scholarly journals Case Report: Circulating Anti-SARS-CoV-2 Antibodies Do Not Cross-React With Pemphigus or Pemphigoid Autoantigens

2021 ◽  
Vol 8 ◽  
Author(s):  
Michael Kasperkiewicz ◽  
Marta Bednarek ◽  
Stefan Tukaj
Keyword(s):  
Molecular Mimicry ◽  
Case Series ◽  
Cross Reactivity ◽  
Limited Information ◽  
Serum Samples ◽  
Type Vii Collagen ◽  
Autoimmune Bullous Diseases ◽  
Extracellular Molecules ◽  
Immunogenic Proteins

It is hypothesized that SARS-CoV-2 has the potential to elicit autoimmunity due to molecular mimicry between immunogenic proteins of the virus and human extracellular molecules. While in silico and in vitro evaluation of such immune cross-reactivity of human antibodies to SARS-CoV-2 proteins with several different tissue antigens has been described, there is limited information specifically pertaining to the immunological effects of COVID-19 and vaccines against SARS-CoV-2 on the development of autoimmune bullous diseases (AIBDs). Twelve seropositive post-COVID-19 individuals and 12 seropositive healthy volunteers who received two doses of the mRNA COVID-19 vaccine from Pfizer-BioNTech have been included in this case series investigation. Serum samples of these blood donors were tested for autoantibodies to the main immunobullous autoantigens, i.e., desmoglein 1, desmoglein 3, envoplakin, BP180, BP230, and type VII collagen. Our study revealed that none of the 24 anti-SARS-CoV-2 IgG-positive subjects had concomitant antibody reactivity with any of the tested autoantigens. These results argue against a relationship between SARS-CoV-2 infection/vaccines and AIBDs with respect to disease-triggering antibody cross-reactivity.

scholarly journals Antibodies in the Sera of Host Species with Pythiosis Recognize a Variety of Unique Immunogens in Geographically Divergent Pythium insidiosum Strains

2008 ◽  
Vol 16 (3) ◽  
pp. 330-336 ◽  
Author(s):  
Ariya Chindamporn ◽  
Raquel Vilela ◽  
Kathleen A. Hoag ◽  
Leonel Mendoza
Keyword(s):  
Host Species ◽  
Natural Infection ◽  
Protein Profile ◽  
Serum Samples ◽  
Pythium Insidiosum ◽  
Geographical Regions ◽  
Human Sera ◽  
Immunogenic Proteins

ABSTRACT Studies by Western blot analyses have shown that antibodies in the sera of host species infected by Pythium insidiosum recognized several prominent proteins expressed by this fungus-like pathogen. Although these studies have utilized sera from infected patients and relevant local strains of P. insidiosum, the results are difficult to compare because of the lack of method standardization. In an effort to resolve this issue, we have utilized standardized methodologies to evaluate six P. insidiosum strains from Asia and the Americas and 15 serum samples from cattle, cats, dogs, horses, and humans with pythiosis from the same geographical regions. Our data show that the antibodies present in these sera recognize a wide variety of unique P. insidiosum immunogenic proteins. Although some of the prominent proteins in this study have been previously reported, several others have yet to be described. For instance, a ∼28-kDa-molecular-mass antigen was detected by the antibodies in all serum samples evaluated. However, this antigen was strongly expressed by only one of the strains evaluated. A diffuse ∼51-kDa protein was not detected by the antibodies in the human sera; but it was recognized by the antibodies in the sera of cattle, cats, dogs, and horses. This antigen was expressed by only two of the strains investigated. Several other similar examples were also observed. The variation of the P. insidiosum protein profile identified by the antibodies in the sera evaluated indicates that some geographically diverged P. insidosum strains expressed some unique immunogens in vitro and that during natural infection (in vivo) P. insidiosum might express a broader number of antigens variably detected by individuals within the same species but especially across species.

scholarly journals Identification and Characterization of Immunogenic Proteins of Mycoplasma genitalium

