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At least 19 recordsLinked to original sources
PubMed2025

How to analyze and understand the human immune system.

To enhance our understanding of the pathogenesis of diseases, including rheumatic diseases, and to improve disease control, it is essential to attain a thorough understanding of the human immune system, alongside mouse immunology. Historically, the investigation of the human immune system has posed significant challenges due to methodological limitations. Nonetheless, recent advancements in genomic studies of multifactorial diseases have elucidated that numerous risk-associated genetic variants affecting quantitative differences in cell-specific gene expression. In light of these findings, we are currently examining individual genetic variations in both healthy individuals and patients, as well as categorizing cells into distinct subsets in order to construct a comprehensive dataset concerning the human immune system. This is accomplished by combining data on gene expression, factors influencing the expression mechanisms, protein expression, metabolomics, and environmental variables pertinent to immune functionality-such as gut microbiota. These datasets will facilitate the comprehensive characterization of the human immune system. Using these datasets and through the integrative analyses of data related to risk genetic variations and gene expression profiles of each disease and individual, we anticipate uncovering novel insights into the human immune system, the heterogeneity of diseases, immune function mechanisms, and their regulatory strategies that may not be achievable through murine models.

Humans↗
PubMed2026

Insect immune systems: same same but different but still same.

Insects are the most diverse group of animals in nature, occupying nearly every ecological niche and playing central roles as pollinators, pests, and disease vectors. Despite this vast diversity, insects rely on a set of conserved yet evolutionarily adaptable immune pathways to defend against pathogens. Early studies in insect immunity have laid the foundation for human immunology, and recent advances in genomic and transgenic technologies have renewed interest in understanding how immune responses vary across insect orders. Insects are highly diverse in their immune systems; each species has unique immune responses that help fight infections from specific pathogens. Nevertheless, they share multiple aspects of recognition, regulation, and effector mechanisms. This review focuses on current knowledge of the immune systems of major insect lineages to highlight both shared signaling pathways, immune cells, and humoral factors, as well as lineage-specific responses that reflect distinct ecological pressures that have shaped the host-microbe interactions. Comparing different insect species and orders not only provides insights into the evolutionary divergences and convergences of immune system features but also offers complementary knowledge among species within the same order, helping fill existing gaps. Understanding these evolutionary patterns not only deepens our understanding of insect immunity but also informs the development of transgenic strategies to disrupt pathogen transmission in key vector species.

Animals↗
PubMed2026

Systemic immune activation in hereditary cancer predisposition syndromes: a cross-sectional study.

BACKGROUND: Immune surveillance mechanisms contribute to the elimination of precancerous lesions in hereditary cancer predisposition syndromes (HCPSs). METHODS: By combining single-cell transcriptomics, multiparametric mass cytometry and cytokine profiling of the systemic immune environment in 391 individuals among whom 227 are living with HCPSs we investigated phenotypic alterations in cancer-free individuals with HCPS. RESULTS: A decrease in peripheral B cell abundance and their more differentiated phenotype have been confirmed both in breast cancer patients with germline pathogenic variants in BRCA1 (gpath(BRCA1)) and in patients living with Lynch syndrome (LS). Pre-cancer women with gpath(BRCA1) exhibited an activated phenotype of multiple immune cell lineages, similar to those with manifest disease. In LS, B cell phenotypes exhibited the largest changes in response to cancer eradication, while increased peripheral IL-6 levels was detected even in presymptomatic individuals with LS. CONCLUSIONS: HCPS-specific differences in the phenotype of the systemic immune system might be leveraged in future risk-reducing strategies.

Humans↗
PubMed2025

Cell-type-specific defense priming and NHP-dependent systemic immunity against Pectobacterium in Chinese cabbage.

