Dendritic cells (DCs) are best known for their roles in host resistance and immunogenicity. DCs provide a direct link between innate and adaptive immunity. After antigen capture and processing, DCs control the differentiation and polarization of T cells. However, there is a danger during the antigen presentation because, at the same time DCs are capturing microbial antigens and also dying self cells and environmental proteins, to which the immune system must not respond. There is good evidence that immature DCs, in the absence of infection and inflammation, induce immunological tolerance to innocuous self antigens, avoiding then a non-appropriate response to harmless antigens that may be presented subsequently when infection strikes.