If an individual with a fully functional immune system receives an organ transplant, what explains the initiation of transplant rejection?

💡 Explanation

Transplant rejection begins when the recipient's T-cells recognize the transplanted organ's major histocompatibility complex (MHC) proteins (alloantigens) as foreign, triggering a cell-mediated immune response, because these alloantigens differ from the recipient's own. Therefore, T-cell recognition initiates the rejection process, rather than complement, antibodies, or uncontrolled cytokine release initiating widespread damage.

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