To investigate the effect of M. tuberculosis H37Rv strain infection on the DC phenotype, the expression of the intracellular adhesion molecule (ICAM 1 and CD54), co-stimulatory surface molecules (B7-1 (CD80), B7-2 (CD86) and CD40) and MHC II by immature, H37Rv infected and LPS stimulated DC were assessed using 18 experiments from different subjects by flow cytometry. The gene discussed is CD40; the disease is infection.