A recurring YYDRxG pattern in broadly neutralizing antibodies to a conserved site on SARS-CoV-2, variants of concern, and related viruses

Studying the antibody response to SARS-CoV-2 informs on how the human immune system can respond to antigenic variants as well as other SARS-related viruses. Here, we structurally and functionally characterized a potent human antibody ADI-62113 that also neutralizes SARS-CoV- 2 variants of concern and cross-reacts with many other sarbecoviruses. A YYDRxG motif encoded by IGHD3-22 in CDR H3 facilitates targeting to a highly conserved epitope on the SARS-CoV-2 receptor binding domain. A computational search for a YYDRxG pattern in publicly available sequences identified many antibodies with broad neutralization activity against SARS-CoV-2 variants and SARS-CoV. Thus, the YYDRxG motif represents a common convergent solution for the human humoral immune system to counteract sarbecoviruses. These findings also suggest an epitope targeting strategy to identify potent and broadly neutralizing antibodies that can aid in the design of pan-sarbecovirus vaccines and antibody therapeutics.

Assessment of pathomorphological characteristics of the oral mucosa in patients with HBV, HCV and HIV

Introduction: Oral clinical manifestations in HBV HCV and HIV patients indicate a deterioration in general health status. The aim of the study was to assess pathomorphologic features of oral mucosa observed in patients with these diseases. Methodology: The study was conducted in N1 Dental Clinic of YSMU after M. Heratsi. The total number of patients taking part in the research was 120, including HBV (n = 40), HCV (n = 40) and HIV (n = 40). After biopsy and subsequent histological examination of the oral mucosa, statistical analysis was carried out using Excel 2013 and R software. Results: Pathomorphological examination revealed inflammatory infiltrations in all samples collected from HBV, HCV and HIV patients. These changes included microcirculatory disorders in 98.3% of samples: fibrinous-like deposits lining the surface of erosions and ulcers on the oral mucosa (1.67%), fibrosis of the mucous membrane (70%), dystrophy of squamous epithelium (93.3%) and bone sequestration (3.3%). Comparative analysis of pathomorphological characteristics revealed distinct content of infiltrates: lymphoplasmacytic infiltration in patients with HBV and HCV, while HIV patients showed neutrophils infiltration and lack of plasmocytes. Conclusions: There are common abnormal morphological changes in the oral mucosa typical of all patients with HBV, HCV and HIV, as well as liver diseases specific to each of them. Inflammation in the patients with HIV indicated impairment of the humoral immune system. Understanding the distinct characteristic of inflammation in the oral cavity could be useful for early differential diagnosis and management of patients with HIV, HBV and HCV.

Methylated (−)-epigallocatechin 3-O-gallate potentiates the effect of split vaccine accompanied with upregulation of Toll-like receptor 5

Split-virus vaccine serves as a major countermeasure against influenza virus, but its effectiveness and protective action are not complete. We previously demonstrated the effect of Benifuuki, a green tea cultivar in Japan, on enhancing the split-virus vaccine–elicited immune response. However, little is known about the detail mechanisms. Here, we show that EGCG3”Me intake significantly potentiated the vaccine-elicited hemagglutination inhibition titer increase. Flow cytometry analysis revealed the increased Toll-like receptor 5 (TLR5) expression after EGCG3”Me treatment in lamina propria dendritic cells (LPDCs) and macrophages, which play crucial roles in the humoral immune system. TLR5 expression correlated with the level of interleukin-6 (IL-6)/C–C chemokine type receptor 5, which are important mediators of the humoral immunity. Taken together, In vivo and ex vivo studies showed that EGCG3”Me potentiated the split-virus vaccine–elicited immune response accompanied with the upregulation of TLR5 in intestine and splenocyte macrophages.

Antibody-mediated rejection in heart transplantation

The role of antibody-mediated rejection in predicting survival among heart recipients has been studied in clinical transplantology for over 20 years. This condition is a significant risk factor for heart failure and graft vasculopathy. Antibody-mediated rejection results from activation of the humoral immune system and production of donorspecific antibodies that cause myocardial injury through the complement system. The presence of donor-specific antibodies is associated with lower allograft survival. Treatment of antibody-mediated rejection should take into account the rejection category and the presence or absence of graft dysfunction. The main principle of treatment is to suppress humoral immunity at different levels. World clinical practice has made significant inroads into the study of this issue. However, further research is required to identify and develop optimal treatment regimens for patients with humoral rejection in cardiac transplantation.