2006 ◽  
Vol 13 (8) ◽  
pp. 913-922 ◽  
Author(s):  
Helle Friis Svenstrup ◽  
Jørgen Skov Jensen ◽  
Kris Gevaert ◽  
Svend Birkelund ◽  
Gunna Christiansen
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Mycoplasma Genitalium ◽  
Cross Reactivity ◽  
Rabbit Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Immunogenic Proteins ◽  
Recombinant Fragments

ABSTRACT Mycoplasma genitalium causes nonchlamydial nongonococcal urethritis. M. genitalium was detected by PCR in 17 urethral swabs obtained from 99 men with and without urethritis (J. S. Jensen, R. Orsum, B. Dohn, S. Uldum, A. M. Worm, and K. Lind, Genitourin. Med. 69:265-269, 1993), and later, four M. genitalium strains were isolated (J. S. Jensen, H. T. Hansen, and K. Lind, J. Clin. Microbiol. 34:286-291, 1996). The objective of this study was to characterize immunogenic proteins of M. genitalium by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting by using a hyperimmune rabbit serum against M. genitalium G37, determine their identity by mass spectrometry, and develop an M. genitalium-specific enzyme-linked immunosorbent assay (ELISA) free from cross-reactivity with M. pneumoniae antibodies. Using recombinant fragments of the C-terminal part of MgPa (rMgPa), we developed a specific ELISA for detection of M. genitalium antibodies. This antigen did not bind M. pneumoniae antibodies. Using serum samples from the 99 men with and without urethritis, we found that 26 had immunoglobulin G (IgG) antibodies to M. genitalium. There was a strong statistically significant correlation between PCR and IgG antibodies to M. genitalium (odds ratio [OR], 5.9; 95% confidence interval [CI], 2.3 to 21.5; P = 0.002). Furthermore, men with recurrent urethritis were more likely to have antibodies to M. genitalium than were those without recurrent urethritis (OR, 4.0; 95% CI, 1.1 to 14.5; P = 0.0383) and they had significantly higher antibody titers. By use of the rMgPa ELISA, this study further substantiates the importance of M. genitalium as a cause of male urethritis.

scholarly journals The monoclonal antibody 26 raised against tetanus toxoid also recognizes tetanus toxin and β2-glycoprotein I - its binding properties in vitro and potential applications

2009 ◽  
Vol 74 (3) ◽  
pp. 245-257 ◽  
Author(s):  
Aleksandra Inic-Kanada ◽  
Marijana Stojanovic ◽  
Irena Zivkovic ◽  
Vladimir Petrusic ◽  
Ljiljana Dimitrijevic
Keyword(s):  
Tetanus Toxoid ◽  
Tetanus Toxin ◽  
Molecular Mimicry ◽  
Cross Reactivity ◽  
Affinity Constant ◽  
Glycoprotein I ◽  
Relative Affinity ◽  
Potential Applications ◽  
Scatchard Plots

A murine monoclonal IgG1 antibody, marked as MAb26, specific for tetanus toxoid has been immunochemically characterized. By performing enzyme-linked immunosorbent assays (ELISAs) and western blot analyses, it was demonstrated that MAb26 reacted with tetanus toxoid, tetanus toxin and ?2-glycoprotein I (?2GPI). According to the results, MAb26 recognized the sequential epitope on the tetanus heavy chain. The affinity constant, calculated from Scatchard plots of MAb26 binding to tetanus toxoid, was 1.145?108 M-1 and the measurement of the relative affinity of MAb26 by ELISA using thiocyanate elution showed a significantly higher affinity of MAb26 to the toxoid (p = 0.0012) in comparison to the toxin. Additionally, the reactivity of MAb26 toward the toxoid forms increased when the tetanus toxin was detoxified using 8 mM and higher formaldehyde concentrations. The similarity of the tetanus toxoid to several sera proteins, either at the level of its conformation (IL-1?) or at the level of peptide sequences (?2GPI, laminin) favors its role in autoimmunity by the mechanism of molecular mimicry. As the induction of an autoimmune disease is dependent on the breakdown of tolerance, which could be the result of an overt hyperstimulation, the control of the presence and concentration of self-reactive epitopes in vaccine preparations is a prerequisite. In this study, it was shown that MAb26 can: 1) discriminate between the tetanus toxin and different toxoid forms, which makes it a good candidate for antibody control during vaccine preparation; 2) due to its cross-reactivity with ?2GPI, it could provide information on the presence of a potentially dangerous sequential epitope expressed at the protein surface.

