Use of immunoglobulin-binding bacterial proteins in immunodetection

Abstract

One of the aim of this study was to make universal chimeric conjugates to react with both avian and mammalian immunoglobulins in enzyme-linked immunosorbent assays (ELISAs). The periodate method was used in the conjugation process of cross-linking horseradish peroxidase to immunoglobulin-binding proteins (IBP) including staphylococcal protein A (SpA), streptococcal protein G (SpG) and peptostreptococcal protein L (SpL). By mixing up these three conjugates another four hybrid protein conjugates were created including protein LA (SpLA), protein LG (SpLG), protein AG (SpAG) and protein LAG (PLAG). Thirty-five ELISAs were standardized by a probabilistic combination of these immunoreagents. By using a panel of mainly mammalian immunoglobulins their reproducibility was checked by the determination of coefficient of variations (CV) for each one of the IgG-IBP binding. The source of immunoglobulins was their purification by affinity chromatography using a commercially available kit (PURE-1A). The other aim was to immunize chicken with the peptide fragment 254-274 of gp120 to produce anti-HIV peptide hyper-immune egg. Cats and rats were fed these eggs for a determined period until they produced the anti-HIV peptide antibody, which was tested by an indirect SpLA-ELISA and dot blot analysis that corroborated the production of anti-HIV antibodies by the mammalian species including positive humans samples for HIV. We conclude that the single and hybrid immunoglobulin-binding protein were effective in their binding capacity to immunoglobulins from a variety of mammalian species. The potential use of this proteins is in the arena of immunodiagnosis and immunoglobulin detection. Dot blot analysis proves effective in the detection of HIV anti-gp120 antibodies in several animal species. These antibodies can be used as reagents in the development of immunodiagnostic tests or experimental vaccines.

The Characterization of Disease Severity Associated IgG Subclasses Response in COVID-19 Patients

“…The multi-isotype antibodies in serum include IgA, IgD, IgG, IgM, and IgE, of which IgG is the most abundant, while IgD and IgE are extremely scarce ( 9 ). Thus, assessment of antibody responses has been focused on the titers of IgA, IgG, and IgM ( 10 ). Four IgG subclasses in human have been identified which have more than 90% similar sequence, but distinct functions.…”

Passive Immunity and Antibody Response Induced by Toxoplasma gondii VLP Immunization

“…However, it is widely neglected when evaluating vaccine-induced immunity, as IgG and IgA antibodies are the main targets for immune response assessment. IgM molecules, characterized by their ten antigen-binding sites that contribute to their high antigen avidity, can neutralize pathogens and protect mucosal surfaces [ 47 ]. In this study, VLP immunizations induced parasite-specific IgM in sera and intestines, which may contribute to the protection against T. gondii challenge infection.…”

Universal Enzyme-Linked Immunosorbent Assays (ELISA) and Utility in the Detection of Antibodies against Salmonella spp. in Several Animal Species

“…The IgY fraction was isolated from the egg yolks of various birds, including chicken, bantam hen, guinea hen, quail, goose, duck, wild and domestic pigeons, parakeets, cattle egrets, pheasants, and ostrich. The IgY fraction was isolated using the chloroform-polyethylene glycol (PEG) method [7,8]. Purified immunoglobulin (Ig) was purified using an antibody purification system based on protein A-affinity chromatography (PURE-1A; Sigma-Aldrich).…”