secretory iga
Recently Published Documents


TOTAL DOCUMENTS

972
(FIVE YEARS 169)

H-INDEX

68
(FIVE YEARS 7)

Medicina ◽  
2022 ◽  
Vol 58 (1) ◽  
pp. 129
Author(s):  
Bianca Laura Cinicola ◽  
Federica Pulvirenti ◽  
Martina Capponi ◽  
Marta Bonetti ◽  
Giulia Brindisi ◽  
...  

Selective IgA deficiency (SIgAD) is the most common human primary immune deficiency (PID). It is classified as a humoral PID characterized by isolated deficiency of IgA (less than 7 mg/dL but normal serum IgG and IgM) in subjects greater than 4 years of age. Intrinsic defects in the maturation of B cells and a perturbation of Th cells and/or cytokine signals have been hypothesized to contribute to SIgAD pathogenesis. The genetic basis of IgA deficiency remains to be clarified. Patients with SIgAD can be either asymptomatic or symptomatic with clinical manifestations including allergy, autoimmunity and recurrent infections mainly of the respiratory and gastrointestinal tract. Studies analyzing allergy on SIgAD patients showed prevalence up to 84%, supporting in most cases the relationship between sIgAD and allergic disease. However, the prevalence of allergic disorders may be influenced by various factors. Thus, the question of whether allergy is more common in SIgAD patients compared to healthy subjects remains to be defined. Different hypotheses support an increased susceptibility to allergy in subjects with SIgAD. Recurrent infections due to loss of secretory IgA might have a role in the pathogenesis of allergy, and vice versa. Perturbation of microbiota also plays a role. The aim of this review is to examine the association between SIgAD and atopic disease and to update readers on advances over time at this important interface between allergy and SIgAD.


2022 ◽  
Author(s):  
Keiichi Tsukinoki ◽  
Tetsuro Yamamoto ◽  
Jiro Saito ◽  
Wakako Sakaguchi ◽  
Keiichiro Iguchi ◽  
...  

While the COVID-19 pandemic caused by SARS-CoV-2 has posed a threat to public health as the number of cases and COVID-19-related deaths are increasing worldwide, the incidence of the virus infection are extremely low in Japan compared with many other countries. To explore the reason for this strange phenomenon, we hypothesized the high prevalence of natural secretory IgA in saliva as mucosal IgA reacting with SARS-CoV-2, and thus surveyed the positivity for, as well as levels of, such reactive salivary IgA in a cohort of Japanese people of a wide range of age. The major findings were that 95/180 (52.78 %) of overall individuals who had not been exposed to SARS-CoV-2 were positive for salivary IgA with the levels ranging from 0.002 to 3.272 ng/ml, and that there may be a negative trend in positivity for salivary IgA according to age. These results suggest a role of mucosal IgA in host defense against SARS-CoV-2 infection.


2021 ◽  
Vol 31 (6) ◽  
pp. 792-798
Author(s):  
Nadezhda O. Kryukova ◽  
Ekaterina B. Rakunova ◽  
M. P. Kostinov ◽  
Irina A. Baranova ◽  
Oxana A. Svitich

The main focus in the course of COVID-19 goes on assessing the overall immune response. The role of mucosal immunity in this disease has not been studied sufficiently.The study aimed to analyze published data about secretory IgA as a significant indicator of the mucosal immune response of the respiratory tract in the context of the COVID-19 pandemic.Methods. Articles were identified via PubMed bibliographic database. The time-span of research was two years (2020, 2021).Results. The search identified 54 articles. There is evidence that secretory IgA (sIgA) is the main antibody isotype of the mucosal immunity. It is produced in quantities significantly higher than those of all other isotypes of immunoglobulins combined. sIgA antibodies are effective against various pathogens, including the SARS-CoV-2 virus, due to mechanisms such as neutralization, suppression of adhesion to the mucosal surface and invasion of epithelial cells, agglutination and facilitating the removal of pathogenic microorganisms with the mucosal secretions. Virus-specific IgA antibodies in the blood serum are detected in patients with COVID-19 as early as two days after the first symptoms, while IgM or IgG class antibodies appear only after 5 days. We accessed the efficacy of intranasal immunization as to induction of predominant production of sIgA in the upper and lower respiratory tract.Conclusion. The current information on the local immune response of the respiratory mucosa is important for understanding the pathophysiological mechanisms of the disease, diagnosis, and development of new methods of treatment and prevention of COVID-19.