Bacillus subtilis ANSB168 Producing d-alanyl-d-alanine Carboxypeptidase Could Alleviate the Immune Injury and Inflammation Induced by Ochratoxin A

Ochratoxin A (OTA) is toxic to animals and threatens food safety through residues in animal tissues. A novel degrading strain Bacillus subtilis ANSB168 was isolated and further investigated. We cloned d-alanyl-d-alanine carboxypeptidase DacA and DacB from ANSB168 and over-expressed them in Escherichia coli Rosetta (DE3). Then, we characterized the OTA degradation mechanism of DacA and DacB, which was degrading OTA into OTα. A total of 45 laying hens were divided into three equal groups. The control group was fed basal feed, and other groups were administered with OTA (250 μg/kg of feed). A freeze-dried culture powder of ANSB168 (3 × 107 CFU/g, 2 kg/T of feed) was added to one of the OTA-fed groups for 28 days from day one of the experiment. We found that OTA significantly damaged the kidney and liver, inducing inflammation and activating the humoral immune system, causing oxidative stress in the layers. The ANSB168 bioproduct was able to alleviate OTA-induced kidney and liver damage, relieving OTA-induced inflammation and oxidative stress. Overall, DacA and DacB derived from ANSB168 degraded OTA into OTα, while the ANSB168 bioproduct was able to alleviate damages induced by OTA in laying hens.

Autoantibodies against Progranulin and IL-1 receptor antagonist due to immunogenic posttranslational isoforms contribute to hyperinflammation in critically ill COVID-19

Hyperinflammation is frequently observed in patients with severe COVID-19. Inadequate and defective IFN type I responses against SARS-CoV-2, associated with autoantibodies in a proportion of patients, lead to severe courses of disease. In addition, hyperactive responses of the humoral immune system have been described. In the current study we investigated a possible role of neutralizing autoantibodies against anti-inflammatory mediators. Plasma from adult patients with severe and critical COVID-19 was screened by ELISA for antibodies against PGRN, IL-1-Ra, IL-10, IL-18BP, IL-22BP, IL-36-Ra, CD40, IFN-α2, IFN-γ, IFN-ω and serpinB1. Autoantibodies were characterized and the antigens were analyzed for immunogenic alterations. In a discovery cohort with severe to critical COVID-19 high titers of PGRN-autoantibodies were detected in 11 of 30 (36.7%), and of IL-1-Ra-autoantibodies in 14 of 30 (46.7%) patients. In a validation cohort of 64 patients with critical COVID-19 high-titer PGRN-Abs were detected in 25 (39%) and IL-1-Ra-Abs in 32 of 64 patients (50%). PGRN-Abs and IL-1-Ra-Abs belonged to IgM and several IgG subclasses. In separate cohorts with non-critical COVID-19, PGRN-Abs and IL-1-Ra-Abs were detected in low frequency (i.e. in < 5% of patients) and at low titers. Neither PGRN- nor IL-1-Ra-Abs were found in 40 healthy controls vaccinated against SARS-CoV-2 or 188 unvaccinated healthy controls. PGRN-Abs were not cross-reactive against SARS-CoV-2 structural proteins nor against IL-1-Ra. Plasma levels of both free PGRN and free IL-1-Ra were significantly decreased in autoantibody-positive patients compared to Ab-negative and non-COVID-19 controls. In vitro PGRN-Abs from patients functionally reduced PGRN-dependent inhibition of TNF-α signaling, and IL-1-Ra-Abs from patients reduced IL-1-Ra- or anakinra-dependent inhibition of IL-1ß signaling. The pSer81 hyperphosphorylated PGRN isoform was exclusively detected in patients with high-titer PGRN-Abs; likewise, a hyperphosphorylated IL-1-Ra isoform was only found in patients with high-titer IL-1-Ra-Abs. Thr111 was identified as the hyperphophorylated amino acid of IL-1-Ra. In longitudinally collected samples hyperphosphorylated isoforms of both PGRN and IL-1-Ra emerged transiently, and preceded the appearance of autoantibodies. In hospitalized patients, the presence of IL-1-Ra-Abs or IL-1-Ra-Abs in combination with PGRN-Abs was associated with a higher morbidity and mortality.To conclude, neutralizing autoantibodies to IL-1-Ra and PGRN occur in a significant portion of patients with critical COVID-19, with a concomitant decrease in circulating free PGRN and IL-1-Ra, indicative of a misdirected, proinflammatory autoimmune response. The break of self-tolerance is likely caused by atypical hyperphosphorylated isoforms of both antigens, whose appearances precede autoantibody induction. Our data suggest that these immunogenic secondary modifications are induced by the SARS-CoV-2-infection itself or the inflammatory environment evoked by the infection and predispose for a critical course of COVID-19.

