Serum IgA Antibodies Research Articles

Long-Term SARS-CoV-2-Specific Humoral and T Cell Responses after the BNT162b2 or BBIBP-CorV Booster and the Incidence of Breakthrough Infections among Healthcare Workers.

The effectiveness of COVID-19 vaccines developed against the original virus strain deteriorated noticeably in efficacy against the Omicron variant (B.1.1.529). Moreover, the immunity developed after vaccination or due to natural infection rapidly waned. In the present study, covering this period, we summarize the incidence of breakthrough infections among healthcare workers (HCWs) with respect to administration of the three vaccine doses. Additionally, we evaluate the long-term SARS-CoV-2-specific humoral and T cell responses at two different time points: six and twelve months after receipt of the third (booster) dose. The spike-protein-specific antibody levels and the quantity of structural-protein-specific T cells were evaluated at these time points and compared with the values measured earlier, 14 days after the booster vaccination. The study participants were categorized into two cohorts: Members of the first cohort received a two-dose BNT162b2 mRNA-based vaccine regimen, followed by an additional BNT162b2 booster six months later. Individuals in the second cohort received an inactivated-virus-based BBIBP-CorV booster six months after the initial two-dose BNT162b2 vaccination. Overall, 64.3% of participants were infected with SARS-CoV-2 confirmed by PCR or antigen test; however, additional subjects from the first cohort (23%) who did not know about their previous infection but had an anti-nucleocapsid T cell response were also considered virus-experienced. According to our results, no statistically significant difference was found between the two cohorts regarding the SARS-CoV-2-specific T cell response, neutralizing anti-RBD IgG, and anti-S IgA serum antibody levels either six or twelve months after receiving the booster, despite the overall higher median values of the first cohort. The only significant difference was the higher anti-S1/S2 IgG antibody level in the first cohort one year after the BNT162b2 booster (p = 0.039). In summary, the BNT162b2 and BBIBP-CorV boosters maintain durable humoral and T cell-mediated immune memory even one year after application. Although the booster provided limited protection against Omicron breakthrough infections, as 73.6% of these infections occurred after the booster vaccination, which means 53.5% cumulative incidence, it still offered excellent protection against severe disease and hospitalization in both cohorts.

Serological analysis reveals differential antibody responses between TB patients and latently infected individuals from the TB endemic country of Mozambique.

Serological antibody profiling of tuberculosis (TB) patients and household contacts with latent TB infection (LTBI) could identify risk indicators of disease progression, and potentially also serve as an easily accessible diagnostic tool to discriminate between these two stages of Mycobacterium tuberculosis (Mtb) infection. Yet, despite significant efforts over many decades, neither application has yet fully materialised, and this is at least in part due to inconsistent and varying antibody profiles from different TB endemic regions. In this study, we conducted a retrospective exploratory analysis of serum antibodies in a cohort of active TB patients (ATB) and their interferon-gamma release assay (IGRA) positive household contacts (LTBI), as well as healthy controls (HC) from Mozambique, a country with a high TB burden from the Sub-Saharan region. Using several Mtb antigens as well as crude preparations of culture filtrate proteins (CFP) from Mtb and Bacille Calmette Guérin (BCG), we report that the most discriminatory response for TB and LTBI was observed for serum IgA antibodies to the MPT64 antigen, followed by IgG antibodies to Ag85B and CFP, with ATB patients having significantly higher levels than LTBI or BCG-vaccinated healthy controls. Conversely, sera from LTBI individuals had higher levels of IgG antibodies to the HBHA antigen than ATB. While our sample size (n = 21 for ATB, 18 for LTBI and 17 for HC) was too small to fully evaluate the diagnostic potential of these differing serological profiles, our study however preliminarily indicated high level of sensitivity (95%) and specificity (97%) of an ELISA MPT64-IgA test for discriminating TB from LTBI and healthy controls, supporting the notion that it alone, or possibly in combination with other antigens such as Ag85B or CFP could lead to development of an easily accessible diagnostic tool for TB.

Local and Systemic Immunity During Five Vaccinations Against SARS-CoV-2 in Zanubrutinib-Treated Patients With Chronic Lymphocytic Leukemia.

