Which cell surface marker identifies helper T cells?
Answer and explanation
Correct answer: D. CD4
- Step 1: Helper T cells carry CD4. Answer: CD4. Why not the others: CD8 marks cytotoxic T cells, CD19 B cells and CD56 natural killer cells.
Practise more Microbiology and Immunology.
Free questions with an explanation for every one, and full timed USMLE Step 1 mock tests.
More Microbiology and Immunology questions
- A 30-year-old woman has dysuria. Urinalysis shows nitrites and leukocyte esterase. Which organism is most common?
- A patient has an abscess with gram-positive cocci in clusters that are catalase and coagulase positive. Which organism is it?
- A man has a painless genital ulcer with a clean base. Which organism is the cause?
- Which immunoglobulin is the first made in a primary response?
- Which immunoglobulin crosses the placenta?
- A hiker has a bull's-eye rash and then facial palsy. Which organism is the cause?