Frontiers in Immunology最新文献

Introduction: Very little is known about the role of macrophages as immune mediators during natural HIV infection. Humanized mice are an extremely valuable in vivo model for studying HIV pathogenesis. However, the presence of murine mononuclear phagocytes in these models represents a significant limitation for studying their human counterpart. Therefore, we have developed a novel humanized mouse model that allows selective depletion of human myeloid cells at a time point of our choosing.

Methods: We genetically engineered human hematopoietic stem and progenitor cells (HSPCs) to express an inducible caspase-9 (iCas9) suicide system under a synthetic myeloid promoter. Using these HSPCs, we generated humanized mice. iCasp9 induction in vivo resulted in selective human myeloid cell death in this inducible human myeloid depletion (iHMD) mouse model. In addition, we co-cultured monocyte-derived macrophages with ex vivo HIV-infected PBMCs to further mechanistically investigate the effect of macrophages on HIV replication using flow cytometry, cytokine analysis, and RNA sequencing of both macrophages and CD4+ T cells.

Results: HIV infection induced a pro-inflammatory phenotype in HIV-infected humanized NSG mice during the early and late stages of HIV infection. Myeloid cell depletion in HIV-infected iHMD-NSG mice resulted in a rapid increase in HIV RNA replication, which was accompanied by a loss of pro-inflammatory cytokines. Co-culture of macrophages with ex vivo HIV-infected PBMCs reproduced their anti-HIV effects observed in vivo. Transcriptomic data showed macrophages upregulate antiviral cytokines and chemokines in co-culture, while inducing CD4+ T cells to upregulate HIV restriction factors and downregulate pathways involved in protein expression and cell replication.

Discussion: This study describes a novel role of macrophages as effector cells, both ex vivo and in vivo, acting against HIV replication and limiting disease progression.

Introduction: Preclinical evidence suggests that host obesity is associated with tumor progression due to immuno-metabolic dysfunction, but the impact of obesity on immunity and clinical outcomes in patients is poorly understood, with some studies suggesting an obesity paradox. We recently reported that high-adiposity and low-muscle body composition phenotypes are associated with striking increases in epithelial ovarian cancer (EOC) mortality and we observed no evidence of an obesity paradox. However, whether at-risk versus optimal body composition phenotypes are associated with distinct immuno-metabolic milieus remains a fundamental gap in knowledge. Herein, we defined differentially abundant circulating immuno-metabolic biomarkers according to body composition phenotypes in EOC.

Methods: Muscle and adiposity cross-sectional area (cm²) was assessed using CT images from 200 EOC patients in The Body Composition and Epithelial Ovarian Cancer Survival Study at Roswell Park. Adiposity was dichotomized as low versus high; patients with skeletal muscle index (SMI) <38.5 (muscle cm²/height m²) were classified as low SMI (sarcopenia). Joint-exposure phenotypes were categorized as: Fit (normal SMI/low-adiposity), Overweight/Obese (normal SMI/high-adiposity), Sarcopenia/Obese (low SMI/high adiposity), and Sarcopenia/Cachexia (low SMI/low-adiposity). Treatment-naïve serum samples were assessed using Biocrates MxP Quant 500 for targeted metabolomics and commercially available Luminex kits for adipokines and Th1/Th2 cytokines. Limma moderated T-tests were used to identify differentially abundant metabolites and cytokines according to body composition phenotypes.

Results: Patients with 'risk' phenotypes had significantly increased abundance of metabolites and cytokines that were unique according to body composition phenotype. Specifically, the metabolites and cytokines in increased abundance in the at-risk phenotypes are implicated in immune suppression and tumor progression. Conversely, increased abundance of lauric acid, IL-1β, and IL-2 in the Fit phenotype was observed, which have been previously implicated in tumor suppression and anti-tumor immunity.

