1. Hematology and Hemotherapy Center, UNICAMP, Campinas, SP, Rua Carlos Chagas, 480. 13083-878, Brazil
2. Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, Brazil
3. Department of Microbiology and Immunology, Emory University, School of Medicine, Atlanta, GA, USA