IgG Levels Research Articles

Glycoprotein E-Displaying Nanoparticles Induce Robust Neutralizing Antibodies and T-Cell Response against Varicella Zoster Virus.

The Varicella zoster virus (VZV), responsible for both varicella (chickenpox) and herpes zoster (shingles), presents significant global health challenges. While primary VZV infection primarily affects children, leading to chickenpox, reactivation in later life can result in herpes zoster and associated post-herpetic neuralgia, among other complications. Vaccination remains the most effective strategy for VZV prevention, with current vaccines largely based on the attenuated vOka strains. Although these vaccines are generally effective, they can induce varicella-like rashes and have sparked concerns regarding cell virulence. As a safer alternative, subunit vaccines circumvent these issues. In this study, we developed a nanoparticle-based vaccine displaying the glycoprotein E (gE) on ferritin particles using the SpyCatcher/SpyTag system, termed FR-gE. This FR-gE nanoparticle antigen elicited substantial gE-specific binding and VZV-neutralizing antibody responses in BALB/c and C57BL/6 mice-responses that were up to 3.2-fold greater than those elicited by the subunit gE while formulated with FH002C, aluminum hydroxide, or a liposome-based XUA01 adjuvant. Antibody subclass analysis revealed that FR-gE produced comparable levels of IgG1 and significantly higher levels of IgG2a compared to subunit gE, indicating a Th1-biased immune response. Notably, XUA01-adjuvanted FR-gE induced a significant increase in neutralizing antibody response compared to the live attenuated varicella vaccine and recombinant vaccine, Shingrix. Furthermore, ELISPOT assays demonstrated that immunization with FR-gE/XUA01 generated IFN-γ and IL-2 levels comparable to those induced by Shingrix. These findings underscore the potential of FR-gE as a promising immunogen for the development of varicella and herpes zoster vaccines.

Treatment patterns and burden of infection in patients with chronic lymphocytic leukemia and secondary immunodeficiency: a retrospective database study

Patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and secondary immunodeficiency disease (SID) are susceptible to severe, recurrent, or persistent infections. This retrospective cohort study assessed the burden of infection in patients with CLL/SLL with and without SID, and in immunoglobulin replacement therapy (IgRT)-treated and -untreated patients with CLL/SLL and SID. Anonymized data from the US Optum-Humedica database (Oct-1-2015–Mar-10-2020) were used. Eligible patients aged ≥ 18 years with a confirmed CLL/SLL diagnosis were assigned to cohorts (SID or no-SID) using an algorithm based on serum IgG levels < 5.0 g/L, hypogammaglobulinemia diagnosis codes, and ≥ 1 major infection. A further sub-categorization was made based on patients with SID who received IgRT and those who did not. During 12-month follow-up, patients with CLL/SLL and SID were significantly more likely to experience infections (70.1% vs. 30.4%), including severe bacterial infections (39.8% vs. 9.2%), and infections requiring hospitalization (27.7% vs. 5.8%) than patients without SID. The use of anti-infectives and healthcare resource utilization (HCRU) was also higher in the SID cohort versus the no-SID cohort. Overall survival was shorter in patients with SID than those without (12.3 vs. 16.9 months). In patients with CLL/SLL and SID, burden of infection and HCRU were greater in IgRT-treated patients than in no-IgRT patients, potentially highlighting the IgRT-treated cohort as a more vulnerable population. Increasing understanding of SID burden may help to improve outcomes in patients with CLL/SLL. Further research is needed to develop guidance for IgRT use and to assess the benefits of IgRT in this vulnerable population.

Clinical characteristics, treatment, and outcomes of nivolumab induced immune thrombocytopenia.

Immune thrombocytopenia (ITP) represents an uncommon hematological side effect associated with nivolumab, and its distinct clinical attributes remain poorly defined. This research aimed to explore the clinical manifestations and outcomes of ITP induced by nivolumab. Reports on nivolumab induced ITP up to April 30, 2024, were collected for retrospective analysis. The study involved 34 patients with a median age of 67 years (range 32, 82). The onset of ITP varied from 10 to 100 days post initial dosage, with a median onset at 70 days. The majority of patients exhibited no symptoms, with only 23.5% experiencing clinically significant bleeding and 11.8% facing non-clinically significant bleeding. The median platelet count was 12 × 109/L (range 0, 115), with 67.6% of patients having platelet levels below 25 × 109/L. Bone marrow biopsy revealed mainly elevated megakaryocytes. Platelet-associated IgG levels were elevated with a median of 210 ng/107 cells (range 73, 1130). Subsequent interventions, which included cessation of nivolumab, administration of systemic corticosteroids, intravenous immunoglobulin therapy, a thrombopoietin receptor agonist, platelet transfusion, and rituximab treatment, resulted in 82.4% of subjects achieving normalized platelet counts, whereas 5.9% passed away due to ITP. ITP is a rare life-threatening immune-related adverse event and necessitates close monitoring. Systemic steroids are the primary treatment for ITP, while intravenous immunoglobulin, thrombopoietin receptor agonist and rituximab are other options.

