IgA Concentrations Research Articles

Gardnerellavaginalis-binding IgA in the urethra of sexually experienced males

BackgroundGenital inflammation increases HIV susceptibility and is associated with the density of pro-inflammatory anaerobes in the vagina and coronal sulcus. The penile urethra is a critical site of HIV acquisition, although correlates of urethral HIV acquisition are largely unknown. While Streptococcus mitis is a consistent component of the urethral flora, the presence of Gardnerella vaginalis has been linked with prior penile-vaginal sex and urethral inflammation. Here, we use a flow cytometry-based bacterial assay to quantify urethral IgA and IgG that bind G. vaginalis and S. mitis in a cross-sectional cohort of 45 uncircumcised Ugandan men and to evaluate their association with the urethral microbiome and local soluble immune factors.ResultsUrethral antibodies binding both bacterial species were readily detectable, with G. vaginalis predominantly bound by IgA, and S. mitis equivalently by IgA and IgG. Gardnerella vaginalis-binding IgA was elevated in participants with detectable urethral Gardnerella, with the latter only present in participants who reported prior penile-vaginal sex. In contrast, detectable urethral S. mitis was not associated with sexual history or levels of S. mitis-binding IgA/IgG. The time from the last penile-vaginal sex was inversely correlated with the urethral concentrations of total IgA, G. vaginalis-binding IgA, and chemokines IL-8 and MIP-1β; these inflammatory chemokines were independently associated with higher total IgA concentration, but not with G. vaginalis-binding IgA.ConclusionsThis first description of microbe-binding antibodies in the penile urethra suggests that urethral colonization by Gardnerella after penile-vaginal sex specifically induces a G. vaginalis-binding IgA response. Prospective studies of the host-microbe relationship in the urethra may have implications for the development of vaccines against sexually-transmitted bacteria.EnGLria5fUgKACmpttUN3NVideo

Effects of Replacing Inorganic Sources of Copper, Manganese, and Zinc with Different Organic Forms on Mineral Status, Immune Biomarkers, and Lameness of Lactating Cows.

(Objectives) The objectives of this study were to evaluate the effect of half-replacement of the supplementary sulfate sources of Cu, Mn, and Zn with methionine-hydroxy-analog-chelated (MHAC) mineral or amino-acid-complexed (AAC) mineral forms in diets on the mineral status, blood immune biomarkers, and lameness of lactating cows. (Methods) Sixty multiparous Holstein cows (158 ± 26 days in milk; body weight: 665 ± 52 kg; milk yield: 32 ± 7 kg/day) were randomly assigned into one of three dietary treatments (n = 20 per group): (1) MHAC: 50% replacement of sulfate minerals with MHAC forms. (2) AAC: 50% replacement of sulfate minerals with AAC forms. (3) S: 100% sulfate minerals (control). Their Cu, Mn, and Zn concentrations, blood immune biomarkers, and lameness were measured monthly. Repeated-measure mixed models were used to evaluate the effects on trace mineral status over time. As the responses with the MHAC and AAC forms were similar, the treatments were also analyzed as organic trace minerals (OTMs, combining the MHAC and AAC groups, n = 40) versus inorganic trace minerals (ITMs, the S group, n = 20). (Results) Cows supplemented with OTMs had higher concentrations of Cu and Mn in their serum (p ≤ 0.05), a higher hoof hardness (p ≤ 0.05), and a lower incidence of lameness compared to those with ITMs on d 90. There were no statistical differences (p > 0.10) in the concentrations of IgA, IgG, or ceruloplasmin, but there were significant differences (p = 0.03) in the concentrations of IgM in the serum as fixed effects of the diet treatments during the whole trial. On d 30 and 90, the serum IgA concentrations of the cows supplemented with OTMs tended to be higher (0.05 < p ≤ 0.10) than those in the cows supplemented with ITMs. (Conclusions) The half-replacement strategy showed that the MHAC and AAC sources of Cu, Mn, and Zn additives had similar effects on the production performance, blood immune biomarkers, and lameness of the lactating cows. The long-term replacement strategy with OTMs led to the enhancement of the trace mineral concentrations in their body fluids, blood immune biomarkers, and hoof health.