2021 ◽  
Author(s):  
Kaori Sano ◽  
Disha Bhavsar ◽  
Gagandeep Singh ◽  
Daniel Floda ◽  
Komal Srivastava ◽  
...  

AbstractMucosal immune responses are critical to prevent respiratory infections but it is unclear to what extent antigen specific mucosal secretory IgA (SIgA) antibodies are induced by mRNA vaccination in humans. We analyzed, therefore, paired serum and saliva samples from study participants with and without COVID-19 at multiple timepoints before and after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccination. Our results suggest that the level of mucosal SIgA responses induced by mRNA vaccination depend on pre-existing immunity. Indeed, vaccination induced only a weak mucosal SIgA response in individuals without pre-existing mucosal antibody responses to SARS-CoV-2 while SIgA induction after vaccination was efficient in COVID-19 survivors. Our data indicate that vaccinated seropositive individuals were able to swiftly induce relatively high anti-spike SIgA responses by boosting pre-existing mucosal immunity. In contrast, seronegative individuals did not have pre-existing anti-SARS-CoV-2 or cross-reacting anti-HCoV SIgA antibodies prior to vaccination, and, thus, little or no anti-SARS-CoV-2 SIgA antibodies were induced by vaccination in these individuals.


Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1453
Author(s):  
Cansu Karyal ◽  
Panayiota Palazi ◽  
Jaime Hughes ◽  
Rhys C. Griffiths ◽  
Ruby R. Persaud ◽  
...  

Mucosal vaccination aims to prevent infection mainly by inducing secretory IgA (sIgA) antibody, which neutralises pathogens and enterotoxins by blocking their attachment to epithelial cells. We previously demonstrated that encapsulated protein antigen CD0873 given orally to hamsters induces neutralising antibodies locally as well as systemically, affording partial protection against Clostridioides difficile infection. The aim of this study was to determine whether displaying CD0873 on liposomes, mimicking native presentation, would drive a stronger antibody response. The recombinant form we previously tested resembles the naturally cleaved lipoprotein commencing with a cysteine but lacking lipid modification. A synthetic lipid (DHPPA-Mal) was designed for conjugation of this protein via its N-terminal cysteine to the maleimide headgroup. DHPPA-Mal was first formulated with liposomes to produce MalLipo; then, CD0873 was conjugated to headgroups protruding from the outer envelope to generate CD0873-MalLipo. The immunogenicity of CD0873-MalLipo was compared to CD0873 in hamsters. Intestinal sIgA and CD0873-specific serum IgG were induced in all vaccinated animals; however, neutralising activity was greatest for the CD0873-MalLipo group. Our data hold great promise for development of a novel oral vaccine platform driving intestinal and systemic immune responses.


Pharmacology ◽  
2021 ◽  
pp. 1-10
Author(s):  
Ekaterina N. Gorshkova ◽  
Shina Pashova ◽  
Ekaterina A. Vasilenko ◽  
Tatiana S. Tchurina ◽  
Elizaveta A. Razzorenova ◽  
...  