Patients with chronic lymphocytic leukemia (CLL) are vulnerable to coronavirus disease 2019 (COVID-19) and are at risk of inferior response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, especially if treated with the first-generation Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib. We aimed to evaluate the impact of the third-generation BTKi, zanubrutinib, on systemic and mucosal response to SARS-CoV-2 vaccination. Nine patients with CLL with ongoing zanubrutinib therapy were included and donated blood and saliva during SARS-CoV-2 vaccination, before vaccine doses 3 and 5 and 2 - 3 weeks after doses 3, 4, and 5. Ibrutinib-treated control patients (n = 7) and healthy aged-matched controls (n = 7) gave blood 2 - 3 weeks after vaccine dose 5. We quantified reactivity and neutralization capacity of SARS-CoV-2-specific IgG and IgA antibodies (Abs) in both serum and saliva, and reactivity of T cells activated with viral peptides. Both zanubrutinib- and ibrutinib-treated patients had significantly, up to 1,000-fold, lower total spike-specific Ab levels after dose 5 compared to healthy controls (P < 0.01). Spike-IgG levels in serum from zanubrutinib-treated patients correlated well to neutralization capacity (r = 0.68; P < 0.0001) and were thus functional. Mucosal immunity (specific IgA in serum and saliva) was practically absent in zanubrutinib-treated patients even after five vaccine doses, whereas healthy controls had significantly higher levels (tested in serum after vaccine dose 5) (P < 0.05). In contrast, T-cell reactivity against SARS-CoV-2 peptides was equally high in zanubrutinib- and ibrutinib-treated patients as in healthy control donors. In our small cohort of zanubrutinib-treated CLL patients, we conclude that up to five doses of SARS-CoV-2 vaccination induced no detectable IgA mucosal immunity, which likely will impair the primary barrier defence against the infection. Systemic IgG responses were also impaired, whereas T-cell responses were normal. Further and larger studies are needed to evaluate the impact of these findings on disease protection.

Development of Chimeric Hepatitis B (HBV) – Norovirus (NoV) P particle as candidate vaccine against Hepatitis B and norovirus infection

IntroductionHepatitis B remains a global problem with no effective treatment. Here, a mucosal vaccine candidate was developed with HBsAg and HBcAg, to provide both prophylactic and therapeutic protection against hepatitis B. The antigens were presented using the P particle of human norovirus (HuNov). As a result, the chimeric HBV – HuNoV P particle can act as a dual vaccine for hepatitis B and HuNoV. MethodsThe vaccine candidate was expressed and purified from Escherichia coli BL21 (DE3) cells. HBV-HuNoV chimeric P particles were successfully expressed and isolated, with sizes of approximately 25.64 nm. Then, the HBV-HuNoV chimeric P particles were evaluated for safety and immunogenicity in mice and gnotobiotic (Gn) pigs. After three doses (5 µg/dose in mice and 200 µg/dose in Gn pigs) of intranasal immunization, humoral and cellular immune responses, as well as toxicity, were evaluated. ResultsThe vaccine candidate induced strong HBV-HuNoV specific IFN-γ producing T-cell responses in the ileum, spleen, and blood of Gn pigs. Serum IgG and IgA antibodies against HBV-HuNoV chimeric P particles also increased significantly in Gn pigs. Increased HBsAg- and HuNoV-specific serum IgG responses were observed in mice and Gn pigs, although not statistically significant. The vaccine candidate did not show any toxicity in mice. ConclusionsIn summary, the chimeric HBV-HuNoV P particle vaccine given intranasally was safe and induced strong cellular and humoral immune responses in Gn pig. Modifications to the vaccine structure and dosage need to be evaluated in future studies to further enhance immunogenicity and induce more balanced humoral and cellular responses.

Frequency of dyspeptic symptoms, anxiety, depression and health-related quality of life among patients with chronic gastritis according to Helicobacter pylori CagA and VacA status: a cross-sectional study

Objective — to determine the frequency of dyspeptic symptoms, anxiety and depression and to describe health‑related quality of life in patients with chronic gastritis according to Helicobacter pylori cytotoxin‑associated gene A and vacuolating cytotoxin A status.&#x0D; Materials and methods. This cross‑sectional study included a total of 84 patients with H. pylori‑associated chronic gastritis (CG). Based on H. pylori virulence factors status patients were categorized into 2 groups: 50 patients with the cytotoxin‑associated gene A (CagA) and vacuolating cytotoxin A (VacA)‑positive H. pylori strains (Group 1) and 34 patients with CagA‑ and VacA‑negative H. pylori strains (Group 2). The H. pylori virulence factors were determined by the polymerase chain reaction using paraffin stomach biopsies. Serum IgA and IgG antibodies to CagA and VacA were evaluated by solid‑phase enzyme‑linked immunoabsorbent assay. The Hospital Anxiety and Depression Scale (HADS) was used to identify anxiety disorders and depression. The MOS 36‑Item Short Form Health Survey (SF‑36) questionnaire was used to assess the health‑related quality of life (HRQoL). Statistical analysis was performed using Stata 11 and Statistica 6 software packages.&#x0D; Results. Patients with CagA‑ and VacA‑positive H. pylori strains were more likely to have epigastric pain than patients with CagA‑ and VacA‑negative H. pylori strains (60% vs. 35.3%, p=0.026). No statistical difference was observed between the frequency of epigastric burning, early satiety, and postprandial fullness in both groups (р &gt;0.05). Anxiety and depression were significantly more prevalent in patients with CagA‑ and VacA‑positive H. pylori strains (p=0.041; р=0.032, respectively). Patients of Group 1 had significantly lower HRQoL in the domains of Role‑Physical (50 vs. 75; p=0.0001), Bodily Pain (57.5 vs. 77.5; p=0.0001), General Health (45 vs. 75; p=0.0001), Vitality (55 vs. 80; p=0.0011) and Mental Health (56 vs. 84; p=0.0001).&#x0D; Conclusions. H. pylori CagA and VacA‑positive status is an important factor that may have an impact on the clinical course of H. pylori‑associated gastritis. Higher frequency of epigastric pain, anxiety, and depression, as well as lower health‑related quality of life were observed in patients with CagA‑ and VacA‑positive H. pylori strains.&#x0D;