Association between serum markers of the humoral immune system and inflammation in the Swedish AMORIS study

Background Although the onset of inflammatory cascades may profoundly influence the nature of antibody responses, the interplay between inflammatory and humoral (antibody) immune markers remains unclear. Thus, we explored the reciprocity between the humoral immune system and inflammation and assessed how external socio-demographic factors may influence these interactions. From the AMORIS cohort, 5513 individuals were identified with baseline measurements of serum humoral immune [immunoglobulin G, A & M (IgG, IgA, IgM)] and inflammation (C-reactive protein (CRP), albumin, haptoglobin, white blood cells (WBC), iron and total iron-binding capacity) markers measured on the same day. Correlation analysis, principal component analysis and hierarchical clustering were used to evaluate biomarkers correlation, variation and associations. Multivariate analysis of variance was used to assess associations between biomarkers and educational level, socio-economic status, sex and age. Results Frequently used serum markers for inflammation, CRP, haptoglobin and white blood cells, correlated together. Hierarchical clustering and principal component analysis confirmed the interaction between these main biological responses, showing an acute response component (CRP, Haptoglobin, WBC, IgM) and adaptive response component (Albumin, Iron, TIBC, IgA, IgG). A socioeconomic gradient associated with worse health outcomes was observed, specifically low educational level, older age and male sex were associated with serum levels that indicated infection and inflammation. Conclusions These findings indicate that serum markers of the humoral immune system and inflammation closely interact in response to infection or inflammation. Clustering analysis presented two main immune response components: an acute and an adaptive response, comprising markers of both biological pathways. Future studies should shift from single internal marker assessment to multiple humoral and inflammation serum markers combined, when assessing risk of clinical outcomes such as cancer.

The Effects of Lampung Robusta Green Coffee Extract (Coffee Canephora Var Robusta) on Layer Chicken’s Humoral Immune System and Intestinal Histophalogy

Lampung Robusta green coffee is an authentic Indonesian coffee that is in great demand by the public. The active ingredients in coffee such as chlorogenic acid and polyphenols are useful antihypertensive, antibacterial, immunomodulator, and antioxidant. Research on the effects of coffee in chicken’s health such as the immune system or as antioxidants has not yet existed. The aim of the study, therefore, was to determine the effects of giving Robusta coffee extract on chickens to the antibody titers and intestinal damage. The study was experimental with post-test control only design, using Isa Brown layer chickens, consisting of 60. The treatment group included: negative control (healthy, without coffee), P1: 500mg coffee/kg bw (body weight), P2: 1000mg coffee/kg bw, and P3: 1500mg coffee/kg bw. The coffee was given using gastric tube when the chickens were 3-16 days old, and the serum was taken on day 18. Data on antibody titer and MDA levels were analyzed using One Way ANOVA with a standard error of 0.05 while histopathology of jejunum was analyzed qualitatively. The results showed that the extracts of Lampung robusta coffee could not increase antibodies against AI virus (Avian Influenza) or the ND virus (Newcastle disease), decrease levels of MDA (Malondyaldehyde), or improve jejunum histopathology in P3 as the analysis found no erosion of epithelial cells or cell infiltration inflammation. These findings suggest that Lampung robusta coffee extract can be used as an imunosupressor against humoral, antioxidant and anti-inflammatory responses in laying hens.

