SBA — Single Best Answer · Review
Question 614
Immunology → General
Classification
Question
SSBAQuestion Header
Which combination correctly identifies important opsonins that enhance phagocytosis?
Question Stem
Select the single best answer.
Options
A
CD2 and CD3
B
CD16 and CD56
C
MHC class I and MHC class II
D
C3b and the Fc portion of IgG1/IgG3
E
CD19 and CR2
Explanation
Opsonisation enhances phagocytosis. C3b acts as an opsonin and phagocytes possess receptors for it. Immunoglobulin, particularly the Fc portion of IgG1 and IgG3, also acts as a potent opsonin.
Option Validity
A) CD2 and CD3 are T-cell-associated molecules rather than the opsonins identified here.
B) CD16 and CD56 characterise natural killer cells rather than this opsonin combination.
C) MHC class I and II molecules are involved in immune recognition, not identified here as opsonins.
E) CD19 and CR2 are B-cell-associated markers/receptors rather than this opsonin combination.
Further Reading
Saxena MRCOG-1 Basic Sciences — Immunology: Opsonisation, printed page 211.