Evaluation of lyophilized bacteriophage cocktail efficiency against multidrug-resistant Salmonella in broiler chickens

Currently, phage biocontrol is increasingly used as a green and natural technology for treating Salmonella and other infections, but phages exhibit instability and activity loss during storage. Therefore, in this study, the effects of lyophilization on the activity and stability of phage cocktails for the control of multidrug-resistant Salmonella in broiler chickens were determined. Eight serotypes of Salmonella were isolated and identified from broiler chicken farms, and bacteriophages against multidrug-resistant Salmonella enterica subsp. enterica serovar Kentucky, Salmonella enterica subsp. enterica serovar Typhimrium and Salmonella enterica subsp. enterica serovar Enteritidis were isolated. The bacteriophage cocktail was prepared and lyophilized, and it was subjected to in vitro and in vivo examinations. A reconstituted lyophilized bacteriophage cocktail was used for the oral treatment of chicks before and after challenge with multidrug-resistant S. Kentucky. The colonization of cecum by S. Kentucky was detected by using real-time PCR, and the serum levels of IgM, IgA and IL-4 and pathological changes in the different groups were detected. Three Caudovirales phages families were identified including Autographiviridae, Straboviridae and Drexlerviridae against multidrug-resistant S. Kentucky, S. Typhimrium and S. Enteritidis. The groups treated with the bacteriophage cocktail showed no clinical signs, no postmortem lesions, and a mortality rate of 0%, which improved the growth performance parameters. Additionally, the estimated serum levels of IgM, IgA and IL-4 were significantly greater in the bacteriophage cocktail-treated groups. Lyophilization effectively preserves the long-term storage stability of phages. Therefore, lyophilized bacteriophage cocktail therapy is a valuable approach for controlling multidrug-resistant Salmonella infections in broiler chickens.

Prevalence of Anisakiasis in Madrid (Spain) after 20 Years of Preventive Legislation.

Historical seroprevalence data for Anisakis in Spain vary greatly depending on the sampling region owing to different fish consumption habits. As a result of European Regulation (EC) No. 853/2004, the Royal Decree 1420/2006 on the prevention of parasitosis by Anisakis in fishery products supplied by establishments that serve food to final consumers or to communities came into force in Spain. In this study, a prevalence study of Anisakis in Madrid has been conducted to verify the prophylactic effects of the application of the law. Sera from 500 blood donors from the Fundación Jiménez Díaz University Hospital (Madrid/2021-2023) were collected, and the levels of anti-Anisakis IgG, IgA, and IgE were analyzed by ELISA, comparing them with those obtained with 110 donors from the Red Cross and the "Gómez Ulla" Central Defense Hospital (Madrid/2001-2002). The percentages of positivity in the 2021-2023 donor group were IgG (13.6%), IgA (13.6%), and IgE (2.2%), while in the 2001-2002 donors they were positive for IgG (15.45%), IgA (14.54%), and IgE (11.65%). A reduction of more than 80% was observed in the prevalence of anti-Anisakis IgE in the healthy population of Madrid, which confirmed the positive effect of RD1420/2006, which was later incorporated into RD1021/2022.

Association of anti-HMGCR antibodies of the IgM isotype with refractory immune-mediated necrotizing myopathy.

Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) autoantibodies are one of the myositis-specific antibodies which is associated with immune-mediated necrotizing myopathy (IMNM). However, the relationship between anti-HMGCR isotypes and prognosis has not yet been fully investigated. This study was conducted to gain insight into the association between anti-HMGCR isotypes and clinical, and prognosis in IMNM patients who were positive for anti-HMGCR antibodies. Levels of anti-HMGCR isotypes (IgG, IgA and IgM) were assessed by enzyme-linked immunosorbent assay (ELISA) in 123 consecutive serum samples obtained from 71 patients who were positive for anti-HMGCR IgG at baseline. Disease activity was assessed by manual muscle testing (MMT) 8, Physician's Global Assessment (PGA) visual analog scale (VAS), and muscle VAS. Baseline anti-HMGCR IgG levels were correlated with PGA VAS (r = 0.24; p = 0.04), muscle VAS (r = 0.32; p < 0.01), and MMT8(r=-0.24; p = 0.04), and baseline anti-HMGCR IgM levels were positively correlated with PGA VAS (r = 0.27, p = 0.02), muscle VAS (r = 0.24, p = 0.04). Anti-HMGCR IgM positive patients had a lower age of onset [29(25,46) vs. 51(33,65), p = 0.006], and a higher proportion of neck weakness (63.5% vs. 34.6%, p = 0.031) compared with anti-HMGCR IgM negative patients. Longitudinal analysis showed that the changes in anti-HMGCR IgG levels were correlated with the changes in the PGA VAS (β = 3.830; p < 0.0001), muscle VAS (β = 2.893; p < 0.0001), MMT8 (β=-19.368; p < 0.0001), and creatine kinase (CK) levels (β = 3900.05, p < 0.0001). Anti-HMGCR IgM levels were weakly correlated with anti-HMGCR IgA levels at baseline (r = 0.33, p < 0.01), and the variations in anti-HMGCR IgA levels were correlated with the changes in anti-HMGCR IgM levels during follow-up (β = 0.885; p < 0.0001). There were more patients with anti-HMGCR IgM who showed a refractory course than those who were with anti-HMGCR IgM negative (polycyclic course: 40% vs. 25%; chronic continuous course: 46.7% vs. 20.5%, p = 0.018). In anti-HMGCR IgG-positive IMNM patients, the levels of anti-HMGCR IgG are associated with disease activity, and anti-HMGCR IgM is associated with refractory outcome and poor prognosis.

Low Rates of Immunity among Medical Students and Residents in the Era of the Resurgence of Measles.

Measles is a highly contagious viral disease spread through respiratory droplets. The number of reported cases increased worldwide in 2023, particularly in the European Region. Italy reported 213 cases in the first quarter of 2024, with most of them in unvaccinated adults aged 15-64. Maintaining high vaccination coverage is essential to prevent outbreaks, especially in healthcare settings where measles transmission is a significant risk. In our study, we collected serological and demographic information from all Italian and foreign medical students and residents (850) who underwent a pre-training assessment at the Tor Vergata Occupational Medicine Service, Rome, between 3 April 2023 and 31 January 2024. Of the 850 students and residents analyzed, we found only 546 (64.2%) with a protective level of IgG antibodies against measles, with a median IgG level of 2.00 AI. A significant proportion of students and residents were serologically non-immune, raising concerns about the potential risk of hospital transmission. To manage this risk, it is important to assess serological levels, vaccinate those with inadequate levels, and promote vaccination in the general population.

COVID-19 mRNA vaccines induce robust levels of IgG but limited amounts of IgA within the oronasopharynx of young children.

Understanding antibody responses to SARS-CoV-2 vaccination is crucial for refining COVID-19 immunization strategies. Generation of mucosal immune responses, including mucosal IgA, could be of potential benefit to vaccine efficacy, yet limited evidence exists regarding the production of mucosal antibodies following the administration of current mRNA vaccines to young children. We measured the levels of antibodies against SARS-CoV-2 from a cohort of children under 5 years of age (N=24) undergoing SARS-CoV-2 mRNA vaccination (serially collected, matched serum and saliva samples) or in a convenience sample of children under 5 years of age presenting to pediatric emergency department (nasal swabs, N=103). Further, we assessed salivary and nasal samples for the ability to induce SARS-CoV-2 spike-mediated neutrophil extracellular traps (NET) formation. Longitudinal analysis of post-vaccine responses in saliva revealed the induction of SARS-CoV-2 specific IgG but not IgA. Similarly, SARS-CoV-2 specific IgA was only observed in nasal samples obtained from previously infected children with or without vaccination, but not in vaccinated children without a history of infection. In addition, oronasopharyngeal samples obtained from children with prior infection were able to trigger enhanced spike-mediated NET formation, and IgA played a key role in driving this process. Despite the induction of specific IgG in the oronasal mucosa, current intramuscular vaccines have limited ability to generate mucosal IgA in young children. These results confirm the independence of mucosal IgA responses from systemic humoral responses following mRNA vaccination and suggest potential future vaccination strategies for enhancing mucosal protection in this young age group.

