LEISHMANIA-DONOVANI LIPOPHOSPHOGLYCAN (LPG) INHIBITS RESPIRATORY BURST AND CHEMOTAXIS OF DOG PHAGOCYTES

Lipophosphoglycan (LPG) is the major glycoconjugate of Leishmania prom astigote surface membrane. Previous studies on human and murine models have demonstrated that this molecule is involved in the attachment an d survival of Leishmania in the host cells. Dog is the main reservoir of Leishmania strains responsible for human leishmaniasis in Italy. Si nce no studies have been performed on the LPG-canine phagocyte interac tions, we investigated the LPG effects on dog phagocyte functions by e valuating: 1) the chemotactic activity of peripheral monocytes and pol ymorphonuclear (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 emp hasizing the ability of this molecule to impair also the canine phagoc yte responses.