Search Results (323)

Background: The development of safe and effective vaccines against SARS-CoV-2 was crucial for controlling COVID-19 and establishing long-lasting immune memory in the population. Methods: This study evaluated cellular immune memory in individuals vaccinated with different regimens in Rio Grande do Sul using flow cytometry. Additionally, the rs2228059 polymorphism in the IL15RA gene was genotyped. A total of 62 participants were randomly recruited. Results: A decrease in memory T cell subsets in response to SARS-CoV-2 stimuli was observed in total CD3⁺, CD4⁺, and CD8⁺ T cells. Regarding the timing of the last vaccine dose, 94.4% of participants had received their final COVID-19 vaccination at least two years prior to recruitment. The rs2228059 polymorphism was genotyped in 443 individuals from the Rio Grande do Sul population. Among participants who received the ChAdOx1/ChAdOx1/BNT162b2 vaccination regimen and carried the TT genotype, an increase in CD8⁺ naive, CD8⁺ effector and CD4⁺ naive subsets was observed in stimulated cells. Although preliminary, the results suggest no major differences between vaccination regimens. Conclusions: The progressive reduction in memory T cell counts supports the need for booster doses, which is essential not only in the context of new emerging variants but also especially to maintain adequate cellular immune protection. Full article

Background and Objectives: MGN-3/Biobran (BRM4, Lentin Plus or Ribraxx) is a natural, rice bran-derived arabinoxylan immunoceutical that modulates the adaptive immune response to viral infections. In response to bacterial infections, basophils act as “first responders” and are also associated with modulation of the adaptive immune response. The maturation of pluripotent CD34⁺ stem cells into basophils is supported by the cytokine interleukin-3 (IL-3). The aim was to test the hypothesis that modulation of the adaptive immune response in bacterial infection by MGN-3/Biobran entails a basophilic response. The tick-related disorder Lyme borreliosis was chosen as the disease model; tick bites are associated with cutaneous IL-3-mediated basophil recruitment. Materials and Methods: A three-month randomised double-blind placebo-controlled trial was conducted in patients with a history of borreliosis who were suffering from symptoms attributable to this disorder. The immunoceutical group received oral Biobran; the dosage for both groups was 1 g thrice daily. Both groups were matched for age, sex, and ethnicity. Results: A higher percentage of basophil count occurred in the immunoceutical group (p = 0.038). The final general linear model included the group (immunoceutical/placebo) and change in fatigue assessed by the 11-item Chalder Fatigue Questionnaire (CFQ) (r² = 0.63; p = 0.0066). The change in basophil count was positively correlated with CFQ change (r_s = 0.633; p = 0.020); only the immunoceutical group showed a positive correlation. Conclusions: These results support the hypothesis being tested. Basophils may modulate the adaptive immune response by acting as immunoregulatory cells. They can regulate the functioning of type 2 T-helper lymphocytes, enhance immunological memory, and present antigens to CD8 T lymphocytes. Further studies are needed to clarify potential mechanistic factors and the timing of this basophilic response. Full article

Background: Immunological monitoring in multiple sclerosis (MS) patients treated with disease-modifying drugs may help predict infectious complications and guide treatment. The main objective of this study was to evaluate whether anti-CD20 treatments in MS patients induce immunodeficiency and whether certain immunological parameters can predict the risk of infection and response to treatment. Methods: This retrospective, observational, single-centre study included MS patients who started treatment with ocrelizumab or rituximab and received follow-up in the Neuroimmunology Unit of our centre between January 2017 and January 2023. The study was conducted in collaboration with the Immunology Department of this hospital. Results: Fifty-five patients were included, with a mean age of 47 years and a follow-up period of 24 months. Analyses of lymphocyte subpopulations (T, B, NK) and immunoglobulin levels (IgG, IgA, IgM) were performed before treatment and at 6-, 12- and 24-month follow-ups. In addition, we carried out an exhaustive study of B cells in the baseline analysis. Sixty-four percent of patients presented infections, mostly due to COVID-19. Three patients developed cryptogenic organising pneumonia. IgG hypogammaglobulinemia was the main risk factor for developing infections. Patients with infections had fewer mature memory B cells and a lower percentage of NK cells. Furthermore, a lower proportion of naïve and mature memory B cells was associated with inflammatory activity and disease progression, respectively. The absence of CD20 depletion during follow-up was associated with clinical worsening. Conclusions: Baseline immunophenotype and immunological monitoring can help predict the risk of infections and the efficacy of anti-CD20 therapy in MS patients. Full article