Increased levels of anti-Encephalitozoon intestinalis antibodies in patients with colorectal cancer.

The prevalence of microsporidiosis in the general population, or within specific groups of individuals/patients, is largely underestimated. The absence of specific seroprevalence tools limits knowledge of the epidemiology of these opportunistic pathogens, although known since the 1980s. Since microsporidia hijack the machinery of its host cell and certain species multiply within intestinal cells, a potential link between the parasite and colorectal cancer (CRC) has been suggested. To explore a potential epidemiological link between microsporidia and CRC, we evaluated the seroprevalence of Encephalitozoon intestinalis among CRC patients and healthy subjects using ELISA assays based on two recombinant proteins, namely rEiPTP1 and rEiSWP1, targeting polar tube and spore wall proteins. ELISA were performed in 141 CRC patients and 135 healthy controls. Patients with CRC had significantly higher anti-rEiPTP1 IgG levels than subjects in the control group. Anti-rEiPTP1 IgG, anti-rEiSWP1 IgG and anti-rEiPTP1 IgA levels were significantly increased among men with CRC compared to healthy men. Women with CRC who had died had higher rEiSWP1 IgG levels than those who were still alive. These higher antibody levels against microsporidia in patients with CRC suggest a relationship between microsporidia and pathophysiology of CRC.

Rational use of immunoglobulins (IVIgs and SCIgs) in secondary antibody deficiencies.

Immunoglobulins for intravenous use (IVIgs) and subcutaneous use (SCIgs) can prevent recurrent and severe infections in patients with secondary antibody deficiencies that are frequently linked to haematological/oncological malignancies as well as other clinical conditions and their respective treatments. Even so, as IVIgs and SCIgs are costly and their supply is limited, their clinical use must be optimised. The aim of this position paper is to provide structured practical guidance on the optimal use of IVIgs and SCIgs in secondary antibody deficiencies, particularly in haematological and oncological practice. The authors agree that the occurrence of severe infections is a prerequisite for the use of IVIgs. Serum IgG levels in general as well as IgG subclass levels can be additional indicators of whether a patient could benefit from IVIgs. Responsiveness to vaccines can help to identify immunodeficiency. Patients with chronic lymphocytic leukaemia or multiple myeloma who are receiving respective treatment, especially B-cell depletion therapy, but also some patients with autoimmune diseases are prone to antibody deficiencies and need IVIgs. For the optimal use of IVIgs and to maximise their potential benefit, the indication must be individually assessed for each patient. As a primary treatment goal, the authors define a sufficient prophylaxis of severe infections, which can be supported by normalising IgG levels. If the initiated treatment is insufficient or linked to intolerable adverse reactions, switching the product within the class of IVIgs or changing to a different batch of the same product can be considered. Pausing treatment can also be considered if there are no infections, which happens more frequently in summer, but treatment needs to be resumed once infections return. These structured recommendations for IVIg treatment in patients with secondary antibody deficiency may provide guidance for clinical practice and therefore help to allocate IVIgs to those who will benefit the most, without overusing valuable resources.

Assessing Fecal Microbial Diversity and Hormone Levels as Indicators of Gastrointestinal Health in Reintroduced Przewalski's Horses (Equus ferus przewalskii).

Diarrhea serves as a vital health indicator for assessing wildlife populations post-reintroduction. Upon release into the wild, wild animals undergo adaptation to diverse habitats and dietary patterns. While such changes prompt adaptive responses in the fecal microbiota, they also render these animals susceptible to gastrointestinal diseases, particularly diarrhea. This study investigates variations in fecal microorganisms and hormone levels between diarrhea-afflicted and healthy Przewalski's horses. The results demonstrate a significant reduction in the alpha diversity of the fecal bacterial community among diarrheal Przewalski's horses, accompanied by notable alterations in taxonomic composition. Firmicutes, Proteobacteria, and Bacteroidetes emerge as dominant phyla across all fecal samples, irrespective of health status. However, discernible differences in fecal bacterial abundance are observed between healthy and diarrhea-stricken individuals at the genus level, specifically, a diminished relative abundance of Pseudobutyrivibrio is observed. The majority of the bacteria that facilitate the synthesis of short-chain fatty acids, Christensenellaceae_R_7_group (Christensenellaceae), NK4A214_group (Ruminococcus), Lachnospiraceae_XPB1014_group (Lachnospiraceae), [Eubacterium]_coprostanoligenes_group (Eubacterium), Rikenellaceae_RC9_gut_group, Lachnospiraceae_AC2044_group (Lachnospiraceae), and Prevotellaceae_UcG_001 (Prevotella) are noted in diarrhea-affected Przewalski's horses, while Erysipelotrichaceae, Phoenicibacter, Candidatus_Saccharimonas (Salmonella), and Mogibacterium are present in significantly increased amounts. Moreover, levels of immunoglobulin IgA and cortisol are significantly elevated in the diarrhea group compared with the non-diarrhea group. Overall, this study underscores substantial shifts in fecal bacterial diversity, abundance, and hormone levels in Przewalski's horses during episodes of diarrhea.

