Immune Response of Neonates Born to Mothers Infected With SARS-CoV-2.

Importance: Although several studies have provided information on short-term clinical outcomes in children with perinatal exposure to SARS-CoV-2, data on the immune response in the first months of life among newborns exposed to the virus in utero are lacking. Objective: To characterize systemic and mucosal antibody production during the first 2 months of life among infants who were born to mothers infected with SARS-CoV-2. Design, Setting, and Participants: This prospective cohort study enrolled 28 pregnant women who tested positive for SARS-CoV-2 infection and who gave birth at Policlinico Umberto I in Rome, Italy, from November 2020 to May 2021, and their newborns. Maternal and neonatal systemic immune responses were investigated by detecting spike-specific antibodies in serum, and the mucosal immune response was assessed by measuring specific antibodies in maternal breastmilk and infant saliva 48 hours after delivery and 2 months later. Exposures: Maternal infection with SARS-CoV-2 in late pregnancy. Main Outcomes and Measures: The systemic immune response was evaluated by the detection of SARS-CoV-2 IgG and IgA antibodies and receptor binding domain-specific IgM antibodies in maternal and neonatal serum. The mucosal immune response was assessed by measuring spike-specific antibodies in breastmilk and in infant saliva, and the presence of antigen-antibody spike IgA immune complexes was investigated in breastmilk samples. All antibodies were detected using an enzyme-linked immunosorbent assay. Results: In total, 28 mother-infant dyads (mean [SD] maternal age, 31.8 [6.4] years; mean [SD] gestational age, 38.1 [2.3] weeks; 18 [60%] male infants) were enrolled at delivery, and 21 dyads completed the study at 2 months' follow-up. Because maternal infection was recent in all cases, transplacental transfer of virus spike-specific IgG antibodies occurred in only 1 infant. One case of potential vertical transmission and 1 case of horizontal infection were observed. Virus spike protein-specific salivary IgA antibodies were significantly increased (P = .01) in infants fed breastmilk (0.99 arbitrary units [AU]; IQR, 0.39-1.68 AU) vs infants fed an exclusive formula diet (0.16 AU; IQR, 0.02-0.83 AU). Maternal milk contained IgA spike immune complexes at 48 hours (0.53 AU; IQR, 0.25-0.39 AU) and at 2 months (0.09 AU; IQR, 0.03-0.17 AU) and may have functioned as specific stimuli for the infant mucosal immune response. Conclusions and Relevance: In this cohort study, SARS-CoV-2 spike-specific IgA antibodies were detected in infant saliva, which may partly explain why newborns are resistant to SARS-CoV-2 infection. Mothers infected in the peripartum period appear to not only passively protect the newborn via breastmilk secretory IgA but also actively stimulate and train the neonatal immune system via breastmilk immune complexes.

First report of detection of IgA anti-Acanthamoeba antibodies among Saudi population and amoeba isolation from their surroundings.

Acanthamoeba is an opportunistic protozoan pathogen which is found in diverse environment worldwide. Being ubiquitous nature of this amoeba we come across it in our daily life. Acanthamoeba species are recognized as human pathogens; that may cause blinding keratitis and rare but fatal granulomatous encephalitis involving central nervous system. To date, there is not a single report in literature demonstrating anti-Acanthamoeba antibodies among the Saudi population, and thus aim of the present study. Using ELISA, we identified the antibody level in the local population. Our results represent the secretory IgA antiAcanthamoeba in mucosal secretions from 133 individuals aged 15-60 years. The antiAcanthamoeba antibody prevalence rate was > 80%, and no considerable differences were observed between prevalence in males (80.28%) and that in females (80.64%). In addition, environmental sources (soil and water) from the environment of the participants in our study were evaluated for amoeba incidence. The amoeba was identified by morphological characteristics of cysts or trophozoites on non-nutrient agar plates grown with E. coli. Overall, 58.75% of samples from water and 32.85% of those from soil were culture positive for outgrowth of amoeba on non-nutrient agar plates. Furthermore, PCR was carried out with genus-specific primers to confirm the presence of Acanthamoeba DNA. Our results revealed that about 68% of cultures from water and 43% of those from soil were successfully amplified and proved to be amoeba DNA. Interestingly, a few samples yielded more than one product, which suggests that some other amoebic species may be present in the same sample (MAC-W1 and MADW1). To the best of our knowledge, we described for the first time the amoeba isolation from the participant's close environment and antibodies level among Saudi population. Our future studies will be focused on additional molecular characterization of isolated amoeba and their pathogenic potential which could be a possible threat for the community.

