The human immunodeficiency virus (hiv) infects helper t cells. What is the role of these cells?

Cellular immunity. These are cells that work as part of the cellular immune system, fighting certain fungal (e.g. Cryptococcus), viral (e.g. Herpesviruses), parastic (e.g. Toxoplasma), and bacterial (e.g. Tuberulosis) infections. The cellular immune system also helps to prevent certain cancers, such as lymphomas.