Ultrastructural Changes in Tumor Cells During Human Peripheral Blood Monocyte-Mediated Cytotoxicity

1981 ◽  
Vol 39 ◽  
pp. 452-453
Author(s):  
K. E. Muse ◽  
D. G. Fischer ◽  
H. S. Koren
Keyword(s):  
Target Cell ◽  
Human Peripheral Blood ◽  
Mononuclear Phagocytes ◽  
Ultrastructural Changes ◽  
Target Cells ◽  
Limited Information ◽  
Blood Monocytes ◽  
Tumoricidal Activity ◽  
Activated State

Mononuclear phagocytes, a pluripotential cell line, manifest an array of basic extracellular functions. Among these physiological regulatory functions is the expression of spontaneous cytolytic potential against tumor cell targets.The limited observations on human cells, almost exclusively blood monocytes, initially reported limited or a lack of tumoricidal activity in the absence of antibody. More recently, freshly obtained monocytes have been reported to spontaneously impair the biability of tumor target cells in vitro (Harowitz et al., 1979; Montavani et al., 1979; Hammerstrom, 1979). Although the mechanism by which effector cells express cytotoxicity is poorly understood, discrete steps can be distinguished in the process of cell mediated cytotoxicity: recognition and binding of effector to target cells,a lethal-hit stage, and subsequent lysis of the target cell. Other important parameters in monocyte-mediated cytotoxicity include, activated state of the monocyte, effector cell concentrations, and target cell suseptibility. However, limited information is available with regard to the ultrastructural changes accompanying monocyte-mediated cytotoxicity.

scholarly journals IL-6 Receptor Blockade Increases Circulating Adiponectin Levels in People with Obesity: An Explanatory Analysis

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 79
Author(s):  
Stephan Wueest ◽  
Eleonora Seelig ◽  
Katharina Timper ◽  
Mark P. Lyngbaek ◽  
Kristian Karstoft ◽  
...  
Keyword(s):  
Exercise Training ◽  
Human Subjects ◽  
Receptor Blockade ◽  
Model Assessment ◽  
Serum Samples ◽  
Double Blind ◽  
Double Blind Clinical Trial ◽  
Homeostatic Model Assessment ◽  
Obese Human

Human obesity is associated with decreased circulating adiponectin and elevated leptin levels. In vitro experiments and studies in high fat diet (HFD)-fed mice suggest that interleukin-6 (IL-6) may regulate adiponectin and leptin release from white adipose tissue (WAT). Herein, we aimed to investigate whether IL-6 receptor blockade affects the levels of circulating adiponectin and leptin in obese human individuals. To this end, serum samples collected during a multicenter, double-blind clinical trial were analyzed. In the latter study, obese human subjects with or without type 2 diabetes were randomly assigned to recurrent placebo or intravenous tocilizumab (an IL-6 receptor antibody) administration during a 12-week exercise training intervention. Twelve weeks of tocilizumab administration (in combination with exercise training) trend wise enhanced the decrease in circulating leptin levels (−2.7 ± 8.2% in the placebo vs. −20.6 ± 5.6% in tocilizumab, p = 0.08) and significantly enhanced the increase in circulating adiponectin (3.4 ± 3.7% in the placebo vs. 27.0 ± 6.6% in tocilizumab, p = 0.01). In addition, circulating adiponectin levels were negatively correlated with the homeostatic model assessment of insulin resistance (HOMA-IR), indicating that increased adiponectin levels positively affect insulin sensitivity in people with obesity. In conclusion, IL-6 receptor blockade increases circulating adiponectin levels in people with obesity.