Evaluation of commercially available immuno-magnetic agglutination in comparison to enzyme-linked immunosorbent assays for rapid point-of-care diagnostics of COVID-19.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) is caused by Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Fast, accurate, and simple blood-based assays for quantification of anti-SARS-CoV-2 antibodies are urgently needed to identify infected individuals and keep track of the spread of disease. METHODS: The study included 33 plasma samples from 20 individuals with confirmed COVID-19 by real-time reverse-transcriptase polymerase chain reaction and 40 non-COVID-19 plasma samples. Anti-SARS-CoV-2 immunoglobulin M (IgM)/immunoglobulin A (IgA) or immunoglobulin G (IgG) antibodies were detected by a microfluidic quantitative immunomagnetic assay (IMA) (ViroTrack Sero COVID IgM + IgA/IgG Ab, Blusense Diagnostics) and compared to an enzyme-linked immunosorbent assay (ELISA) (EuroImmun Medizinische Labordiagnostika). RESULTS: Of the 33 plasma samples from the COVID-19 patients, 28 were positive for IgA/IgM or IgG by IMA and 29 samples were positive by ELISA. Sensitivity for only one sample per patient was 68% for IgA + IgM and 75% IgG by IMA and 80% by ELISA. For samples collected 14 days after symptom onset, the sensitivity of both IMA and ELISA was around 91%. The specificity of the IMA reached 100% compared to 95% for ELISA IgA and 97.5% for ELISA IgG. CONCLUSION: IMA for COVID-19 is a rapid simple-to-use point-of-care test with sensitivity and specificity similar to a commercial ELISA.

Upregulation of microRNA­140­3p mediates dachshund family transcription factor 1 expression in immunoglobulin A nephropathy through cell cycle­dependent mechanisms.

Immunoglobulin A nephropathy (IgAN) is a kidney disease and one of the commonest forms of glomerulonephritis worldwide. The present study investigated the role of dachshund family transcription factor 1 (DACH1) in IgAN and identified one of its binding microRNAs (miRNAs). The expression of DACH1 in human mesangial cells (HMCs) incubated with polymeric IgA (pIgA) isolated and purified from the serum of patients with IgAN or healthy individuals was evaluated by reverse transcription­quantitative (RT­q) PCR and western blotting. Cell proliferation and cell cycle assays were performed in DACH1­overexpressing HMCs to identify the role of DACH1 in IgAN and enzyme­linked immunosorbent assay was carried out to verify the release of inflammatory factors from HMCs. The target miRNAs of DACH1 were predicted using bioinformatics software and miR­140­3p was identified as a target of DACH1 by luciferase report assay, RT­qPCR and western blotting. The results demonstrated that DACH1 was downregulated in HMCs cultured with pIgA­IgAN at both mRNA and protein levels. Overexpression of DACH1 suppressed HMC growth and inhibited inflammatory cytokine release from HMCs cultured with pIgA­IgAN. The expression of DACH1 was negatively regulated by miR­140­3p in IgAN and miR­140­3p inhibition suppressed HMC growth and inhibited inflammatory cytokine release from HMCs cultured with pIgA­IgAN. The findings of the present study demonstrated that DACH1 decreased HMC growth and the release of inflammatory cytokines from HMCs may be targeted by miR­140­3p. The results suggested that DACH1 could be associated with the progression of IgAN and provide a potential target for further studies related to the mechanism of IgAN.

Pulmonary embolism as the primary presentation of IgA vasculitis.

A 47-year-old man presented to the emergency department with acute onset of dyspnoea and a week history of painful erythematous rash on both of his legs. CT angiogram of the chest showed saddle pulmonary embolism resulting in right ventricular strain and obstructive shock. Due to the atypical nature of his skin rash, a skin biopsy from one of these lesions was done and came consistent with the diagnosis of IgA vasculitis.

Longitudinal Human Antibody Repertoire against Complete Viral Proteome from Ebola Virus Survivor Reveals Protective Sites for Vaccine Design.

