Journal of Immunology Research最新文献

Nucleated red blood cells (NRBCs) are precursors of red blood cells (RBCs), but also possess variety of immunomodulatory effects. However, among the three types of NRBCs, the immunological effects of human CD45- NRBCs remain largely unknown. We have previously shown that cord blood-derived CD45- NRBCs and adult peripheral blood-derived monocytes cocultured in a lipopolysaccharide (LPS)-stimulated indirect coculture system that avoided cell-to-cell contact, increase IL-10 and decrease TNF-α secretion, suggesting an immunosuppressive function of CD45- NRBCs via an unknown soluble factor. The peripheral blood of fetuses and neonates has abundant NRBCs and is physiologically polycythemic, which may lead to the peripheral accumulation of toxic plasma-free hemoglobin. Plasma-free hemoglobin binds to haptoglobin, forming a haptoglobin-hemoglobin complex, which is processed within monocytes via the CD163- heme oxygenase 1 (HO-1) axis and secretes IL-10. Therefore, we hypothesized that NRBCs secrete haptoglobin and induce the immunosuppressive function of monocytes by activating the CD163-HO-1 axis. We found that immunosuppressive response decreased when the coculture medium was supplemented with an anti-CD163 blocking antibody or the HO-1 inhibitor zinc protoporphyrin IX (ZnPP-IX). Haptoglobin levels in the culture medium containing NRBCs were high and expressed the haptoglobin gene. Thus, CD45- NRBCs secreted haptoglobin and activated the immunosuppressive function of monocytes.

Hepatic macrophages respond to various microenvironmental signals and play a central role in maintaining hepatic homeostasis, dysregulation of which leads to various liver diseases. Fatty acid-binding protein 7 (FABP7), an intracellular lipid chaperone for polyunsaturated fatty acids (PUFAs), is highly expressed in liver macrophages. However, the mechanisms by which FABP7 regulates hepatic macrophage activation remain unclear. Therefore, we aimed to elucidate the mechanisms underlying the effects of FABP7 on the functions of hepatic macrophages in metabolic dysfunction-associated steatohepatitis (MASH) and liver fibrosis models. In this study, we found that FABP7-deficient macrophages exhibited impaired M2 polarization, which reduced the fibrotic response of myofibroblasts and CD4⁺ T-cell infiltration into the liver tissues in a carbon tetrachloride (CCl₄)-induced hepatic fibrosis model. In vitro, FABP7-deficient macrophages exhibited decreased levels of peroxisome proliferator-activated receptor (PPAR)-γ and its target genes, including C-C motif chemokine ligand (CCL)-17 and transforming growth factor-β (TGF-β), compared to the wild-type (WT) macrophages post-interleukin (IL)-4 stimulation. However, these effects were inhibited by a PPARγ inhibitor. IL-4-stimulated WT macrophages also promoted CD4⁺ T-cell migration and hepatic fibroblast (TWNT-1 hepatic stellate cell [HSC]) activation, indicated by increased mRNA levels of actin alpha 2, smooth muscle (ACTA2), and collagen type I alpha 1 (COL1A1); however, these effects were inhibited in FABP7-deficient macrophages. Overall, FABP7 in hepatic macrophages modulated the crosstalk between hepatic fibroblasts and T cells by regulating M2 polarization. Therefore, regulation of hepatic macrophage function by FABP7 is a potential therapeutic target for liver fibrosis.

Objectives: Primary Sjögren's syndrome (pSS) is associated with a risk allele T of rs117026326 located at a potential splicing enhancer within the intronic region of general transcription factor II-I (GTF2I). This study aimed to explore the rs117026326-regulated alternative splicing of GTF2I and its role in B cell overactivation in pSS. Methods: GTF2I isoform expressions and rs117026326 genotypes of pSS peripheral blood mononuclear cells (PBMCs) were examined using quantitative PCR and Sanger sequencing, respectively. GTF2IΔ was overexpressed in B cells, T cells, and macrophages using plasmid transfection. Proliferation of B cells and T cells was determined using Cell Counting Kit-8 (CCK8) assay. CD4⁺ T cell differentiation was inspected using flow cytometry. Proinflammatory cytokine production of macrophages was investigated using quantitative PCR. c-FOS expression in GTF2IΔ-transfected B cells was tested by quantitative PCR, and proliferation of GTF2IΔ-transfected B cells treated with c-FOS siRNA or c-FOS inhibitor was interrogated using CCK8 assay. Results: pSS patients with risk allele of rs117026326 expressed higher levels of GTF2IΔ and GTF2Iζ isoforms. GTF2IΔ expression was correlated with serum immunoglobulin G (IgG). GTF2IΔ promoted B cell proliferation and upregulated c-FOS expression. Knocking down or inhibition of c-FOS reversed B cell proliferation driven by GTF2IΔ. Conclusion: pSS risk allele of rs117026326 modulates alternative splicing of GTF2I and upregulates GTF2IΔ isoform, which promotes B cell proliferation through enhancing binding and transcription of c-FOS.