Feeding Sows with Multi-Species Probiotics During Late Pregnancy and the Lactating Period Influences IgA Concentration in Colostrum and Subsequently Increases the Survival Rate of Piglets in Porcine Epidemic Diarrhea Outbreak Herd

Porcine epidemic diarrhea (PED) virus is an important cause of diarrhea in sows and piglets [...]

Maternal obesity associates with altered humoral immunity in blood and colostrum.

Maternal obesity is a condition with increasing prevalence worldwide, that correlates with negative infant outcomes. Here we performed an observational cross-sectional study, where peripheral blood and colostrum samples from 37 mothers with BMI between 18.5-25 or > 30 kg/m2 (21 and 16 mothers, respectively) were collected 24-48 h postpartum. B lymphocyte subpopulations were investigated using flow cytometry. IgG, IgA, and IgM concentrations, and antibody production from colostrum-resident B cells were quantified. Overall, naïve B lymphocytes were the most abundant subtype in peripheral blood, while CD27-IgD- double-negative B cells were the most B lymphocyte subtype abundant in colostrum. The colostrum from mothers with BMI > 30 kg/m2 contained significantly more IgG-secreting colostrum-resident B cells, more IgG, and less IgA. Mothers with BMI > 30 kg/m2 who had been vaccinated with the Pfizer BioNTech bivalent vaccine during the third trimester of pregnancy (n = 8) did not show higher IgA or IgG antibody responses against SARS-CoV-2 RBD in either tissue types compared to unvaccinated mothers, contrasting with mother of BMI between 18.5-25 kg/m2 (n = 7). Similar trends were evidenced in colostrum post-Tdap vaccination. This is the first characterization of B lymphocyte subpopulations and antibodies in the colostrum of mothers with obesity. This work uncovers maternal obesity as a possible modifier of humoral immune components in colostrum.

Comprehensive analysis of gene expressions in ileal mucosa of chickens fed paddy rice and their IgA response to oral vaccination.

Paddy rice ingestion increases intestinal mucin secretion and production by enhancing MUC2 gene expression and epithelial turnover. In this study, we performed a comprehensive analysis of intestinal gene expression in chickens fed paddy rice and investigated whether the intestinal IgA response was modified by paddy rice ingestion. Furthermore, we investigated the possible involvement of gut fermentation. Layer male chicks were divided into two groups according to diet i.e., corn or paddy rice at 650 g/kg diet, which were given for 14 consecutive days at 7 d of age. The ileal gene expression levels in both groups were compared using DNA microarray analysis. A total of 120 genes were upregulated >1.5-fold in the paddy rice group, whereas 159 genes were downregulated <1.5-fold. Remarkably, the gene expression levels of immunoglobulin heavy chain α (IGHA), immunoglobulin J chain (IGJ), and immunoglobulin light chain λ chain region (IGLL1), which constitute immunoglobulin A, decreased 3-10 times in the paddy rice group. Infectious bursal disease virus (IBDV) vaccine were orally administered to chickens fed corn or paddy rice to examine the intestinal immune response. Paddy rice ingestion diminished both the total IgA concentration and IBDV-specific IgA in the bile. Cecal total short-chain fatty acid and butyric acid concentrations decreased by 30 % in the paddy rice group compared to those in the corn group. In conclusion, feeding paddy rice to chickens decreased intestinal IgA production, which was partly attributable to the low fermentability of paddy rice in the intestinal tract.

Association of baseline cytokines with antibody concentrations after diphtheria-tetanus-acellular pertussis booster vaccination in Finnish children

