Question

Which of the following cell types is infected by the human immunodeficiency virus-1?

• A. T-helper lymphocytes
• B. T-cytotoxic lymphocytes
• C. Plasma cells
• D. B-lymphocytes

Hint:

HIV attacks CD4+ T-helper cells → weakens immunity → hallmark of AIDS.

Answer 1

The Correct Option is A

Step 1: Identify target of HIV-1.
HIV specifically binds to CD4 receptors, which are highly expressed on T-helper lymphocytes (CD4+ cells).
Step 2: Mechanism.
Entry requires CD4 receptor plus co-receptors (CCR5 or CXCR4). The virus destroys T-helper cells, leading to immunodeficiency.
Step 3: Rule out other options.
- Cytotoxic T cells (CD8+) are not directly infected.
- Plasma cells and B-lymphocytes are not the primary targets.
Final Answer: \[ \boxed{\text{HIV infects CD4+ T-helper lymphocytes.}} \]