CD4 and type 2 diabetes mellitus: This further suggests that CD4+ T lymphocytes are not the single most important component of cell-mediated immunity, which, at least in the context of acute TB and T2D, comes from the fact that BCGΔBCG1419c promoted an increased ratio of T CD8+/CD4+ lymphocytes (Fig. 3); yet, lung pathology and M. tuberculosis load in lungs were close when compared with levels reached after BCG immunization (Fig. 2).