Intranasal VLP-RBD vaccine adjuvanted with BECC470 confers immunity against Delta SARS-CoV-2 challenge in K18-hACE2-mice

As the COVID-19 pandemic transitions into endemicity, seasonal boosters are a plausible reality across the globe. We hypothesize that intranasal vaccines can provide better protection against asymptomatic infections and more transmissible variants of SARS-CoV-2. To formulate a protective intranasal vaccine, we utilized a VLP-based platform. Hepatitis B surface antigen-based virus like particles (VLP) linked with receptor binding domain (RBD) antigen were paired with the TLR4-based agonist adjuvant, BECC 470. K18-hACE2 mice were primed and boosted at four-week intervals with either VLP-RBD-BECC or mRNA-1273. Both VLP-RBD-BECC and mRNA-1273 vaccination resulted in production of RBD-specific IgA antibodies in serum. RBD-specific IgA was also detected in the nasal wash and lung supernatants and were highest in VLP-RBD-BECC vaccinated mice. Interestingly, VLP-RBD-BECC vaccinated mice showed slightly lower levels of pre-challenge IgG responses, decreased RBD-ACE2 binding inhibition, and lower neutralizing activity in vitro than mRNA-1273 vaccinated mice. Both VLP-RBD-BECC and mRNA-1273 vaccinated mice were protected against challenge with a lethal dose of Delta variant SARS-CoV-2. Both vaccines limited viral replication and viral RNA burden in the lungs of mice. CXCL10 is a biomarker of severe SARS-CoV-2 infection and we observed both vaccines limited expression of serum and lung CXCL10. Strikingly, VLP-RBD-BECC when administered intranasally, limited lung inflammation at early timepoints that mRNA-1273 vaccination did not. VLP-RBD-BECC immunization elicited antibodies that do recognize SARS-CoV-2 Omicron variant. However, VLP-RBD-BECC immunized mice were protected from Omicron challenge with low viral burden. Conversely, mRNA-1273 immunized mice had low to no detectable virus in the lungs at day 2. Together, these data suggest that VLP-based vaccines paired with BECC adjuvant can be used to induce protective mucosal and systemic responses against SARS-CoV-2.

Natural autoimmunity in oligoarticular juvenile idiopathic arthritis

BackgroundOligoarticular juvenile idiopathic arthritis (oligo-JIA) is considered as an antigen-driven lymphocyte-mediated autoimmune disease. Natural antibodies (NAbs) are pre-immune antibodies produced in the absence of exogenous antigen stimulation, participating in both, innate and adaptive immunity. Considering their major immunoregulatory role in homeostasis and autoimmune pathogenesis, we designed this study to further elucidate their role in oligo-JIA pathogenesis.MethodsSeventy children with persistent oligo-JIA and 20 healthy matched controls were enrolled in the study. Serum IgM and IgA antibodies against human G-actin, human IgG F(ab΄)2 fragments and the hapten TriNitroPhenol (TNP) as well as the total concentration of serum IgM and IgA were measured by in-house enzyme-immunoassays. Kolmogorov–Smirnov normality test, Kruskal–Wallis H and Mann–Whitney tests were used to assess data distribution, and significant differences of non-parametric data between groups of the study. Backward regression analysis was used to analyze the effect of multiple factors (age, gender, disease activity, anti-nuclear antibody positivity, presence of uveitis) on continuous dependent variables (activities and activity/ concentration ratios of IgM and IgA NAbs).ResultsThe ratios of IgA anti-TNP, anti-actin and anti-F(ab΄)2 levels to total serum IgA concentration were found to be significantly increased in patients with oligo-JIA compared to healthy subjects. Significantly elevated levels of IgM anti-TNP antibodies were also found in children with inactive oligo-JIA compared to those of children with active disease and of healthy controls. In the presence of anterior uveitis, IgM anti-TNP levels were significantly higher than in patients without uveitis or in healthy controls. Backward regression analysis revealed that the disease activity and the presence of anterior uveitis independently affect IgM anti-TNP levels.ConclusuionsOur findings are in accordance with the hypothesis that NAbs contribute to the pathogenesis of autoimmune diseases and provide additional evidence that disturbances in natural autoimmunity may contribute to the as yet unclarified pathogenesis of oligo-JIA.

Combined Live Oral Priming and Intramuscular Boosting Regimen with Rotarix® and a Nanoparticle-Based Trivalent Rotavirus Vaccine Evaluated in Gnotobiotic Pig Models of G4P[6] and G1P[8] Human Rotavirus Infection.

