scholarly journals Immunoglobulin A, an Active Liaison for Host-Microbiota Homeostasis

2021 ◽  
Vol 9 (10) ◽  
pp. 2117
Author(s):  
Ahmed Abokor ◽  
Grant McDaniel ◽  
Rachel Golonka ◽  
Connor Campbell ◽  
Sreya Brahmandam ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
Enteric Pathogens ◽  
Structural Form ◽  
Opportunistic Pathogens ◽  
Physiological Conditions ◽  
Intestinal Epithelia ◽  
Mucosal Surfaces ◽  
Growth Of Knowledge ◽  
Life Threatening ◽  
Humoral Responses

Mucosal surfaces in the gastrointestinal tract are continually exposed to native, commensal antigens and susceptible to foreign, infectious antigens. Immunoglobulin A (IgA) provides dual humoral responses that create a symbiotic environment for the resident gut microbiota and prevent the invasion of enteric pathogens. This review features recent immunological and microbial studies that elucidate the underlying IgA and microbiota-dependent mechanisms for mutualism at physiological conditions. IgA derailment and concurrent microbiota instability in pathological diseases are also discussed in detail. Highlights of this review underscore that the source of IgA and its structural form can dictate microbiota reactivity to sustain a diverse niche where both host and bacteria benefit. Other important studies emphasize IgA insufficiency can result in the bloom of opportunistic pathogens that encroach the intestinal epithelia and disseminate into circulation. The continual growth of knowledge in these subjects can lead to the development of therapeutics targeting IgA and/or the microbiota to treat life threatening diseases.

scholarly journals IgA: Structure, Function, and Developability

Antibodies ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 57 ◽  
Author(s):  
Patrícia de Sousa-Pereira ◽  
Jenny M. Woof
Keyword(s):  
Monoclonal Antibodies ◽  
Structure Function ◽  
Immunoglobulin A ◽  
Structural Features ◽  
The Other ◽  
Immune Defence ◽  
Major Site ◽  
Mucosal Surfaces ◽  
Serum Iga ◽  
Antibody Class

Immunoglobulin A (IgA) plays a key role in defending mucosal surfaces against attack by infectious microorganisms. Such sites present a major site of susceptibility due to their vast surface area and their constant exposure to ingested and inhaled material. The importance of IgA to effective immune defence is signalled by the fact that more IgA is produced than all the other immunoglobulin classes combined. Indeed, IgA is not just the most prevalent antibody class at mucosal sites, but is also present at significant concentrations in serum. The unique structural features of the IgA heavy chain allow IgA to polymerise, resulting in mainly dimeric forms, along with some higher polymers, in secretions. Both serum IgA, which is principally monomeric, and secretory forms of IgA are capable of neutralising and removing pathogens through a range of mechanisms, including triggering the IgA Fc receptor known as FcαRI or CD89 on phagocytes. The effectiveness of these elimination processes is highlighted by the fact that various pathogens have evolved mechanisms to thwart such IgA-mediated clearance. As the structure–function relationships governing the varied capabilities of this immunoglobulin class come into increasingly clear focus, and means to circumvent any inherent limitations are developed, IgA-based monoclonal antibodies are set to emerge as new and potent options in the therapeutic arena.

scholarly journals Correlations between Antibody Immune Responses at Different Mucosal Effector Sites Are Controlled by Antigen Type and Dosage

2000 ◽  
Vol 68 (7) ◽  
pp. 3830-3839 ◽  
Author(s):  
Dörthe Externest ◽  
Barbara Meckelein ◽  
M. Alexander Schmidt ◽  
Andreas Frey
Keyword(s):  
Cholera Toxin ◽  
Plasma Cells ◽  
Immunoglobulin A ◽  
Secretory Iga ◽  
Enzyme Linked Immunosorbent Assay ◽  
Routine Diagnostics ◽  
Significant Relationships ◽  
Serum Igg ◽  
Mucosal Surfaces ◽  
Secretory Immunoglobulin

