T-Lymphocyte Migration and Function

Steps:

• Recall T-lymphocytes are adaptive immune cells that mature in the thymus and circulate in blood and lymph.
• Identify their key ability to extravasate from blood vessels into tissues during immune responses.
• Evaluate each option against T-cell properties: circulation, migration, antigen recognition, and cytokine secretion.
• Select the option accurately describing their behavior at inflammation sites.

Why B is correct:

• T-lymphocytes express adhesion molecules allowing them to adhere to endothelium and migrate into inflamed tissues, as per leukocyte extravasation process.

Why the others are wrong:

• A: T-lymphocytes reside in lymphoid organs too and produce varied cytokines, not just inflammatory ones.
• C: T-lymphocytes require antigen presentation by APCs to activate and secrete cytokines, not direct bacterial exposure.
• D: T-lymphocytes recognize presented antigens but do not present them; that's dendritic cell function.

Final answer: B