Human rotavirus (HRV) is the causative agent of severe dehydrating diarrhea in children under the age of five, resulting in up to 215,000 deaths each year. These deaths almost exclusively occur in low- and middle-income countries where vaccine efficacy is the lowest due to chronic malnutrition, gut dysbiosis, and concurrent enteric viral infection. Parenteral vaccines for HRV are particularly attractive as they avoid many of the concerns associated with currently used live oral vaccines. In this study, a two-dose intramuscular (IM) regimen of the trivalent, nanoparticle-based, nonreplicating HRV vaccine (trivalent S60-VP8*), utilizing the shell (S) domain of the capsid of norovirus as an HRV VP8* antigen display platform, was evaluated for immunogenicity and protective efficacy against P[6] and P[8] HRV using gnotobiotic pig models. A prime-boost strategy using one dose of the oral Rotarix® vaccine, followed by one dose of the IM trivalent nanoparticle vaccine was also evaluated. Both regimens were highly immunogenic in inducing serum virus neutralizing, IgG, and IgA antibodies. The two vaccine regimens failed to confer significant protection against diarrhea; however, the prime-boost regimen significantly shortened the duration of virus shedding in pigs challenged orally with the virulent Wa (G1P[8]) HRV and significantly shortened the mean duration of virus shedding, mean peak titer, and area under the curve of virus shedding after challenge with Arg (G4P[6]) HRV. Prime-boost-vaccinated pigs challenged with P[8] HRV had significantly higher P[8]-specific IgG antibody-secreting cells (ASCs) in the spleen post-challenge. Prime-boost-vaccinated pigs challenged with P[6] HRV had significantly higher numbers of P[6]- and P[8]-specific IgG ASCs in the ileum, as well as significantly higher numbers of P[8]-specific IgA ASCs in the spleen post-challenge. These results suggest the promise of and warrant further investigation into the oral priming and parenteral boosting strategy for future HRV vaccines.

Oral and intranasal Ad5 influenza vaccination induces hemagglutinin-specific and influenza neutralizing antibodies in serum and milk of pregnant and lactating ferrets

Abstract Pregnant women and young children are at increased risk for severe influenza infection. While there are intramuscular (IM) inactivated influenza vaccines available to pregnant individuals, IM immunization may not be an ideal route to boost neutralizing antibodies in breastmilk (BM). Therefore, innovative vaccine strategies are needed to increase BM antibodies that promote neonatal protection against influenza. We hypothesize that maternal mucosal immunization stimulates a protective influenza-specific antibody response, by generating antibodies in both blood and BM. To test this, we immunized pregnant and lactating ferrets at two weeks prepartum and two weeks postpartum with an H1N1 hemagglutinin (HA) adenovirus type 5 (Ad5) vaccine via oral or intranasal routes. We detected HA-specific IgG antibodies in dam serum and HA-specific IgG and IgA antibodies in secreted milk after oral and intranasal immunization by ELISA and chemiluminescence assays. We demonstrated that serum and BM from oral and intranasally immunized dams neutralized influenza virus in vitro. Additionally, ferret kits born to oral and intanasally immunized dams had HA-specific IgG antibodies in circulation at 5–6 weeks of life. These preclinical data led to the announcement by Vaxart, Inc. that they will test their oral tablet vaccine in human lactating mothers to determine if vaccination induces BM antibodies. Future work includes using our ferret model to determine the relationship between BM antibody quantity and function and neonatal protection against influenza. An easy-to-deliver mucosal vaccine that boosts systemic and mucosal protective antibodies in the maternal-neonatal dyad is an ideal strategy for protection of these vulnerable populations. Bill and Melinda Gates Foundation grant INV-22595D

Development of a Duplex Serological Multiplex Assay for the Simultaneous Detection of Epstein-Barr Virus IgA and IgG Antibodies in Nasopharyngeal Carcinoma Patients.

Epstein-Barr virus (EBV) IgA and IgG antibodies in serum from nasopharyngeal carcinoma (NPC) patients are well-established markers for EBV-positive NPC. Luminex-based multiplex serology can analyze antibodies to multiple antigens simultaneously; however, the detection of both IgA and IgG antibodies requires separate measurements. Here we describe the development and validation of a novel duplex multiplex serology assay, which can analyze IgA and IgG antibodies against several antigens simultaneously. Secondary antibody/dye combinations, as well as serum dilution factors, were optimized, and 98 NPC cases matched to 142 controls from the Head and Neck 5000 study (HN5000) were assessed and compared to data previously generated in separate IgA and IgG multiplex assays. EBER in situ hybridization (EBER-ISH) data available for 41 tumors was used to calibrate antigen-specific cut-offs using receiver operating characteristic (ROC) analysis with a prespecified specificity of ≥90%. A directly R-Phycoerythrin-labeled IgG antibody in combination with a biotinylated IgA antibody and streptavidin-BV421 reporter conjugate was able to quantify both IgA and IgG antibodies in a duplex reaction in a 1:1000 serum dilution. The combined assessment of IgA and IgG antibodies in NPC cases and controls from the HN5000 study yielded similar sensitivities as the separate IgA and IgG multiplex assays (all > 90%), and the duplex serological multiplex assay was able to unequivocally define the EBV-positive NPC cases (AUC = 1). In conclusion, the simultaneous detection of IgA and IgG antibodies provides an alternative for the separate IgA/IgG antibody quantification and may present a promising approach for larger NPC screening studies in NPC endemic areas.

