scholarly journals Optimization of a human milk–directed quantitative sIgA ELISA method substantiated by mass spectrometry

2021 ◽  
Author(s):  
Kelly A. Dingess ◽  
Pauline van Dam ◽  
Jing Zhu ◽  
Marko Mank ◽  
Karen Knipping ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Human Milk ◽  
Immunoglobulin A ◽  
Secretory Component ◽  
Detection Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Breastfed Infants ◽  
Serum Iga ◽  
Standard Serum ◽  
Analytical Approaches

AbstractImmunoglobulins are the primary protective products in human milk and are responsible for transferring maternal pathogen memory to the infant, providing protection by binding to recognized pathogens and inhibiting virulence. To better understand potentially protective/anti-infective compounds in human milk, the establishment of human milk–tailored analytical approaches is crucial, as most contemporary analytical methods have been optimized for plasma or serum. One of the most prominent immunoglobulins in human milk is secretory immunoglobulin A (sIgA), which may be relevant for the protection of breastfed infants from harmful pathogens. Advanced sIgA detection methods can help monitor the immune status and development of the mother-infant dyad. We therefore developed an enzyme-linked immunosorbent assay (ELISA) sIgA method for the quantitative analysis of IgA plus secretory component (SC), validated with sIgA standards and substantiated by mass spectrometry (MS)–based proteomics. A very strong correlation was observed between the MS-detected IgA1 and the human milk–specific sIgA ELISA (r = 0.82). Overall, the MS data indicate that the developed human milk sIgA ELISA does not differentiate between sIgA1 and sIgA2 and is, therefore, a reflection of total sIgA. Furthermore, our MS data and the human milk–derived sIgA ELISA data are better correlated than data derived from a standard serum IgA ELISA kit (relative to MS IgA1 r = 0.82 and r = 0.42, respectively). We therefore propose our human milk–specific sIgA ELISA as an ideal quantitative indicator of total sIgA with advantages over current serum IgA ELISA kits.

scholarly journals Antibodies Against SARS-CoV-2 in Human Milk: Milk Conversion Rates in the Netherlands

2021 ◽  
pp. 089033442110181
Author(s):  
Hannah G. Juncker ◽  
Michelle Romijn ◽  
Veerle N. Loth ◽  
Eliza J. M. Ruhé ◽  
Sjors Bakker ◽  
...  
Keyword(s):  
The Netherlands ◽  
Human Milk ◽  
Immunoglobulin A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Breastfed Infants ◽  
Lactating Mothers ◽  
Conversion Rates ◽  
Iga Antibodies ◽  
Large Prospective Cohort Study

Background It has been demonstrated that human milk from mothers who have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains antibodies against the virus, which could play an important role in protecting the recipient infant against coronavirus disease 2019 (COVID-19). Seroconversion is measured frequently around the world, but the milk conversion rate is unknown. Research Aims To determine (1) the prevalence and (2) the dynamics of immunoglobulin A (IgA) antibodies against SARS-CoV-2 in human milk amongst lactating mothers in the Netherlands. Methods In this large prospective cohort study, lactating mothers ( N = 2312) were included between October 12, 2020 and February 24, 2021. Enzyme-linked immunosorbent assay was used to determine levels of IgA antibodies in human milk and immunoglobulin G (IgG) antibodies in serum against the ectodomain of the SARS-CoV-2 spike protein. Results A total of 691 (30.6%) participants had SARS-CoV-2 specific antibodies in human milk and/or serum. Of these participants, 524 (23.1%) had IgA antibodies against SARS-CoV-2 in human milk, and 356 (15.7%) had IgG antibodies against SARS-CoV-2 in serum. A total of 199 (8.8%) participants had antibodies in both human milk and serum. SARS-CoV-2 specific IgA antibodies in human milk remain present at least 10 months after a polymerase chain reaction confirmed infection. Conclusion The prevalence of IgA antibodies against SARS-CoV-2 in human milk was 23.1% in our cohort. This high prevalence of antibodies in human milk might lead to passive immunity in many breastfed infants and may serve as protection against COVID-19.

scholarly journals Human Milk Antibodies Against SARS-CoV-2: A Longitudinal Follow-Up Study

2021 ◽  
pp. 089033442110301
Author(s):  
Hannah G. Juncker ◽  
M. Romijn ◽  
Veerle N. Loth ◽  
Tom G. Caniels ◽  
Christianne J.M. de Groot ◽  
...  
Keyword(s):  
Human Milk ◽  
Clinical Symptoms ◽  
Immunoglobulin A ◽  
Spike Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Follow Up Study ◽  
Lactating Mothers ◽  
Milk Antibodies ◽  
Over Time