Defense priming is an effective strategy for mounting the defensive capacity of plants. Primed plants undergo minimal changes, enabling rapid, robust responses to subsequent pathogen attack. The cell-type-specific mechanisms underlying priming and systemic immunity remain unclear. Using single-nucleus RNA sequencing (snRNA-seq), we reveal how primed Chinese cabbage coordinates N-hydroxypipecolic acid (NHP)-dependent systemic immunity against Pectobacterium carotovorum. NHP accumulates as a phloem-mobile priming signal. snRNA-seq identified a priming-specific epidermal cell state transition and transcriptional cascade: BrWRKY18-1 activates BrWRKY33-1 expression during priming, initiating NHP-dependent systemic immunity. At post-challenge primed state, pathogenesis-related genes (PRs), such as BrPR3, BrPR4-1, and BrPR4-2, are predominantly expressed in systemic tissues to inhibit infection. Notably, the functionality of these PR genes in immunity necessitates their expression in all cells to effectively enhance defensive resistance. This NHP-transcription factor-PR axis couples mobile signaling to systemic immunity, elucidating cell-type-specific defense priming.

Plant Immunity↗
PubMed1975

Effects of aging on the differentiation and proliferation potentials of cells of the immune system.

An attempt has been made here to show that the immune system can begin to decline in function shortly after an individual reaches maturity. The decline is due in part to changes in the environment of the cells but primarily to changes in the precursor cells of the system. This is reflected in their inability to proliferate and possibly differentiate efficiently. These findings show that the immune system can serve as an excellent model to study how aging can perturb the process of cells undergoing proliferation and differentiation.

Aging↗
PubMed2025

Bacterial immune systems as causes and consequences of microbiome structure.

Attacks from molecular parasites such as mobile genetic elements (MGEs) have driven the evolution of defense systems in bacterial genomes. Yet, despite significant advances in understanding the molecular mechanisms of these bacterial immune systems, we have only a rudimentary understanding of their ecology and evolution. Bacteria exist as part of complex microbiomes, but community ecology and microbiome research has yet to characterize the impacts of interactions between MGEs and defense mechanisms upon the structure, dynamics and evolution of microbiomes. This Essay introduces and discusses the interplay between bacterial community dynamics and bacterial immune systems, speculating about how these reciprocal interactions may shape microbial community structure and function.

Bacteria↗
PubMed2025

The ecology and evolution of microbial immune systems: a look on the wild vibrio side.

Natural populations of vibrio beyond the well-studied pandemic strains of Vibrio cholerae, provide a powerful model for investigating the eco-evolutionary dynamics of microbial immune systems. Their genetic diversity, ecological versatility, ease of culturability and the availability of time-series data enable detailed studies of phage-host interactions in natural contexts. This review synthesizes recent advances in vibriophage research, highlighting key findings and emerging tools. High-throughput assays and genomic tools have offered new perspectives on phage specificity, host range and the evolutionary pressures shaping these interactions. Theoretical frameworks, such as arms race and fluctuating selection dynamics, are informed by empirical data from vibrio-phage systems, with time-series sampling providing crucial insights into their temporal and spatial dynamics. A major finding is the role of mobile genetic elements (MGEs) in encoding bacterial defence systems, which shape phage-host coevolution. Discoveries like the phage satellite PICMI illustrate how MGEs facilitate the transfer of antiviral systems, influencing ecological and evolutionary dynamics. The paradox of generalist vibriophages, rare despite their broad host ranges, is also explored. By integrating experimental approaches with field observations, vibriophage research advances microbial ecology and informs sustainable applications in aquaculture and phage therapy, reinforcing vibrios as a versatile model system.This article is part of the discussion meeting issue 'The ecology and evolution of bacterial immune systems'.