Evolution of antibody repertoire against the Ebola virus (EBOV) proteome was characterized in an acutely infected patient receiving supportive care alone to elucidate virus-host interactions over time. Differential kinetics are observed for IgM-IgG-IgA epitope diversity, antibody binding, and affinity maturation to EBOV proteins. During acute illness, antibodies predominate to VP40 and glycoprotein (GP). At day 13 of clinical illness, a marked increase in antibody titers to most EBOV proteins and affinity maturation to GP is associated with rapid decline in viral replication and illness severity. At one year, despite undetectable virus, a diverse IgM repertoire against VP40 and GP epitopes is observed suggesting occult viral persistence. Rabbit immunization experiments identify key immunodominant sites of GP, while challenge studies in mice found these epitopes induce EBOV-neutralizing antibodies and protect against lethal EBOV challenge. This study reveals markers of viral persistence and provides promising approaches for development and evaluation of vaccines and therapeutics.

Proteomic Characterization of Immunoglobulin Content in Dermal Interstitial Fluid.

Microneedles have been demonstrated to be a minimally invasive technique for sampling dermal interstitial fluid (ISF). Shotgun quantitative proteomics has already identified hundreds of proteins in ISF and quantitatively compared the proteome to matching serum and plasma. Interstitial fluid was determined to be a viable minimally invasive alternative to blood-derived fluids. In this communication, we re-examined the proteomic data from previous work to determine the diversity of immunoglobulins present compared with serum and plasma. Similar to our previous findings regarding the proteomic content across fluid types, ISF had a similar composition of IgG, IgA, IgD, and IgE antibodies as plasma or serum and lower quantities of IgM, which reflects the relative concentrations of dermal tissue T-cell and B-cell populations, indicating that the Ig's were likely locally derived. This work has significant implications for the utility of measuring Ig's in ISF for the clinical diagnosis of immunological diseases and skin infections. Data are available via ProteomeXchange with identifier PXD012658.

The Consistency Research of Two Incubation Methods in Anti-EBNA1-IgA Antibody Detection.

BACKGROUND: The aim of this study was to prove the difference between 37°C water incubation method and the BEP III automated immunoassay analyzer incubation method in anti-EBNA1-IgA antibody detection and to find the best way to improve the consistency of the two incubation methods. METHODS: The 37°C water incubation method and BEP III analyzer incubation method were used with the same panel of samples (n = 39) in anti-EBNA1-IgA antibody detection. Except for incubation, the rest of the steps were performed by the BEP III analyzer in both groups. All the data were analyzed by SPSS 17.0 software. Line charts and bar charts were used to compare the difference between the two incubation methods in anti-EBNA1-IgA antibody detection. We planned to find the best incubation scheme for BEP III analyzer, consistent with the water incubation method, using three groups of prolonged incubation time experiments. RESULTS: A sample panel of 39 outpatients were analyzed by two incubation methods. The results showed by line charts that the water incubation method had higher S/CO values than the BEP III analyzer incubation method. Meanwhile the water incubation group had more positive results (61.5%) and less borderline positive results (35.9%) than that of the BEP III analyzer incubation group which were 43.5% and 51.2%, respectively, in the stacked bar charts. We found that by prolonging the incubation time in the BEP III analyzer for 6 minutes in the first and second incubation steps the S/CO values we increased and achieved statistically coincident results with water incubation group. CONCLUSIONS: There were biases between the 37°C water incubation method and the BEP III analyzer incubation method in anti-EBNA1-IgA antibody detection. The water incubation method had higher S/CO values than the BEP III analyzer incubation method in paired groups and led partly to a difference in test results. By prolonging the BEP III analyzer incubation time properly, it can reduce the difference to some extent resulting in statistically similar results with the water incubation method.

Intestinal IgA positive lymphocytes in acute liver necrosis decrease due to lymphocyte homing disturbance and apoptosis

