inhibitors/therapeutic use*

Objective To investigate the effects of LBL-007, a novel fully human lymphocyte activation gene 3 (LAG-3) monoclonal antibody, in combination with programmed cell death protein 1 (PD-1) antibody, on the invasion, migration and proliferation of tumor cells, and to elucidate the underlying mechanisms. Methods Human lymphocyte cells Jurkat were co-cultured with A549 and MGC803 tumor cell lines and treated with the isotype control antibody human IgG, LBL-007, anti-PD-1 antibody BE0188, or tumor necrosis factor-alpha (TNF-α, the NF-κB signaling pathway agonist). Tumor cell proliferation was assessed using a colony formation assay; invasion was measured by Transwell^TM assay; migration was evaluated using a wound healing assay. Western blotting was employed to determine the expression levels of NF-κB pathway-related proteins: IκB inhibitor kinase alpha (Ikkα), phosphorylated Ikkα (p-IKKα), NF-κB subunit p65, phosphorylated p65 (p-p65), NF-κB Inhibitor Alpha (IκBα), phosphorylated IκBα (p-IκBα), matrix metalloproteinase 9 (MMP9), and MMP2. Results Compared with the control and IgG isotype groups, LBL-007 and BE0188 significantly reduced tumor cell proliferation, invasion, and migration. They also decreased the phosphorylation of p-IKKα, p-p65 and p-IκBα, and the expression of MMP9 and MMP2 of tumor cells in the co-culture system. The combined treatment of LBL-007 and BE0188 enhanced inhibitory effects. Treatment with the NF-κB signaling pathway agonist TNF-α reversed the suppressive effects of LBL-007 and BE0188 on tumor cell proliferation, invasion, migration, and NF-κB signaling. Conclusion LBL-007 and anti-PD-1 antibody synergistically inhibit the invasion, migration, and proliferation of A549 and MGC803 tumor cells by blocking the NF-κB signaling pathway.
Humans ; Cell Proliferation/drug effects* ; Cell Movement/drug effects* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Neoplasm Invasiveness ; Antibodies, Monoclonal/pharmacology* ; Programmed Cell Death 1 Receptor/antagonists & inhibitors* ; Cell Line, Tumor ; Antigens, CD/immunology* ; Lymphocyte Activation Gene 3 Protein ; A549 Cells ; I-kappa B Kinase/metabolism* ; Jurkat Cells ; Matrix Metalloproteinase 9/metabolism*

Objective To prepare CD318-specific monoclonal antibodies and evaluate their specificity, affinity, and application in immunological detection, laying the foundation for the development of CD318-targeted antibody drugs. MethodsCD318 protein was expressed and purified, and was used as an antigen to immunize mice, then mice with higher antiserum titers were screened. We prepared CD318-specific monoclonal antibodies through cell fusion and monoclonal screening, and the specificity, affinity, and application of the obtained monoclonal antibodies in immunological assays were evaluated. Then we constructed a CD318/CD3-targeting bispecific antibody and assessed its impact on T-cell cytotoxicity. Results Thirteen monoclonal antibodies were successfully generated, with the hybridoma clone 13-8-G2 exhibiting the highest titer, strongest specificity, and broadest applicability. The antibody was identified as an IgG1 isotype with a kappa light chain. The variable region of the light chain measured 318 bp, while the heavy chain variable region was 357 bp, yielding an affinity constant of approximately 7.68×10⁹. The specificity of CD318 was confirmed using flow cytometry and immunofluorescence assays. Additionally, a CD318/CD3-targeting bispecific antibody was constructed using the variable regions of this CD318 monoclonal antibody, which demonstrated enhanced T-cell cytotoxicity. Conclusion High-affinity and highly specific CD318 monoclonal antibodies were successfully prepared, laying a foundation for the development of therapeutic antibodies targeting CD318.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice ; Antibodies, Bispecific/immunology* ; Humans ; Mice, Inbred BALB C ; Antibody Specificity/immunology* ; CD3 Complex/immunology* ; Antigens, CD/genetics* ; T-Lymphocytes/immunology* ; Hybridomas/immunology* ; Female

