Abstrato

MicroRNA mediates CD8+ T cell dysfunction in chronic viral infection

Riyasat Ali*

Primary infections are generally cleared by antigen-specific effector T cells. As a result of clearance of primary infections, memory T cells are produced that are highly functional and provide a long-lasting protective immunity. In contrast, chronic viral infections often cause the development of dysfunctional T cells that respond to the antigen very poorly and are not sufficient to mount an efficient protective immune response. In case of chronic lymphocytic choriomeningitis virus (LCMV) infection in mice, some of the effector CD8+ T cells get exhausted while others are deleted. Thus, a persistently high level of antigens caused CD8+ T cells exhaustion or dysfunction. In case of chronic viral infection, the exhausted CD8+ T cells overexpress several inhibitory receptors and show altered expression of other genes involved in performing antiviral function efficiently.