CD28 and Chagas disease: CD8+ T lymphocytes play a crucial role during the acute and chronic phases of Chagas disease, and, considering that their activation may be dependent of CD80 and CD86 molecules performance (20, 45, 46), our next step was to evaluate the expression of the CD25, CD28, and CTLA-4 activation molecules in total CD8+ T lymphocytes after anti-CD80 or anti-CD86 antibody blockade of NI, IND, and CARD groups.