Aim: the number of intestinal IgA+ lymphocytes are decreased in acute liver necrosis and the mechanism remains poorly understood. The purpose of this study was to observe the role of lymphocyte homing and apoptosis associated with decreased intestinal IgA positive lymphocytes in acute liver necrosis. Methods: the acute liver necrosis mouse model and LTßR pre-treatment were used to assess intestinal mucosal addressin cell adhesion molecule-1 (MAdCAM - 1) expression, cell apoptosis, IgA+ cells and secretory immunoglobulin A (SIgA). Results: MAdCAM - 1 mRNA and protein expression decreased significantly in the acute necrosis group; 0.57 ± 0.032 fold vs. baseline (p < 0.05) and 0.45 ± 0.072 fold vs. baseline (p < 0.05), respectively. LTßR pre-treatment could significantly improve the decline of MAdCAM - 1 mRNA and protein expression in the intestinal mucosa (1.83 ± 0.064 fold vs. baseline, p < 0.05 and 1.75 ± 0.046 fold vs. baseline, p < 0.05, respectively) and partially restore the decline in IgA+ lymphocytes and SIgA levels. There were increased rates of enterocyte apoptosis in both the acute liver necrosis and LTßR pre-treatment group; 0.79% vs. control (p < 0.05) and 0.77% vs. control (p < 0.05), respectively). Conclusion: our results suggest that the dysfunction of lymphocyte homing and apoptosis are both involved with decreased intestinal IgA+ lymphocytes in acute liver necrosis. LTßR pre-treatment can partially restore IgA+ cells and SIgA by increasing MAdCAM - 1 expression, rather than inhibiting lymphocyte apoptosis

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Detection of classical swine fever virus (CSFV) E2 and Erns antibody (IgG, IgA) in oral fluid specimens from inoculated (ALD strain) or vaccinated (LOM strain) pigs.

The objective of this study was to describe oral fluid and serum antibody (IgG, IgA) responses against classical swine fever virus (CSFV) E2 and Erns proteins in pigs (n = 60) inoculated with a moderately virulent field strain (ALD, n = 30) or a modified live virus vaccine strain (LOM, n = 30). Oral fluid (n = 1391) and serum (n = 591) samples were collected from individually-housed pigs between day post inoculation (DPI) -14 to 28. Testing revealed the synchronous appearance of E2- and Erns-specific IgG and IgA antibodies in serum and oral fluids over time, with E2 and Erns IgG ELISAs providing better diagnostic performance than the IgA ELISAs. Overall the data suggest the feasibility of large-scale, cost-effective screening of populations for CSFV using oral fluid samples. Given the historic issues of cross-reactivity among pestiviruses, future research should focus on the development of CSFV-specific testing platforms for the detection of E2 and/or Erns IgG in oral fluid, ideally to be used in combination with DIVA vaccines.

Determination of Lipoprotein Z-Specific IgA in Tuberculosis and Latent Tuberculosis Infection.

Tuberculosis (TB) remains one of the most severe infectious diseases. It is still of paramount importance to establish more accurate, rapid, and efficient diagnostic methods. Since infection with Mycobacterium tuberculosis (M. tb) is largely mediated through the respiratory tract, IgA responses against mycobacterial proteins are worthy of investigation for their potential clinical utility. In this study, the IgA response targeting lipoprotein Z (LppZ) was determined by using a homemade ELISA with plasma of TB patients (N = 125), LTBI individuals (N = 92), healthy controls (HCs) (N = 165), as well as TB patients undergoing anti-TB treatment (N = 9). In parallel the antigen-specific IFN-γ release from PBMCs triggered by LppZ and M. tb-specific ESAT-6 or CFP-10 was detected by using an ELISPOT assay. It was found that the LppZ-specific IgA level was dramatically higher in TB patients than in HCs (p < 0.0001). Compared to that before anti-TB treatment, the LppZ-specific IgA level decreased substantially after 2 months of anti-TB treatment (p = 0.0297) and remained at low levels until the end of the treatment. What is more, pulmonary TB patients exhibited significantly higher LppZ-specific IgA-values than extra-pulmonary TB patients (p = 0.0296). Interestingly, the LppZ-specific IgA-values were negatively correlated to the amounts of IFN-γ released in response to LppZ with statistical significance (r = -0.5806, p = 0.0002). LppZ-specific IgA level was also higher in LTBI individuals than in HCs (p < 0.0001). Additionally there were some PPD+ HC individuals with high LppZ-specific IgA levels but the potential of this assay for identifying leaky LTBI in PPD+ HCs needs to be further investigated through follow-up studies. The sensitivity of detecting TB solely with ESAT-6 or CFP-10-specific IFN-γ release was increased by including the LppZ-specific IgA results, respectively, from 86.11 to 100% and 88.89 to 100%; the sensitivity of screening for LTBI was increased from 80.36 to 83.93% and 57.14 to 69.64%, respectively. The higher LppZ-specific IgA responses in TB and LTBI populations than in controls indicated high immunoreactivity to LppZ upon M. tb infection. Although the assay was not efficient enough for independent application in sero-diagnosis, LppZ-specific IgA might become a complementary biomarker for the improvement of TB and LTBI screening.