Progranulin mediates the onset of pristane induced systemic lupus erythematosus

BackgroundsProgranulin (PGRN) is a growth factor-like molecule with diverse roles in homeostatic and pathogenic processes including the control of immune and inflammatory responses. Pathogenic inflammation is a hallmark of systemic lupus erythematosus (SLE) and elevated serum levels of PGRN has been evaluated as a biomarker of disease activity in SLE. However, the role of PGRN in SLE has not been fully investigated. This study is aimed to determine the potential involvements of PGRN in SLE.MethodsWild type (WT) and PGRN knockout (PGRN-/-) C57BL/6 mice received intraperitoneal injection of pristane for induction of a murine model of SLE. Sera were collected every biweekly and levels of anti-dsDNA antibody, IgG, and inflammatory factors were measured. Mice were sacrificed 5 months later and the renal lesions, as well as the proportions of T cell subtypes in the spleen were analyzed.ResultsFollowing exposure to pristane, PGRN-/- mice generated significantly lower levels of anti-dsDNA antibody and IgG relative to WT mice. PGRN-/- mouse kidneys had less IgG and collagen deposition compared with WT mice after pristane injection.ConclusionThe results indicate that PGRN participates in inflammatory response and renal damage in pristane induced SLE models, suggesting that PGRN mediates the onset of SLE.

Immunogenicity and protective efficacy of a recombinant lactococcus lactis vaccine against HSV-1 infection

BackgroundHerpes simplex virus type 1 (HSV-1) is a major cause of viral encephalitis, genital mucosal infections, and neonatal infections. Lactococcus lactis (L. lactis) has been proven to be an effective vehicle for delivering protein antigens and stimulating both mucosal and systemic immune responses. In this study, we constructed a recombinant L. lactis system expressing the protective antigen glycoprotein D (gD) of HSV-1.ResultsTo improve the stability and persistence of antigen stimulation of the local mucosa, we inserted the immunologic adjuvant interleukin (IL)-2 and the Fc fragment of IgG into the expression system, and a recombinant L. lactis named NZ3900-gD-IL-2-Fc was constructed. By utilizing this recombinant L. lactis strain to elicit an immune response and evaluate the protective effect in mice, the recombinant L. lactis vaccine induced a significant increase in specific neutralizing antibodies, IgG, IgA, interferon-γ, and IL-4 levels in the serum of mice. Furthermore, in comparison to the mice in the control group, the vaccine also enhanced the proliferation levels of lymphocytes in response to gD. Moreover, recombinant L. lactis expressing gD significantly boosted nonspecific immune reactions in mice through the activation of immune-related genes. Furthermore, following the HSV-1 challenge of the murine lung mucosa, mice inoculated with the experimental vaccine exhibited less lung damage than control mice.ConclusionOur study presents a novel method for constructing a recombinant vaccine using the food-grade, non-pathogenic, and non-commercial bacterium L. lactis. The findings indicate that this recombinant vaccine shows promise in preventing HSV-1 infection in mice.

Sequence Matters: Primary COVID-19 Vaccination after Infection Elicits Similar Anti-spike Antibody Levels, but Stronger Antibody Dependent Cell-mediated Cytotoxicity than Breakthrough Infection.

