Neutralizing antibodies are antibodies that are produced by B lymphocytes and can recognize specific parts of an antigen to deactivate the antigen and inhibit its function. It is also called a protective antibody. The antigen combined with the protective antibody (ie, the neutralizing antibody) is called the protective antigen, which is the main target in the vaccine development process.

In immunology-related experimental research, neutralizing antibodies can also be used as specific inhibitors of signaling pathway-related proteins, such as interleukin-related neutralizing antibodies and CD surface marker-related neutralizing antibodies.

Neutralizing antibody is an antibody that can bind to key antigen sites of the virus and block its infectivity. It can be IgM, IgG or IgA. The neutralization efficiency is determined by many factors, such as the heterogeneity of the antibody, the antigenic determinant that the antibody is directed against, the affinity of the antibody's antigen binding, and the characteristics of complement binding. The simple combination of virus and antibody does not all cause neutralization. Some antibodies remain infectious when they bind to the virus and form a complex. Such antibodies are called non-neutralizing antibodies.

The capsid or envelope of the virus is multimeric, so the virus surface antigen is densely covered. Two Fab fragments of a neutralizing antibody can bind to two adjacent antigen sites to form an abnormally stable complex that is not easy to separate. Neutralizing antibodies are mostly directed against antigenic determinants on the virus capsid or envelope.

The mechanism of its action includes four parts:

(1) Interfering with virus adsorption and penetration. The antibody bound to the virus can prevent the virus from adsorbing to the host cell receptor through simple spatial interference.

(2) Prevent virus infection by forming immune condensate. The aggregation of viruses can effectively reduce the number of infectious virus particles, and promote the phagocytosis of phagocytes so that they can be quickly eliminated.

(3) With the participation of complement, the immune lysis caused by the binding of antibodies to the viral envelope can inactivate the virus.

(4) Some viruses bound to antibodies can adsorb and penetrate into host cells, but they cannot replicate because they have lost the ability to unshell.

Neutralizing antibodies and SARS-CoV-2

On May 4, Utrecht University and Erasmus Medical Center in the Netherlands reported that they have identified a completely human monoclonal antibody that can prevent the novel coronavirus from infecting cultured cells.

On May 5, the journal Cell published a new study: Belgian scientists discovered that antibodies produced in the alpaca can eliminate the novel coronavirus with good results.

In addition, the US "Manhattan Project" report also particularly emphasized the role of monoclonal antibodies, calling them the most promising antiviral therapy.

China has also carried out related research, and currently at least four teams have obtained neutralizing antibodies against the coronavirus.

About Creative Biolabs

Founded in 2005, Creative Biolabs Laboratories are dedicated to serving life science research clients through our global operations networks. Creative Biolabs is internationally renowned as a leader of neutralizing antibody (NeutraAB) discovery and custom service, providing high-quality NeutraABs and expert services for NeutraAB analysis to the customers in academia and industry fields all over the world. During the past decade, thousands of NeutraABs have been isolated and expressed. These antibodies are now guiding the design of novel vaccine candidate for virus infection or used for biological therapeutics in any class of large molecule drugs. Creative Biolabs' unparalleled skill in mammalian cell (293F or CHO) transient transfection and transient transfection platform enables us to provide a wide range of NeutraABs with high-quality in short time.

Author's Bio: 

Founded in 2005, Creative Biolabs Laboratories are dedicated to serving life science research clients through our global operations networks. Creative Biolabs is internationally renowned as a leader of neutralizing antibody (NeutraAB) discovery and custom service, providing high-quality NeutraABs and expert services for NeutraAB analysis to the customers in academia and industry fields all over the world. During the past decade, thousands of NeutraABs have been isolated and expressed. These antibodies are now guiding the design of novel vaccine candidate for virus infection or used for biological therapeutics in any class of large molecule drugs. Creative Biolabs' unparalleled skill in mammalian cell (293F or CHO) transient transfection and transient transfection platform enables us to provide a wide range of NeutraABs with high-quality in short time.