Aim: This study aimed to characterize and compare the composition of central (TCM), effector (TEM), tissue-resident (TRM), and terminally differentiated (TEMRA) memory T cells in mid-luteal endometrium during the window of implantation (WOI) in women with and without a previous miscarriage. Methods: Stromal lymphocytes from endometrial samples (P + 5) were analyzed by multicolor flow cytometry to quantify total, CD4⁺ and CD8⁺ TCM (CD45RA⁻CCR7⁺), TEM (CD45RA⁻CCR7⁻), TRM (CD69⁺), and TEMRA (CD45RA⁺CCR7⁻) subsets. Participants were grouped as having no previous miscarriage (n = 38) or ≥1 previous miscarriage (n = 33), and the relative distribution of these memory subsets was compared between groups. Correlations, PCA and logistic regression were used to assess global memory network organization. Results: Women with prior miscarriage exhibited higher TCM proportions among total and CD8⁺ lymphocytes (p < 0.01), alongside lower CD8⁺ TEM (p = 0.02) and higher CD4⁺ TEM (p = 0.01). TRM showed a mild, non-significant increase (p = 0.18), while TEMRA remained stable. TRM correlated positively with both TCM (r = 0.51) and CD4⁺ TEM (r = 0.40), indicating coordinated organization among memory subsets. Multivariate analyses (PCA and logistic regression) confirmed these trends and identified the TCM/TEM ratio as the most discriminative parameter. Conclusions: Endometrial memory T-cell composition during the WOI differs in women with miscarriage history, characterized by central memory expansion and reduced effector memory proportions, with parallel increases in tissue-resident cells. These changes suggest persistent remodeling of the local immune memory network toward a long-lived, less differentiated phenotype that may influence implantation readiness in subsequent cycles. Full article

We previously described an increased incidence of HIV among individuals infected with Wuchereria bancrofti (WB). However, no host, parasite, or viral factors were reported as directly associated with the increase in HIV incidence in this group. To investigate this, we compared T cell phenotypes between WB+ and WB− women. Flow cytometry analysis of activation and differentiation markers on CD4 T cells, as well as HIV entry receptor CCR5 was performed on cervical and peripheral blood samples from 54 women living without HIV (WLWoH). Additionally, HPV testing was performed on their specimens and for 13 WLWH. WB infection was associated with a significantly increased frequency of CD3⁺γδ2⁺ T cells in the cervical mucosa (median 4.0% vs. 1.4%, p = 0.012). Contrary to our expectations, we found lower frequencies of CCR5 on total, memory and activated memory CD4 T cells in the WB+ group. However, differences diminished after accounting for age and site of recruitment. WB and HIV infections were associated with an increased likelihood of high-risk human papillomavirus (HR HPV) positivity. (WB status: odds ratio (OR) 4.1, p = 0.066; HIV status: OR 5.5, p = 0.068). Our findings suggest immunological mechanisms by which WB increases the risk for other infections, e.g., HIV and HR HPV, albeit independent of the CCR5 receptor. Full article

Background: Permanent cancer resolution requires a complete immunological response with generation of memory against malignant cells. Immunogenic cell death (ICD) achieves this by coupling cell death with the emission of damage-associated molecular patterns (DAMPs). Current cancer treatments immunosuppress the host; thus, new alternatives are needed. Ganoderma species produce anticancer triterpenoids (GTs); however, their mechanism remains unclear. Objective: This systematic review aims to provide insights into GTs’ pharmacodynamics and assess hypothetical ICD potential. Methods: Web of Science and PubMed databases were consulted following PRISMA guidelines. Studies from inception until 2024, reporting molecular changes associated with GTs’ anticancer effects, were considered. Nonhuman models were excluded. GTs and GTs-ICD converging molecular targets were listed and submitted to Cytoscape’s stringApp to construct protein interaction networks. Topological and enrichment analysis were performed. Results: A total of 204 articles were found, and 69 remained after screening. Overall anticancer effects include loss of mitochondrial membrane potential, DNA and RNA damage, autophagy, cell cycle arrest, and leukocyte activation. 136 molecular targets of GTs were identified; upregulated proteins include CHOP, PERK, p-eIF2α, and HSP70, a key DAMP. GTs and ICD share 24 molecular targets. GO:BP and KEGG enrichment analysis suggest that GTs’ anticancer effects are related to stress response, cell death regulation, and PD-L1/PD-1 checkpoint inhibition. GT-ICD enrichment converges on endoplasmic reticulum stress, unfolded protein response, and organelle membrane perforation. Conclusions: GTs exhibit polypharmacological anticancer effects, including anti-immunosuppression, upregulation of ICD-adjacent machinery, and even an increase in HSP. However, further studies are required to confirm a proper causal link between GTs’ cancer cell treatment and DAMP emission. Full article