Bacteriophages↗
PubMed2026

Admission whole-blood transcriptomic characterization of a neutrophil-predominant systemic immune response in patients with acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury (TBI) is accompanied by systemic immune responses, but their whole-blood transcriptomic features at hospital arrival remain incompletely characterized. We aimed to characterize these features in patients with acute TBI compared with healthy controls. METHODS: In this single-center prospective observational study, we performed whole-blood RNA sequencing on hospital-arrival samples from 42 patients with acute TBI and 21 healthy controls. Analyses included differential expression (limma-voom; FDR < 0.05, |log2FC| > 0.7), functional enrichment, Ingenuity Pathway Analysis, CIBERSORTx LM22 deconvolution, and per-sample neutrophil degranulation signature scoring. RESULTS: Differential expression analysis identified 996 upregulated and 863 downregulated genes, with marked upregulation of inflammation-, innate immunity-, and neutrophil-related genes including DUSP1, HMGB2, MMP9, and S100A8. Canonical pathways with positive IPA z-scores included Neutrophil degranulation, Neutrophil Extracellular Trap Signaling Pathway, and Toll-like Receptor Signaling; upstream regulators included TNF, IL1B, IFNG, and STAT3. Deconvolution identified 7 of 22 differing subsets (q < 0.05), with relatively higher myeloid and lower lymphoid fractions in TBI. The Neutrophil degranulation signature score correlated with Injury Severity Score within TBI (Spearman &#x3c1; = +0.55; q < 0.001). CONCLUSIONS: Admission whole-blood transcriptomics characterized a neutrophil-predominant systemic transcriptional response in patients with acute TBI. This response was also evident among patients without major extracranial injury and was associated with total ISS. However, because the study lacked an appropriately matched non-TBI trauma comparator, the findings should be interpreted as a descriptive characterization of a systemic injury response accompanying TBI and do not establish a TBI-specific molecular signature or mechanism.

gene expression↗
PubMed2022

Epigenome-wide meta-analysis of PTSD symptom severity in three military cohorts implicates DNA methylation changes in genes involved in immune system and oxidative stress.

Epigenetic factors modify the effects of environmental factors on biological outcomes. Identification of epigenetic changes that associate with PTSD is therefore a crucial step in deciphering mechanisms of risk and resilience. In this study, our goal is to identify epigenetic signatures associated with PTSD symptom severity (PTSS) and changes in PTSS over time, using whole blood DNA methylation (DNAm) data (MethylationEPIC BeadChip) of military personnel prior to and following combat deployment. A total of 429 subjects (858 samples across 2 time points) from three male military cohorts were included in the analyses. We conducted two different meta-analyses to answer two different scientific questions: one to identify a DNAm profile of PTSS using a random effects model including both time points for each subject, and the other to identify a DNAm profile of change in PTSS conditioned on pre-deployment DNAm. Four CpGs near four genes (F2R, CNPY2, BAIAP2L1, and TBXAS1) and 88 differentially methylated regions (DMRs) were associated with PTSS. Change in PTSS after deployment was associated with 15 DMRs, of those 2 DMRs near OTUD5 and ELF4 were also associated with PTSS. Notably, three PTSS-associated CpGs near F2R, BAIAP2L1 and TBXAS1 also showed nominal evidence of association with change in PTSS. This study, which identifies PTSD-associated changes in genes involved in oxidative stress and immune system, provides novel evidence that epigenetic differences are associated with PTSS.

Adaptor Proteins, Signal Transducing↗
PubMed1975

Immunologic and virologic aspects of secretory immune system in human respiratory tract.

Many external mucosal surfaces in man are replete with immunoglobulin containing plasma cells and thymic dependent (T) lymphocytes. Immunization with viral vaccines administered via different routes have indicated that viral specific secretory immunoglobulins particularly of gamma A class are synthesized locally in the external mucosal surfaces. Local availability of viral antigens especially after local mucosal immunization appears to be the most effective means of inducing viral specific secretory antibody responses in the respiratory tract. Similarly, local induction of specific cellular immune responses in the respiratory tract and tonsilar lymphoid cells has been demonstrated after intranasal immunization with viral vaccines. Generally, the locally induced secretory antibody and cell-mediated immune responses in the respiratory tract appear to be independent of the immune response in the systemic sites, with little or no contribution from circulating immunoglobulins and T-cells. Information obtained after natural or vaccine induced infections with polio, influenza, measles, rubella and other viruses suggest that the outcome of a reinfection challenge in the respiratory and alimentary tracts is determined to a major extent by the presence and level of pre-existing secretory antibody. Although the precise role of locally induced cellular immunity in protection against viral infection remains to be determined, these observations suggest that the mechanism of immunologic defence in external surfaces may be mediated largely through specific secretory immunoglobulin and cellular immune response.

Agammaglobulinemia↗
PubMed1978

Effect of aflatoxin on the humoral and cell-mediated immune systems of the chicken.