Conclusion: In this pilot study, we identified several significantly differentially abundant metabolites according to body composition phenotypes, confirming that clinically significant joint-exposure body composition phenotypes are also biologically distinct. Although we observed evidence that at-risk phenotypes were associated with increased abundance of immuno-metabolic biomarkers indicated in immune suppression, additional confirmatory studies focused on defining the link between body composition and immune cell composition and spatial relationships in the EOC tumor microenvironment are warranted.

Background: Autoimmune diseases (ADs) are a category of conditions characterized by misrecognition of autologous tissues and organs by the immune system, leading to severe impairment of patients' health and quality of life. Increasing evidence suggests a connection between fluctuations in plasma metabolites and ADs. However, the existence of a causal relationship behind these associations remains uncertain.

Methods: Applying the two-sample mendelian randomization (MR) method, the reciprocal causality between plasma metabolites and ADs was analyzed. We took the intersection of two metabolite genome-wide association study (GWAS) datasets for GWAS-meta and obtained 1,009 metabolites' GWAS data using METAL software. We accessed GWAS summary statistics for 5 common ADs, inflammatory bowel disease (IBD), multiple sclerosis (MS), type 1 diabetes (T1D), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) from published GWAS data. MR analyses were performed in discovery and replication stage simultaneously. Meanwhile, the reverse MR analysis was conducted to investigate the possibility of reverse causal association. Furthermore, a series of sensitivity analyses were conducted to validate the robustness of the results. These statistical analyses were conducted using R software. Finally, the web version of MetaboAnalyst 5.0. was applied to analyze metabolic pathways. Ultimately, we conducted ELISA assays on plasma samples from patients to validate the results.

Results: 4 metabolites were identified to have causal relationships with IBD, 2 metabolites with MS, 13 metabolites with RA, and 4 metabolites with T1D. In the reverse MR analysis, we recognized causality between SLE and 22 metabolites, IBD and 4 metabolites, RA and 22 metabolites, and T1D and 37 metabolites. Additionally, 4 significant metabolic pathways were identified in RA by metabolic pathway analysis in the forward MR analysis. Correspondingly, in the reverse, 11 significant metabolic pathways in RA, 8 in SLE, and 4 in T1D were obtained using identical approaches. Furthermore, the protective role of glutamate was confirmed through ELISA assays.

Conclusions: Our research established a reciprocal causality between plasma metabolites and ADs. Furthermore, diverse metabolic pathways correlated with ADs were uncovered. Novel insights into the prediction and diagnosis were provided, as well as new targets for precise treatment of these conditions were discovered.

Background: WHIM syndrome is a rare, autosomal dominant inborn error of immunity characterized by warts, hypogammaglobulinemia, infection, and myelokathexis. It is caused mainly by heterozygous mutations at the C-terminus of the C-X-C chemokine receptor type 4 (CXCR4) gene.

Methods: We described the detailed clinical, genetic, immunological and treatment characteristic of four WHIM patients from a single Chinese family.

Results: Here, we report four patients from a family carrying a variant of CXCR4 (c.1016_1017dupCT), which introduces a frameshift at codon V340, resulting in an extension of 14 amino acids (p.V340L fs*27). We provide and in-depth analysis of their clinical, genetic, immunological and treatment characteristic, noting that these patients exhibited an atypical clinical phenotype when compared to reported CXCR4^R334X patients. Additionally, the frameshift variant CXCR4^V340fs led to impaired receptor downregulation in patients' PBMCs, and in HEK293T cells transfected with the variant plasmids.

Conclusions: Our study provided detailed clinical features of four CXCR4^V340fs WHIM patients from one Chinese family who presented atypical phenotype and enrich the spectrum of WHIM syndrome.

CD80 is a molecule that plays an important role in the immune system, especially during T-cell activation, and its ligands are mainly CD28, PD-L1, and CTLA-4. CD80 is expressed on the surface of tumor cells, and it can be used as a molecular target in the process of T-cell anti-tumor immune response. In autoimmune diseases, CD80 can also regulate autoimmune diseases by modulating immunity. This review mainly focus on the role of CD80 in the immune system, as well as the research progress on the application of CD80-related immunopharmaceuticals in the treatment of tumors and autoimmune diseases.

