HIV tropism — The HIV virus primarily infects which cell population in humans?

Introduction:Human immunodeficiency virus (HIV) causes progressive immune deficiency by targeting key immune cells. Recognizing the primary cellular targets explains both pathogenesis and clinical vulnerability to opportunistic infections.

Given Data / Assumptions:

• HIV entry requires CD4 along with coreceptors such as CCR5 or CXCR4.
• CD4 is expressed on helper T cells and subsets of macrophages and dendritic cells.
• RBCs lack nuclei and CD4, making them non-permissive for HIV infection.

Concept / Approach:Match viral receptor usage (CD4 plus coreceptors) to host cell types to identify the primary infected populations that drive immunodeficiency.

Step-by-Step Solution:

Verification / Alternative check:Clinical monitoring of HIV focuses on CD4 T-cell counts and viral load; antiretroviral therapy restores CD4 levels by suppressing replication in these cell types.

Why Other Options Are Wrong:

Common Pitfalls:Assuming any cell can be infected; overlooking receptor/coreceptor requirements for viral entry.

Final Answer:Cells of the immune system (CD4 T cells, macrophages, dendritic cells).