Comparative Analyses of IgA Antibody Response of Non-COVID-19 Infected People Over 60 Years Old Following CoronaVac and Pfizer-BioNTech COVID-19 Vaccination

The formation rate, magnitude, and duration of the antibody-mediated humoral immune response that develops against different viral proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are considered important in vaccine success. It is known that the response to vaccinations decreases due to immunosenescence in older adults. This study was aimed to investigate the levels of serum IgA response at 1st and 3rd month after vaccination of people over 60 years old who were immunized with CoronaVac and Pfizer-BioNTech. A total of 35 people living in the North Cyprus who have not previously had COVID-19 infection were included in the study. After the 2nd dose of vaccination, serum IgA levels were measured after the 1st and 3rd month with the anti-SARS-CoV-2 IgA (Euroimmun, Lubeck, Germany) kit. The statistical significance was determined as 0.05 in the whole study. SPSS and GraphPad Prism software were used for calculations, analyses and graphs. The possible effect of demographic variables on serum IgA level was compared between the vaccine groups and it was found that there was no statistically significant difference between them. For the IgA titer-positive individuals who had been vaccinated with the Pfizer-BioNTech vaccine, for both 1st and 3rd months were observed to be higher than CoronaVac vaccinated IgA titer-positive individuals. In individuals who received the CoronaVac vaccine, there was a statistically significant change in serum IgA levels between 1st and 3rd months, but there was no statistically significant change in the Pfizer-BioNTech vaccine administered group. When the Pfizer/BioNTech and CoronaVac vaccines were compared with each other in terms of serum IgA antibody titers, it was found that the mean serum IgA levels of the individuals in the Pfizer/BioNTech group were statistically higher at the 1st and 3rd months than the CoronaVac group. Serum IgA titers in both vaccine groups were statistically significantly decreased from 1st month to 3rd month. This study showed that the Pfizer/BioNTech vaccine induced higher SARS-CoV-2 specific serum IgA antibodies than the CoronaVac vaccine and remained seropositive for a longer time in individuals aged 60 years and older. It is believed that the serum IgA levels that were determined may not reflect the serum IgA levels. However, these findings support the studies in other literature, showing that the Pfizer-BioNTech mRNA vaccine induces higher SARS-CoV-2 specific serum IgA antibodies than the inactive CoronaVac vaccine and that it remains seropositive for a longer period of time. This study is important as it is the first study to compare the SARS-CoV-2 IgA antibody responses of individuals over 60 years of age in the Turkish Republic of Northern Cyprus in two different vaccine groups.

Development of SARS-CoV-2 specific IgG and IgA antibodies in serum and milk with different SARS-COV-2 vaccines in lactating women

BackgroundOur main objective was to determine the evolution of IgG and IgA antibodies directed against SARS-CoV-2 protein S in the blood of lactating women and in breast milk.MethodsA cohort of 110 uninfected and vaccinated breastfeeding women was followed-up for 6 months at the Marqués de Valdecilla University Hospital, Spain, in 2020. An additional group of 23 breastfeeding mothers who had no previously documented infection and had not been vaccinated against SARS-CoV-2 were included as a control group. The antibodies in blood and breast milk and their evolution at 6 months post-vaccination were analysed.ResultsOne hundred ten breastfeeding mothers were included; 70 women (63.6%) were vaccinated with two doses of BNT162b2, 20 women (18.2%) received two doses of mRNA-1273, and 20 women (18.2%) received a single dose of ChAdOx1-S. No evidence of differences between concentrations of antibodies was found according to the type of vaccine, with the exception of serum IgA antibodies, which was higher in women vaccinated with mRNA-1273: mean [95%CI]: 0.05 AU/mL [0.03,0.06] with mRNA-1273, 0.02 AU/mL [0.01,0.03] with BNT162b2 and 0.01 AU/mL [0.00,0.03] with ChAdOx1-S, ANOVA p value = 0.03. The lack of difference between vaccines was also found when anti-S1 specific IgG in serum and breast milk were measured.ConclusionsIn lactating women vaccinated against COVID-19, anti-SARS-CoV-2 antibodies can be detected in both serum and breastmilk 6 months after receiving the second dose, although their concentrations decreased when compared with concentrations reached immediately after vaccination.

Are children with attention-deficit/ hyperactivity disorder (ADHD) more likely to develop celiac disease? A prospective study.