Purpose: We aimed to investigate risk factors for COVID-19 pneumonia in patients with hematological malignancies (HM) after Omicron infection.

Methods: Data from a registered multi-center, prospective, observational study (ChiCTR2300071830) during the latest Omicron BA.5.2 wave in Chongqing, China was used for analysis.

Results: A total of 475 HM patients enrolled in this study. COVID-19 pneumonia was observed in 15.8% (75/475) of patients, with a median age of 58 years (interquartile range [IQR], 48-69 years) and males accounting for 61.3%. Risk factors associated with COVID-19 pneumonia included: 1) Active disease status of HM at infection, with an odds ratio (OR) of 3.42 (95% confidence interval [CI]: 1.59-7.37, P=0.002) compared to complete remission (CR); 2) Incomplete COVID-19 vaccination, 1-2 doses of the vaccine (OR=2.55, 95% CI: 1.28-5.10, P=0.008) or no vaccination (OR=4.81, 95% CI: 2.45-9.43, P<0.001), as opposed to 3 doses (booster); 3) chemotherapy prior to infection, <6 months (OR=2.58, 95% CI: 1.12-5.96, P=0.027) or ≥ 6 months (OR=2.93, 95% CI: 1.31-6.53, P=0.009) compared to no chemotherapy history; 4) NK-cell reduction (< 150/μL) (OR=2.19, 95% CI: 1.27-3.79, P=0.005) versus a normal range of NK cells. During the 6-week follow-up period, 12 patients (2.5%) died, accounting for 16% of COVID-19 pneumonia patients.

Conclusions: Our study investigated risk factors for COVID-19 pneumonia in HM patients after Omicron BA.5.2 infection. Highlights that HM patients with these risk factors may be susceptible to lung involvement after Omicron BA.5.2 infection and need to be taken seriously in clinical practice.

Clinical trial registration: https://www.chictr.org.cn/bin/project/edit?pid=195998, identifier ChiCTR2300071830.

Introduction: The clinical characteristics of patients positive for anti-small ubiquitin-like modifier 1-activating enzyme subunit 1 (SAE1) antibodies and diagnosed with idiopathic inflammatory myopathies (IIMs) vary across different cohorts and ethnicities, particularly concerning interstitial lung disease (ILD). We aimed to assess the clinical utility of the line immunoblot assay (LIA) in detecting anti-SAE1 autoantibodies and evaluate the clinical relevance and chronology of ILD development in relation to SAE1 autoantibody positivity among Taiwanese patients.

Methods: We retrospectively conducted a population-based cohort analysis involving 6,496 patients who visited Chang Gung Memorial Health System across Taiwan from May 2018 to December 2021. Patients were assayed for myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) using the LIA method, and the antinuclear antibody (ANA) indirect immunofluorescence (IIF) method was used to evaluate ANA patterns. Of these, 70 SAE1-positive patients (1.08%) were included and followed up until December 2023. Associations with clinical characteristics and final diagnosis, particularly ILD, were assessed.

Results: Among the 70 SAE1-positive patients, 10 (14.3%) were strongly positive and 60 (85.7%) were weakly positive. In the strong positive group, 70% (7/10) were diagnosed with IIM, with most (5/7) showing a concordant ANA IIF pattern (speckled type). Six patients presented ILD either before (1/6) or after (5/6) IIM diagnosis; the majority (4/6) were classified as organizing pneumonia. The remaining 30.0% (3/10) had connective tissue disease (CTD) other than IIM without detectable ILD during follow-up, and none demonstrated a concordant ANA IIF pattern. In the weakly positive group, only 5.0% (3/60) had IIM and 3.3% (2/60) had ILD. The positive predictive value for strong positive SAE1 autoantibodies in diagnosing IIM was significantly higher than for weak positives (70.0% vs. 5.0%; p < 0.001).

