# Phospholipid metabolism in Leishmania

> **NIH NIH R15** · TEXAS TECH UNIVERSITY · 2024 · $498,722

## Abstract

Leishmania parasites alternate between extracellular promastigotes in sandfly midgut and intracellular
amastigotes in mammals. These protozoan parasites cause significant morbidity and mortality due to the lack
of a vaccine, limitations of vector control, and inadequacy of drugs. The long-term goal of this project is to
elucidate the roles of lipid metabolism in Leishmania survival and infection. Understanding how parasites
acquire essential lipids from the mammalian host will shed new light into Leishmania-host interaction and the
findings may lead to novel drug targets and drug candidates. The previous funding period focused on how
Leishmania parasites generate phosphatidylethanolamine (PE) including plasmalogen PE and diacyl PE. A key
finding is that the enzyme ethanolamine-phosphate cytidylyltransferase (EPCT) is essential for both the
promastigotes and amastigotes of Leishmania major. EPCT is required for the de novo synthesis of PE via the
Kennedy pathway. The essentiality of EPCT in the pathogenic amastigote stage is likely due to the high
demand of plasmalogen PE in amastigotes, and the lack of plasmalogen PE scavenging from the mammalian
host. Another important finding from the previous funding period is that intracellular amastigotes contain an
unusually high level of lysophosphatidylcholine (lyso PC) which has only one fatty acyl chain on the glycerol
backbone. In most eukaryotes, lyso PC is a minor lipid component with signaling roles in several processes
including intracellular calcium homeostasis, cell migration, inflammation, and apoptosis. Lyso PC also
possesses membrane permeabilization activity and promotes positive membrane curvature due to its inverted
cone shape. The objective of the next funding period is to determine how Leishmania amastigotes
acquire lyso PC and elucidate its functions. Based on our understanding of Leishmania lipid metabolism,
we hypothesize that amastigotes acquire lyso PC by hydrolyzing host PC with a parasite-derived
phospholipase A2 (PLA2) and efficient lyso PC production is required for their intracellular proliferation. Two
specific aims will be pursued concurrently to test this hypothesis. Aim 1 will characterize the molecular
machinery involved in lyso PC metabolism in L. major amastigote using molecular biology approaches. Aim 2
will explore the origin and impact of amastigote lyso PC on Leishmania-macrophage interactions. These
proposed studies are designed based on published and unpublished work from the previous funding period
and are well within the research team’s area of expertise. Successful completion of these aims will lead to new
insight into the interaction between Leishmania amastigotes and mammalian host. The findings will also help
identify novel drug targets on lyso PC metabolism and understand the mechanism of action for miltefosine, a
non-hydrolysable lyso PC analog and the only oral drug to treat leishmaniasis. Finally, the renewal application
will allow us to continue expanding...

## Key facts

- **NIH application ID:** 10974778
- **Project number:** 2R15AI156746-02
- **Recipient organization:** TEXAS TECH UNIVERSITY
- **Principal Investigator:** Kai Zhang
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $498,722
- **Award type:** 2
- **Project period:** 2021-09-01 → 2027-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10974778

## Citation

> US National Institutes of Health, RePORTER application 10974778, Phospholipid metabolism in Leishmania (2R15AI156746-02). Retrieved via MORVS 2026-10-27 from https://api.morvs.ai/grant/nih/10974778. Licensed CC0.

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