Long COVID (LC) is characterized by a wide range of symptoms, the causes of which remain unclear. We investigated associations between inflammatory and coagulation factors, adaptive immune response to SARS-CoV-2, and LC. We enrolled 196 unvaccinated individuals with SARS-CoV-2 (March–June 2020). Blood samples were collected at three (T3M) and twelve (T12M) months post infection. Plasma concentrations of coagulation factors (D-Dimer, E-Selectin, ICAM-1, VCAM-1) and inflammatory markers (IL-6, IL-8, TNF-α, IL-1β) were measured by ELISA, and SARS-CoV-2-specific T-cell response was assessed by Elispot. LC occurred in 66/196 patients (34%); 77.8% had been hospitalized. Respiratory symptoms were present in 54%, fatigue in 30%, and neuropsychological symptoms in 14%. At T3M, hospitalized patients exhibited higher levels of ICAM-1, VCAM-1, and IL-6, along with increased immunoreactivity. LC patients exhibited elevated IL-8 and TNF-α and enhanced immunoreactivity at T3M, though these differences were not observed at T12M. Inflammatory and coagulation markers were altered at three months after acute infection, with some changes persisting at one year, suggesting a long-term immunological impact of SARS-CoV-2 on the inflammatory response. A SARS-CoV-2-specific T-cell response was still detectable at T12M, albeit at a lower level than at T3M, suggesting the persistence of protective memory T-cells beyond the acute phase. Full article

Various AML treatment regimens might trigger different immunological mechanisms against leukemic cells. The role of different immune cell subsets in the mediation of antileukemic processes is not clear. In this study, we longitudinally assessed (leukemia specific) immune subtype compositions in 17 AML patients before stem cell transplantation (SCT) at different timepoints in the course and in different stages of the disease using flow cytometry. Further we correlated immune cell compositions with patients’ response to induction therapy and the median survival (3.8 months in our cohort) of the patients. Finally, we compared immune cell profiles from patients before and after SCT. (1) Patients in CR (compared to dgn and PD) were characterized by higher frequencies of leukemia-derived DC (DCleu), (leukemia-specific—IFNg or TNFα producing or CD107a degranulating) anti-tumor relevant T cells (Tgd, Tβ7), central/effector memory cells (Tcm, Tem), alongside with lower frequencies of (leukemia-specific) regulatory T cells. (2) Patients with higher frequencies of (leukemia-specific) antitumor relevant T cells, (leukemia-specific) memory T cells and NK cells demonstrated a prolonged median survival time and/or responded better to induction (RTI) treatment (3) Comparing patients before and after SCT, only minimal differences were observed. However, patients in CR_preSCT exhibited higher frequencies of DC, Tcm, Tβ7 and leukemia-specific iNKT cells compared to patients in CR_postSCT. (1) Immune monitoring qualifies to quantify (leukemia-specific) immune cells in different stages and under different treatment strategies in the course of AML. (2) Higher frequencies of activating and antitumor relevant leukemia-specific immune cell subtypes found after ‘costimulatory’ (especially KitM induced) treatment’ and in CR. (3) In particular, DC/DCleu, (leukemia-specific) antitumor-relevant T (memory) and NK cells seem to dominate in CR and positively influence RTI and survival. (4) Monitoring of (leukemia-specific) immune cell subtypes contribute to quantify individual AML patients’ antileukemic potential in different stages and treatment groups and also could be used to predict patients’ survival. Full article

Patients with systemic lupus erythematosus (SLE) and lupus nephritis (LN) are at increased risk of severe infections, making effective vaccination strategies essential. While antibody responses to SARS-CoV-2 vaccination have been studied in SLE, less is known about innate immune correlates. Therefore, we evaluated cytokines with a particular emphasis on interferon and chemokine profiles. To fulfill the immunological picture, we also assessed neutralizing antibodies against SARS-CoV-2 variants, lymphocyte subpopulations, and selected gene expression signatures in 33 patients stratified by vaccination status: fully vaccinated (FV, n = 23) and partially vaccinated (PV, n = 10). Serum analyses showed that FV patients exhibited increased type I (IFN-α2, IFN-β) and type III (IFN-λ1, IFN-λ2/3) interferons, as well as elevated pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-12p70) and IL-10, whereas neutralizing antibody (Neut. Ab.) titers against wild-type and variant strains, including Omicron, were comparable between groups. Immunophenotyping demonstrated preserved T- and B-cell subset distributions, except for reduced CD8⁺CD197⁺CD45RA⁻ (central memory) T cells in FV patients. ISG15 gene expression was upregulated in the T cells of FV patients. Correlation analyses linked IL-6 with disease activity and IL-8, GM-CSF, IFN-β, IL-10, and Alpha Neut. Ab. with organ damage. Complement C3 correlated inversely with IFN-α2 and IFN-γ, while C4 correlated positively with Alpha and Omicron Neut. Ab. These findings highlight that vaccination in SLE induces distinct interferon and cytokine signatures without consistent enhancement of neutralizing antibodies against SARS-CoV-2, underscoring the importance of integrated immune correlates in assessing vaccine responses in this population. Full article

