Variable interactions of recipient killer cell immunoglobulin-like receptors with self and allogenic human leukocyte antigen class I ligands may influence the outcome of solid organ transplants.

PURPOSE OF REVIEW

The present review summarizes the diversity of killer cell immunoglobulin-like receptors and their complex interactions with self human leukocyte antigen class I molecules that control natural killer cell function. Further, a working model has been developed illustrating the potential impact of variable killer cell immunoglobulin-like receptor-human leukocyte antigen interactions on the outcome of solid organ transplants in view of current knowledge from basic and clinical research.

RECENT FINDINGS

In addition to restraining natural killer cell function, the interaction of inhibitory receptors with cognate human leukocyte antigen class I ligands has been recently shown to set the functional threshold for natural killer cells. Therefore, the number and type of inhibitory killer cell immunoglobulin-like receptor-human leukocyte antigen class I interactions in the recipient, as well as the type of human leukocyte antigen class I ligands expressed on the allograft, can determine the degree of natural killer cell alloreactivity and have potential impact in transplant outcome.

SUMMARY

Natural killer cells can respond to allografts. The strength of that response is likely determined by the number and type of inhibitory killer cell immunoglobulin-like receptor-human leukocyte antigen class I ligand combinations in the recipient. Understanding the interactions of these intrinsic immunogenetic factors in patients and donors could have important implications on solid organ transplantation.