BackgroundDespite extensive vaccinations, pertussis remains endemic and epidemic in multiple countries. The persistence of cases can be partly attributed to the significant individual variation in vaccine responses. This study evaluated the association of baseline cytokines (before booster vaccination) on antibody concentrations to Tdap-vaccine antigens. MethodsHealthy Finnish children (7–10y, n = 36), adolescents (11–15y, n = 37), young adults (20–34y, n = 25), and older adults (60–70y, n = 23) received a Tdap3-IPV booster. Serum antibodies against pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (Prn), fimbriae 2/3, diphtheria toxoid (DT), and tetanus toxoid (TT), as well as PT neutralizing antibodies were measured before, one month, and one year after the booster. Baseline serum concentrations of IFN-γ, IL-2, IL-5, IL-10, IL-13, IL-17 A and IL-17F were determined. ResultsThe proportion of detectable and undetectable baseline cytokines varied between age groups 58.3 % of children had a higher proportion of detectable IL-5, IL-10, IL-13, and IL-17F compared to adolescents (IL-5, 37.8 %; IL-10, 48.6 %; IL-13, 48.6 %; IL-17F, 37.7 %), young adults (IL-5, 36.0 %; IL-10, 28.0 %; IL-13, 36.0 %; IL-17F, 44.0 %), and older adults (IL-5, 26.1 %; IL-10, 21.7 %; IL-13, 39.1 %; IL-17F, 30.4 %). IFN-γ had a lower detectability in children (44.4 %) and young (40.0 %) and older adults (39.1 %) in contrast to adolescents (62.2 %). IL-2 was undetectable in all age groups while the proportion of detectable IL-17 A decreased with age. A mixed model showed that undetectable baseline levels of IFN-γ, IL-2, IL-10, and IL-17 A were associated with higher antibody concentrations in children before and after vaccination, particularly against PT. Positive associations were observed in adolescents for anti-TT concentrations and young adults for anti-FHA IgA concentrations. ConclusionThese findings indicate a possible role of existing cytokines in pertussis booster antibody concentrations in children and warrant further studies in different populations. However, the results should be interpreted with caution as the number of subjects is limited.

Identification of Gut Biomarkers of FPIES in a Longitudinal Comparative Pediatric Study.

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated allergy without known biomarkers. We aimed to compare fecal biomarkers related to gut inflammation and immunity in children with FPIES, with resolved FPIES (tolerant), and in matched controls. Stools were collected from FPIES children on elimination diet, before and after an oral food challenge (OFC) performed to assess their natural tolerance, at the end of a follow-up in tolerant FPIES children, and in matched controls (1:1 ratio). Concentrations of calprotectin, EDN (eosinophilic derived neurotoxin), and secretory IgA (sIgA) underwent comparative paired analysis. Thirty-eight patients were included (age: 1.3 years old, interquartile range: IQR [0.9-2.0]), of which 22 became tolerant during follow-up. Upon inclusion, allergic patients and controls had similar concentrations of calprotectin (38 μg/g [8-85] vs. 27 μg/g [11-46], p = 0.15) and EDN (504 ng/g [275-1252] vs. 516 ng/g [215-844], p = 0.86). However, concentrations of these inflammatory biomarkers increased transiently after a failed OFC (p < 0.001 and p = 0.01 respectively), without correlating with the severity of an allergic reaction. sIgA were higher in allergic than in tolerant patients: 2224 μg/g [878-3529] vs. 794 μg/g [699-1767] (p < 0.01). Calprotectin, EDN, and sIgA were comparable in tolerant patients and controls. sIgA less than 2637 μg/g had a negative predictive value of 75.3% for the differentiation allergic patients from tolerant patients and controls (area under curve: 0.63, 95% CI: 0.52-0.74). A few days after an acute allergic reaction, there was no detectable chronic gut inflammation in FPIES. sIgA may be a useful tool for clinicians in timing OFC.

Oral Condition and Salivary pH Down Syndrome Children in the Occurrence of Caries: A Narrative Review

Purpose:. Down syndrome is a genetic disorder caused by trisomy 21, which affects various body systems and morphology, including the oral cavity. Down syndrome shows a intraoral characteristics such as taurodontism, microdontia, hypodontia, and delayed tooth eruption higher salivary pH, elevated bicarbonate levels, and increased IgA concentrations. The higher prevalence of caries in children with DS, mainly due to poor eating habits, neuromuscular dysfunction, and inadequate oral hygiene. Our aim in this study was to analyze the relationship between oral cavity conditions, salivary composition, and caries prevalence in children with Down syndrome highlighting unique factors that contribute to their oral health status. Methodology: Narrative review analyzing 15 relevant journals on oral health in children with Down syndrome. Findings: Salivary pH, delayed tooth eruption, and eating habits contribute to the incidence of caries. Unique contribution to theory, practice and policy: The varying prevalence of caries in children with Down syndrome highlights the importance of a focused approach to dental care, considering the unique challenges they face.

