Which chemokines produced by keratinocytes are responsible for homing T cells to the skin?

The correct answer highlights CCL17 and CCL22 as the chemokines produced by keratinocytes that are essential for the homing of T cells to the skin. These chemokines play a significant role in guiding various subsets of T cells to inflammatory sites within the skin.

CCL17, also known as thymus and activation-regulated chemokine (TARC), primarily attracts CCR4-expressing T helper type 2 (Th2) cells and regulatory T cells (Tregs), promoting an adaptive immune response. CCL22, similarly, attracts naive T cells and is particularly involved in the migration of Tregs to sites of inflammation, which can contribute to maintaining skin homeostasis as well as modulating the immune response during allergic reactions or skin conditions.

The functions of these chemokines underscore their importance in skin immunity and inflammation. In understanding the immune response, it is essential to recognize that their role extends beyond mere attraction; they facilitate the localization of T cells that are crucial for both pathogenic and regulatory functions in the skin.

The other options, while they contain chemokines involved in various immune processes, do not specifically relate to skin homing in the same way that CCL17 and CCL22 do in the