Separation of Two Distinct O-Glycoforms of Human IgA1 by Serial Lectin Chromatography Followed by Mass Spectrometry O-Glycan Analysis.

Human immunoglobulin A1 (IgA1), which carries four to six mucin-type O-glycans (O-glycans) on its hinge region (HR), is the most abundant O-glycoprotein in plasma or serum. While normal O-glycans from hematopoietic-originated cells are core 1-based complex structures, many reports showed that the IgA1 from patients with IgA nephropathy (IgAN) carries undergalactosylated or truncated O-glycans such as the Tn antigen and its sialylated version the SialylTn (STn) antigen on the HR. Yet, there is still a debate whether Tn/STn on the HR of IgA1 is specific to the IgA1 from patients with IgAN since these antigens have also been seen in serum IgA1 of healthy individuals. An additional question is whether the O-glycans at all sites on the two HRs of one IgA1 molecule are homogeneous (either all normal or all Tn/STn) or heterogeneous (both normal and Tn/STn O-glycans). To address these questions, we conducted a systematic study on the O-glycans of plasma IgA1 from both IgAN patients and healthy controls using serial HPA and PNA lectin chromatography followed by western blotting and further analysis of O-glycans from HPA-bound and PNA-bound IgA1 fractions by mass spectrometry. Unexpectedly, we found that a variable minor fraction of IgA1 from both IgAN patients and healthy controls had Tn/STn antigens, and that the O-glycoprotein IgA1 molecules from most samples had only two distinct O-glycoforms: one major glycoform with homogeneous normal core 1-based O-glycans and one minor glycoform with homogeneous Tn/STn antigens. These results raised a serious question about the role of Tn/STn antigens on IgA1 in pathogenesis of IgAN, and there is a demand for a practical methodology that any laboratory can utilize to analyze the O-glycans of IgA1. Herein, we describe the methodology we developed in more detail. The method could also be applied to the analysis of any other O-glycosylated proteins.

Dermatitis herpetiformis: a cutaneous manifestation of coeliac disease.

Dermatitis herpetiformis (DH) is an itchy blistering skin disease with predilection sites on elbows, knees, and buttocks. Diagnosis is confirmed by showing granular immunoglobulin A deposits in perilesional skin. DH is one manifestation of coeliac disease; the skin symptoms heal with gluten free diet (GFD) and relapse on gluten challenge. Of the first-degree relatives, 5% may be affected by either condition. Tissue transglutaminase (TG2) is the autoantigen in coeliac disease and epidermal transglutaminase (TG3) in DH. Both diseases conditions exhibit TG2-specific autoantibodies in serum and small bowel mucosa; patients with DH have IgA-TG3 in the skin. There are some divergencies between these two phenotypes. One-fourth of DH patients do not have small bowel mucosal villous atrophy, but virtually all have coeliac-type inflammatory changes. The skin symptoms respond slowly to GFD. The incidence of coeliac disease is increasing, whereas the opposite is true for DH. A female predominance is evident in coeliac disease, while DH may be more common in males. Coeliac disease carries the risk of small intestinal T-cell lymphoma; in DH B-cell lymphomas at any site may prevail. Adult coeliac disease carries a slightly increased elevated mortality risk, whereas in DH, the relative mortality rate is significantly decreased. Key messages Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease; both conditions are genetically determined and gluten-dependent. Gastrointestinal symptoms and the degree of villous atrophy are less obvious in dermatitis herpetiformis than in coeliac disease. Both show tissue transglutaminase (TG2) specific autoantibodies in serum and small bowel mucosa. In addition, TG3-targeted IgA antibodies are found in the skin of DH patients Both conditions carry an increased elevated risk of lymphoma, in coeliac disease small intestinal T-cell lymphoma, in dermatitis herpetiformis mainly B-cell lymphoma at various sites. Coeliac disease is currently eight times more common that DH; the incidence of DH is decreasing in contrast to that of coeliac disease, where it is increasing.

First Membrane Proximal External Region-Specific Anti-HIV1 Broadly Neutralizing Monoclonal IgA1 Presenting Short CDRH3 and Low Somatic Mutations.