The aim of this study was to evaluate whether the prevalence of celiac among attention-deficit/hyperactivity disorder (ADHD) patients is higher than among the normal population. The present study was a prospective one investigating ADHD children referred to the Neurology Clinic and Pediatric Ward at Amir Al-Momenin Hospital of Zabol (Sistan and Baluchestan, Iran) in 2019 after their parents' signing of a consent form. All patients underwent Biocard™ Celiac and serology tests. Data were analyzed with SPSS version 21 software. Of all 76 ADHD children undergoing a serum IgA antibodies concentration test, 58 (76%) were male and 18 (23.7%) were female. The mean age of the children was 6.9 ± 2.4, ranging from 2 years to 12 years. The diagnosis of IgA immunodeficiency was rejected for all children based on total serum IgA antibody results. The overall mean anti-tissue transglutaminase (TTG) level was 6.8 ± 5.3 U/ml, ranging from 0.2 to 37 U/ml. There was no significant difference regarding TTG levels between boys and girls (5.1 vs. 6.0) U/ml. Based on the anti-TTG level results, no celiac case was found among the ADHD patients. There is as yet no evidence suggesting a link between celiac disease and ADHD. Thus, routine celiac disease screening when evaluating for ADHD (and is not recommended). However, the possibility of untreated celiac disease predisposing an individual to ADHD-like behaviors should be considered. Hence, physicians are recommended to evaluate a broad range of physical symptoms, in addition to typical neuropsychiatric symptoms, when evaluating ADHD patients.

Experimental challenge of horses after prime-boost immunization with a modified live equid alphaherpesvirus 1 vaccine administered by two different routes.

The immune response and protective efficacy of a modified equid alphaherpesvirus 1 (EHV-1) vaccine administered by two different routes were tested in horses. Horses that received intramuscular (IM) priming and an intranasal (IN) booster with a 28-day interval (IM-IN group [n = 6]), IN priming and IM booster (IN-IM group [n = 5]), or no vaccination (control group [n = 6]) were challenged with EHV-1 strain 10-I-224 28 days after the second vaccination. Both vaccinated groups had significantly higher serum virus-neutralizing titers than the control group, with increased levels of serum IgGa, IgGb, and IgA antibodies (p < 0.05). The nasal antibody response was dominated by the IgGa and IgGb subclasses in both vaccinated groups, with no IgA antibody response. After challenge infection, three of six control horses were pyretic for 1-4 days post-inoculation (dpi), whereas none in the vaccinated groups were pyretic during this period. The number of horses that were pyretic at 5-10 dpi was 4 out of 6 for the controls, 3 out of 6 for the IM-IN group, and 2 out of 5 for the IN-IM group. Nasal virus replication in the IN-IM group (3-4 dpi) and IM-IN group (3 dpi) was significantly lower than in the control group (p < 0.05). All of the control horses showed viremia, whereas two horses in the IM-IN group and one in the IN-IM group did not. In conclusion, although IM-IN or IN-IM vaccination did not elicit a mucosal IgA response, it provided partial protection at a level similar to that of the conventional program, likely due to systemic antibodies and mucosal IgG subclass responses.

Complementary measurement of nontyphoidal Salmonella-specific IgG and IgA antibodies in oral fluid and serum

ObjectivesImmuno-epidemiological studies of orally acquired, enteric pathogens such as nontyphoidal Salmonella (NTS) often focus on serological measures of immunity, ignoring potentially relevant oral mucosal responses. In this study we sought to assess the levels and detectability of both oral fluid and serum IgG and IgA to NTS antigens, in endemic and non-endemic populations. MethodsIgG and IgA antibodies specific for Salmonella Typhimurium and Salmonella Enteritidis O antigen and phase 1 flagellin were assessed using Enzyme Linked Immunosorbent Assay (ELISA). Paired oral fluid and serum samples were collected from groups of 50 UK adults, Kenyan adults and Kenyan infants. Additionally, oral fluid alone was collected from 304 Kenyan individuals across a range of ages. ResultsAntigen-specific IgG and IgA was detectable in the oral fluid of both adults and infants. Oral fluid antibody increased with age, peaking in adulthood for both IgG and IgA but a separate peak was also observed for IgA in infants. Oral fluid and serum responses correlated for IgG but not IgA. Despite standardised collection the relationship between oral fluid volume and antibody levels varied with age and country of origin. ConclusionsMeasurement of NTS-specific oral fluid antibody can be used to complement measurement of serum antibody. For IgA in particular, oral fluid may offer insights into how protective immunity to NTS changes as individuals transition with age, from maternal to acquired systemic and mucosal immunity. This may prove useful in helping to guide future vaccine design.

Protective efficacy of intranasal inactivated pseudorabies vaccine is improved by combination adjuvant in mice.