scholarly journals A Label and Probe-Free Zika Virus Immunosensor Prussian Blue@carbon Nanotube-Based for Amperometric Detection of the NS2B Protein

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 157
Author(s):  
Bárbara V. M. Silva ◽  
Marli T. Cordeiro ◽  
Marco A. B. Rodrigues ◽  
Ernesto T. A. Marques ◽  
Rosa F. Dutra
Keyword(s):  
Carbon Nanotube ◽  
Prussian Blue ◽  
Zika Virus ◽  
Point Of Care ◽  
Amperometric Detection ◽  
Cross Reactivity ◽  
Structural Protein ◽  
Serum Samples ◽  
Polypyrrole Composite ◽  
Congenital Disabilities

Zika virus (ZIKV) is a mosquito-borne infection, predominant in tropical and subtropical regions causing international concern due to the ZIKV disease having been associated with congenital disabilities, especially microcephaly and other congenital abnormalities in the fetus and newborns. Development of strategies that minimize the devastating impact by monitoring and preventing ZIKV transmission through sexual intercourse, especially in pregnant women, since no vaccine is yet available for the prevention or treatment, is critically important. ZIKV infection is generally asymptomatic and cross-reactivity with dengue virus (DENV) is a global concern. An innovative screen-printed electrode (SPE) was developed for amperometric detection of the non-structural protein (NS2B) of ZIKV by exploring the intrinsic redox catalytic activity of Prussian blue (PB), incorporated into a carbon nanotube–polypyrrole composite. Thus, this immunosensor has the advantage of electrochemical detection without adding any redox-probe solution (probe-less detection), allowing a point-of-care diagnosis. It was responsive to serum samples of only ZIKV positive patients and non-responsive to negative ZIKV patients, even if the sample was DENV positive, indicating a possible differential diagnosis between them by NS2B. All samples used here were confirmed by CDC protocols, and immunosensor responses were also checked in the supernatant of C6/36 and in Vero cell cultures infected with ZIKV.

scholarly journals Seroprevalence of Anti-SARS-CoV-2 IgG and IgM among Adults over 65 Years Old in the South of Italy

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 483
Author(s):  
Immacolata Polvere ◽  
Alfredina Parrella ◽  
Giovanna Casamassa ◽  
Silvia D’Andrea ◽  
Annamaria Tizzano ◽  
...  
Keyword(s):  
Antibody Response ◽  
Immunoglobulin M ◽  
Molecular Testing ◽  
Elisa Assay ◽  
The South ◽  
Serum Samples ◽  
Serological Screening ◽  
Rna Detection ◽  
In Vitro Diagnostic

SARS-CoV-2 is a zoonotic betacoronavirus associated with worldwide transmission of COVID-19 disease. By the beginning of March, WHO reported about 113,820,000 confirmed cases including more than 2,527,000 deaths all over the world. However, the true extent of virus circulation or its real infection/fatality ratio is not well-estimated due to the huge portion of asymptomatic infections. In this observational study, we have estimated the prevalence of specific immunoglobulin M and G directed towards SARS-CoV-2 antigen in a cohort of 1383 adult volunteers aged over 65 years old, living in the district of Benevento, in the South of Italy. Serological screening was carried out on capillary blood in September 2020, seven months after pandemic outbreak in Italy, to evaluate virus circulation and antibody response among elderly adults, in which severe symptoms due to viral infection are more common. The overall seroprevalence of anti-SARS-CoV-2 antibodies was 4.70% (CI 3.70%–5.95%) with no statistically significant differences between sexes. Among these, 69.69% (CI 55.61%–77.80%) tested positive to IgM, 23.08% (CI 14.51%–34.64%) to IgG and 9.23% (CI 4.30%–18.71%) was positive for both. All patients that were positive to IgM underwent molecular testing through RT-qPCR on oral-rhino pharyngeal swabs and only one specimen was positive for SARS-CoV-2 RNA detection. Instead, the presence of IgG from screened volunteers was confirmed by re-testing serum samples using both an ELISA assay validated for in vitro diagnostic use (IVD) and a recently published synthetic peptide-based ELISA assay. In conclusion, our report suggests that (1) early restrictions were successful in limiting COVID-19 diffusion in the district of Benevento; (2) rapid serological analysis is an ideal testing for both determining real seroprevalence and massive screening, whereas detection of viral RNA remains a gold standard for identification of infected patients; (3) even among people without COVID-19 related symptoms, the antibody response against SARS-CoV-2 antigens has individual features.

