Weekly newsletter:
November 16-22 2020
Level difficulty:
COVID-19 not only weakens the body but also the production of antibodies by over-stimulating inflammation.
Currently, the main aim is the development of a vaccine against COVID-19. Its development is mostly based on the establishment of an immune response, that would provide long lasting and effective protection against any possible infection, by the COVID-19 virus.
The aim is to activate the two main ways of immune response, to fight infections. On one hand, it mobilizes CD8+T lymphocytes which are able to recognize and destroy infected cells. On the other hand, it causes the production of neutralizing antibodies through the B lymphocytes. These are able to interact with the virus and most of all, prevent it from infecting a target cell.
How do our cells produce antibodies? This involves a series of operations, like successive gears in a machine, and all of these are essential. If one of them is missing, then the product of the machine is harmed, and our body can no longer defend itself.
In this case, to produce our antibodies, this machine does not need too much TNF-alpha, the pro-inflammatory cytokine. This isn’t an anti-body, but it can interfere with their production if it is overdosed. However, when the disease breaks out in a severe form, and one requires many antibodies, it turns out that we have too much TNF-alpha, and this comes in the way of the process.
Let’s try to understand the exact role of this molecule.
Here is an explanatory diagram:
During an infection, structures known as germinal centers form on a transitional basis, to allow the production of antibodies. Some B cells proliferate and mature by interacting with specific T cells, known as follicles. B lymphocytes then differ into memory cells or antibody-producing cells.
A study carried out by Kaneko and colleagues on post-mortem tissue from people who died due to COVID-19 found an increase in TNF-alpha, which blocks the differentiation of follicle T cells in germinal centers. This can only harm the production of antibodies, which ones requires in order to fight the virus.
The authors suggest that blocking TNF-alpha in severe cases of COVID-19 may not only prevent the excessive inflammation perceived in COVID-19 infections, but also restore antibody production within germinal centers.