Mucosal HIV-1-specific IgA have been described as being able to neutralize HIV-1 and to block viral transcytosis. In serum and saliva, the anti-HIV IgA response is predominantly raised against the envelope of HIV-1. In this work, we describe the in vivo generation of gp41-specific IgA1 in humanized α1KI mice to produce chimeric IgA1. Mice were immunized with a conformational immunogenic gp41-transfected cell line. Among 2300 clones screened by immunofluorescence microscopy, six different gp41-specific IgA with strong recognition of gp41 were identified. Two of them have strong neutralizing activity against primary HIV-1 tier 1, 2, and 3 strains and present a low rate of somatic mutations and autoreactivity, unlike what was described for classical gp41-specific IgG. Epitopes were identified and located in the hepted repeat 2/membrane proximal external region. These Abs could be of interest in prophylactic treatment to block HIV-1 penetration in mucosa or in chronically infected patients in combination with antiretroviral therapy to reduce viral load and reservoir.

Levels of salivary immunoglobulin A under psychological stress and its relationship with rumination and five personality traits in medical students

Background and Objectives: The measurement of salivary immunoglobulin A is a useful and non-invasive method for measuring stress. Personality traits and rumination act as possible mediators in the relationship between psychological stressors and the immune system. This study was aimed to evaluate the levels of salivary IgA under psychological stress and its relationship with rumination and five personality traits in medical students. Methods: In this cross- sectional study, 45 medical students who intended to participate in the final exam were selected by simple random sampling. Two months before the exam, in the peribasal conditions, the NEO Personality Inventory-Short Form and Emotional Control Questionnaire(ECQ) were completed. Saliva samples were taken from students in both the basal conditions and exam stress conditions. Salivary IgA was measured by an ELISA test. Data was analyzed using paired samples T-test, Pearson correlation analysis, and stepwise regression. Results: A significant reduction of salivary IgA levels was found in exam stress conditions. Also, a significant negative correlation was found between traits of neuroticism and rumination with salivary IgA, as well as a significant positive correlation between of openness to experience and emotional inhibition with salivary IgA. Openness to experience and emotional inhibition may predict a substantial variance (34%) of salivary IgA under exam stress. Conclusions: Salivary IgA is reduced in response to exam stress. In addition, the rumination and personality traits may reduce or increase stress effects on the immune system, particularly the salivary IgA (AU)

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Granulomas cutáneos no infecciosos en inmunodeficiencia común variable / Non-infectious skin granulomas in a common variable immunodeficiency

La inmunodeficiencia variable común es una inmunodeficiencia primaria por hipogamaglobulinemia de IgG e IgA poco frecuente en la población. Clásicamente se presenta durante la juventud y se diagnostica durante la investigación de infecciones respiratorias y gastrointestinales a repetición. Estos pacientes pueden además presentar enfermedades autoinmunes, inflamatorias, neoplásicas, malabsorción y problemas granulomatosos no infecciosos, que afectan el pulmón, ganglios, bazo, hígado, y menos usualmente la piel. Presentamos el caso de una paciente diagnosticada de inmunodeficiencia variable común que se presenta en la consulta dermatológica con múltiples nódulos eritemato-costrosos en miembros, donde se hallaron únicamente granulomas asépticos (AU)

Common variable immunodeficiency is a rare, primary immunodeficiency characterized by hypogammaglobulinemia of IgG and IgA. It classically presents as recurrent respiratory and gastrointestinal infections in young patients, who may also have autoimmune and inflammatory disease, malignancies, malabsorption and non-infectious granulomas, mainly located in the lung, lymph nodes, spleen, liver and, less frequently, in the skin. We report the case of a patient diagnosed with common variable immunodeficiency who presented in the dermatology clinic with multiple, erythematous, crusted nodules on the limbs. Only aseptic granulomas were found (AU)

[Tyramine and tryptamine as ligands for medical and biotechnological affinity sorbents].

A novel technique for preparation affinity sorbent based on tyramine and tryptamine was proposed. It was shown that tryptamine-Sepharose and tyramine-Sepharose effectively bind IgG, IgA, lipoprotein (a) (Lp(a)) and low density lipoproteins (LDL) from blood plasma. The sorption capacity is 4-9 mg of IgG, 2-4 mg IgA, 3-5:mg of Lp(a) and 5-7 mg of LDL per mL of gel. It was found that new sorbents can bind Lp(a) and IgG as themselves or in a complex of Lp(a) with IgG. The existence of this complex may indicate the presence of anti-Lp(a) autoantibodies in the blood of some patients. The advantages of new sorbents are easiness of its synthesis and stability during use and storage. In practice they can be applied for medical and biotechnological purposes where it is necessary to bind Lp(a), LDL, IgG, IgA.

