# Functional analysis of insect-specific adhesion in a model kinetoplastid

> **NIH NIH R21** · UNIVERSITY OF PENNSYLVANIA · 2020 · $257,643

## Abstract

SUMMARY
Kinetoplastid parasites are single-celled eukaryotic parasites, some of which are causative agents of
devastating human diseases, including Chagas disease, Leishmaniasis, and human African
trypanosomiasis. Pathogenic kinetoplastids are transmitted by insect vectors. These parasite-vector
relationships are specific, with different insect species harboring different species of parasite. While the
life cycles of kinetoplastid parasites in their respective insect hosts can differ, one shared feature is
adherence of the parasite to insect tissue. The adhesive stage is necessary for colonization of the
insect, and in some cases allows for development of infectious forms. For all kinetoplastids, the
adhesion itself has shared ultrastructural features, and resembles a hemidesmosome. The molecular
components of this adhesive structure, and the signaling pathways that trigger its formation, are
completely unknown. Crithidia fasciculata is a parasite that only infects one host, the mosquito. It is
generally not considered to be a human pathogen; however, there have been reports of human
infections, typically in immunocompromised patients or in co-infections with Leishmania spp.
C. fasciculata has for years been used as a model for exploring the basic biology of kinetoplastid
parasites. They represent a powerful system to investigate mechanisms of adhesion since they will
adhere not only to the hindgut of their mosquito host, but to artificial substrates such as tissue culture
plastic. This allows us to use in vitro assays to determine the role of various candidate proteins and
pathways in the process of adhesion. In addition, we can observe the stages of the adhesion process in
real time using live-cell imaging.
We hypothesize that the adhesive stage of the parasite is a distinct developmental form, and that
differentiation to this form is mediated by specific signal transduction pathways. In addition, we predict
that adhesion is a multi-stage process involving novel proteins. We will address these hypotheses
through the following Specific Aims: (1) Determine the role of the cyclic AMP signaling pathway in
regulating adhesion, and (2) Establish conditions for rapid creation of genetic knock-outs in C.
fasciculata using CRISPR/Cas9. This project builds upon our published work using RNAseq to compare
gene expression profiles of adherent and swimming cells, and will set the stage for a high-throughput
approach to determine the role of a large number of candidate proteins in adhesion in vitro, which can
then be evaluated in vivo for their ability to colonize mosquitoes. The outcomes of the proposed work
will be improved tools for genetic manipulation of C. fasciculata, which will benefit researchers using
this model, and insight into shared mechanisms for adhesion of diverse kinetoplastid species to their
insect hosts.

## Key facts

- **NIH application ID:** 10041522
- **Project number:** 1R21AI154022-01
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Megan Lindsay Povelones
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $257,643
- **Award type:** 1
- **Project period:** 2020-06-01 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10041522

## Citation

> US National Institutes of Health, RePORTER application 10041522, Functional analysis of insect-specific adhesion in a model kinetoplastid (1R21AI154022-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10041522. Licensed CC0.

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