Leishmania donovani lipophosphoglycan (LPG) inhibits respiratory burst and chemotaxis of dog phagocytes.

Lipophosphoglycan (LPG) is the major glycoconjugate of Leishmania promastigote surface membrane. Previous studies on human and murine models have demonstrated that this molecule is involved in the attachment and survival of Leishmania in the host cells. Dog is the main reservoir of Leishmania strains responsible for human leishmaniasis in Italy. Since no studies have been performed on the LPG-canine phagocyte interactions, we investigated the LPG effects on dog phagocyte functions by evaluating: 1) the chemotactic activity of peripheral monocytes and polymorphonuclear (PMN) cells, in terms of cellular polarization; 2) the PMN cell respiratory burst, by measuring superoxide anion and hydrogen peroxide production. Results demonstrated a significant reduction of metabolic and chemotactic activity in LPG-preincubated cells, thus emphasizing the ability of this molecule to impair also the canine phagocyte responses.