CD4 and infection: However, at day 63 after the infection, the tetramer-bound CD4 T cells increased to almost 0.2% of CD4 T cells in blood, and 0.3% in lymphocytes from spleens and lymph nodes and lungs (Fig. 4a), indicating significant increases in relative numbers of P65-specific CD4 T cells after pulmonary M. tuberculosis infection of the Mamu-DRB*W201+ monkeys (*, p<0.05, (Fig. 4a).