CD19 and tuberculosis: However, pre-coating (20 min) of both lymphocyte subsets with the respective AK constructs (anti-CD33 or anti-CD19, respectively; each with 1 μg/ml) allowed blocking of the TB-induced toxicity (1 μg/ml TBs) down to 0.3% for T cells and 10.2% for B cells after 4 h co-incubations (Figure 4B).