Effects of 3-day fasting on secretory IgA concentration in the saliva and lymphotoxin alpha expression in healthy volunteers: a proof of concept study.

animal studies have shown that enteral stimuli play an important role in modulating gut-associated lymphoid tissue. the main objectives of this study were 1) to evaluate the effect of 3-day fasting on secretory immunoglobulin A (S-IgA) in parotid saliva and 2) to determine the levels of lymphotoxin (LT) transcription in peripheral blood mononuclear cells (PBMNC) from healthy volunteers as a proxy for studying GALT health. these adult volunteers had fasted for three days as part of a cultural ritual. Eleven volunteers (seven men and four women) with a median age of 43 (40-56) were included. Parotid saliva and blood samples were collected on day 0 (no fasting) and three days after fasting. Parotid saliva was obtained using a modified on-Crittenden device, and S-IgA was quantified using ELISA. Total RNA was isolated from peripheral blood mononuclear cells, and the level of lymphotoxin (LT) mRNA expression was determined by RT-PCR. Lipopolysaccharide (LPS), IL-10 (interleukin), tumor necrosis factor (TNF)α, body composition and other metabolic indicators were measured. the median BMI was 27.3 kg/m2 (24.9-29.1). After 3 days of fasting, there were no significant differences in S-IgA concentrations (p = 0.657), LT expression (p = 0.063), LPS (p = 0.182), or IL-10 (p = 0.110). We found a statistical difference in TNFα levels (13.5 vs 11.3 pg/mL; p = 0.005) between the 0 and 3-day samples; TNFα decreased after fasting. further studies are needed to clarify the role of LT in the production of S-IgA and its relationship with nutritional status and inflammatory factors.

Effects of alpha-lipoic acid on productive performance, immunity, antioxidation and serum metabolism in Holstein cows

Abstract The aim of this study was to investigate the antioxidant effect of alpha-lipoic acid (α-LA) in dairy cows and its metabolic mechanism. Thirty Holstein cows weighing 550 ± 25 kg, 200 ± 15 days of lactation and calving 2–3 times were randomly divided into three groups, ten cows in each group. Different doses of α-LA were added based on body weight: 0 (CTL), 30 (LA-L) and 60 (LA-H) mg/kg per head per day; 7 days adaptation period, 30 days formal period. Milk production was recorded daily during the test period. Milk and blood samples were collected on the last day. ELISA kits and automatic biochemical analyser were used to detect the indicators in blood; serum metabolites were detected and analysed by non-target metabolomics. The results of the study showed that the addition of α-LA significantly increased milk yield; blood concentrations for HDL, triglyceride, cortisol and triiodothyronine were significantly elevated; and levels of glutathione reductase and nitric oxide synthase were significantly reduced in LA-L group as compared to CTL group. The concentrations of IL-1β, IL-2, TNF-α, IgG and IgA were significantly higher after supplementation with α-LA. Metabolomics analysis revealed 13 and 15 differential metabolites each in positive or negative modes. Methylmalonic acid levels were significantly higher following α-LA supplementation compared to CTL group, as were D-lactose, D-maltose and oleanolic acid levels in LA-L group. In summary, α-LA can enhance milk production, improve antioxidant capacity and immunity, and is more beneficial for animal production and economic benefits at 30 mg/kg.

Effects of Vitamin and Mineral Supplementation During Gestation in Beef Heifers on Immunoglobulin Concentrations in Colostrum and Immune Responses in Naturally and Artificially Reared Calves.

Two experiments assessed the effects of providing a vitamin and mineral supplement to gestating beef heifers on concentrations of immunoglobulins (Ig) in colostrum and calf serum 24 h after feeding maternal colostrum (Exp. 1) or a colostrum-replacement product (Exp. 2). Angus-based heifers (n = 31, Exp. 1; n = 14, Exp. 2) were fed a basal diet (CON) or were fed a basal diet plus a vitamin and mineral supplement (VTM) from breeding (Exp. 1) or 60 d pre-breeding (Exp. 2) through calving. Colostrum was collected at calving, and serum was collected from calves 24 h after colostrum consumption to evaluate passive transfer. Serum was collected from calves in Exp. 1 to determine serum titers in response to vaccination at birth, pasture turn out, weaning, and 14 d after vaccination. Concentrations of IgG, IgM, or IgA in colostrum or in calf serum at 24 h were not impacted by dam treatment (p ≥ 0.21); however, concentrations of Ig in calf serum at 24 h were greater (p ≤ 0.01) in calves receiving maternal colostrum than those receiving a colostrum replacer. Calves born to VTM heifers had greater antibody titers at birth, pasture turn out, and weaning for infectious bovine rhinotracheitis (IBR), bovine viral diarrhea virus type 2 (BVD-2), and bovine respiratory syncytial virus (BRSV), respectively. Our results suggest that the programming of immune function in calves via prenatal nutrition appears to extend postnatally in CON and VTM offspring.