Infection before primary vaccination (herein termed "hybrid immunity") engenders robust humoral immunity and broad Ab-dependent cell-mediated cytotoxicity (ADCC) across SARS-CoV-2 variants. We measured and compared plasma IgG and IgA against Wuhan-Hu-1 and Omicron (B.1.1.529) full-length spike (FLS) and receptor binding domain after three mRNA vaccines encoding Wuhan-Hu-1 spike (S) and after Omicron breakthrough infection. We also measured IgG binding to Wuhan-Hu-1 and Omicron S1, Wuhan-Hu-1 S2 and Wuhan-Hu-1 and Omicron cell-based S. We compared ADCC using human embryonic lung fibroblast (MRC-5) cells expressing Wuhan-Hu-1 or Omicron S. The effect of Omicron breakthrough infection on IgG anti-Wuhan-Hu-1 and Omicron FLS avidity was also considered. Despite Omicron breakthrough infection increasing IgG and IgA against FLS and receptor binding domain to levels similar to those seen with hybrid immunity, there was no boost to ADCC. Preferential recognition of Wuhan-Hu-1 persisted following Omicron breakthrough infection, which increased IgG avidity against Wuhan-Hu-1 FLS. Despite similar total anti-FLS IgG levels following breakthrough infection, 4-fold higher plasma concentrations were required to elicit ADCC comparable to that elicited by hybrid immunity. The greater capacity for hybrid immunity to elicit ADCC was associated with a differential IgG reactivity pattern against S1, S2, and linear determinants throughout FLS. Immunity against SARS-CoV-2 following Omicron breakthrough infection manifests significantly less ADCC capacity than hybrid immunity. Thus, the sequence of antigenic exposure by infection versus vaccination and other factors such as severity of infection affect antiviral functions of humoral immunity in the absence of overt quantitative differences in the humoral response.

Association of gut commensal translocation with autoantibody production in systemic lupus erythematosus

Abstract Objective Bacterial translocation across the gut barrier has been implicated in the pathogenesis of systemic lupus erythematosus (SLE), though underlying mechanisms remain unclear. This study aimed to investigate the role of translocated bacteria in the context of molecular mimicry by utilizing lupus model mice and blood samples from untreated SLE patients. Methods Bacterial translocation was evaluated using nonselective cultured mesenteric lymph nodes (MLNs) from B6SKG mice, a lupus model characterized by impaired TCR signalling and gut dysbiosis. The relationships of detected pathobionts with autoantibody production were examined using in vivo experiments, enzyme-linked immunosorbent assay, immunoblotting, and epitope mapping. Results Culture-based bacterial profiling in MLNs demonstrated that Lactobacillus murinus was enriched in B6SKG mice with elevated anti-dsDNA IgG levels. Subcutaneous injection of heat-killed L. murinus induced anti-dsDNA IgG production without altering T- or B cell subset composition. Immunoblotting and mass spectrometry analysis identified a peptide ATP-binding cassette (ABC) transporter as a molecular mimicry antigen, with its cross-reactivity in lupus mice confirmed by serological assays and in vivo immunization. The L. murinus ABC transporter exhibited surface epitopes that were cross-reactive with sera from lupus mice and patients. The ABC transporter from R. gnavus, known for its pathogenic role in lupus patients, had a similar epitope sequence to that of the L. murinus ABC transporter and reacted with lupus sera. Conclusion ABC transporters from gut bacteria can serve as cross-reactive antigens that may promote anti-dsDNA antibody production in genetically susceptible mice. These findings underscore the role of commensal-derived molecular mimicry and bacterial translocation in lupus pathogenesis.

Limited O-specific polysaccharide (OSP)-specific functional antibody responses in young children with Shigella infection in Bangladesh.

Shigellosis is the second leading cause of diarrheal death in children younger than five years of age globally. At present, there is no broadly licensed vaccine against shigella infection. Previous vaccine candidates have failed at providing protection for young children in endemic settings. Improved understanding of correlates of protection against Shigella infection and severe shigellosis in young children living in endemic settings is needed. Here, we applied a functional antibody profiling approach to define Shigella-specific antibody responses in young children versus older individuals with culture-confirmed shigellosis in Bangladesh, a Shigella endemic area. We analyzed Shigella-specific antibody isotypes, FcR binding and antibody-mediated innate immune cell activation in longitudinal serum samples collected at clinical presentation and up to 1 year later. We found that higher initial Shigella O-specific polysaccharide (OSP)-specific and protein-specific IgG and FcγR binding levels correlated with less severe disease regardless of patient age, but that individuals under 5 years of age developed a less prominent class switched, FcR-binding, functional and durable antibody response against both OSP and protein Shigella antigens than older individuals. Focusing on the largest cohort, we found that functional S. flexneri 2a OSP-specific responses were significantly induced only in individuals over age 5 years, and that these responses promoted monocyte phagocytosis and activation. Our findings suggest that in a Shigella endemic region, young children with shigellosis harbor a functional antibody response that fails to maximally activate monocytes; such a response may be important in facilitating subsequent innate cell clearance of Shigella, especially via recruitment and activation of polymorphonuclear cells capable of directly killing Shigella.