Conclusions: The study suggests that strong positive SAE1 autoantibodies detected via LIA are more closely associated with IIM compared to weak positive results. A high prevalence of ILD was observed among strong positive Taiwanese patients, indicating the need for prompt screening. Patients with weak positive or discordant ANA IIF results may represent false positives with a lower ILD risk.

Background: Rabies continues to be a significant global public health concern, particularly in the Asia region where it is associated with high mortality rate. The administration of effective vaccination is essential in preventing this potentially fatal viral infection. The objective of this study was to evaluate the immunogenicity and safety of two rabies vaccination schedules: the Zagreb (2-1-1) and Essen (1-1-1-1-1) regimens, in a cohort of healthy Chinese individuals aged 10-60 years.

Methods: We conducted a randomized, open-label, controlled, non-inferiority phase 3 trial from July 2021 to November 2022, enrolling a total of 1200 participants. Participants were randomly assigned to receive either the Zagreb or Essen vaccination regimen. The primary outcomes were safety, immunogenicity, and immune persistence. Safety was monitored through adverse event reporting, while immunogenicity was determined by measuring rabies-virus-neutralizing antibody (RVNA) concentrations using the rapid fluorescent focus inhibition test (RFFIT). Immune persistence was evaluated at 3, 6, and 12 months post-vaccination.

Results: The two vaccination regimens exhibited comparable safety records, with mild and transient adverse events predominantly occurring within 0-3 days post-vaccination. The Zagreb regimen demonstrated non-inferiority in terms of seroconversion rates and geometric mean concentrations (GMCs) of antibodies compared to the Essen regimen at both 14 days post-first vaccination and 14 days post-full vaccination. Additionally, both groups displayed nearly 100% seropositivity rate at 3,6, and 12 months. No serious adverse events associated with vaccination were reported.

Conclusion: The findings of this Phase 3 clinical trial provide compelling evidence that the Zagreb regimen is a feasible alternative when compared to the Essen regimen for rabies vaccination, offering a more pragmatic and cost-efficient approach to rabies prevention and control.

Clinical trial registration: http://www.chinadrugtrials.org.cn, identifier CTR20210426.

Background: Antibody-mediated rejection is a significant cause of kidney transplant failure. Recent studies have shown that the MHC class I MICA gene influences the transplantation outcome. However, the role of the primary MICA receptor, NKG2D, has yet to be explored.

Aim: We aimed to investigate the correlation between recipient/donor MICA allele matching and NKG2D genotype with the risk of antibody-mediated rejection and their potential clinical effects and implications for organ maintenance therapy.

Methods: Of the 524 patients who underwent transplantation, 387 were eligible for the study. Complete MICA allele and two functional polymorphisms of NKG2D (rs1049174C>G and rs2255336G>A) were analyzed in 148 transplanted patients and 146 controls.

Results: Increased recipient/donor MICA allele mismatches correlate with an elevated risk of antibody-mediated rejection (X² = 6.95; Log-rank=0.031). Notably, the rs1049174[GG] genotype contributes to a significantly increased risk of antibody-mediated rejection (X² = 13.44; Log-rank=0.001 and X ² = 0.34; Log-rank=0.84). The combined effect of two MICA allele mismatches and rs1049174[GG] genotype shows the highest risk (X² = 23.21; Log-rank<0.001). Most importantly, patients with rs1049174[GG] and rs2255336[AA] genotypes may respond less to mTOR inhibitor immunosuppressive therapy than Calcineurin inhibitors (rs1049174[GG]; P=0.035; and rs2255336[AA]; P=0.002).

Conclusion: Recipient/donor MICA allele mismatches and specific NKG2D variants, as well as their combinations, influence kidney transplant outcomes, providing insights for personalized treatment and enhancing graft survival.