Mycolic acids from Mycobacterium tuberculosis: purification by countercurrent distribution and T-cell stimulation

Bacterial cell wall lipids are recognized as immunostimulatory molecules wh ich make an important component of vaccines against bacterial diseases. Eve n mycolic acids, forming the waxy outer layer of the bacilli which cause tu berculosis, have been shown to stimulate human CD4/8 double negative T-cell s. The role of these cells in resistance to tuberculosis is currently still debated. In this work, a method is described to purify mycolic acids from bacterial crude extracts in a single step using countercurrent distribution . Mycolic acids obtained in this way approach 100% purity and stimulate bot h double negative and CD4 positive T-cells in peripheral blood leucocytes o btained from healthy human donors. Stimulation of CD4 cells by mycolic acid antigens has not been reported before, emphasizing the potential importanc e of mycolic acids in the context of the fight against tuberculosis.