Impaired Periodontitis-Induced Cytokine Production by Peripheral Blood Monocytes and Myeloid Dendritic Cells in Patients with Rheumatoid Arthritis: A Case-Control Study.

Background: Immune cells from rheumatoid arthritis (RA) patients display a reduced in vitro response to Porphyromonas gingivalis (P. gingivalis), which may have functional immune consequences. The aim of this study was to characterize, by flow cytometry, the frequency/activity of monocytes and naturally occurring myeloid dendritic cells (mDCs) in peripheral blood samples from patients with periodontitis and patients with periodontitis and RA. Methods: The relative frequency of monocytes and mDCs in the whole blood, the frequency of these cells producing TNFα or IL-6 and the protein expression levels for each cytokine, before and after stimulation with lipopolysaccharide (LPS) from Escherichia coli plus interferon-γ (IFN-γ), were assessed by flow cytometry, in peripheral blood samples from 10 healthy individuals (HEALTHY), 10 patients with periodontitis (PERIO) and 17 patients with periodontitis and RA (PERIO+RA). Results: The frequency of monocytes and mDCs producing IL-6 or TNF-α and the expression of IL-6 and TNF-α in the PERIO group were generally higher. Within the PERIO+RA group, P. gingivalis and related antibodies were negatively correlated with the monocyte and mDC expression of IL-6. A subgroup of the PERIO+RA patients that displayed statistically significantly lower frequencies of monocytes producing IL-6 after activation presented statistically significantly higher peptidylarginine deiminase (PAD)2/4 activity, anti-arg-gingipain (RgpB) IgG levels, mean probing depth (PD), periodontal inflamed surface area (PISA) and bleeding on probing (BoP). Conclusions: In the patients with PERIO+RA, innate immune cells seemed to produce lower amounts of pro-inflammatory cytokines, which are correlated with worse periodontitis-related clinical and microbiological parameters.

The distribution of biomarkers for Behcet syndrome and their clinical relevance in real-world studies

Objective: To explore the distribution of different biomarkers for Behcet's syndrome (BS) and their correlation with distinct clinical phenotypes of BS patients in real-world studies. Methods: This study was a retrospective cross-sectional study. A total of 483 patients diagnosed with BS in the Department of Rheumatology and Immunology, Peking University People's Hospital from 2019 to 2022 were enrolled. The baseline information and clinical features of the patients were recorded at their first diagnosis and tested the level of HLA-B51, several auto-antibodies, antistreptolysin-O(ASO), immune globulin, complement in blood serum and interleukin-6 (IL-6). Logistic regression was used to analyze the correlation of biomarkers and phenotypes. Results: Among BS patients, the number of positive cases for HLA-B51, anti-endothelial cell antibody (AECA), antinuclear antibodies (ANA) and ASO was 129, 115, 79 and 54, respectively. The positive rate of other biomarkers was less than 5.0%. About 12.6% of patients with BS had an increased level of IgA (n=61), and 10.8% of patients had an increased level of IgG (n=52). About 41.0% of patients had increased levels of IL-6 (n=198), and 6.4% of patients had decreased levels of IgM (n=31). About 11.2% of patients had decreased levels of C3 (n=54), and 6.0% of patients had decreased levels of C4 (n=29). Elevated IgA was a risk factor for the articular phenotype of BS (OR=2.652, P=0.011). Decreased complement C4 was a risk factor for the neurological phenotype of BS (OR=3.594, P=0.039). Positive ASO was a risk factor for the gastrointestinal phenotype of BS (OR=2.578, P=0.041). Elevated IL-6 was a risk factor for the ocular phenotype of BS (OR=7.560, P=0.016). Conclusion: HLA-B51 and AECA are common biomarkers in BS. Elevated IgA, decreased complement C4, positive ASO, and elevated IL-6 are risk factors for different phenotypes of BS.

