ABSTRACT
Prophylactic vaccination against tuberculosis (TB) with a live attenuated strain of Mycobacterium bovis bacille Calmette-Guérin (BCG) has been used worldwide. However, TB remains one of the most significant diseases of humans and animals. Better understanding of the mechanisms of human immunity to mycobacteria is essential for the development of new vaccines and the estimation of their efficacy. In this study we determined the levels of known humoral mediators of mycobacterial phagocytosis, i.e. mannose-binding lectin (MBL), soluble CD14 (sCD14), antibodies of the immunoglobulin G (IgG) class against mycobacterial purified protein derivative (PPD), and mycobacterial Hsp65 antigen, in the sera from healthy young volunteers vaccinated with BCG and presenting positive and negative Mantoux responses to PPD. Then we asked the question as to whether macrophages and polymorphonuclear leukocytes (PMNs) from the individuals with positive tuberculin test (TT(+)) and negative tuberculin test (TT(-)) differed in their ability to ingest mycobacteria. We also looked for a relationship between the intensity of mycobacterial ingestion by phagocytes in a medium of autologous sera containing different concentrations of MBL, sCD14 and anti-mycobacterial IgG. We found no significant differences between the investigated parameters for TT(+) and TT(-) volunteers. Our result suggest that the ability of macrophages and PMNs to ingest mycobacteria depends on an individual, intrinsic capacity of the phagocytes.