scholarly journals Effect of postoperative corticosteroids on surgical outcome and aqueous autotaxin following combined cataract and microhook ab interno trabeculotomy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Megumi Honjo ◽  
Reiko Yamagishi ◽  
Nozomi Igarashi ◽  
Chui Yong Ku ◽  
Makoto Kurano ◽  
...  
Keyword(s):  
Surgical Outcome ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Case Series ◽  
Iop Elevation ◽  
Immunoenzymatic Assay ◽  
Postoperative Fibrosis ◽  
Ab Interno

AbstractTo evaluate the effect of postoperative corticosteroids on surgical outcome and autotaxin (ATX) levels after microhook ab interno trabeculotomy combined with cataract surgery (μLOT-CS), prospective, consecutive non-randomized case series comparing outcomes of 30 eyes with primary open angle glaucoma was performed. The aqueous ATX, intraocular pressure (IOP) and glaucoma medications were monitored for 3 months postoperatively. An in-vivo mouse μLOT model was generated. In vitro, ATX and fibrotic changes induced by dexamethasone (Dex) treatment following scratch (S) in cultured human trabecular meshwork (hTM) cells were assessed by immunofluorescence, immunoenzymatic assay, and RT-qPCR. Postoperative ATX at 1 week and the number of antiglaucoma medications at 3 months were significantly lower in non-steroid group, and steroid use was the only variable significantly associated with postoperative medications at 3 months in multiregression analyses. In vitro, ATX activity was significantly upregulated in the Dex + S group, and αSMA was significantly upregulated in the Dex and Dex + S groups. Fibronectin and COL1A1 were significantly upregulated in the S group. μLOT-CS decreased IOP and medications in the overall cohort, and non-use of postoperative steroids resulted in a smaller number of postoperative medications. Limiting postoperative steroids in μLOT may minimize IOP elevation and postoperative fibrosis.

Angiogenic Effect of Pravastatin Alone and with Sera from Healthy and Complicated Pregnancies Studied by in vitro Vasculogenesis/Angiogenesis Assay

2021 ◽  
pp. 1-9
Author(s):  
Anita Virtanen ◽  
Outi Huttala ◽  
Kati Tihtonen ◽  
Tarja Toimela ◽  
Tuula Heinonen ◽  
...  
Keyword(s):  
Direct Effect ◽  
Late Onset ◽  
Maternal Serum ◽  
In Vitro Assay ◽  
Serum Samples ◽  
Therapeutic Concentration ◽  
Tubule Formation ◽  
Vitro Assay ◽  
Angiogenesis Assay

