TIGIT: ONE OF THE IMMUNE CONTROL PROTEINS IN VIRAL INFECTION

TIGIT: ONE OF THE IMMUNE CONTROL PROTEINS IN VIRAL INFECTION

June 3, 2020 0 By Mashid

In the context in which we find ourselves in terms of infections caused by viruses, we want to talk about the importance of certain proteins for the study and treatment of certain chronic diseases caused by a viral infection.

Chronic viral infections have a major impact on human health, and their effective treatment remains a major challenge today.

One of the most notable features of this type of chronic disease is that effector T cells enter a dysfunctional state, also known as T cell depletion.

In this sense, the immune control proteins in viral infection play a key role in regulating the responses of these T cells through two routes:

Improving the efficiency of T cells for virus removal.
To some extent inhibit the activity of T cells to prevent immunopathology.
To study this type of regulation, there are certain proteins such as PD-1, LAG-3 and TIGIT, which are expressed on the surface of cells that harbor chronic viruses and can be considered as a good study point.

TIGIT AS A REGULATOR OF THE IMMUNE RESPONSE
Specifically, TIGIT (T-cell immunoglobulin and ITIM domain) is a co-inhibitory receptor that limits both T-cell-driven inflammation and T-cell and NK-dependent anti-tumor immunity, thus serving as an important immune checkpoint .

Furthermore, TIGIT signaling is known to be functionally linked to the expression of IL-10 (interleukin 10), since it promotes its activation and its function. This interleukin works both in virus control and in maintaining tissue homeostasis. However, it is not known whether this protein directly affects this tissue balance or has on the spread of the virus.

TIGIT is expressed in regulatory T cells, NK cells, and activated T cells, and also binds two ligands CD155 (PVR) and CD112 (PVRL2 or Necl5). These ligands are expressed in antigen presenting cells (APCs) and tumor cells.

A study was conducted with a TIGIT anti-mouse antibody, which found that TIGIT blockade failed to promote viral clearance, but TIGIT stimulation has been found to remarkably protect mice from induced liver and lung immunopathology. from a viral infection.

In conclusion, this study sheds light on the protective role of TIGIT tissue in response to viral challenges.

This fact is important since, understanding and knowing the effects of immune control proteins on viral infection in order to regulate the balance between both aforementioned pathways, could lead to the development of new therapies to treat viral infections.