Purification and functional characterization of mucosal IgA from vaccinated and SIV-infected rhesus macaques.

Vaccine-induced mucosal antibodies are often evaluated using small volumes of secretory fluids. However, fecal matter containing mucosal IgA is abundant. We purified fecal IgA from five SIV-vaccinated and five SIV-infected rhesus macaques by sequential affinity chromatography. The purified IgA was dimeric by native PAGE, contained secretory component, and was analogous to IgA in colostrum and vaginal fluid by western blot. IgA from one infected and four vaccinated animals neutralized H9-derived SIV(mac)251 with IC(50)s as low as 1 µg/mL. Purified IgAs inhibited transcytosis and exhibited phagocytic activity, the latter significantly correlated with SIV(mac)251 Env-specific IgA in the purified samples. Among different affinity resins, peptide M was optimal compared to jacalin, anti-monkey IgA and SSL7 for IgA purification, as confirmed using tandem peptide M/anti-monkey IgA columns. Fecal IgA provided material sufficient for several assays relevant to protective efficacy, and was shown to be multifunctional. Our approach is potentially applicable to human clinical studies.

[Signs of microbial sensibilization in patients with various cardiovascular diseases].

AIM: Analysis of intensity of non-specific (level of sera cytokines) and specific (titers of antibodies against Chlamydophila pneumoniae) factors of humoral immunity in patients with arterial hypertension and various forms of ischemic heart diseases. MATERIALS AND METHODS: 282 individuals were the object of examination--157 (55.7%) males. 8 groups were formed, comparable by age: 1 - 32 individuals with exertional angina pectoris of the III functional class; 2 - 20 individuals with healing Q-positive myocardial infarction (MI); 3 - 15 individuals with Q-negative healing MI; 4 - 15 individuals with unstable angina pectoris; 5 - 40 individuals with persisting atrium fibrillation; 6 - 35 individuals with clinically significant chronic heart failure; 7 - 92 patients with hypertension of the II stage; 33 conditionally healthy composed the control group. Class A and G immunoglobulins against C. pneumoniae, IL-1ß, -6, -17, TNFα content in blood were determined. RESULTS: The proportion of seropositive individuals in groups with IgG and IgA titer characteristics was determined. Data on the level of cytokines, taking into the account seropositivity, and titer increase are presented. Correlations between hemostasis system were established, that demonstrate increase of thrombophilia in the presence of persistent infection, mediated via induction of cytokine production. Significant differences by instrumental parameters depending on seropositivity were not obtained. CONCLUSION: Contribution of microbial sensibilization and latent inflammation in the development and destabilization of atherogenesis-associated diseases seems evident.

Comparison of different ELISA protocols for the detection of IgA against influenza nucleoproteins in trachea of vaccinated chickens.

Vaccines targeting mucosal immunity are important for the control of infection by pathogens with mucosal portals of entry, such as avian influenza. However, reliable and effective methods for determining levels of mucosal IgA stimulated by vaccination are not well developed in poultry and are necessary for determining efficacy. The objective of the present study was to compare different ELISA protocols to evaluate levels of mucosal IgA against two different sequences of nucleoprotein (NP:), a highly conserved internal protein in avian influenza virus, in trachea. Positive control tracheas were obtained through hyperimmunization of birds with adjuvated NP1 and NP2 peptide conjugated with keyhole limpet hemocyanin administered both orally and parenterally; negative birds received no antigen. Trachea samples were homogenized, and supernatant fluid was collected to separate IgA. ELISA was performed on NP1- or NP2-positive trachea samples, negative trachea samples, and blank wells with different levels of NP1 and NP2 coating peptides (5 or 10 µg/mL) using two different secondary antibodies (Gene Tex, GT:, or Thermo Scientific, TS:), with or without an acetate wash, and using maximum, medium, or low binding ELISA plates. The TS antibody resulted in a higher background signal compared to GT. Furthermore, coating plate wells with NP2 resulted in very high background compared to NP1. An acetate buffer wash resulted in the muffling of signals, and medium and low binding plates used in the study resulted in better results than maximum binding plates. These results suggest that the selection of appropriate secondary antibodies, binding plates, and ELISA reagent protocols all play important roles in determining NP1- or NP2-specific IgA levels in trachea samples.