Pseudorabies virus (PRV) not only causes great economic loss to the pig industry but also seriously threatens the biosafety of other mammals, including humans. Since 2011, PRV mutant strains have emerged widely in China, and the classical Bartha-K61 vaccine cannot confer complete protection for pigs. PRV mainly infects pigs via the respiratory tract. Intranasal immunization with PRV has received more attention because intranasal vaccination elicits systemic and mucosal immune responses. To induce systemic and mucosal immune responses against PRV, we developed a combination adjuvant as a delivery system for intranasal vaccine, which was formulated with MONTANIDE™ Gel 01 and CVCVA5. In comparison to naked antigen of inactivated PRV, single Gel 01 adjuvanted inactivated antigen and single CVCVA5 adjuvanted inactivated antigen, intranasal inactivated PRV vaccine formulated with the combination adjuvant induced greater mucosal IgA immunity and serum antibody responses (IgG, IgG1, and IgG2a). Furthermore, the production of the Th1-type cytokine IFN-γ and the Th2-type cytokine IL-4 indicated that the cellular and humoral responses to the intranasal vaccine were improved by the combination adjuvant. In addition, the intranasal vaccine formulated with the combination adjuvant induced long-term T lymphocyte memory with increased central (CD62L+CD44+) and effector (CD62L–CD44+) memory subsets of both CD4 and CD8 T cells in nasal-associated lymphoid tissue. Intranasal challenge with virulent PRV in mice showed that the protective efficacy of the intranasal PRV vaccine was improved by the combination adjuvant compared with the other single-adjuvanted vaccines. In summary, these data demonstrated that Gel 01 combined with the CVCVA5 adjuvant induced a synergistic effect to improve mucosal immunity and protective efficacy of the intranasally inactivated PRV vaccine in mice. It represents a promising vaccination approach against PRV infection.

Intranasal administration of a single dose of MVA-based vaccine candidates against COVID-19 induced local and systemic immune responses and protects mice from a lethal SARS-CoV-2 infection

Current coronavirus disease-19 (COVID-19) vaccines are administered by the intramuscular route, but this vaccine administration failed to prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus infection in the upper respiratory tract, mainly due to the absence of virus-specific mucosal immune responses. It is hypothesized that intranasal (IN) vaccination could induce both mucosal and systemic immune responses that blocked SARS-CoV-2 transmission and COVID-19 progression. Here, we evaluated in mice IN administration of three modified vaccinia virus Ankara (MVA)-based vaccine candidates expressing the SARS-CoV-2 spike (S) protein, either the full-length native S or a prefusion-stabilized [S(3P)] protein; SARS-CoV-2-specific immune responses and efficacy were determined after a single IN vaccine application. Results showed that in C57BL/6 mice, MVA-based vaccine candidates elicited S-specific IgG and IgA antibodies in serum and bronchoalveolar lavages, respectively, and neutralizing antibodies against parental and SARS-CoV-2 variants of concern (VoC), with MVA-S(3P) being the most immunogenic vaccine candidate. IN vaccine administration also induced polyfunctional S-specific Th1-skewed CD4+ and cytotoxic CD8+ T-cell immune responses locally (in lungs and bronchoalveolar lymph nodes) or systemically (in spleen). Remarkably, a single IN vaccine dose protected susceptible K18-hACE2 transgenic mice from morbidity and mortality caused by SARS-CoV-2 infection, with MVA-S(3P) being the most effective candidate. Infectious SARS-CoV-2 viruses were undetectable in lungs and nasal washes, correlating with high titers of S-specific IgGs and neutralizing antibodies against parental SARS-CoV-2 and several VoC. Moreover, low histopathological lung lesions and low levels of pro-inflammatory cytokines in lungs and nasal washes were detected in vaccinated animals. These results demonstrated that a single IN inoculation of our MVA-based vaccine candidates induced potent immune responses, either locally or systemically, and protected animal models from COVID-19. These results also identified an effective vaccine administration route to induce mucosal immunity that should prevent SARS-CoV-2 host-to-host transmission.

Evaluation of the Efficacy of an S-INDEL PEDV Strain Administered to Pregnant Gilts against a Virulent Non-S-INDEL PEDV Challenge in Newborn Piglets.

A safe and efficacious live-attenuated vaccine for porcine epidemic diarrhea virus (PEDV) is not commercially available in the United States yet. Two major PEDV strains are currently circulating in US swine: highly virulent non-S-INDEL strain and milder virulent S-INDEL strain. In this study, the safety and protective efficacy of a plaque-purified S-INDEL PEDV isolate formulated as a vaccine candidate was evaluated. Ten pregnant gilts were divided into three groups and orally inoculated at 79 days of gestation and then boosted at 100 days gestation (T01: n = 4, vaccination/challenge; T02: n = 4, non-vaccination/challenge; T03: n = 2, non-vaccination/non-challenge). None of the gilts had adverse clinical signs after vaccination. Only one T01 gilt (#5026) had viral replication and detectible viral RNA in feces. The same gilt had consistent levels of PEDV-specific IgG and IgA antibodies in serum and colostrum/milk. Farrowed piglets at 3 to 5 days of age from T01 and T02 gilts were orally challenged with 103 TCID50/pig of the virulent non-S-INDEL PEDV while T03 piglets were orally inoculated with virus-negative medium. T01 litters had overall lower mortality than T02 (T01 36.4% vs. T02 74.4%). Specifically, there was 0% litter mortality from T01 gilt 5026. Overall, it appears that vaccination of pregnant gilts with S-INDEL PEDV can passively protect piglets if there is virus replication and immune response induction in the pregnant gilts.

