Analysis of gene expression in pathogens and investigation of host-pathogen interactions are a critical step in fueling new drug and vaccine discovery projects. In this study, we focus on the protozoan parasite Leishmania major, the causative agent of human cutaneous leishmaniasis. While significant progress has been made over the past 20 years toward understanding the molecular and cellular basis for intracellular survival of Leishmania, we still lack information regarding the biology of intracellular amastigotes. In particular, little is known about gene expression in the parasite prior to and following phago-lysosomal fusion and the genes required to facilitate adaptation to, and survival within, the host cell. Furthermore, genes that are uniquely activated and expressed in the human macrophage, in the context the infection, have not been systematically determined. The recent emergence of next-generation sequencing technologies opens up unprecedented opportunities to gain an in-depth view of the transcriptome of L. major and the macrophage in the context of infection. The goal of this study is to obtain the first comprehensive transcriptome profiling data for the three main developmental stages of L.
major (Aim 1) and to simultaneously analyze gene expression programs in the intracellular amastigote stage of L. major along with the trancriptional response of the infected human host cell, the macrophage (Aim 2). These studies should provide insight into host defense mechanisms initiated by macrophages and lead to a better understanding of what the macrophage """"""""sees"""""""" on the parasite as it is being ingested. To further examine the interactions between the parasite and the human macrophage, we will identify a subset of important Leishmania-human protein-protein interaction (PPI) partners using well-established yeast two-hybrid screens (Aim 3). Very few experimental studies have investigated host-pathogen PPIs. Extending those to the intracellular parasite Leishmania will not only allow the identification PPIs that enable this parasite to infect its host cells, acquire nutrients and evade its immune defenses, but will also provide a more global functional view of pathogenesis in general. In summary, this study will provide the first massive-scale and simultaneous interrogation of the transcriptomes of an intracellular protozoan parasite and its macrophage host cell and will provide a first look at the infectome, the part of a host cell's genome and proteome that is important for infection by a pathogen as well as the part of the pathogen's genome/proteome that allows it to subvert the functions of some host cell receptors, signaling proteins and molecular machinery. .

Public Health Relevance

Protozoan parasites of the genus Leishmania afflict millions of people worldwide and pathologies range from mild cutaneous, self-healing lesions to fatal visceral disease. The proposed study aims to use new DNA sequencing technologies to identify genes in the mammalian-infective Leishmania stages on a genome-wide scale. Interactions between parasite and human proteins will be investigated, and results from this work will provide novel insights into Leishmania pathogenesis and guide efforts toward effective prevention or control of Leishmaniasis.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI094773-04
Application #
8717560
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Joy, Deirdre A
Project Start
2011-09-01
Project End
2015-08-31
Budget Start
2014-09-01
Budget End
2015-08-31
Support Year
4
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of Maryland College Park
Department
Biostatistics & Other Math Sci
Type
Schools of Arts and Sciences
DUNS #
City
College Park
State
MD
Country
United States
Zip Code
20742
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Geis-Asteggiante, LucĂ­a; Belew, Ashton T; Clements, Virginia K et al. (2018) Differential Content of Proteins, mRNAs, and miRNAs Suggests that MDSC and Their Exosomes May Mediate Distinct Immune Suppressive Functions. J Proteome Res 17:486-498
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Fernandes, Maria Cecilia; Dillon, Laura A L; Belew, Ashton Trey et al. (2016) Dual Transcriptome Profiling of Leishmania-Infected Human Macrophages Reveals Distinct Reprogramming Signatures. MBio 7:
Christensen, Stephen M; Dillon, Laura A L; Carvalho, Lucas P et al. (2016) Meta-transcriptome Profiling of the Human-Leishmania braziliensis Cutaneous Lesion. PLoS Negl Trop Dis 10:e0004992
Valdes, Kayla M; Sundar, Ganesh S; Vega, Luis A et al. (2016) The fruRBA Operon Is Necessary for Group A Streptococcal Growth in Fructose and for Resistance to Neutrophil Killing during Growth in Whole Human Blood. Infect Immun 84:1016-1031
Dillon, Laura A L; Suresh, Rahul; Okrah, Kwame et al. (2015) Simultaneous transcriptional profiling of Leishmania major and its murine macrophage host cell reveals insights into host-pathogen interactions. BMC Genomics 16:1108

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