IgMs Are Capable of Curing Viral Infection Including COVID-19

Posted by Candy Swift on December 29th, 2021

Immunoglobulin M (IgM) is the first line of defense against foreign invaders, such as viruses. It is the only kind of antibody found in all vertebrate animals. Monomeric IgM is primarily expressed on B cells as a surface-bound receptor and is required for B-cell growth. In healthy people, IgMs are mostly polymeric when they are secreted. Monomeric IgM, on the other hand, is commonly generated in autoimmune disease patients.

Natural (innate) and adaptive (immune) IgM are the two forms of secreted IgM (sIgM).

Circulating antibodies can be seen in human cord blood and the blood of germ/antigen-free mice even when no antigenic stimulus is present. They are called natural antibodies, and the IgM class predominates, though IgG and IgA natural antibodies have also been identified.

Natural IgM reacts to a wide range of antigens, including protein and non-protein antigens. Natural IgM, because of its polyreactivity, may identify foreign antigens without ever having come into contact with them, making it the first line of defense against invaders. Natural IgM defends against viral infections through three mechanisms: to direct bind to viral proteins or viral receptors expressed on potential viral target cells, or to trap virions by aggregation, or to transport viral antigens to lymphoid organs, boosting adaptive immune responses.

Adaptive IgM, unlike natural IgM, is the first antibody type created by the body in reaction to an invading pathogen, and it is produced mostly by B2 cells in the spleen and lymph nodes. T he main difference between them is that natural IgM has more flexible antigen-binding sites that enable wider responsiveness to multiple antigens.

Although adaptive IgM is not considered to have a major role in long-term humoral immunity, the recent finding of long-lived IgM plasma cells shows that adaptive IgM may be an underappreciated part of humoral immune defenses against viral infections.

For example, on June 3, 2021, research published on Nature suggested that a kind of engineered IgM antibodies was found to be significantly more potent than standard IgG antibodies in neutralizing the SARS-CoV-2, the virus causing COVID-19. IgM neutralizing antibody (IgM-14) showed a significant increase in potency against the original SARS-CoV-2 and emerging variants, including three variants of concern—B.1.1.7 (Alpha, which first emerged in the UK), P.1 (Gamma, which first emerged in Brazil) and B.1.351 (Beta, which first emerged in South Africa). Researchers conducted the experiment in rodents, and results show that intranasal administration of IgM-14 can improve efficacy, reduce resistance and simplify the prophylactic and therapeutic treatment of COVID-19. The title of this research is Nasal delivery of an IgM offers broad protection from SARS-CoV-2 variants, and the authors are from the University of Texas Health Science Center at Houston.

“Recent research suggests that active immunization may be able to induce protective, long-term IgM responses. Vaccines that feature long-term antiviral IgM responses may show benefits over traditional IgG responses when it comes to fast-mutating viruses like HIV and SARS-CoV-2,” as introduced by a scientist at Creative Biolabs. Creative Biolabs is a biotech company focusing on customized, one-stop solutions for non-IgG antibody development, covering IgE, IgA, and IgM.