Since early 2020, the coronavirus disease of 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has turned into a global pandemic causing millions of deaths worldwide, whose high infectivity resulted in the rapid spread in several countries, thereby affecting the total global population. IgMs are mucosal antibodies that constitute the first line of defense against mucosal pathogens, which can play an important role in the diagnosis, precaution, and treatment of SARS-CoV-2. As a responsible and advanced biotech company, Creative Biolabs is eager to contribute to the fight against the epidemic. Based on our established platforms including microassay, engineered antibody, and drug evaluation, as well as rich experience in the field of protein engineering and therapeutic antibodies, we have undertaken various programs about SARS-CoV-2 and got remarkable achievements. Therefore, it is our pleasure to share our idea about the application of IgM in SARS-CoV-2 with our partners all over the world.
Introduction of IgM Antibody in SARS-CoV-2 Infection
Since its discovery in Wuhan, China, in 2019, the causative agent of COVID-19, the SARS-CoV-2 virus, has become a major global public health problem. SARS‑CoV‑2 is a positive-sense single-stranded RNA virus belonging to coronaviruses. SARS-CoV-2 has four structural proteins, known as the spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins, while S proteins provide major antigenicity of SARS-COV-2. Though there is presently tremendous worldwide effort to identify and develop effective therapeutic approaches against this virus, none of this work has been successful now. Indeed, it is known that in combating many viral infections IgM antibodies play many critical roles.
Fig.1 SARS-CoV-2 structure. (Wu, 2020)
IgM Antibody in Diagnosis
Evidence suggested that the principle of early detection, early reporting, early isolation, early diagnosis, early management is necessary for the course of COVID-19 patients. However, due to some limitations including long turnaround time and requirements for equipment, RT-PCR as ‘golden standard’ is not totally satisfactory. Hence, detecting antibodies of SARS-CoV-2 provide another key piece of evidence for the diagnosis of viral infections. It was reported that after SARS-CoV-2 infection, IgM antibody could be detected in patient blood after 3 to 6 days while IgG could be detected after 8 days. Furthermore, detection of IgM antibodies tends to indicate recent exposure to SARS-CoV-2, which provides more information to the investigation of cataphoresis. Nowadays, there are many approaches to detect specific IgM including microassay and microfluidic chip, colloidal gold technique, ELISA kits, etc. While most of them are applied in different situations to detect COVID-19 patients earlier and more exactly.
Fig.2 Schematic illustration of rapid SARS-CoV-2 IgM-IgG combined antibody test. (Li, 2020)
IgM Antibody in Treatment
SARS-CoV-2 enters into a human cell through its S protein binding to angiotensin-converting enzyme 2 (ACE2). Neutralizing antibodies that target the S protein have been developed to treat COVID-19. However, because the respiratory tract is the major target for SARS-CoV-2 infection, administered IgG lack efficient access to mucosal compartments. Recently, a group has developed an advanced method to control COVID-19 by Nasal delivery of IgM. IgM constitutes the first line of defense in the respiratory tract against mucosal pathogens, whose pentamers facilitate efficient mucosal transcytosis, while the multivalent antibodies can exhibit enhanced neutralization of SARS-CoV-2. These unique features make the intranasal delivery of IgM neutralizing monoclonal antibodies appealing for the prevention and treatment of COVID-19.
Fig.3 Depiction of IgM-14 nasal spray neutralizing the SARS-CoV-2 in the respiratory tract. (Yerabham, 2021)
The fight against COVID-19 is a war for all mankind over the world. Creative Biolabs is glad to contribute our share to overcome the epidemic. If you are interested in the research of IgM antibody in SARS-CoV-2 infection, or for more details in the research of the therapeutic molecular field, please feel free to contact us.
- Wu, D.; et al. Vaccines and therapies in development for SARS-CoV-2 infections. Journal of clinical medicine. 2020, 9(6), 1885.
- Li, Z.; et al. Development and clinical application of a rapid IgM-IgG combined antibody test for SARS-CoV-2 infection diagnosis. Journal of medical virology. 2020, 92(9), 1518-1524.
- Yerabham, A.; et al. A novel IgM intranasal intervention against SARS-CoV-2. Antibody Therapeutics. 2021, 4(3), 171-174.
!! For Research Use Only. Our products and services are NOT intended for diagnostic or therapeutic applications.