<b><i>Introduction:</i></b> As has been shown previously, various protein-modifying agents can change the antigen-binding properties of immunoglobulins. However, induced polyspecificity of human secretory immunoglobulin A (sIgA) has not been previously characterized in detail. <b><i>Methods:</i></b> In the present study, human secretory immunoglobulin A (IgA) was exposed to buffers with acidic pH, to free heme, or to pro-oxidative ferrous ions, and the antigen-binding behavior of the native and modified IgA to viral and bacterial antigens was compared using Western blotting and enzyme-linked immunosorbent assay. The ability of these agents to modulate the antigen-binding properties of human sIgA toward a wide range of pathogen peptides was investigated using an epitope microarray. <b><i>Results:</i></b> We have shown that acidic pH, heme, and pro-oxidative ferrous ions influenced the binding of secretory IgA in opposite directions (either increasing or decreasing); however, the strongest effect was observed when using buffers with low pH. This fraction had the highest number of affected reactivities; most of them were increased and most of the new ones were toward common pathogens. <b><i>Conclusions:</i></b> Thus, it was shown that all investigated treatments can alter to some degree the antigen-binding of secretory IgA, but acidic pH has the most potentially beneficial effect by increasing binding to a largest number of common pathogens’ antigens.


2021 ◽  
pp. 100468
Author(s):  
Juliana Gonçalves ◽  
A. Margarida Juliano ◽  
Nádia Charepe ◽  
Marta Alenquer ◽  
Diogo Athayde ◽  
...  
Keyword(s):  
T Cells ◽  

2021 ◽  
Vol 12 ◽  
Author(s):  
Bereket Dessalegn ◽  
Molalegne Bitew ◽  
Destaw Asfaw ◽  
Esraa Khojaly ◽  
Saddam Mohammed Ibrahim ◽  
...  

Fowl cholera (FC) caused by Pasteurella multocida is among the serious infectious diseases of poultry. Currently, formalin inactivated FC (FI-FC) vaccine is widely used in Ethiopia. However, reports of the disease complaint remain higher despite the use of the vaccine. The aim of this study was to develop and evaluate gamma-irradiated mucosal FC vaccines that can be used nationally. In a vaccination-challenge experiment, the performance of gamma-irradiated P. multocida (at 1 kGy) formulated with Montanide gel/01 PR adjuvant was evaluated at different dose rates (0.5 and 0.3 ml) and routes (intranasal, intraocular, and oral), in comparison with FI-FC vaccine in chicken. Chickens received three doses of the candidate vaccine at 3-week intervals. Sera, and trachea and crop lavage were collected to assess the antibody levels using indirect and sandwich ELISAs, respectively. Challenge exposure was conducted by inoculation at 3.5×109 CFU/ml of P. multocida biotype A intranasally 2 weeks after the last immunization. Repeated measures ANOVA test and Kaplan Meier curve analysis were used to examine for statistical significance of antibody titers and survival analysis, respectively. Sera IgG and secretory IgA titers were significantly raised after second immunization (p=0.0001). Chicken survival analysis showed that intranasal and intraocular administration of the candidate vaccine at the dose of 0.3 ml resulted in 100% protection as compared to intramuscular injection of FI-FC vaccine, which conferred 85% protection (p=0.002). In conclusion, the results of this study showed that gamma-irradiated FC mucosal vaccine is safe and protective, indicating its potential use for immunization of chicken against FC.


2021 ◽  
Author(s):  
Kathrin Göritzer ◽  
Elisabetta Groppelli ◽  
Clemens Grünwald-Gruber ◽  
Rudolf Figl ◽  
Fengfeng Ni ◽  
...  

Abstract Passive delivery of antibodies to mucosal sites might be a valuable adjunct to COVID-19 vaccination to prevent infection, treat viral carriage, or block transmission. However, monoclonal IgG antibody therapies, currently used for treatment of severe infections, are unlikely to prove useful in mucosal sites where SARS-CoV-2 resides and replicates in early infection. Here, we investigated the feasibility of producing neutralising monoclonal IgA antibodies against SARS-COV-2. We identified two class-switched mAbs that express well as monomeric and secretory IgA variants with retained antigen binding affinities and increased stability in mucosal secretions compared to their IgG counterparts. SIgAs had stronger virus neutralisation activities than IgG mAbs and were able to reduce SARS-CoV-2 infection in an in vivo murine model. Our findings provide a persuasive case for developing recombinant SIgAs for mucosal application as a new tool in the fight against COVID-19.


Sign in / Sign up

Export Citation Format

Share Document