Background: Human milk contains antibodies against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) following Coronavirus Disease 2019 (COVID-19). These antibodies may serve as protection against COVID-19 in infants. However, the evolution of these human milk antibodies over time is unclear. Research Aim: To elucidate the evolution of immunoglobulin A (IgA) against SARS-CoV-2 in human milk after a SARS-CoV-2 infection. Methods: This longitudinal follow-up study included lactating mothers ( N = 24) who had participated in the COVID MILK study. To assess the evolution of SARS-CoV-2 antibodies, serum and human milk samples were collected 14–143 days after the onset of clinical symptoms related to COVID-19. Enzyme-Linked ImmunoSorbent Assay was used to detect antibodies against the ectodomain of the SARS-CoV-2 spike protein. Results: SARS-CoV-2 antibodies remain present up to 5 months (143 days) in human milk after onset of COVID-19 symptoms. Overall, SARS-CoV-2 IgA in human milk seems to gradually decrease over time. Conclusion: Human milk from SARS-CoV-2 convalescent lactating mothers contains specific IgA antibodies against SARS-CoV-2 spike protein up to at least 5 months post-infection. Passive viral immunity can be transferred via human milk and may serve as protection for infants against COVID-19. Dutch Trial Register on May 1st, 2020, number: NL 8575, URL: https://www.trialregister.nl/trial/8575 .

Secretory Immunoglobulin a in Oral and Respiratory Passages in Man

1975 ◽  
Vol 84 (20_suppl) ◽  
pp. 1-23 ◽  
Author(s):  
Goro Mogi
Keyword(s):  
Immunoglobulin A ◽  
Secretory Component ◽  
Secretory Iga ◽  
Secretory Cells ◽  
Antigenic Relationship ◽  
Serum Iga ◽  
Human Colostrum ◽  
Specific Antisera ◽  
Antigenic Relationships ◽  
Secretory Immunoglobulin

Secretory IgA (SIgA) is the predominant immunoglobulin in certain external secretions and may have an important role in immunological mucosal resistance. SIgA differs in chemical and immunological properties from serum IgA. The present study was undertaken to investigate the antigenic relationship between SIgA, free secretory component (FSC) and serum IgA and the localization of SIgA as well as other immunological classes in tissues of oral and respiratory passages by use of immunofluorescence technique. SIgA and FSC were highly purified from human colostrum and rabbit anti-SIgA and anti-SC antisera were prepared. On the basis of antigenic relationships between SIgA, FSC and serum IgA, it was emphasized that individual specific antisera for SC and IgA and/or SIgA should be used in immunochemical or immunohistological investigations for SIgA. The present study failed to detect SC determinants in palatine and lingual tonsils. However, it was evident that cells present in the pharyngeal tonsillar epithelium contain SC determinants. SC molecules may be synthesized in certain secretory cells of mucous membrane and glandular epithelium and the combining of SC with IgA could occur in the cytoplasm of epithelial cells, the intercellular spaces and/or in the lumens of glandular acini and ductules.

scholarly journals A Direct MS-Based Approach to Profile Human Milk Secretory Immunoglobulin A (IgA1) Reveals Donor-Specific Clonal Repertoires With High Longitudinal Stability

2021 ◽  
Vol 12 ◽  
Author(s):  
Albert Bondt ◽  
Kelly A. Dingess ◽  
Max Hoek ◽  
Danique M. H. van Rijswijck ◽  
Albert J. R. Heck
Keyword(s):  
Mass Spectrometry ◽  
Human Milk ◽  
Human Body ◽  
Immunoglobulin A ◽  
Newborn Infants ◽  
Secretory Immunoglobulin A ◽  
Important Class ◽  
Plasma Samples ◽  
Healthy Donors ◽  
Secretory Immunoglobulin

Recently, a mass spectrometry-based approach was introduced to directly assess the IgG1 immunoglobulin clonal repertoires in plasma. Here we expanded upon this approach by describing a mass spectrometry-based technique to assess specifically the clonal repertoire of another important class of immunoglobulin molecules, IgA1, and show it is efficiently and robustly applicable to either milk or plasma samples. Focusing on two individual healthy donors, whose milk was sampled longitudinally during the first 16 weeks of lactation, we demonstrate that the total repertoire of milk sIgA1 is dominated by only 50-500 clones, even though the human body theoretically can generate several orders of magnitude more clones. We show that in each donor the sIgA1 repertoire only changes marginally and quite gradually over the monitored 16-week period of lactation. Furthermore, the observed overlap in clonal repertoires between the two individual donors is close to non-existent. Mothers provide protection to their newborn infants directly by the transfer of antibodies via breastfeeding. The approach introduced here, can be used to visualize the clonal repertoire transferred from mother to infant and to detect changes in-time in that repertoire adapting to changes in maternal physiology.

