1. Department of Microbiology and Immunology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, U.S.A.
2. Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, and Sealy Center for Vaccine Development, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, U.S.A.
3. Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555, U.S.A.