Effect of milk thistle (Silybum marianum L.) oil on pro-inflammatory cytokines, acute phase proteins, rumen metagenomic profile, rumen fluid variables and performance in calves.

The aim of this study was to determine the effect of milk thistle (Silybum marianumL., SM) oil supplementation on proinflammatory cytokines, acute phase proteins, rumen metagenomic profile, rumen fluid variables and performance during the milk feeding period of Holstein calves. In the present study, 24 calves that consumed quality and sufficient amount of colostrum (≥50 mg/ml IgG) after birth were divided into three groups, with 8 animals in each group (4 males + 4 females). Individually fed calves were given added SM oil as 0 µL/day/calf (Control group, SM0), 100 µL/day/calf (SM100) and 200 µL/day/calf (SM200). The ration containing concentrated feed mix (90%) + wheat straw (10%) was offered to the calves. SM oil did not change the ammonia nitrogen and pH values of the rumen fluid of calf (P>0.05). The molarities of PA, IBA, IVA and BSCFA in the rumen fluid increased linearly with SM oil dose (P<0.05). The relative abundance of Firmicutes linearly increased and the relative abundance of Actinobacteriota decreased with the addition of SM oil (P<0.05). Relative abundances of Erysipelotrichaceae_UCG_002, Eubacterium_coprostanoligenes_group, Clostridia_UCG_014, Lachnospiraceae_Unknown_1, Lachnospiraceae_NK3A20_group, Shuttleworthia, Selenomonadaceae_Uncultured_1, Rikenellaceae_RC9_gut_group and Succinivibrionaceae_UCG_001 linearly increased with SM oil (P<0.05). Relative abundances of Methanobrevibacter, Acetitomaculum, Olsenella and Megasphaera in calf rumen fluid linearly decreased with SM oil (P<0.05). Concentrations of TNF-α, IFN-ɣ, and SAA of calf' serum at weaning stage linearly decreased with SM oil doses (P<0.05). Serum IgA concentration increased with 100 µL SM oil /day (P<0.05). As a result, the addition of SM oil to calves has the potential to reduce the immune suppression of calves during the milk feeding period and at weaning time, has a positive effect on the microbiome involved in starch and protein catabolism in the rumen fluid, and increases the fermentation end products (PA, IVA and BA). Milk thistle oil has an inhibitory effect on methanogenic archaea and can be used as an anti-methanogenic feed additive and will contribute to the effective use of feed energy.

Co-evolution of the humoral immune and serotonergic systems in chickens selected for high or low blood antibody titer response to sheep red blood cells.

Serotonin is a potent immunomodulatory neurohormone. Activities of the serotonergic and immune systems are often reported together in poultry studies with unidirectional analyses focused on serotonergic signaling mediating immune response. Considering serotonin's relevance across a range of immune-related poultry topics, elucidation of whether the immune system affects the serotonergic system can provide valuable insights into the bi-directionality of poultry neuroendocrine-immune interactions. The present study sought to determine whether selection for divergence in blood antibody titers to a non-pathogenic antigen coincides with parallel changes in the chicken's serotonergic system over the life of the bird. We utilized generations 49 and 50 male and female White Leghorn chickens (n = 10-12/chickens/line/sex/age) that have been selected long-term for high (HAS) or low (LAS) blood antibody response to intravenous sheep red blood cell injection. Because serotonin is predominantly produced in the gut and acts as an interkingdom signaling molecule, the first experiment sampled cecal tissue and luminal content samples from male and female HAS and LAS chickens at 293 days of age. In the second experiment, cecal tissue and luminal content, as well as plasma, were collected from HAS and LAS chickens at 28 and 56 days of age. Serotonin and its main metabolite, 5-hydroxyindoleacetic acid (5-HIAA), concentrations were determined in cecal tissue, luminal content, and plasma samples. Immunoglobulins IgA and IgY concentrations were analyzed in cecal luminal content or plasma, respectively. The HAS chickens had lower (p < 0.05) cecal IgA concentrations but higher (p < 0.05) plasma IgY concentrations than LAS chickens, suggesting a compensatory response within the intestinal tract following selection for high or low blood antibody titers. Serotonin and 5-HIAA concentrations in the ceca and plasma diverged (p < 0.05) in a pattern that mirrored ceca IgA and plasma IgY differences according to genetic line. The results from this study demonstrate that evolutionary selection pressure for humoral immune response in chickens causes responses in the serotonergic system at both enteric and systemic levels.

