Recombinant IgA Antibodies

ABSTRACTThe human middle ear is devoid of any immunocompetent cells in normal mucosa. We sought to determine the source of antibody present in the middle ear of children. Total IgG, IgA, and secretory IgA antibodies were determined by enzyme-linked immunosorbent assay from the nasopharyngeal, middle ear, and serum samples of children with acute otitis media. The two-dimensional gel electrophoresis pattern of the entire array of IgA antibodies in the nasal wash (NW) and middle ear fluid (MEF) was compared from the MEF and NW samples using isoelectric focusing and Western blotting. The total IgG and IgA antibodies in the MEF and NW samples of 137 children were compared. The ratio of IgG to IgA in the MEF was significantly different (P< 0.008) compared to NW because IgA levels were higher and IgG levels lower in NW. The IgG/IgA ratio of MEF resembled serum consistent with transudation to the MEF. Small amounts of secretory IgA were detected in MEF but the electrophoresis patterns of the entire array of IgA antibodies in the MEF and NW were virtually identical in each child evaluated; thus, IgA in MEF derived predominantly from serum and the nasopharynx by reflux via the Eustachian tube. The IgG/IgA antibody levels in the MEF and the same composition of IgA antibody in the MEF and NW identifies the predominant source of antibody in the MEF as a transudate of serum combined with nasal secretions refluxed from the nasopharynx in children.

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Rapid seroconversion and persistent functional IgG antibodies in severe COVID-19 patients correlates with an IL-12p70 and IL-33 signature

Scientific Reports ◽

10.1038/s41598-021-83019-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ariel Munitz ◽

L. Edry-Botzer ◽

M. Itan ◽

R. Tur-Kaspa ◽

D. Dicker ◽

...

Keyword(s):

Nucleocapsid Protein ◽

Neutralizing Antibodies ◽

Host Response ◽

Humoral Response ◽

Rapid Onset ◽

Response Analysis ◽

Receptor Binding Domain ◽

Igg Antibodies ◽

Viral Receptor ◽

Iga Antibodies

AbstractDespite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.

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Presence of anti-Toxoplasma antibodies in humans and their cats in the urban zone of Guadalajara

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86821999000500003 ◽

1999 ◽

Vol 32 (5) ◽

pp. 483-488 ◽

Cited By ~ 14

Author(s):

María de la Luz Galván Ramírez ◽

Guillermo Sánchez Vargas ◽

Marcos Vielma Sandoval ◽

Juan Luis Soto Mancilla

Keyword(s):

Risk Factors ◽

Toxoplasma Gondii ◽

Immunosorbent Assay ◽

Enzyme Linked Immunosorbent Assay ◽

Toxoplasma Infection ◽

Urban Zone ◽

Lack Of Control ◽

Iga Antibodies

Cats are the definitive hosts of Toxoplasma gondii. Infected cats excrete oocysts in their feces, infecting humans and other animals. The objective of the present study was to determine the presence of anti-Toxoplasma antibodies in cat owners and their pets, and determine if there was a relationship between Toxoplasma infection and humans who live with infected cats. IgG anti-Toxoplasma antibodies in sera of 59 cat owners were determined by enzyme-linked immunosorbent assay (ELISA), in 24 sera from their cats, IgG, IgM, and IgA antibodies were found using Burney's ELISA. Thirty-eight (64%) of 59 cat owners were positive to IgG anti-Toxoplasma. Seropositivity for cats was 70.8% IgG, 8.3% IgM, and 62.5% IgA. Cohabitation with cats infected by T. gondii, feeding with leftovers or raw viscera, and lack of control over how their feces were handled are risk factors conducive for humans to become infected by T. gondii.

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