1. From the Department of Medicine (R.P.-G., K.W., L.C., M.A.M., and R.F.), University of Virginia, Charlottesville; the Department of Medicine (J.J.F.), Washington University, St Louis Mo; the Department of Biochemistry and Molecular Genetics (A.R.L.G.), University of Virginia, Charlottesville; and La Jolla Institute for Allergy and Immunology (J.L.), La Jolla, Calif.