Pattern of cytokine and chemokine production by THP-1 derived macrophages in response to live or heat-killed Mycobacterium bovis bacillus Calmette-Guérin Moreau strain

Tuberculosis has great public health impact with high rates of mortality and the only prophylactic measure for it is the Mycobacterium bovisbacillus Calmette-Guérin (BCG) vaccine. The present study evaluated the release of cytokines [interleukin (IL)-1, tumour necrosis factor and IL-6] and chemokines [macrophage inflammatory protein (MIP)-1α and MIP-1β] by THP-1 derived macrophages infected with BCG vaccine obtained by growing mycobacteria in Viscondessa de Moraes Institute medium medium (oral) or Sauton medium (intradermic) to compare the effects of live and heat-killed (HK) mycobacteria. Because BCG has been reported to lose viability during the lyophilisation process and during storage, we examined whether exposing BCG to different temperatures also triggers differences in the expression of some important cytokines and chemokines of the immune response. Interestingly, we observed that HK mycobacteria stimulated cytokine and chemokine production in a different pattern from that observed with live mycobacteria.

Oral bacillus Calmette-Guérin vaccine against tuberculosis: why not?

The bacillus Calmette-Guérin (BCG) vaccine is the only licensed vaccine for human use against tuberculosis (TB). Although controversy exists about its efficacy, the BCG vaccine is able to protect newborns and children against disseminated forms of TB, but fails to protect adults against active forms of TB. In the last few years, interest in the mucosal delivery route for the vaccine has been increasing owing to its increased capacity to induce protective immune responses both in the mucosal and the systemic immune compartments. Here, we show the importance of this route of vaccination in newly developed vaccines, especially for vaccines against TB.