Researchers from Canary Islands University Hospital have determined which proteins and which structural protein fragments SARS-Cov-2 are recognized by the immune system and help in the elimination of virus.
Specifically, in this work, published in the magazine Biochemical and Biophysical Research Communications, it has been determined which proteins and which structural protein fragments severe acute respiratory syndrome type 2 coronavirus (SARS-CoV-2) are recognized by immunoglobulins from COVID-19 patients that carry the infection, comparing them with people who have not had the infection.
A note from the hospital indicates that the virus infects the body as a viral particle, which is made up of several proteins called structural, a membrane and its genetic material, which is RNA.
Once it enters the cell, the viral RNA is capable of producing other proteins that facilitate the expansion of RNA within the cell and also the structural proteins to form new viruses.
There are defense mechanisms of infection in humans that recognize virus proteins as foreign bodies and help in the elimination of the virus.
This response is known as an immune response and immunoglobulins (or antibodies) produced by B lymphocytes play an important role in it, which specifically recognize foreign proteins and neutralize them.
In the work, a simple method was developed for the detection of specific antibodies in the serum of patients against structural proteins of the coronavirus.
Specifically the M proteins, located in the virus membrane, the N protein (or Nucleocapside) that is complexed to its genetic material and the S protein (from the English Spike or "peak" protein) that serves for the entry of the virus into the cells it infects.
In the work it was determined that the antibodies of COVID-19 patients mainly recognized the N protein, to a lesser extent the S protein and very little the M protein.
Antibodies against protein N corresponded against several areas of the protein since they were able to recognize fragments of the amino-terminal, carboxyl-terminal and central areas of protein N. In the case of protein S, the greatest reaction between patients COVID-19 occurred in a core zone of the protein.
According to the hospital, this research is relevant when it comes to detecting patients who have developed the infection, analyzing immunoglobulins against different viral proteins.
With the whole protein N, it is capable of detecting 80% of COVID-19 patients, in the case of protein S the result was that using the central fragment 55% of these patients were detected. Since protein S is important for viral infection, many of the current vaccines are based on the expression of this protein. The study suggests that a region within this protein is the most immunogenic and therefore could have relevance in the design of possible future vaccines.
The work was led by Raimundo freire, researcher at the HUC Research Unit, in collaboration with the Veronique Smits group and carried out by members of both research teams in particular, Esperanza Hernández, Cristina Paz, Elisa Cabrera, Juan Ramón Hernández, Yeray Hernández and David Gillespie.
In addition, they participated in the study Eduardo Salido, head of the Pathological Anatomy service and Miriam Hernandez, doctor of the Microbiology and Infection Control service of this hospital.
This research has been made possible by the funding of a project from the Fundación Canaria Instituto de Investigación Sanitaria de Canarias (FIISC) for Research on Covid-19 to Dr. Freire.