Identification, expression and subcellular localization of <i>Leishmania amazonensis</i> and <i>Leishmania infantum</i> Phospholipases A ₁

Abstract Leishmaniases remain a significant global public health threat, with Leishmania amazonensis and Leishmania infantum representing the etiological agents of the cutaneous and visceral forms in the Americas, respectively. Building on our previous identification of Phospholipase A 1 (PLA 1 ) in Leishmania braziliensis , this study provides a comprehensive molecular, immunological, and biochemical characterization of PLA 1 in L. amazonensis and L. infantum promastigotes. We analyzed PLA 1 activity and expression, purified the recombinant enzyme from L. amazonensis , and validated protein expression using a specific anti-PLA 1 serum. The major contribution of this research is the first description of the subcellular localization of a PLA 1 within the Leishmania genus. Moreover, our results reveal an unprecedented association between PLA 1 and lipid droplets within the parasites. This discovery is of particular interest as it provides the first evidence linking this enzyme to lipid storage organelles in Leishmania . Given that PLA 1 is an established virulence factor in other trypanosomatids, these findings suggest a specialized role for the enzyme in parasite lipid metabolism and potentially in its pathogenic mechanisms, opening new perspectives for understanding Leishmania biology.