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

Objective To prepare mouse anti-human lymphocyte activation gene 3 (LAG3) monoclonal antibody (mAb) and perform immunological identification of the antibody. Methods BALB/c mice were immunized with LAG3-mLumin-3T3 cells, which stably express the extracellular and transmembrane regions of human LAG3 in mouse 3T3 cells. The secretion of anti-human LAG3 antibodies in mouse serum was assessed using flow cytometry and immunofluorescence. SP2/0 cells were injected subcutaneously into the mice to elicit solid myelomas, and mouse myeloma cells were subsequently isolated. Spleen cells from the immunized mice were fused with the myeloma cells to establish hybridomas, which were then separated using the limiting dilution method. Flow cytometry was used to detect LAG3 mAbs in the hybridoma culture medium. To map the epitopes recognized by these mAbs, 3T3 cells expressing individual extracellular domains of LAG3(LAG3 domains 1/-2/-3/-4-3T3) were used. Flow cytometry was also applied to analyze LAG3 expression on activated human peripheral blood mononuclear cells (PBMC) before and after co-culture with the LAG3 mAbs. Results Mice immunized with the recombinant eukaryotic cell antigen produced anti-LAG3 antibodies. The generated hybridomas secreted mouse anti-human LAG3 mAbs, with each hybridoma line recognizing different LAG3 antigenic domains. Conclusion Mouse anti-human LAG3 mAbs were successfully generated, with different hybridoma clones secreting antibodies that recognize distinct LAG3 epitopes. These findings lay the groundwork for further studies into the biological properties of LAG3 and the development of diagnostic reagents and therapeutic blocking antibodies for cancer treatment.
Animals ; Humans ; Mice ; Lymphocyte Activation Gene 3 Protein ; Antibodies, Monoclonal/immunology* ; Mice, Inbred BALB C ; Hybridomas/immunology* ; Antigens, CD/genetics* ; Immunization ; Recombinant Proteins/immunology* ; Female ; Eukaryotic Cells/immunology* ; Flow Cytometry ; Epitopes/immunology*

OBJECTIVE: To assess the effect of neutralizing CD96 on natural killer (NK) cell functions in mice with pulmonary infection and explore the possible mechanism. METHODS: Male BALB/c mice were randomly divided into infection group (Cm group), anti-CD96 treatment group (anti-CD96 group) and control group (=5). In the former two groups, was inoculated intranasal administration to establish mouse models of pulmonary infection, and the mice in the control group received intranasal administration of the inhalation buffer. In anti-CD96 group, the mice were injected with anti-CD96 antibody intraperitoneally at the dose of 250 μg every 3 days after the infection; the mice in Cm group received intraperitoneal injections of saline. The body weight of the mice was recorded daily. The mice were sacrificed 5 days after infection, and CD96 expression was detected by quantitative real-time PCR and Western blotting. HE staining and pathological scores were used to evaluate pneumonia of the mice. The inclusion body forming units (IFUs) were detected in the lung tissue homogenates to assess lung tissue chlamydia load. Flow cytometry and ELISA were used to assess the capacity of the lung NK cells to produce interferon-γ (IFN-γ) and regulate macrophages and Th1 cells. RESULTS: infection inhibited CD96 expression in NK cells of the mice. Compared with those in Cm group, the mice in antiCD96 mice showed significantly milder lung inflammation ( < 0.05) and reduced chlamydia load in the lung tissue ( < 0.05). Neutralizing CD96 with anti-CD96 significantly enhanced IFN-γ secretion by the NK cells ( < 0.05) and augmented the immunoregulatory effect of the NK cells shown by enhanced responses of the lung macrophages ( < 0.05) and Th1 cells ( < 0.05). CONCLUSIONS Inhibition of CD96 alleviates pneumonia in -infected mice possibly by enhancing IFN-γ secretion by NK cells and augmenting the immunoregulatory effect of the NK cells on innate and adaptive immunity.
Animals ; Antigens, CD ; metabolism ; Chlamydia Infections ; complications ; immunology ; physiopathology ; Chlamydia muridarum ; Interferon-gamma ; genetics ; metabolism ; Killer Cells, Natural ; metabolism ; Lung Injury ; etiology ; genetics ; prevention & control ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL

Neisseria gonorrhoeae (NG), as a pathogen of gonorrhea, is strictly limited to growth on the human host. In case of gonococcal infection, the body may recruit such inflammatory cells as neutrophils to resist the invasion of NG or initiate its adaptive immune response by antigen presentation to eliminate the pathogen. However, a series of immune escape mechanisms of NG make it difficult to clear up the infection. In the innate immune system, NG can not only secrete thermonuclease to degrade neutrophile granulocytes, inhibit respiratory burst to resist killing by neutrophils, activate NLRP3 to prompt the pyronecrosis of inflammatory cells, but also regulate the differentiation of macrophages to reduce the inflammatory response, combine with factor H to evade complement-mediated killing. NG infection can hardly give rise to effective adaptive immune response and immune memory, but can promote TGF-β production to inhibit Th1/Th2-mediated adaptive immune response, bind to CEACAM1 on the B cell surface to promote apoptosis in B cells, and combine with CEACAM1 on the T cell surface to inhibit helper T cell proliferation, which makes it difficult for B cells to produce high-affinity specific antibodies. With the increasing drug-resistance of NG, immunological studies may play a significant role in the development of novel therapies and effective vaccines against the infection.
Adaptive Immunity ; Antibodies ; immunology ; Antigens, CD ; immunology ; Cell Adhesion Molecules ; immunology ; Complement Factor H ; immunology ; Gonorrhea ; immunology ; Humans ; Immune Evasion ; immunology ; Immunity, Innate ; immunology ; Neisseria gonorrhoeae ; immunology

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

Asthma is a chronic disease of airway inflammation due to excessive T helper cell type 2 (Th2) response. Present treatment based on inhalation of synthetic glucocorticoids can only control Th2-driven chronic eosinophilic inflammation, but cannot change the immune tolerance of the body to external allergens. Regulatory T cells (Tregs) are the main negative regulatory cells of the immune response. Tregs play a great role in regulating allergic, autoimmune, graft-versus-host responses, and other immune responses. In this review, we will discuss the classification and biological characteristics, the established immunomodulatory mechanisms, and the characteristics of induced differentiation of Tregs. We will also discuss the progress of Tregs in the field of asthma. We believe that further studies on the regulatory mechanisms of Tregs will provide better treatments and control strategies for asthma.
Antigens, CD/analysis* ; Apyrase/analysis* ; Asthma/immunology* ; Cell Differentiation ; Cytokines/metabolism* ; Humans ; Lymphocyte Transfusion ; T-Lymphocytes, Regulatory/immunology*

OBJECTIVETo study the clinical manifestation, pathologic features and immunophenotype of histiocytic necrotizing lymphadenitis (HNL).

METHODSThe clinicopathologic data of 84 patients with HNL from 2005 to 2014 were retrospectively studied. Immunohistochemical staining using EliVision method for CD20, PAX5, CD3, CD45RO, CD4, CD8, CD56, CD68, CD123, granzyme-B, TIA1 and MPO was carried out. In-situ hybridization for Epstein-Barr virus RNA was performed on archival lymph node biopsy tissue.

RESULTSImmunohistochemical study showed that the lesional cells were predominantly histiocytes (CD68+), plasmacytoid dendritic cells (CD123+) and T lymphocytes (CD3+ and CD45RO+). Clusters of CD68-positive cells with strong and diffuse MPO expression were identified. T lymphocytes with CD4 and CD8 positivity were noted. CD56+ natural killer cells and CD20+/PAX5 B cells were rare. Apoptosis-related markers, including TIA1 and granzyme B were expressed by T lymphocytes and histiocytes in lymph nodes of HNL. In-situ hybridization for Epstein-Barr virus RNA was positive in only 10.0% of the cases.

CONCLUSIONSHNL shows no specific clinical and laboratory findings. Recognition of the characteristic histopathologic changes in lymph node biopsy of HNL is the key to correct diagnosis. Immunohistochemical study using a panel of markers, including CD3, CD4, CD8, MPO, CD123, granzyme-B and TIA1, is helpful in the differential diagnosis of HNL.

Antigens, CD ; analysis ; Biomarkers ; Dendritic Cells ; pathology ; Diagnosis, Differential ; Granzymes ; analysis ; Herpesvirus 4, Human ; genetics ; Histiocytes ; pathology ; Histiocytic Necrotizing Lymphadenitis ; complications ; immunology ; pathology ; virology ; Humans ; Immunohistochemistry ; Immunophenotyping ; In Situ Hybridization ; methods ; Lymph Nodes ; RNA, Viral ; analysis ; Retrospective Studies ; T-Lymphocytes ; immunology ; pathology