ABSTRACT Monitoring specific secretory immunoglobulin A (IgA) responses in the intestines after mucosal immunization or infection is impeded by the fact that sampling of small intestinal secretions requires invasive methods not feasible for routine diagnostics. Since IgA plasma cells generated after intragastric immunization are known to populate remote mucosal sites as well, secretory IgA responses at other mucosal surfaces may correlate to those in the intestines and could serve as proxy measures for IgA secretion in the gut. To evaluate the practicability of this approach, mice were immunized intragastrically with 0.2, 2, and 20 mg of ovalbumin plus 10 μg of cholera toxin, and the antigen-specific local secretory IgA responses in duodenal, ileal, jejunal, rectal, and vaginal secretions, saliva, urine, and feces, as well as serum IgG and IgA responses were analyzed by enzyme-linked immunosorbent assay. Correlation analysis revealed significant relationships between serum IgG and IgA, urinary IgA, salivary IgA, and secretory IgA in duodenal, jejunal, ileal, and rectal secretions for the 0.2-mg but not for the 20-mg ovalbumin dose. Fecal samples were poor predictors for intestinal antiovalbumin IgA responses, and no correlations could be established for cholera toxin, neither between local anti-cholera toxin levels nor to the antiovalbumin responses. Thus, specific IgA in serum, saliva, or urine can serve as a predictor of the release of specific IgA at intestinal surfaces after intragastric immunization, but the lack of correlations for high ovalbumin doses and for cholera toxin indicates a strong dependency on antigen type and dosage for these relationships.

scholarly journals Occurrence and species diversity of human-pathogenic Mucorales in commercial food-stuffs purchased in Paris area

2018 ◽  
Vol 57 (6) ◽  
pp. 739-744 ◽  
Author(s):  
Bita Mousavi ◽  
Françoise Botterel ◽  
Jean-Marc Costa ◽  
Pascal Arné ◽  
Jacques Guillot ◽  
...  
Keyword(s):  
Food Samples ◽  
Its Sequencing ◽  
Opportunistic Pathogens ◽  
Herbal Tea ◽  
Rhizopus Microsporus ◽  
Syncephalastrum Racemosum ◽  
Paris Area ◽  
Life Threatening ◽  
Lichtheimia Corymbifera ◽  
Culture Positive

AbstractMucormycoses are life-threatening fungal diseases that affect a variety of patients including those with diabetes mellitus or hematological malignancies. The responsible agents, the Mucorales, are opportunistic pathogens originating from the environment such as soil or decaying organic matter. The aim of the present study was to assess the prevalence and diversity of human-pathogenic species of Mucorales in commercially available foodstuffs in France. All food samples were purchased from January 2014 to May 2015 in France. A total of 159 dried food samples including spices and herbs (n = 68), herbal tea (n = 19), cereals (n = 19), vegetables (n = 14), and other foodstuffs (n = 39) were analyzed. Each strain of Mucorales was identified phenotypically, and molecular identification was performed by ITS sequencing. From the 28 (17.6%) samples that were culture-positive for Mucorales, 30 isolates were recovered. Among the isolates, 13 were identified as Rhizopus arrhizus var. arrhizus, 10 R. arrhizus var. delemar, two Rhizopus microsporus, one Lichtheimia corymbifera, three Lichtheimia ramosa, and one Syncephalastrum racemosum. Culture-positive samples originated from different countries (Europe, Asia) and brands. The samples most frequently contaminated by Mucorales were spices and herbs (19/68, 27.9%), followed by herbal tea (2/19, 10.5%), cereals (2/19, 10.5%), other food products (5/39, 12.8%). The present study showed that human-pathogenic Mucorales were frequently recovered from commercially available foodstuffs in France with a large diversity of species. The potential danger represented by Mucorales present in food for immunocompromised patients should be further analyzed.

scholarly journals Interactions between Candida albicans and Enterococcus faecalis in an Organotypic Oral Epithelial Model

2020 ◽  
Vol 8 (11) ◽  
pp. 1771
Author(s):  
Akshaya Lakshmi Krishnamoorthy ◽  
Alex A. Lemus ◽  
Adline Princy Solomon ◽  
Alex M. Valm ◽  
Prasanna Neelakantan
Keyword(s):  
Candida Albicans ◽  
Enterococcus Faecalis ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Surface Erosion ◽  
Host Immune System ◽  
Microbial Invasion ◽  
Mucosal Surfaces ◽  
Life Threatening ◽  
Hyphal Formation

