HIV primarily infects and depletes which immune cell type, leading to immunosuppression?

Human Immunodeficiency Virus (HIV) preferentially infects CD4+ T-helper lymphocytes by binding to the CD4 receptor (primary receptor) and CCR5 or CXCR4 (co-receptors) on the cell surface. HIV uses reverse transcriptase to integrate its RNA genome into host cell DNA, establishing a persistent infection. Progressive depletion of CD4+ T-helper cells impairs the coordination of both humoral and cell-mediated immune responses. A CD4+ count below 200 cells/μL defines AIDS (Acquired Immunodeficiency Syndrome). In dental practice, the CD4 count guides risk assessment: patients with CD4 < 200 have increased risk for oral candidiasis, hairy leukoplakia, Kaposi's sarcoma, and other AIDS-defining conditions.