The Influence of Elevated Concentrations of Secretory IgA on the Level of Immunocompetent Cells, Cytokines, Reagins, Circulating Immune Complexes, and C-Reactive Protein in the Blood of Practically Healthy Residents of Murmansk Oblast

The Influence of Elevated Concentrations of Secretory IgA on the Level of Immunocompetent Cells, Cytokines, Reagins, Circulating Immune Complexes, and C-Reactive Protein in the Blood of Practically Healthy Residents of Murmansk Oblast

Early-life Clostridium butyricum supplementation improved rumen development and immune by promoting the maturation of intestinal microbiota

This study evaluated the effects of Clostridium butyricum supplementation on rumen fermentation, serum immunoglobulins, and fecal microbiota in dairy calves. Seventy-five 3-days-age calves were divided into five groups (n = 15 per group) receiving 0, 0.2, 0.4, 0.8, and 1.6 g/day of C. butyricum freeze-dried powder (10ˆ10 CFU/g) in milk replacer. Rumen fluid and blood samples were collected at various intervals, and fecal samples from eight calves per group were collected at 3, 28, and 42 days. C. butyricum supplementation showed a negative correlation with rumen pH (P = 0.032) and positive correlations with acetate/propionate (P = 0.007) and acetate + butyrate/propionate (P = 0.022). It had quadratic effects on rumen acetate (P = 0.029) and isobutyrate (P = 0.021). IgA concentration increased with dose (P = 0.002), and dose-time interactions affected serum IgM (P = 0.013) and IgG (P < 0.001). C. butyricum did not influence fecal microbiota diversity but increased the abundance of Helicobacter japonicus, Weissella viridescens, Leuconostoc mesenteroides, Leuconostoc citreum, while negatively correlating with Streptococcus hyointestinalis (P < 0.05). Microbiota functions related to galactose metabolism, and fatty acid degradation decreased with age (P < 0.05), while fatty acid biosynthesis and glycolysis/gluconeogenesis increased (P < 0.05). L. mesenteroides, and L. citreum, and negatively correlated with galactose metabolism and fatty acid degradation but positively with fatty acid biosynthesis (P < 0.01). C. butyricum supplementation variably impacted rumen pH, acetate/propionate, and acetate + butyrate/propionate, particularly on day 42 versus day 60, affecting acetate, butyrate, and isovalerate differently over time. Our findings suggest that early-life C. butyricum supplementation may promote the maturation of immunity and intestinal microbiota of pre-weaning dairy calves, the optimal dose was 0.8 to 1.6 x 10ˆ10 CFU/d.

Extensive characterization of COVID-19 convalescent plasma from Bulgarian donors

The total and SARS-CoV-2-specific antibody content in convalescent plasma (CP) samples from Bulgarian donors and their therapeutic potential for COVID-19 patients was subjected to characterization. CPs (n = 90) were obtained after informed consent at National Centre of Transfusion Hematology in Sofia, Bulgaria, in the period 01 June 2021 and were tested for RBD-IgG, RBD-IgA and anti-nuclear antibodies (ANA) by semi-quantitative ELISA. Concentrations of total IgG, IgG isotypes, IgA, and IgM, as well as of 25 Th1, Th2, Th17 and regulatory cytokines were determined for all samples; concentrations of Neutralizing antibodies against six SARS-CoV-2 variants were determined in Receptor-Binding Domain (RBD-positive) samples (Luminex xMAP technology). Concordant production of RBD-specific IgG and IgA was detected in 45 (50%); 12 (13.3%) were RBD-IgG single-positive, 8 (8.8%) RBD-IgA single-positive, and 25 (27.7%) – double negative. Absence of neutralizing activity was documented for 8/65 (12.3%) of RBD-positive samples. No correlation existed between the levels of RBD-IgG and RBD-IgA and the total neutralizing activity of CPs (p > 0.05). Total IgG, IgA, IgM and IgG Isotype concentrations did not differ from reference values. Increased concentrations of IL-18, IL-27, IL-1Ra, IL-21 and IL-22 were detected in most tested samples (80% respectively). The comparison between 45 RBD-double positive and 25 RBD-double negative CPs showed significant differences for the concentrations of IL-22 (2.4 vs 40, p < 0.05) and IL-10 (1 vs 15, p < 0.001). All CPs were ANA negative. Detailed characterization for SARS-CoV-2 specific antibody content and cytokine concentrations might improve the results of CPs application for in early stage treatment in resource-limited settings.

