[1] Univ Tennessee, Coll Vet Med, Dept Pathobiol, Knoxville, TN 37996 USA
[2] Scripps Res Inst, Dept Immunol, La Jolla, CA 92037 USA
[3] Univ Tennessee, Ctr Hlth Sci, Dept Pharmaceut Sci, Memphis, TN 38163 USA
[4] Univ Tennessee, Ctr Hlth Sci, Dept Physiol, Memphis, TN 38163 USA