Pregnant sows immunized with Cryptosporidium parvum significantly reduced infection in newborn piglets challenged with C. parvum but not with C. hominis.

BackgroundThe piglet is the only model to investigate the immunogenic relationship between Cryptosporidium hominis and C. parvum, the species responsible for diarrhea in humans. Despite being indistinguishable antigenically, and high genetic homology between them, they are only moderately cross protective after an active infection.Methodology/Principal findingsHere we examined the degree of passive protection conferred to piglets suckling sows immunized during pregnancy with C. parvum. After birth suckling piglets were challenged orally with either C. parvum or C. hominis at age 5 days. Animals challenged with C. parvum had significant reduction of infection rate, while piglets challenged with C. hominis showed no reduction despite high C. parvum serum and colostrum IgG and IgA antibody.Conclusions/SignificanceWe add these data to earlier studies where we described that infection derived immunity provides partial cross-protection. Together, it appears that for full protection, vaccines against human cryptosporidiosis must contain antigenic elements derived from both species.

Immunological imbalance, gene polymorphism of biotransformation enzymes, and steroid hormone receptors in tumors in breast cancer patients

It is well known that results of breast cancer (BC) hormonal therapy depend on expression of tumor estradiol and progesterone receptors (ER and PR) in tumor tissue. Mechanisms of ER+/PR+ tumors conversion to ER+/PR- and ER-/PR- tumors remain scarcely studied. The decrease of steroid receptors expression seems to depend on action of genotoxic metabolites of environmental carcinogens (particularly, benzo[a]pyrene, BP) and endogenous steroids (in particular, estradiol, E2). The formation of these metabolites is regulated by the biotransformation enzymes. On the other hand, the formation of DNA-adducts with genotoxic metabolites may induce the synthesis of specific antibodies. Previously, it was shown that increase of the serum IgA-antibodies levels against Bp and E2 over the levels of IgA-antibodies against progesterone (IgA-Bp/IgA-Pg &gt; 1 and IgA-E2/IgA-Pg), could be interpreted as immunological imbalance associated with high BC risk in healthy women. The purpose of this study was to detect the suggested associations between ER+/PR+ tumors conversion to ER+/PR+ and ER-/PR- tumors and immunological imbalance in the BC patients with distinct gene variants of biotransformation enzymes: CYP1A1*2A (rs 4646903), CYP1B1 (rs1056836), CYP19A1 (rs2470152), GSTT1 (del), GSTP1 (rs1695). The IgA-Bp, IgA-E2 and IgA-Pg were studied in 1321 non-smoking BC patients by non-competitive solid phase immunoassay. The conjugates of Bp, E2 and Pg with bovine serum albumin were adsorbed as target antibodies. The goat antibodies against human IgA conjugated with horseradish peroxidase were used for detection of the studied specific antibodies. Gene polymorphisms of biotransformation enzymes were analyzed by the real-time PCR. Tumor ER and PR were detected by the standard immunohistochemical methods.ER+/PR+ tumors in BC patients at the stage I (N = 534) were found in 68.7%, ER+/PR- in 15.6%, ER-/ PR- in 15.7%. In BC patients at the II-IV stage (N = 787), frequency of ER+/PR+ tumors decreased to 60.2%, ER+/PR- was similar (15.8%), and ER-/PR- increased to 24.0% (p &lt; 0.0001). These alterations were revealed in BC patients at the IgA-Bp/IgA-Pg ratios &gt; 1, and IgA-E2/IgA-Pg &gt; 1 only. There were no differences found between BC patients at stage I and II-IV at the ER+/PR+, ER+/PR-, ER-/PR- frequencies when these ratios were low.The frequency of ER+/PR+ tumors in homozygotes TT of CYP19A1 was 77.1% at the I stage and 60.1% at the II-IV stages. Respectively the frequencies of ER-/PR- tumors were 11.8% and 26.1% (p &lt; 0.001). ER+/ PR+ tumors were revealed in GSTT1 “+” BC patients at the I stage in 68.7% and at the II-IV stages in 58.0%. Respectively ER-/PR- tumors were found in 16.6% and 24.5% (p &lt; 0.0004). The frequency of ER+/PR+ tumors was 57.1% in homozygotes GG of GSTP1 at the I stage and 60.7% at the II-IV stages. Respectively the frequencies of ER+/PR- were 14.3% and 22.2% and ER-/PR- were 28.6% and 19.0% (p &lt; 0.001). Proportions of low and high IgA-Bp/IgA-Pg and IgA-E2/IgA-Pg ratios were the same at the any enzyme genotype of studied CYP or GST variants. In conclusion, we have revealed a sufficient contribution of immunological imbalance to the conversion of steroid receptors in breast cancer growth, being independent of several CYP and GST gene polymorphisms.