MSD application case: AIDS vaccine development, multi-factor technology detection antibody specificity

[MSD Applications] Virology top journals Journal of Virology: HIV vaccine development, multi-factor technology to detect antibody specificity

Neutralizing antibodies are a class of soluble proteins produced by exposure of acquired immune cells to blood in the blood. In the blood, they bind to the virus, preventing it from further infecting human cells, and can cause viral particles to cleave, causing a "neutralizing" reaction. Since neutralizing antibodies can "kill" a virus before it infects human cells, it can prevent infection if such antibodies are present before the human body is exposed to HIV. Only a few HIV-positive patients produce potent, broad-spectrum neutralizing antibodies after years of HIV infection. Animal experiments have shown that if a preventive vaccine triggers these antibodies, it can stop HIV infection. PG9 and PG16 are the first potent HIV broad-spectrum antibodies discovered by scientists to bind to a specific epitope of glycoprotein (gp120) in HIV-1, preventing HIV-1 from infecting human cells. Traditional antibody ELISA and virus neutralization experiments do not address the antibody specificity produced by vaccinated animals. To identify epitope specificity, Hoffenberg and other factors in a multi-point of the microplate MSD PG9, PGT126, PGV04, b6, 17b, and 2F5 antibodies and the like. This is based on Meso Scale Discovery (MSD) technology to develop a competition-binding assay to detect whether sera from vaccinated animals contain antibodies that recognize epitopes. In the Journal of Virology, there are several articles on the application and development of Meso Scale Discovery (MSD) electrochemiluminescence technology.

MSD multi-factor competitive antibody binding:

Multiplexed competition antibody binding assay. To determine epitope specificity, we developed a competition-binding assay (CBA) based on Meso Scale Discovery (MSD) Sector Imager technology. MSD uses electrochemiluminescence (ECL) to detect binding events in a unique and sensitive manner with a _4-log dynamic range. The goal of the CBA is to determine whether sera from vaccinated animals contain Abs recognizing epitopes similar to those bound by well-characterized Env-specific Abs. The Abs PG9, PGT126, PGV04, b6, 17b, and 2F5 were each spotted onto MSD multiarrays. Dilutions of sera were preincubated for 1 h at 37°C with an excess of soluble biotinylated BG505 L111A gp120 or with a clade C gp120 chimera based on isolate 16096 with a V1 to V3 loop substitution from subtype 16055 , a clade C isolate that we term 16936-V55. This mixture was then transferred to an MSD plate blocked with PBS containing 3% BSA and incubated for 1 h at room temperature. Plates were washed with PBS containing Plates were read using the Sector Imager 2400 . A reduction in signal reflects the presence of Abs in serum that competed with spotted Abs for binding to gp120. An advantage of this assay Configuration is that it binding binding to soluble antigen, which may possess a more native structure compared with plate-bound antigen.

Experimental results:

Original: Hoffenberg S, Powell R, Carpov A, Wagner D, Wilson A, Kosakovsky Pond S, Lindsay R, Arendt H, Destefano J, Phogat S, Poignard P, Fling SP, Simek M, Labranche C, Montefiori D, Wrin T , Phung P, Burton D, Koff W, King CR, Parks CL, Caulfield MJ. Identification of an HIV-1 clade A envelope that exhibits broad antigenicity and neutralization sensitivity and elicits antibodies targeting three distinct epitopes. J Virol. 2013 May;87 (10): 5372-83. doi: 10.1128/JVI.02827-12. Epub 2013 Mar 6.

About Meso Scale Discovery ( MSD ): Sam Wohlstadter, one of Amgen's founders, invested in MSD. Founded in 1995, MSD was the first to detect human-borne H1N1 virus in the world in 2009. In 2013, it was named “the top five immunoassay brand in the world”. The microplate-based electrochemiluminescence detection technology (referred to as microplate ECL) developed by the company is a third-generation immunoassay technology for comprehensive upgrade/substitution ELISA, Western Blot and multi-protein factor detection. Has been widely used by pharmaceutical research and development centers, drug safety evaluation centers, GLP laboratories, contract outsourcing companies (CRO), diagnostics, biotechnology companies for drug screening, animal models, drug metabolism, blood drug concentration, immunogenicity, neutralization Experiments, Biomarker Screening, Antibody Affinity, Vaccine Evaluation, Host Cell Residues, Diagnostic Studies.

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