Carol  Gilchrist
Degree(s): PhD
Graduate School: Univ of Western Ontario
Primary Appointment: Assistant Professor, Medicine, Infectious Diseases and International Health
Research Interests:
My long-term goal is to identify the genetic program required to cause amebic colitis. My studies have focused on defining factors that control virulence and the outcome of infection.
Email Address: cg2p@Virginia.EDU

Research Description

Entamoeba histolytica, the causative agent of amebiasis, is prevalent in areas of poor sanitation. For example, E. histolytica infection was detected in 80% of the children from an urban slum in Dhaka, Bangladesh (40% per annum). The consequences of a new E. histolytica infection are unpredictable. Not only does disease occur in only a minority of infections (20%), but an initially asymptomatic infection can result in future invasive disease (~12.5%). Patients can present with liver abscess years after travel to an endemic area. While human genetics, environmental conditions, and parasite genotype influence the infection outcome, these factors don’t account for the majority of differential susceptibility. Only a ~two fold increase in E. histolytica infections occurred in malnourished children, or children lacking the protective HLA class II DQB1*0601 allele. It is remains puzzling why only some infections with E. histolytica result in disease. The variable outcome of infection and latent period between colonization and disease suggests that adaption of the parasite to the host via altered gene expression could contribute to the virulent phenotype. In this application we will focus on the hypothesis that parasite regulation of virulence factor gene expression is responsible for the switch from asymptomatic colonization to invasive disease. The transcription factor URE3-BP is known to regulate the expression of two known amebic virulence genes, the Gal/GalNAc adherence lectin and ferredoxin. Over-expression of a dominant positive version of the URE3-BP protein alters the expression of a subset of genes and produces a more a virulent phenotype. Understanding the broader role of this regulatory factor in virulence will help define the genetic program that is required for invasion of the host, identify new biomarkers of disease progression, and lead to a better understanding of the parasite factors that contribute to invasive disease.


Selected Publications
  • Carol A Gilchrist, Ellyn S. Moore, Yan Zhang, Christina B. Bousquet, Joanne A. Lannigan , Barbara J. Mann, and William A Petri Jr Regulation of Virulence of Entamoeba histolytica by the URE3-BP Transcription Factor. mBio (in press).
  • Heriberto Moreno, Alicia S. Linford, Carol A. Gilchrist, and William A. Petri Jr. Phospholipid-binding protein EhC2A mediates calcium-dependent translocation of transcription factor URE3-BP to the plasma membrane of Entamoeba histolytica. Eukaryot Cell. 2009 [Epub ahead of print]. PMC Journal - In Process.
  • Carol A Gilchrist, Duza J. Baba, Yan Zhang, Oswald Crasta, Clive Evans, Elisabet Caler, Bruno W. S. Sobral, Christina B. Bousquet, Megan Leo, Ameilia Hochreiter, Sarah K Connell, Barbara J Mann, and William A. Petri Jr. Targets of the E. histolytica transcription factor URE3-BP PLoS Neglected Tropical Diseases 2:e282, (2008) PMCID: PMC2565699.
  • Carol A Gilchrist, Eric Houpt, Nino Trapaidze, Zhangjun Fei, Oswald Crasta, Amon Asgharpour, Clive Evans, Susan Martino-Catt, Duza J. Baba, Suzanne Stroup, Shinjiro Hamano, Gretchen Ehrenkaufer, Mami Okada, Upinder Singh, Tomoyoshi Nozaki, Barbara J. Mann, and William A. Petri, Jr. Impact of intestinal colonization and invasion on the Entamoeba histolytica transcriptome Mol Biochem Parasitol. (2006) Jun;147(2):163-76. Epub 2006 Mar 7 PMID: 16569449.
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