Terminalia Chebula Extract Replacing Zinc Oxide Enhances Antioxidant and Anti-Inflammatory Capabilities, Improves Growth Performance, and Promotes Intestinal Health in Weaned Piglets.

This study aimed to assess the effects of substituting zinc oxide with terminalia chebula extract (TCE) on growth performance, antioxidant capacity, immune function, and intestinal health in weaned pigs. Initially, 72 weaned Duroc × Landrace × Large White piglets, 28 days old with an initial weight of 7.43 ± 0.14 kg, equally divided by gender, were randomly assigned into three groups, with six replicates and four piglets per replicate. They were fed a basal diet (CON group), a diet containing 2 g/kg zinc oxide (ZnO group), or 2 g/kg TCE (TCE group) for a duration of 28 days. Subsequently, to further confirm the most appropriate levels of TCE in piglets, 96 piglets of the same breeds and age, with an initial weight of 7.42 ± 0.12 kg, also equally divided by gender, were randomly assigned into four groups, each with six replicates and four piglets per replicate, and fed a basal diet (CON group), or diets supplemented with 1 g/kg TCE (LTCE group), 2 g/kg TCE (MTCE group), or 4 g/kg TCE (HTCE group) for a duration of 28 days. The results demonstrated that both TCE and ZnO reduced diarrhea rates (p = 0.001) and enhanced average daily gain (ADG) (p = 0.014) compared to the control group. TCE at 1 g/kg and 4 g/kg reduced the feed to gain ratio (p = 0.050). Dietary supplementing with TCE and ZnO increased serum total antioxidant capacity (T-AOC) (p = 0.020). Various doses of TCE also increased jejunal IgA (p = 0.000) levels and IL-10 expression (p = 0.004), and decreased the levels of TNF-α in both serum (p = 0.043) and jejunal mucosa (p = 0.000). Notably, TCE reduced the crypt depth (CD) of the duodenal (p = 0.007) and increased the villus height (VH) of the ileal (p = 0.045), and with increased dosage, there was a rise in the villus height to crypt depth ratio (VH:CD) in the duodenum (p = 0.000) and jejunum (p = 0.001). Higher abundances of Lactobacillaceae (p = 0.000) and lower levels of Streptococcaceae (p = 0.000) and Peptostreptococcaceae (p = 0.035) in cecal contents were fed the ZnO and TCE pigs compared with CON pigs. Therefore, TCE was firstly presented as being able to replace zinc oxide, improve intestinal morphology, and enhance antioxidant and immune functions, thus safeguarding intestinal mucosal health and promoting piglet growth.

Asymptomatic carriage of Plasmodium falciparum in children living in a hyperendemic area occurs independently of IgG responses but is associated with a balanced inflammatory cytokine ratio

BackgroundAsymptomatic carriage of infected red blood cells (iRBCs) can be prevalent in communities regardless of transmission patterns and can occur with infection of different Plasmodium species. Clinical immunity dampens the inflammatory responses leading to disease symptoms in malaria. The aim of this study was to define the immunological correlates of asymptomatic carriage of Plasmodium falciparum in a highly exposed population.Methods142 asymptomatic Plasmodium-infected individuals greater than 2 years of age without fever (body temperature <37.5 ℃) were followed weekly for 10 weeks before being treated with artemisinin-based combination therapy (ACT). Plasma levels of 38 cytokines were measured at baseline by Luminex and the quantity and growth inhibitory activities of circulating parasite-reactive antibodies measured. The Plasmodium antigen tested included P. falciparum merozoite extract (ME) and schizont extract (SE), and the recombinant proteins erythrocyte binding antigen 175 (EBA-175) and merozoite surface protein 1 (MSP-119).ResultsMedian levels of IgG against P. falciparum EBA-175 and MSP-119 at baseline were significantly higher in those older than 20 years of age compared with the younger age group and appeared to correlate with better parasite control. Amongst all participants there were no discernible changes in IgG levels over time. Parasite density was higher in the younger age group and associated with IL-10, TNF and MCP-1 levels. A balanced IL-10:TNF ratio was associated with asymptomatic malaria regardless of age, and balanced ratios of IL-10/TNF and IL-10/IFN-γ were the only significant correlate of maintenance of asymptomatic malaria over the course of the study in individuals 20 years of age and younger.ConclusionThe above findings indicate that asymptomatic carriage of P. falciparum in children living in a hyperendemic area occurs independently of IgG but is associated with a balanced inflammatory cytokine ratio.