Myocarditis is an inflammatory disease of the heart characterized by a complex interplay between innate and adaptive immune responses. The innate immune system provides first-line defense and includes soluble molecules, including macrophages, neutrophils, dendritic cells, and molecular mediators, but lacks immunological memory. In contrast, the adaptive immune system, via T and B lymphocytes, offers high specificity and long-term memory, which can sometimes target myocardial tissue, causing autoimmune injury. Particularly, acute myocarditis is characterized by dysregulated immune signaling, with cytokines (IL-2, IFN-γ, IL-12, IL-4, IL-10) and chemokines (MCP-1, CXCL4, CXCL10) driving disease progression, while adhesion molecules (ICAM-1, VCAM-1, VAP-1) promote leukocyte trafficking and cardiac inflammation. The balance between pro-inflammatory and regulatory responses determines disease outcomes, ranging from resolution with recovery to fulminant myocarditis or progression to dilated cardiomyopathy. Emerging therapeutic approaches targeting cytokines, chemokines, and adhesion molecules, along with established immunosuppressive treatments, underline the potential for modulating immune responses in myocarditis and, thereby, improving patient outcomes. Full article

Background: Streptococcus equi subspecies equi (S. equi) is the cause of strangles, one of the most prevalent diseases of horses worldwide. The disease is characterised by fever and the formation of abscesses in the lymph nodes of the head and neck, which can restrict the airway. A multicomponent subunit vaccine, Strangvac, has been shown to effectively reduce clinical signs of strangles and to reduce its incidence. Objective: The aim of this study was to determine the immune response against the immunoglobulin-cleaving endopeptidase IdeE, a key protective component within the vaccine and the ability of antibodies to neutralize the proteolytic activity of IdeE. Methods: An in vitro assay was developed to measure the functional inhibition of recombinant IdeE by horse sera pre- and post-vaccination. The IdeE-neutralising titres were compared to the corresponding IdeE-specific antibody titres measured by iELISA (indirect Enzyme-Linked Immunosorbent Assay). Results: A significant IdeE-specific antibody response in blood serum collected from ponies was induced after Strangvac vaccinations. Concomitantly, significant increases in the neutralising activity of IdeE occurred, persisting for at least 12 months post-second vaccination. IdeE-neutralising activity was further increased significantly after a third vaccination, even when the third dose was administered 12 months after the second dose, demonstrating that immunological memory to the vaccine persisted for 12 months. There was a significant correlation between the IdeE-neutralising activity of blood sera and the level of IdeE-specific antibodies. Conclusions: These data provide insights into one potential mechanism by which this vaccine protects Equids against or during S. equi infection. Full article

Investigating immunological and viral reservoir dynamics in blood and GALT during acute HIV phase advances understanding of HIV persistence. Dynamics of T cells and HIV reservoirs immediately after early ART require further investigation. We evaluated the ART impact at 12 (M12) and 24 months (M24) on immunological, virological and reservoir markers of 24 participants starting ART at Fiebig ≤ V (Baseline = D0) in a Brazilian cohort. We measured the frequency of T cell activation, exhaustion, memory subsets, Th17 and pTfh cells by flow cytometry and quantified total HIV DNA by qPCR in PBMC and GALT. Most participants were cisgender MSM (95.9%), with a median age of 27 years (IQR 25–36). At enrollment (D0), four participants used triple ART as PEP, and two were under oral PrEP and they exhibited higher CD4/CD8 ratios. Higher CD4/CD8 ratios were also observed in participants classified as Fiebig I to III. A total of 92% achieved viral suppression at M12 and 96% at M24. CD4 counts rose from 646 to 861 cells/mm³, and the CD4/CD8 ratio improved from 0.76 to 1.24 (p < 0.01). HIV DNA in PBMCs decreased 4-fold by M12 and 61-fold by M24, with 50% of participants reaching undetectable levels by M24 (p < 0.01). In GALT, undetectable HIV DNA increased from 27% at D0 to 75% at M12. HIV DNA in PBMCs and GALT correlated with plasma VL, while the CD4/CD8 ratio was inversely linked to PBMC reservoirs (rho = −0.66; p < 0.05). Early ART reduced activated CD8⁺ T cells (p < 0.05) but had minimal effects on CD4⁺ T cells or exhaustion markers. By M24, CD8⁺ TCM increased, and CD8⁺ TEF decreased (p < 0.01), while Th17 and pTfh levels remained stable. Early ART led to viral suppression and immune restoration, and influenced reservoir dynamics. The CD4/CD8 ratio was shown to be a key marker of early treatment success. Since a quarter of the participants were identified while initiating PrEP/PEP, it is important to consider the acute phase window according to vulnerability. Recent PEP/PrEP use often excludes participants from clinical trials on bNAbs and therapeutic vaccines targeting viral reservoirs during the acute phase of HIV. Since these are the populations that may benefit from these strategies, larger studies including those people are needed. Full article