Chickens fed 2.5 microgram of aflatoxin/g of diet from 2 to 4 weeks of age or from hatching to 4 weeks were deficient in cell-mediated immunity, as measured at 4 weeks of age by the graft-versus-host reaction. Delayed-type hypersensitive skin reactions to tuberculin were also reduced in chickens given dietary aflatoxin from hatching to 7 weeks of age. Humoral immunity, as measured by the ability of 4-week-old chicks to produce natural agglutinins to rabbit red blood cells, was not significantly altered by dietary aflatoxin. A significant decrease in concentrations of serum immunoglobulins (Ig) IgG and IgA, but no IgM, however, did occur in chicks given dietary aflatoxin from hatching to 4 weeks or between 2 and 4 weeks of age. Aflatoxin consumption from 0 to 2 weeks of age produced no marked effect on either cell-mediated or humoral immunity in 4-week-old chicks.

Aflatoxins↗
PubMed2026

EBV reactivation priming of the peripheral immune system in multiple sclerosis relapse.

Despite decades of research, the cellular and molecular events preceding multiple sclerosis (MS) relapse remain incompletely understood. Here, in this observational study of longitudinal blood samples from patients with relapsing-remitting MS, we used single-cell RNA sequencing, bulk transcriptomics, multiparameter flow cytometry and targeted viral reverse transcription quantitative polymerase chain reaction (RT-qPCR) to construct a time-resolved atlas of immune perturbations surrounding relapse. A reproducible pre-relapse signature in monocytes and B cells, emerging up to 3&#x2009;months before clinical onset, was enriched for host genes responsive to Epstein-Barr virus (EBV) lytic reactivation factors. RT-qPCR confirmed elevated EBV LMP-1 transcripts in pre-relapse B cells, and flow cytometry demonstrated expansion of CD11c+ atypical B cell populations displaying EBV surface protein gp350. Pre-relapse transcriptional modules overlapped with MS genome-wide association study (GWAS) risk loci and EBNA-2-bound enhancers, suggesting that inherited MS susceptibility and EBV-responsive programs operate through shared regulatory elements. How this peripheral activation relates to central nervous system lesion formation remains to be established. These findings nonetheless suggest that EBV reactivation, when occurring within a genetically predisposed peripheral immune environment, is a proximal precursor of MS relapse.

Journal Article↗
PubMed1976

Immune system to uremia.

Pneumonia [4,9] and septicemia are still the principle causes of the high mortality in acute renal failure. Moreover, according to the EDTA report, 19% of chronic intermittent dialysis patients die from infection [17]. The resulting conclusion, that cellular and humoral immune responses are suppressed in renal insufficiency, is further supported by experimental evidence.

Animals↗
PubMed2026

Widespread Molecular Imprints in the Serum Proteome of COVID-19 Convalescents Uncovering Immune System Sequelae.

Post-COVID-19 sequelae have become an emerging global health issue, but the mechanisms for the sustained susceptibility of convalescents to the sequelae remain poorly understood. Here we report the use of a restricted open-search approach to explore the molecular imprints of SARS-CoV-2 infection left on the proteome of 412 COVID-19 patients and convalescences. A total of 827 non-standard amino acid variations, chemically modified residues as well as post-translational modifications, termed non-coded amino acids (ncAAs), are found spreading over 29,814 sites in patient's serum proteins. Markedly, widespread ncAAs are induced and sustainedly imprinted on the serum proteome predominately perturbing the immunoglobulin-mediated immune response, complement activation and coagulation regulation even 12 months after recovery. Sustained amino acid variations and chemical modifications are found in the complementary&#x2011;determining regions (CDRs) of the variable region of immunoglobulin contributing to the interactions between the emerging antibody and antigens; durable chemical amino acid modifications found in the hyper ncAA-modified regions of the constant region of immunoglobulin important for the interaction with the complement and regulatory receptors. In the complement system, inducible ncAAs are memorized in the components essential for the complement activation, amplification cascades and membrane attack processes. Thus, the workflow described in this study can be used to identify the molecular imprints of viral infection at the proteomic scale, particularly the specific antibodies and the immune targets left in COVID-19 patients and convalescents.

Humans↗