scholarly journals A Comparative Analysis of Methods (LC-MS/MS, LC-MS and Rapid Test Kits) for the Determination of Diarrhetic Shellfish Toxins in Oysters, Mussels and Pipis

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 563
Author(s):  
Penelope A. Ajani ◽  
Chowdhury Sarowar ◽  
Alison Turnbull ◽  
Hazel Farrell ◽  
Anthony Zammit ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Quantitative Methods ◽  
Rapid Test ◽  
Detection Methods ◽  
Enzyme Linked Immunosorbent Assay ◽  
Shellfish Toxins ◽  
Test Kit ◽  
High Level ◽  
Diarrhetic Shellfish Toxins

Rapid methods for the detection of biotoxins in shellfish can assist the seafood industry and safeguard public health. Diarrhetic Shellfish Toxins (DSTs) are produced by species of the dinoflagellate genus Dinophysis, yet the comparative efficacy of their detection methods has not been systematically determined. Here, we examined DSTs in spiked and naturally contaminated shellfish–Sydney Rock Oysters (Saccostrea glomerata), Pacific Oysters (Magallana gigas/Crassostrea gigas), Blue Mussels (Mytilus galloprovincialis) and Pipis (Plebidonax deltoides/Donax deltoides), using LC-MS/MS and LC-MS in 4 laboratories, and 5 rapid test kits (quantitative Enzyme-Linked Immunosorbent Assay (ELISA) and Protein Phosphatase Inhibition Assay (PP2A), and qualitative Lateral Flow Assay (LFA)). We found all toxins in all species could be recovered by all laboratories using LC-MS/MS (Liquid Chromatography—tandem Mass Spectrometry) and LC-MS (Liquid Chromatography—Mass Spectrometry); however, DST recovery at low and mid-level concentrations (<0.1 mg/kg) was variable (0–150%), while recovery at high-level concentrations (>0.86 mg/kg) was higher (60–262%). While no clear differences were observed between shellfish, all kits delivered an unacceptably high level (25–100%) of falsely compliant results for spiked samples. The LFA and the PP2A kits performed satisfactorily for naturally contaminated pipis (0%, 5% falsely compliant, respectively). There were correlations between spiked DSTs and quantitative methods was highest for LC-MS (r2 = 0.86) and the PP2A kit (r2 = 0.72). Overall, our results do not support the use of any DST rapid test kit as a stand-alone quality assurance measure at this time.

scholarly journals Altered Systemic and Intestinal IgA Immune Responses in Individuals With Type 1 Diabetes

2020 ◽  
Vol 105 (12) ◽  
pp. e4616-e4625
Author(s):  
Juan Huang ◽  
Gan Huang ◽  
Xia Li ◽  
Fang Hu ◽  
Zhiguo Xie ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Immune Responses ◽  
Immunoglobulin A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Acid Decarboxylase ◽  
Islet Autoantibody ◽  
Glutamic Acid Decarboxylase Autoantibody ◽  
Serum Iga ◽  
Healthy Control

Abstract Objective Increasing evidence supports the observation that immunoglobulin A (IgA) exerts a critical effect on the susceptibility to autoimmunity by modulating gut homeostasis and subsequent host immunity. We hypothesized that the IgA immunity is altered in individuals with type 1 diabetes. To test our hypothesis, we investigated intestinal, oral, and peripheral IgA immune responses in individuals with type 1 diabetes. Methods We collected stool, oral cavity, and blood samples from participants diagnosed with type 1 diabetes (within 1 year and more than 1 year) and healthy control individuals. Serum islet autoantibody titers were detected by radioligand assays. IgA-bound bacteria and IgA-expressing B cells were studied by flow cytometry. Oral free IgA level was measured by enzyme-linked immunosorbent assay. Serum and stool free IgA concentrations were determined by immune-turbidimetry method. Results Individuals diagnosed with type 1 diabetes within 1 year had an increased proportion of stool IgA-bound bacteria compared with healthy control individuals. The proportion of stool IgA-bound bacteria was positively associated with glutamic acid decarboxylase autoantibody titer. Moreover, individuals with a longer disease duration displayed a higher level of IgA-bound bacteria than those diagnosed within 1 year. In contrast to healthy control individuals, type 1 diabetes patients had increased serum IgA concentrations. Conclusions Individuals with type 1 diabetes display altered IgA immunity, especially increased stool IgA-bound bacteria, which is likely to contribute to β-cell autoimmunity and the disease development, and thus, might be considered as a novel therapeutic target for the treatment of type 1 diabetes.