Research in the past fifteen years has established that innate immune cells can develop immune memory, termed trained immunity. Trained innate immune cells exhibit distinct lasting epigenetic and metabolic changes that prime these cells upon repeated exposure. The gastrointestinal tract provides an important immunological barrier and is home to many innate immune cells, where trained immunity serves an essential role. This review summarizes what is currently known about the basic mechanisms behind innate immune memory, the roles of innate immune cells within the intestine, intestinal-specific trained immunity, and therapeutic potential for targeting trained immunity in the context of gastrointestinal disorders. Full article

Plants have evolved a complex, multilayered immune system that integrates molecular recognition, signaling pathways, epigenetic regulation, and small RNA-mediated control. Recent studies have shown that DNA-level regulatory mechanisms, such as RNA-directed DNA methylation (RdDM), histone modifications, and chromatin remodeling, are critical for modulating immune gene expression, allowing for rapid and accurate pathogen-defense responses. The epigenetic landscape not only maintains immunological homeostasis but also promotes stress-responsive transcription via stable chromatin modifications. These changes contribute to immunological priming, a process in which earlier exposure to pathogens or abiotic stress causes a heightened state of preparedness for future encounters. Small RNAs, including siRNAs, miRNAs, and phasiRNAs, are essential for gene silencing before and after transcription, fine-tuning immune responses, and inhibiting negative regulators. These RNA molecules interact closely with chromatin features, influencing histone acetylation/methylation (e.g., H3K4me3, H3K27me3) and guiding DNA methylation patterns. Epigenetically encoded immune memory can be stable across multiple generations, resulting in the transgenerational inheritance of stress resilience. Such memory effects have been observed in rice, tomato, maize, and Arabidopsis. This review summarizes new findings on short RNA biology, chromatin-level immunological control, and epigenetic memory in plant defense. Emerging technologies, such as ATAC-seq (Assay for Transposase-Accessible Chromatin using Sequencing), ChIP-seq (Chromatin Immunoprecipitation followed by Sequencing), bisulfite sequencing, and CRISPR/dCas9-based epigenome editing, are helping researchers comprehend these pathways. These developments hold an opportunity for establishing epigenetic breeding strategies that target the production of non-GMO, stress-resistant crops for sustainable agriculture. Full article

The success of mRNA-based SARS-CoV-2 vaccines has been confirmed in both preclinical and clinical settings. However, the development of safe and efficient mRNA vaccine delivery platforms remains challenging. In this report, PBAE-G-B-SS-modified CaO₂ nanofibers and Au@OVA@Cu@Dendrobium huoshanense polysaccharides were employed to establish novel self-assembling polymeric micelles (CaO₂@Au@OVA@Cu@DHPs) capable of serving as both an adjuvant and a delivery system for mRNA vaccines. In vitro, CaO₂@Au@OVA@Cu@DHPs nanoparticles (NPs) were conducive to effective macrophage antigen uptake and efficient antigen processing. In vivo, P-CaO₂@Au@OVA@Cu@DHPs NP administration was associated with a reduction in the ovalbumin (OVA) release rate that was conducive to the sustained induction of long-term immunity and to the production of higher levels of different IgG subtypes, suggesting that these effects were attributable to enhanced antigen uptake by antigen-presenting cells. Overall, these present data highlight the promise of these P-CaO₂@Au@OVA@Cu@DHPs NPs as an effective and safe platform amenable to vaccine delivery through their ability to provide robust adjuvant activity and sustained antigen release capable of eliciting long-term immunological memory while potentiating humoral and cellular immune responses. Full article