Potentially interesting substances are also brought to lymph nodes and the spleen by dendritic cells. Dendritic cells act as messengers between innate and adaptive immunity. Their job is presenting antigens. Dendritic cells uptake various possible protein antigens and process them into peptides (protein fragments) on their surface.
There are 2 pathways that dendritic cells use to present antigens to T cells: one for CD4 (helper) T cells, and one for CD8 (killer) T cells.
Dendritic cells are part of the mammalian immune system. Dendritic cells are present in tissues exposed to the outside, such as skin, nose, lungs, stomach, and intestines. Once activated by pattern recognition receptors, dendritic cells migrate to the lymph nodes, bearing bad tidings.