TbpB-based oral mucosal vaccine provides heterologous protection against Glässer’s disease caused by different serovars of Spanish field isolates of Glaesserella parasuis

BackgroundGlaesserella parasuis (G. parasuis) is the primary agent of Glässer’s disease, significantly affecting nursery and early fattening piglets. Current prophylactic measures, mainly serovar-specific bacterins administered to sows, are limited by maternal immunity, which can interfere with active immunization in piglets. Subunit vaccines containing G. parasuis-specific antigenic molecules show promise but are not yet commercially available. Transferrin-binding proteins (Tbp), which enable G. parasuis to acquire iron in low-iron environments like mucosal surfaces, have been proposed as potential vaccine antigens. The mucosal administration of a TbpB-based subunit vaccine could provide a promising solution to overcome the limitations posed by maternal immunity, offering an effective approach to control the disease in weaning piglets. This study, conducted in two phases, primarily evaluates (days 0–45) the immunogenicity of a two-dose oral mucosal TbpB-based subunit vaccine (TbpBY167A) administered to colostrum-deprived piglets, and subsequently (days 45–52), its heterologous protection by challenging these piglets with four G. parasuis clinical isolates from different TbpB clusters (I, III) and serovars (SV1, SV4, SV5, SV7) recovered from Spanish pig farms.ResultsThe oral mucosal administration of the two-dose TbpB-based vaccine induced a robust humoral immune response in immunized colostrum-deprived piglets, significantly increasing IgA and IgM concentration 15 days after the second dose (p < 0.01). Upon challenge with four G. parasuis clinical isolates, the vaccine demonstrated heterologous protection, markedly improving survival rates (OR: 8.45; CI 95%: 4.97–14.36) and significantly reducing clinical signs and lesions, regardless of the TbpB cluster and serovar. The vaccine reduced G. parasuis colonization in the respiratory tract (p < 0.0001) and G. parasuis systemic target tissues, like tarsus and carpus joints, liver, and brain (p < 0.05). Immunohistochemical analysis showed a lower macrophage count in different lung locations of immunized piglets (p < 0.0001).ConclusionsThis study demonstrates that oral mucosal administration of the TbpBY167A subunit vaccine in piglets provides effective heterologous protection against diverse virulent European G. parasuis field isolates, significantly reducing bacterial colonization and dissemination. This vaccine offers a promising alternative to traditional bacterins, overcoming limitations due to maternal immunity, and represents a strong candidate for universal vaccination against Glässer’s disease.

A new combination of a prebiotic and postbiotic mitigates immunosenescence in vaccinated healthy senior dogs.

