The fungal strain Paracoccidioides brasiliensis
remains viable inside of epithelial cells and can induce apoptosis
in this population. However, until now, the molecules that participate in this process remained unknown. Thus, this
study evaluated the contribution of two P. brasiliensis
molecules, the 14-3-3 and glycoprotein of 43 kDa proteins,
which had been previously described as extracellular matrix adhesins and apoptosis inductors in human pneumocytes.
Accordingly, epithelial cells were treated with these molecules for different periods of time and the expression
of the apoptosis regulating-proteins Bak, Bax, Bcl-2, p53 and caspases were evaluated by terminal deoxynucleotidyl
transferase dUTP nick end labelling, flow cytometry and real-time polymerase chain reaction analysis. Our results
demonstrated that treatment with these molecules induces apoptosis signalling in pulmonary epithelial cells, showing
the same pattern of programmed cell-death as that observed during infection with P. brasiliensis
. Thus, we could
conclude that P. brasiliensis
uses these molecules as virulence factors that participate not only in the fungal adhesion
process to host cells, but also in other important cellular mechanisms such as apoptosis.