Research on long-term follow-up in individuals who have recovered from coronavirus disease-19 (COVID-19) would yield insights regarding their immunity status and identify those who need booster vaccinations. This study evaluated the longevity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular and humoral memory responses, as well as T cell effector functionalities, at 1-2 months (n = 40), 8-9 months (n = 40), and 12 months/1 year (n = 27) following recovery from SARS-CoV-2 infection. CTL response by enzyme-linked immunospot (ELISPOT); levels of cytokine by Bio-Plex, natural killer (NK), CD4+ helper, and CD8+ cytotoxic T cell functionalities using flow cytometry; anti-SARS-CoV-2 IgG by ELISA; and levels of neutralizing antibodies (NAbs) by surrogate virus NAb assay were assessed. The levels of SARS-CoV-2-specific IgG and NAb at 1-2 and 8-9 months postrecovery were hand in hand and appeared declining. SARS-CoV-2-specific B, memory B and plasma cells, and T cells sustained up to 8-9 months. Increased expression of CD107a/IFN-γ by NK cells and cytotoxic T cells at 8-9 months could be indicative of SARS-CoV-2-specific effector functions. Recovered individuals with positive and negative IgG antibody status displayed T cell response up to 1 year and 8-9 months, respectively, emphasizing the durabilty of effector immunity up to 8-9 months regardless of IgG antibody status. Overall, the recovered individuals exhibited robust immunological memory, sustained T cell response with effector functionality against SARS-CoV-2 that persists for at least 8-9 months.

Leishmaniasis is a group of parasitic diseases whose etiological agent is the protozoa Leishmania. These diseases afflict impoverished populations in tropical and subtropical regions and affect wild and domestic animals. Canine leishmaniasis is a global disease mostly caused by L. infantum. Dogs are recognized as a good reservoir since harbor the infection long before developing the disease, facilitating parasite transmission. Furthermore, there is growing evidence that dogs may also be the reservoir of the American Leishmania spp. as L. amazonensis. The innate immune response is the first defense line against pathogens, which includes natural killer (NK) and dendritic cells (DCs). By recognizing and ultimately destroying infected cells, and by secreting immune mediators that favor inflammatory microenvironments, NK cells take the lead in the infectious process. When interacting with Leishmania parasites, DCs become activated and play a key role in driving the host immune response. While activated DCs can modulate NK cell activity, Leishmania parasites can directly activate NK cells by interacting with innate immune receptors. Once activated, NK cells can engage in a bidirectional interplay with DCs. However, the complexity of these interactions during Leishmania infection makes it challenging to fully understand the underlying processes. To further explore this, the present study investigated the dynamic interplay established between monocyte-derived DCs (moDCs) and putative NK (pNK) cells of dogs during Leishmania infection. Findings indicate that the crosstalk between moDCs exposed to L. infantum or L. amazonensis and pNK cells enhances chemokine upregulation, potentially attracting other leukocytes to the site of infection. pNK cells activated by L. infantum infected DCs upregulate IL-10, which can lead to a regulatory immune response while moDCs exposed to L. amazonensis induced pNK cells to overexpress IFN-γ and IL-13, favoring a mix of pro- and anti-inflammatory response. In addition, parasite-derived extracellular vesicles (EVs) can modulate the host immune response by stimulating the upregulation of anti-inflammatory cytokines and perforin release, which may impact infection outcomes. Thus, Leishmania and parasitic EVs can influence the bidirectional interplay between canine NK cells and DCs.