Elderly dogs often suffer from chronic diseases, in part attributed to immunosenescence, characterized by reduced blood CD4+ T cells (helper T cells) and elevation in the CD8+ T cells subset (cytotoxic T cells). Studies conducted in adult dogs suggested that supplementing short chain fructo-oligosaccharides (scFOS) or postbiotics derived from yeasts may positively influence the immune response. The aim of the current study was to investigate whether dietary supplementation with a combination of scFOS with a new yeast postbiotic (Profeed ADVANCED® called scFOS+) could have a positive influence on the immune status of senior dogs subjected to an immune challenge (Lyme disease vaccination). To this end, 22 healthy senior client-owned dogs were divided into two groups: one group received a placebo diet without scFOS+ and the other group the basal diet supplemented with 1.1% scFOS+. In order to assess immune function, complete blood count, serum acute phase proteins, immunoglobulins, cytokines, T-cell subsets and antibody secreting cells were analyzed. Furthermore, faecal score and pH were recorded. Dogs fed the scFOS+ supplement had decreased total serum IgA concentrations (p < 0.01), which might suggest a more local IgA response in agreement with what was previously found when adult dogs were supplemented with β-1, 3/1, 6-glucan, a yeast-based product. More importantly, the present study demonstrated that feeding 1.1% scFOS+ to healthy senior dogs increased the CD4+:CD8+ T-cell (Helper:Cytotoxic T cell) ratio (p < 0.001) during and after vaccination against Lyme disease. Combining scFOS and yeast-derived postbiotics in the diet can therefore counter certain characteristics of T-cell immunosenescence in dogs.

Disorders of acid-base balance promote rumen lipopolysaccharide biosynthesis in dairy cows by modulating the microbiome.

Disorders of acid-base balance in the rumen of dairy cows have a significant impact on their health and performance. However, the effect of transient differences in pH on susceptibility to subacute ruminal acidosis (SARA) and lipopolysaccharide (LPS) biosynthesis in dairy cows remains unclear. In this study, milk, serum, and rumen fluid samples from 40 Holstein dairy cows (on d 56 postpartum) with different rumen pH (2-4 h after morning feeding) were explored to investigate the difference of susceptibility to SARA and the correlation between microbiome, LPS and inflammation. These cows were categorized into low pH (LPH, pH ≤ 6.0, n = 20) and high pH (HPH, pH ≥ 6.5, n = 20) groups. The results showed that LPH group increased the concentrations of total volatile fatty acids, acetate, propionate, butyrate and valerate. However, milk yield and milk compositions were unaffected. Compared to the HPH group, the LPH group increased the concentrations of serum BHBA, NEFA, LPS, HIS, IL-2, IL-6, TNF-α, and MDA, and decreased the concentrations of serum IgA, IgM, IgG, SOD, T-AOC, and mTOR. In addition, the LPH group decreased the copies of Ruminococcus flavefaciens and increased the copies of Fibrobacter succinogenes. Microbial community analysis isupplendicated a significant difference in bacterial composition between the two groups. At the phylum level, Bacteroidota and Firmicutes were enriched in the LPH and HPH groups, respectively. At the genus level, the dominant bacteria in the LPH group were Prevotella. Additionally, the LPH group increased the proportions of Gram-negative phenotypes, potentially pathogenic phenotypes and LPS biosynthesis. The close correlation between two key enzymes for LPS synthesis LpxL and LpxM with rumen pH, inflammatory markers, and microorganisms indicates that low pH may increase the risk of inflammation by facilitating the lysis of Gram-negative bacteria and the release of penta-acylated LPS. Penta-acylated and hexa-acylated LPS may be mainly derived from Prevotella and Succinivibrionaceae_UCG-001, respectively. Overall, these results support the notion that transient low pH could reflect the risk of cows suffering from SARA and associated inflammation and is strongly associated with penta-acylated LPS. Our findings provide new insights into ruminant health improvement and disease prevention strategies.

2'-Fucosyllactose and 3'-Sialyllactose Reduce Mortality in Neonatal Enteroaggregative Escherichia coli Infection by Improving the Construction of Intestinal Mucosal Immunity.

Human milk oligosaccharides could prevent pathogenic bacterial infections in neonates; however, direct in vivo anti-infection evidence was still lacking. Here, we systematically evaluated the effects of 2'-fucosyllactose (2'-FL) and 3'-sialyllactose (3'-SL) on the structural development and functional maturation in neonates and their defense against enteroaggregative Escherichia coli infection. It was found that supplementation with 2'-FL and 3'-SL improved the resistance of weaned mice to enteroaggregative E. coli. The mechanism related to the promotion of 2'-FL and 3'-SL in the maturation of intestinal mucosal immunity by promoting stem cell differentiation, mucus layer integrity, and tight junction formation. 2'-FL and 3'-SL significantly increased the ratio of Th1 and Treg cells in the lamina propria, contents of short-chain fatty acids, as well as the serum content of IgA. This study lays a theoretical basis for the application of 2'-FL and 3'-SL in infant formula, as well as the development of intestinal health products.