Dr. Garcia's laboratory studies the structural and functional basis of receptor/ligand interactions in systems which are relevant to human health and disease. Their investigations are aimed at understanding the molecular recognition properties governing the interactions of receptors with their ligands, and the subsequent molecular events which couple ligand recognition to receptor activation. Many of the systems they are studying in the laboratory are related to the interaction of the host with the environment. The structural studies are complemented by functional approaches using molecular biology and protein engineering to dissect the structural information, design new or altered proteins with modified specificities and activities, and ultimately contribute to the development of proteins or molecules with therapeutic potential. Molecules currently under study include receptors of the immune system involved in autoimmune disorders (T cell receptors, co-receptors, MHC, cytokines), proteins involved in host-pathogen interactions and molecular mimicry (CMV and Toxoplasma surface antigens), proteins of nervous system (peptide hormone receptors, neural guidance proteins), and membrane proteins (chemokine receptors). An emerging focus of their research is to develop, using combinatorial biology approaches, novel ligands for receptors, which may have altered activities, that may serve as therapeutic starting points.