Human lymph node development: An inflammatory interaction.

In the developing human fetus, lymph nodes and Peyer's patches are formed during the first and second trimester of pregnancy. The cells responsible for this process, lymphoid tissue inducer (LTi) cells, share a number of characteristics with Natural Killer (NK) cells and produce cytokines related to inflammation. Here I will discuss recent advances in our understanding of human lymph node development, in particular the characterization of LTi cells and the relationship of these innate lymphocytes to conventional NK cells.