Inhibitory effect of deferoxamine or macrophage activation on transformation of Paracoccidioides brasiliensis conidia ingested by macrophages: reversal by holotransferrin.
Conidia of P. brasiliensis ingested by murine macrophages at 37 degrees C showed enhanced transformation to yeast cells and further intracellular growth compared with conidia in culture medium alone. Treatment of macrophages with the iron chelator deferoxamine inhibited the intracellular conidium-to-yeast transformation. Cytokine-activated macrophages could also exert this inhibitory effect. Holotransferrin reversed the inhibitory effect of either deferoxamine or activated macrophages on intracellular conidium-to-yeast transformation. These results indicate that iron restriction is one of the mechanisms by which activated macrophages control the intracellular transformation of ingested conidia and growth of yeast cells.
Cano
L E
LE
Corporacion para Investigaciones Biologicas, Hospital Pablo Tobon Uribe, Medellin, Colombia.
Gomez
B
B
Brummer
E
E
Restrepo
A
A
Stevens
D A
DA
D000818:Animals; D003676:Deferoxamine / Q000494:pharmacology*; D007501:Iron / Q000502:physiology*; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010228:Paracoccidioides / Q000254:growth & development*; D011990:Receptors, Transferrin / Q000502:physiology; D014168:Transferrin / Q000494:pharmacology*
D011990:Receptors, Transferrin; D014168:Transferrin; D007501:Iron; D003676:Deferoxamine