Candida albicans as an opportunistic pathogen exploits the host immune system and causes a variety of life-threatening infections. The polymorphic nature of this fungus gives it tremendous advantage to breach mucosal barriers and cause oral and disseminated infections. Similar to C. albicans, Enterococcus faecalis is a major opportunistic pathogen, which is of critical concern in immunocompromised patients. There is increasing evidence that E. faecalis co-exists with C. albicans in the human body in disease samples. While the interactive profiles between these two organisms have been studied on abiotic substrates and mouse models, studies on their interactions on human oral mucosal surfaces are non-existent. Here, for the first time, we comprehensively characterized the interactive profiles between laboratory and clinical isolates of C. albicans (SC5314 and BF1) and E. faecalis (OG1RF and P52S) on an organotypic oral mucosal model. Our results demonstrated that the dual species biofilms resulted in profound surface erosion and significantly increased microbial invasion into mucosal compartments, compared to either species alone. Notably, several genes of C. albicans involved in tissue adhesion, hyphal formation, fungal invasion, and biofilm formation were significantly upregulated in the presence of E. faecalis. By contrast, E. faecalis genes involved in quorum sensing, biofilm formation, virulence, and mammalian cell invasion were downregulated. This study highlights the synergistic cross-kingdom interactions between E. faecalis and C. albicans in mucosal tissue invasion.

scholarly journals A case of Henoch-Schönlein purpura with cardiopulmonary involvement

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Guang Ming Tan
Keyword(s):  
Older Patients ◽  
Rare Case ◽  
Cardiac Involvement ◽  
Case Reports ◽  
Immunoglobulin A ◽  
Life Threatening

Henoch-Shönlein purpura (HSP) commonly affects the kidney, causing hematuria and Immunoglobulin A type nephropathy. Extra-renal involvements are rare but can be life threatening if missed. Cardiac involvement has been described only in a handful of case reports. Although HSP is predominantly a pediatric disease, it should not be overlooked in older patients presenting with typical triad of symptoms. We report a rare case of HSP with both cardiac of pulmonary systems involvement and his clinical progress

scholarly journals Impact of Diabetes on the Gut and Salivary IgA Microbiomes

2020 ◽  
Vol 88 (12) ◽  
Author(s):  
Eric L. Brown ◽  
Heather T. Essigmann ◽  
Kristi L. Hoffman ◽  
Noah W. Palm ◽  
Sarah M. Gunter ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Immunoglobulin A ◽  
Alpha Diversity ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Host Immune Responses ◽  
Mucosal Surfaces ◽  
Immune Mediated ◽  
Rrna Gene Sequencing ◽  
Immune Exclusion

ABSTRACT Mucosal surfaces like those present in the lung, gut, and mouth interface with distinct external environments. These mucosal gateways are not only portals of entry for potential pathogens but also homes to microbial communities that impact host health. Secretory immunoglobulin A (SIgA) is the single most abundant acquired immune component secreted onto mucosal surfaces and, via the process of immune exclusion, shapes the architecture of these microbiomes. Not all microorganisms at mucosal surfaces are targeted by SIgA; therefore, a better understanding of the SIgA-coated fraction may identify the microbial constituents that stimulate host immune responses in the context of health and disease. Chronic diseases like type 2 diabetes are associated with altered microbial communities (dysbiosis) that in turn affect immune-mediated homeostasis. 16S rRNA gene sequencing of SIgA-coated/uncoated bacteria (IgA-Biome) was conducted on stool and saliva samples of normoglycemic participants and individuals with prediabetes or diabetes (n = 8/group). These analyses demonstrated shifts in relative abundance in the IgA-Biome profiles between normoglycemic, prediabetic, or diabetic samples distinct from that of the overall microbiome. Differences in IgA-Biome alpha diversity were apparent for both stool and saliva, while overarching bacterial community differences (beta diversity) were also observed in saliva. These data suggest that IgA-Biome analyses can be used to identify novel microbial signatures associated with diabetes and support the need for further studies exploring these communities. Ultimately, an understanding of the IgA-Biome may promote the development of novel strategies to restructure the microbiome as a means of preventing or treating diseases associated with dysbiosis at mucosal surfaces.

scholarly journals CandidaInfections, Causes, Targets, and Resistance Mechanisms: Traditional and Alternative Antifungal Agents

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Claudia Spampinato ◽  
Darío Leonardi
Keyword(s):  
Antifungal Agents ◽  
Fungal Infections ◽  
Current Knowledge ◽  
Resistance Mechanisms ◽  
Antifungal Drugs ◽  
Diagnostic Methods ◽  
Opportunistic Pathogens ◽  
Yeast Infection ◽  
Life Threatening ◽  
Therapeutic Alternatives

