The role of complement in regulating the alloresponse.

PURPOSE OF REVIEW

This review emphasizes new information concerning the role of anaphylatoxins in the regulation of the immune response to allografts. Its timeliness relates the growing concept of the innate immune response as a regulator of the adaptive immune system and to how this concept lends itself to therapeutic advance.

RECENT FINDINGS

Recent work has extended our understanding of the role of local complement synthesis and how this facilitates the interaction between antigen-presenting cells and alloreactive T cells, resulting in a potent effector response. In particular, this work has identified new roles for anaphylatoxins as regulators of antigen presentation, T-cell proliferation and T-cell longevity.

SUMMARY

Strategies for comprehensive blockade of complement at the site of action, or for more selective blockade of specific complement components, are not only possible but merit further exploration based on these results.