Autoantibodies against Progranulin and IL-1 receptor antagonist in critically ill COVID-19

STRUCTURED ABSTRACTINTRODUCTIONHyperinflammation is frequently observed in patients with severe COVID-19. Inadequate and defective IFN type I responses against SARS-CoV-2, caused by autoantibodies in a proportion of patients, lead to severe courses. In addition, hyperactive responses of the humoral immune system have been described so far.RATIONALEIn the current study we investigated a possible role of neutralizing autoantibodies against anti-inflammatory mediators. Plasma from patients with severe and critical COVID-19 was screened by ELISA for antibodies against PGRN, IL-10, IL-18BP, IL-22BP and IL-1-RA. Autoantibodies were characterized and the antigens were analyzed for immunogenic alterations.RESULTSPGRN-autoantibodies were detected with high titers in 11 of 30 (36.7%), and IL-1-RA-autoantibodies in 14 of 30 (46.7%) patients of a discovery cohort with severe to critical COVID-19. In a validation cohort of 41 patients with critical COVID-19 high-titered PGRN-Abs were detected in 12 (29.3%) and IL-1-RA-Abs in 19 of 41 patients (46.2%). PGRN-Abs and IL-1-RA-Abs belonged to IgM and several IgG subclasses. In separate cohorts with non-critical COVID-19, PGRN-Abs and IL-1-RA-Abs were detected significantly less frequently and at low titers. Neither PGRN-nor IL-1-RA-Abs were found in 40 healthy controls vaccinated against SARS-CoV-2. PGRN-Abs were not cross-reactive against SARS-CoV-2 structural proteins or against IL-1-RA. Plasma levels of both free PGRN and IL-1-RA were significantly decreased in autoantibody-positive patients compared to Ab-negative and non-COVID controls. Functionally, PGRN-Abs from patients reduced PGRN-dependent inhibition of TNF-α signaling in vitro. The pSer81 hyperphosphorylated PGRN isoform was exclusively detected in patients with high-titer PGRN-Abs; likewise, a yet unidentified hyperphosphorylated IL-1-RA isoform was only found in patients with high-titer IL-1-RA-Abs. No autoantibodies against IL-10, IL-18BP or IL-22BP were found.CONCLUSIONTo conclude, neutralizing autoantibodies to IL-1-RA and PGRN occur in a significant proportion of patients with critical COVID-19, with a concomitant decrease in circulating PGRN and IL-1-RA, which is indicative of a misdirected, proinflammatory autoimmune response. The break of self-tolerance is likely caused by atypical isoforms of both antigens due to hyperphosphorylation. It remains to be determined whether these secondary modifications are induced by the SARS-CoV-2-infection itself, or are preexisting and predispose for a critical course.

Abstract P646: The Aging Immune Transcriptome is Linked to Ischemic Stroke Outcome

Background: Advancing age is associated with changes to the immune system, which affect stroke outcome. We previously demonstrated an age-associated alteration in leukocyte gene expression in patients with ischemic stroke. The aim of this study is to validate these findings in an independent stroke cohort and assess the relationship to stroke outcome. Methods: Genes associated with age were identified in a cohort of 57 patients with acute ischemic stroke. Peripheral blood RNA was measured using whole genome microarrays and genes associated with advancing age identified (FDR-corrected p < 0.05, partial correlation coefficient r > |0.3|); age-associated gene expression differences in patients with poor 90-day outcome (mRS < 2) were also compared. Genes were functionally characterized by pathway and enrichment analysis and verified against age-associated genes from two additional stroke cohorts containing a total of 173 patients. Results: There were 536 genes associated with age in the new stroke cohort, of which 286 decreased and 253 increased with age. Thirty-nine (39) of the age-associated genes were present in previous stroke cohorts analyzed, including a decrease in CCR6, CXCR5, BLNK and NT5E. A decrease in CXCR5 and CD79B was also identified in patients with poor outcome. Pathways and enriched terms relating to the humoral adaptive system immune system, including B-cell and lymphocyte activation, were among those represented in age-associated genes. Conclusions: Age-related changes in leukocyte gene expression were validated in an independent cohort of patients with ischemic stroke. Verified changes include alterations to the humoral immune system and a relationship to stroke outcome. Further investigation of the aging immune system in stroke is warranted.