The genusCandidaincludes about 200 different species, but only a few species are human opportunistic pathogens and cause infections when the host becomes debilitated or immunocompromised.Candidainfections can be superficial or invasive. Superficial infections often affect the skin or mucous membranes and can be treated successfully with topical antifungal drugs. However, invasive fungal infections are often life-threatening, probably due to inefficient diagnostic methods and inappropriate initial antifungal therapies. Here, we briefly review our current knowledge of pathogenic species of the genusCandidaand yeast infection causes and then focus on current antifungal drugs and resistance mechanisms. An overview of new therapeutic alternatives for the treatment ofCandidainfections is also provided.

scholarly journals Oral pemphigus vulgaris

2017 ◽  
Vol 4 (3) ◽  
pp. 100-103
Author(s):  
Mohit Sharma
Keyword(s):  
Clinical Manifestations ◽  
Pemphigus Vulgaris ◽  
Oral Literature ◽  
Therapeutic Approaches ◽  
The Past ◽  
Mucosal Surfaces ◽  
Life Threatening ◽  
Delays In Diagnosis ◽  
Oral Involvement ◽  
Dental Professionals

Pemphigus is a group of potentially life-threatening autoimmune mucocutaneous diseases characterized by epithelial blistering affecting cutaneous and/ or mucosal surfaces. Pemphigus affects 0.1-0.5 patients per 100,000 population per year. Oral lesions of pemphigus are seen in up to 18% of patients at dermatology out-patient clinics, but despite the frequency of oral involvement, and novel therapeutic approaches, there are surprisingly few recent studies of either the oral manifestations of pemphigus or their management, and delays in diagnosis are still common. Most patients are initially misdiagnosed and improperly treated for many months or even years. Dental professionals must be sufficiently familiar with the clinical manifestations of pemphigus vulgaris to ensure early diagnosis and treatment, since this in turn determines the prognosis and course of the disease. Pemphigus has been reviewed in the oral literature in the past decade, but several advances in the understanding of the etiopathogenesis, pemphigus variants, and management warrant an update. Here, we report a case of pemphigus vulgaris that was misdiagnosed in its earliest stage. Oral ulceration may arise from a variety of causes. This case illustrates that, although rare, pemphigus vulgaris may need to be included in differential diagnosis.

scholarly journals Successful Prevention of Fetal Autoimmune-Mediated Heart Block by Combined Therapies With Hydroxychloroquine and Intravenous Immunoglobulin: A Case Report

2021 ◽  
Vol 8 ◽  
Author(s):  
Li Zhao ◽  
Yan Zhou ◽  
Chuan Wang ◽  
Yifei Li ◽  
Qi Zhu ◽  
...  
Keyword(s):  
Intravenous Immunoglobulin ◽  
Atrioventricular Block ◽  
Heart Block ◽  
Immunoglobulin A ◽  
Atrioventricular Node ◽  
Complete Atrioventricular Block ◽  
Life Threatening ◽  
Short Time ◽  
Successful Prevention ◽  
Complete Atrioventricular

A fetal autoimmune-mediated atrioventricular block is a passively acquired autoimmune disease in which maternal autoantibodies enter the fetal circulation via the placenta and subsequently cause inflammation and fibrosis of the atrioventricular node. Once fetal autoimmune-mediated atrioventricular block occurs, it only takes a short time to progress from first-degree atrioventricular block to complete atrioventricular block, meaning that the damage is often irreversible. Autoimmune—associated AVB, a rare but life—threatening disorder, occurs in 2–5% of pregnancies with positive anti—Ro/SSA (the most common one) and La/SSB antibodies. The perinatal mortality of neonates with AVB outlined in research is approximately 30%. Thus far, for autoimmune-associated AVB fetuses, currently used treatments include corticosteroids, hydroxychloroquine, intravenous immunoglobulin (IVIG), b—sympathomimetic agent, and even plasma exchange. Currently, approaches for preventing the progression and recurrence of a fetal atrioventricular block are still controversial. Here, we reported a baby of successful prevention from the fate of the fetal atrioventricular block by adopting prophylactic comprehensive prenatal therapy.

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