Fig. 1.

The activation of lymphocytes results in a vicious cycle. Persistent chronic overactivation of CD4⁺ T lymphocytes and CD8⁺ T lymphocytes after HIV infection, with significantly elevated levels of CD38 expression, which may predispose CD4⁺ T cells to HIV infection and further promote HIV replication, and as CD4⁺ T lymphocytes are depleted, the disease continues to progress, forming a cycle