Objective: This study was conducted to evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) in treating pediatric functional constipation (FC) and to explore its mechanisms by analyzing changes in serum neurotransmitters and gut microbiota. Materials and Methods: This was a prospective cohort study conducted on 60 children aged 4-14 years diagnosed with FC. Participants were divided into two groups, namely, one receiving TENS therapy three times a week for 4 weeks and the control group receiving lactulose. Pretreatment and posttreatment evaluations included serum neurotransmitters, immunological indicators, and gut microbiota composition. Results: The TENS group demonstrated significant improvements in defecation frequency and constipation symptoms compared with the lactulose group (p < 0.001). Posttreatment, remarkable increases were detected in serum motilin and vasoactive intestinal peptide (VIP) levels, along with a significant decrease in interleukin-12 levels (p < 0.05), indicating anti-inflammatory effects. Gut microbiota analysis revealed significant shifts in microbial composition, with an increase in the abundance of Bacteroidetes and a decrease in the abundance of Firmicutes/Bacteroidetes ratio, suggesting improved gut health and metabolic function. Conclusion: TENS effectively improves symptoms of pediatric FC and induces beneficial changes in immunological indicators and gut microbiota. These results suggest potential anti-inflammatory and microbiota-modulating effects. However, due to the limited sample size, further studies are needed to confirm these findings and explore the long-term benefits of TENS therapy. Trial Registration: Clinical Trial Registry identifier: ChiCTR2200059549.

Amino acid metabolism in T cells determines the therapeutic efficacy of T-cell-targeting drugs. To assess the direction of amino acid metabolism in T cells and construct related knowledge structure, we performed a bibliometric analysis aiming at amino acid metabolism in T cells utilizing studies publicized in recent 15 years. Three hundred thirty-seven related studies were downloaded from the Web of Science Core Collection (WoSCC), and the information on countries, institutes, and authors was collected and analyzed. In addition, the present research status and future trends were explored according to the results yielded from the analysis of cited references and keywords. This study revealed that publications regarding amino acid metabolism in T cells gradually increased each year. The USA is the top producer and most influential country in this field. Recent research has focused on the correlation between the metabolism of several amino acids and regulatory T cells (Tregs) and CD8⁺ T cells. Overall, this research offers a comprehensive exhibition on the field of amino acid metabolism in T cells, which will help researchers to study this domain more effectively and intuitively.

In recent years, chimeric antigen receptor T-cell (CAR-T) therapy has made groundbreaking progress in the treatment of various cancer types, particularly hematological malignancies. In the meantime, various preclinical and clinical studies have extensively explored dual-target CAR-T therapies which can be designed to recognize two antigens simultaneously based on the immunophenotype of tumor cells. Compared with single-target CAR-T approach, dual-target CAR-T therapies demonstrate varying degrees of superior antitumor CAR effects, prevent antigen escape and relapse, reduce on-target off-tumor effects, and ensure durable responses in different types of cancer. These advantages highlight the potential future prospects in this field, showing varying degrees of advancement in preclinical and clinical studies. Herein, we aimed to review different dual-target CAR-T studies conducted on a wide range of tumor models, summarizing the selection of target combinations, the efficacy and safety demonstrated in preclinical and clinical settings, the existing limitations, and the potential future directions of this promising therapeutic strategy.

Inflammation is a critical response of the immune system to infection or injury, serving to repair and restore tissue homeostasis. While acute inflammation generally protects against harmful stimuli, prolonged and chronic inflammation have detrimental effects and disrupts tissue homeostasis. Due to the complex and multifactorial etiology of chronic inflammation, effective treatment remains elusive. We found that piperlongumine (PL)-18, a di-hydroxy derivative of PL from long pepper, inhibits the nuclear factor kappa B (NF-kB), a master transcription factor of numerous components of the inflammatory response. NF-kB was inhibited by PL-18 in two human cell-lines, L428 and A549, by preventing the nuclear translocation of p65 NF-kB. We also found that IκB kinase (IKK) was degraded in the presence of PL-18. Furthermore, PL-18 inhibited the production of proinflammatory cytokines expressed by L428, a cell line with a constitutive active NF-kB. Altogether, our results suggest that PL-18 is a molecule of interest to be further developed to treat persistent infections with severe inflammation.

The body's immune response plays a critical role in defending against external or foreign antigens while also preserving tolerance to self-antigens. This equilibrium, referred to as immune homeostasis, is paramount for overall health. The regulatory mechanisms governing the maintenance of this delicate immune balance are notably complex. It is currently accepted that immune tolerance is a dynamic outcome regulated by multiple factors, including central and peripheral mechanisms. Its induction or elimination plays a significant role in autoimmune diseases, organ transplantation, and cancer therapy, markedly impacting various major diseases in modern clinical practice. Overall, our current understanding of immune tolerance is still very limited. In this review article, we summarized the main mechanisms that have been known to mediate immune tolerance so far, including endogenous immune tolerance, adaptive immune tolerance, other immune tolerance mechanisms, and the homeostasis of immune tolerance, identified the key factors that regulate immune tolerance, and provided new clues for immune system recovery in many autoimmune diseases, organ transplantation, and tumor therapy.