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Shaw S, Cohn IS, Baptista RP, Xia G, Melillo B, Agyabeng-Dadzie F, Kissinger JC, Striepen B. Genetic crosses within and between species of Cryptosporidium. Proc Natl Acad Sci U S A 2024; 121:e2313210120. [PMID: 38147547 PMCID: PMC10769859 DOI: 10.1073/pnas.2313210120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 11/12/2023] [Indexed: 12/28/2023] Open
Abstract
Parasites and their hosts are engaged in reciprocal coevolution that balances competing mechanisms of virulence, resistance, and evasion. This often leads to host specificity, but genomic reassortment between different strains can enable parasites to jump host barriers and conquer new niches. In the apicomplexan parasite Cryptosporidium, genetic exchange has been hypothesized to play a prominent role in adaptation to humans. The sexual lifecycle of the parasite provides a potential mechanism for such exchange; however, the boundaries of Cryptosporidium sex are currently undefined. To explore this experimentally, we established a model for genetic crosses. Drug resistance was engineered using a mutated phenylalanyl tRNA synthetase gene and marking strains with this and the previously used Neo transgene enabled selection of recombinant progeny. This is highly efficient, and genomic recombination is evident and can be continuously monitored in real time by drug resistance, flow cytometry, and PCR mapping. Using this approach, multiple loci can now be modified with ease. We demonstrate that essential genes can be ablated by crossing a Cre recombinase driver strain with floxed strains. We further find that genetic crosses are also feasible between species. Crossing Cryptosporidium parvum, a parasite of cattle and humans, and Cryptosporidium tyzzeri a mouse parasite resulted in progeny with a recombinant genome derived from both species that continues to vigorously replicate sexually. These experiments have important fundamental and translational implications for the evolution of Cryptosporidium and open the door to reverse- and forward-genetic analysis of parasite biology and host specificity.
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Affiliation(s)
- Sebastian Shaw
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Ian S. Cohn
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA19104
| | - Rodrigo P. Baptista
- Department of Medicine, Houston Methodist Research Institute, Houston, TX77030
| | - Guoqin Xia
- Department of Chemistry, Scripps Research, La Jolla, CA92037
| | - Bruno Melillo
- Department of Chemistry, Scripps Research, La Jolla, CA92037
- Chemical Biology and Therapeutics Science Program, Broad Institute, Cambridge, MA02142
| | | | - Jessica C. Kissinger
- Department of Genetics, University of Georgia, Athens, GA30602
- Center for Tropical and Emerging Global Diseases and Institute of Bioinformatics, University of Georgia, Athens, GA30602
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA19104
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Pardy RD, Walzer KA, Wallbank BA, Byerly JH, O’Dea KM, Cohn IS, Haskins BE, Roncaioli JL, Smith EJ, Buenconsejo GY, Striepen B, Hunter CA. Analysis of intestinal epithelial cell responses to Cryptosporidium highlights the temporal effects of IFN-γ on parasite restriction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.14.567008. [PMID: 38014210 PMCID: PMC10680692 DOI: 10.1101/2023.11.14.567008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The production of IFN-γ is crucial for control of multiple enteric infections, but its impact on intestinal epithelial cells (IEC) is not well understood. Cryptosporidium parasites exclusively infect epithelial cells and the ability of interferons to activate the transcription factor STAT1 in IEC is required for parasite clearance. The use of single cell RNA sequencing to profile IEC during infection revealed induction of IFN-γ-dependent gene signatures that was comparable between uninfected and infected cells, and IEC expression of the IFN-γ receptor was required for parasite control. Unexpectedly, treatment of Ifng-/- mice with IFN-γ demonstrated the IEC response to this cytokine correlates with a delayed reduction in parasite burden but did not affect parasite development. These data sets provide insight into the impact of IFN-γ on IEC and suggest a model in which IFN-γ-mediated bystander activation of uninfected enterocytes is important for control of Cryptosporidium.
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Affiliation(s)
- Ryan D. Pardy
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Katelyn A. Walzer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bethan A. Wallbank
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jessica H. Byerly
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Keenan M. O’Dea
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ian S. Cohn
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Breanne E. Haskins
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Justin L. Roncaioli
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Eleanor J. Smith
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gracyn Y. Buenconsejo
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Christopher A. Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Cohn IS, Wallbank BA, Haskins BE, O’Dea KM, Pardy RD, Shaw S, Merolle MI, Gullicksrud JA, Christian DA, Striepen B, Hunter CA. Intestinal cDC1s provide IL-12 dependent and independent functions required for CD4 + T cell-mediated resistance to Cryptosporidium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.11.566669. [PMID: 38014026 PMCID: PMC10680586 DOI: 10.1101/2023.11.11.566669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Cryptosporidium is an enteric pathogen that is a prominent cause of diarrheal disease. Control of this infection requires CD4+ T cells, though the processes that lead to T cell-mediated resistance have been difficult to assess. Here, Cryptosporidium parasites that express MHCII-restricted model antigens were generated to dissect the early events that influence CD4+ T cell priming and effector function. These studies highlight that parasite-specific CD4+ T cells are primed in the draining mesenteric lymph node (mesLN) and differentiate into Th1 cells in the gut, where they mediate IFN-γ-dependent control of the infection. Although type 1 conventional dendritic cells (cDC1s) were not required for initial priming of CD4+ T cells, cDC1s were required for CD4+ T cell expansion and gut homing. cDC1s were also a major source of IL-12 that was not required for priming but promoted full differentiation of CD4+ T cells and local production of IFN-γ. Together, these studies reveal distinct roles for cDC1s in shaping CD4+ T cell responses to enteric infection: first to drive early expansion in the mesLN and second to drive effector responses in the gut.
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Affiliation(s)
- Ian S. Cohn
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bethan A. Wallbank
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Breanne E. Haskins
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Keenan M. O’Dea
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ryan D. Pardy
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sebastian Shaw
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Maria I. Merolle
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jodi A. Gullicksrud
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David A. Christian
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Boris Striepen
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Christopher A. Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
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