∞ generated and posted on 2016.01.21 ∞
Key sites of development of adaptive immune responses, found in numerous, discrete locations throughout the body and that filter the drainage from body interstitium.
Specifically, lymph vessels drain through lymph nodes which are a crucial location of activation of T helper cells, i.e., where interaction with MHC class II occurs. Important to this functioning is the flow into lymph nodes of whatever foreign material is found in lymph, which can then be phagocytized by antigen presenting cells which in turn can activate helper t cells.
Because lymph vessels both drain tissues and represent points of constriction in that drainage, metastacizing cancer cells can become lodged within lymph nodes, resulting in the formation of secondary tumors within those lymph nodes.