Immunological Evaluation of Pasteurized, Deaerated Human Milk

1990 ◽  
Vol 53 (11) ◽  
pp. 975-977
Author(s):  
MICHAEL T. MUSGROVE ◽  
MARK A. HARRISON ◽  
RONALD R. EITENMILLER
Keyword(s):  
Escherichia Coli ◽  
Human Milk ◽  
Immunoglobulin A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Processing Conditions ◽  
Enteropathogenic Escherichia Coli ◽  
Milk Samples ◽  
Antibody Levels ◽  
Immunological Evaluation ◽  
Storage Temperatures

Retention of immunoglobulin A (IgA) and IgA specific for enteropathogenic Escherichia coli (EPEC) was determined in human milk that was processed and stored under refrigeration or frozen conditions. Human milk was subjected to three different processing conditions: (a) deaerated, vacuum packaged in metalized polyester bags and pasteurized (64°C for 6 min, 10 s); (b) vacuum packaged and pasteurized; (c) vacuum packaged. Samples were stored at 4°C for 7 d and at −20°C for 28 d. An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to EPEC was developed and used to monitor these antibody levels, while radial immunodiffusion (RID) plates were used to provide information on total IgA of the milk samples. In addition, the dissolved oxygen content of the samples was monitored. It was found that pasteurization and deaeration did not adversely affect the IgA levels, and levels of total IgA and IgA specific for EPEC remained stable or increased slightly during storage in most samples regardless of the storage temperatures.

scholarly journals The Levels of SARS-CoV-2 Specific Antibodies in Human Milk Following Vaccination

2021 ◽  
pp. 089033442110271
Author(s):  
Hannah G. Juncker ◽  
Sien J. Mulleners ◽  
Marit J. van Gils ◽  
Christianne J. M. de Groot ◽  
Dasja Pajkrt ◽  
...  
Keyword(s):  
Antibody Response ◽  
Human Milk ◽  
Natural Infection ◽  
Immunoglobulin A ◽  
Enzyme Linked Immunosorbent Assay ◽  
Prospective Longitudinal Study ◽  
Lactating Women ◽  
Specific Antibodies ◽  
Milk Samples ◽  
Prospective Longitudinal

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are being administered around the world; however, lactating women were excluded from SARS-CoV-2 vaccine trials. Therefore, knowledge about the effect of vaccination in this specific group is limited. This information is essential to empower lactating women to make a well-informed decision on their choice for vaccination. After natural infection, SARS-CoV-2 specific antibodies are present in human milk, which might offer protection for her newborn. The dynamics of these antibodies in human milk following vaccination remain to be elucidated. Research Aim To determine the effect of vaccination with BNT162b2 on the levels of SARS-CoV-2 specific IgA in human milk. Methods In this prospective longitudinal study, we included lactating women who received the BNT162b2 vaccine. Human milk samples were collected prior to vaccination and 3, 5, 7, 9, 11, 13, and 15 days after both vaccine doses. Samples were analyzed using enzyme-linked immunosorbent assay against the spike protein of SARS-CoV-2. Results In total, 366 human milk samples from 26 lactating women were analyzed. A biphasic response was observed, with SARS-CoV-2 specific immunoglobulin A (IgA) starting to increase between day 5 and 7 after the first dose of the vaccine. After the second dose, an accelerated IgA antibody response was observed. Conclusion After vaccination with the mRNA-based BNT162b2 vaccine, a SARS-CoV-2 specific antibody response was observed in human milk. The presence of SARS-CoV-2 specific IgA after vaccination is important as antibodies are transferred via human milk, and thereby might provide protection to infants against COVID-19.

scholarly journals The Effects of Secretory IgA in the Mucosal Immune System

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Yue Li ◽  
Liang Jin ◽  
Tongxin Chen
Keyword(s):  
Immune System ◽  
Critical Role ◽  
Immunoglobulin A ◽  
Secretory Component ◽  
Mucosal Immune System ◽  
Secretory Iga ◽  
Antibody Isotype ◽  
Serum Iga ◽  
Important Field ◽  
Immune Exclusion

Immunoglobulin A (IgA) is the most abundant antibody isotype in the mucosal immune system. Structurally, IgA in the mucosal surface is a polymeric structure, while serum IgA is monomeric. Secretory IgA (sIgA) is one of the polymeric IgAs composed of dimeric IgA, J chain, and secretory component (SC). Most of sIgAs were generated by gut and have effects in situ. Besides the function of “immune exclusion,” a nonspecific immune role, recent studies found it also played an important role in the specific immunity and immunoregulation. Thanks to the critical role of sIgA during the mucosal immune system homeostasis between commensal microorganisms and pathogens; it has been an important field exploring the relationship between sIgA and commensal microorganisms.

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