<b><i>Objective:</i></b> To determine the direct effect of pravastatin on angiogenesis and to study the interaction between pravastatin and maternal sera from women with early- or late-onset pre-eclampsia (PE), intrauterine growth restriction, or healthy pregnancy. <b><i>Methods:</i></b> We collected 5 maternal serum samples from each group. The effect of pravastatin on angiogenesis was assessed with and without maternal sera by quantifying tubule formation in a human-based in vitro assay. Pravastatin was added at 20, 1,000, and 8,000 ng/mL concentrations. Concentrations of angiogenic and inflammatory biomarkers in serum and in test medium after supplementation of serum alone and with pravastatin (1,000 ng/mL) were measured. <b><i>Results:</i></b> Therapeutic concentration of pravastatin (20 ng/mL) did not have significant direct effect on angiogenesis, but the highest concentrations inhibited angiogenesis. Pravastatin did not change the levels of biomarkers in the test media. There were no changes in angiogenesis when therapeutic dose of pravastatin was added with maternal sera, but there was a trend to wide individual variation towards enhanced angiogenesis, particularly in the early-onset PE group. <b><i>Conclusions:</i></b> At therapeutic concentration, pravastatin alone or with maternal sera has no significant effect on angiogenesis, but at high concentrations the effect seems to be anti-angiogenic estimated by in vitro assay.

scholarly journals 10. Kinetics of Post-Vaccination Seroprotection to S. Pneumonia for the Immune-Compromised and Vaccine-Naïve Populations

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S27-S28
Author(s):  
Jeffrey Gruenglas ◽  
James Mond ◽  
Micaela Scobie ◽  
Cynthia Tolman ◽  
Joseph Martinez
Keyword(s):  
Capsular Polysaccharide ◽  
The Elderly ◽  
Community Acquired Pneumonia ◽  
Prior History ◽  
Antibody Activity ◽  
Vaccine Response ◽  
Serum Samples ◽  
Opsonic Activity ◽  
And Control

Abstract Background S. pneumonia infection presents a significant challenge, accounting for 20–38% of hospital-acquired pneumonia, and the leading cause of community-acquired pneumonia despite availability of effective vaccines. Incidence is highest in children under 2 years, the immunocompromised, and elderly. CDC has reported the emergence of antibiotic resistance in ~30% of cases, adding to risk of morbidity and mortality. Fewer than half of the elderly are vaccinated and vulnerable to infection on admission. Passive immunotherapy as an adjunct to vaccines may improve outcomes in such populations. The objective of this study was to evaluate whether seroprotective response induced with a pneumococcal conjugate vaccine could rapidly yield protective opsonic levels of antibody within anticipated duration of hospitalization. Methods Healthy donors (n=30) were immunized with Prevnar. Blood was drawn on days 0, 3, 7, 10, 14, 21, and 28. Samples were pooled and tested for presence of functional opsonic antibodies recognizing capsular polysaccharides. Clearance mechanism of S. pneumonia was based on antibody recognition to pneumococcal capsular polysaccharide and opsonic titers used as an in vitro surrogate to evaluate the efficacy of vaccine. Results There was little to no opsonic activity against most serotypes on day 0, except for low antibody activity with serotypes 1, 3, 4, and 5. Titers increased, with protective levels achieved by day 10 for most serotypes (except 14 and 18C), peaking at day 14 or after across serotypes (Figures 1 and 2). Average titers rose from log2 titer 2 on day 0 to log2 titer 8 on days 21 and 28. Titers against most serotypes reached log2 10 (titer 1024) or higher. Patients remained susceptible to nosocomial infection for at least 10 days post admission until protective titers are reached. OPK titers (log2 scale) for serum samples on day 0 (pre), day 3, 7, 10, 14, 21, 28, and control for S. pneumoniae serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V. N=2. OPK titers (log2 scale) for serum samples on day 0 (pre), day 3, 7, 10, 14, 21, 28, and control for S. pneumoniae serotypes 14, 18C, 19A, 19F, and 23F. N=2. Conclusion Patients with no prior history of vaccination (or inability to mount response) with Prevnar or pneumovax remain vulnerable to S. pneumonia infection even if vaccinated on entry, due to delayed kinetics in reaching protective titers. These patients may require prophylactic intervention of hyperimmune Ig with high opsonic titers to S. pneumonia, providing protection until vaccine response elicits protective antibodies. Disclosures All Authors: No reported disclosures

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