Traditionally, the recognition and tolerance of transplanted grafts has been considered to be
within the realm of the adaptive immune system. Innate immunity, on the other hand, as the
first line of host defense, plays a role in fighting against invading microorganisms. Recently,
with the discovery of the Toll-like receptors (TLRs), the role of innate immune responses in
the control of adaptive immunity has become a new area of interest. Emerging evidence
suggests that in addition to responding to pathogen-associated molecular patterns of …