Project description:Cryptosporidium lacks tools that can identify the targets of emerging compounds that have been developed against this parasite. Thermal proteomic profiling is an unbiased approach that fulfils this unmet need by detecting changes in the thermal stability of target proteins upon the binding of their inhibitor. This technique has been successfully used in other protozoan parasites and here we report the validation and first use of thermal proteome profiling in Cryptosporidium.
Project description:Cryptosporidium parvum is one of the most important opportunistic enteric parasites, causing severe diarrhea in immunocomprised human and animals. However, few effective control agents were available for this parasite. circular RNA (circRNA) was discovered to play key roles in many diseases, and the well-known regulatory mechanism for circRNAs is that act as miRNA sponges competitively binding to miRNAs to block miRNA-mRNA interaction. Here, using microarray assay, we investigated the expression profiles of circRNAs in HCT-8 cells after the infection of C. parvum IId subtype, the prevalent subtype of China. A total of 178 circRNAs were dysregulated expressed in HCT-8 cells at 24 h post infection (pi) of C. parvum IId subtype.
Project description:Cryptosporidium parvum is one of the most important opportunistic enteric parasites, causing severe diarrhea in immunocomprised human and animals. However, few effective control agents were available for this parasite. Long non-coding RNA (lncRNA) was discovered to play key roles in many diseases through regulating the gene expression. Here, using microarray assay, we investigated the expression profiles of mRNA and lncRNA in HCT-8 cells after the infection of C. parvum IId subtype, the prevalent subtype of China. A total of 821 lncRNAs and 1,349 mRNAs were dysregulated expressed in HCT-8 cells at 24 h post infection (pi) of C. parvum IId subtype. Of them, all five types of lncRNAs were identified, including 302 of sense, 280 of antisense, 312 of intergenic, 44 of divergent, and 33 of intronic lncRNAs. Ten lncRNAs and ten mRNAs randomly selected were successfully confirmed the microarray results. The co-expression and target prediction analysis indicated 27 of mRNAs cis-regulated by 29 lncRNAs and 109 of coding genes trans-regulated by 114 lncRNAs. These predicted targets were enriched in pathways involved in the interaction between host and C. parvum, eg. hedgehog signaling pathway, Wnt signaling pathway and tight junction, suggesting that these aberrantly lncRNAs would play important regulating roles during infection of C. parvum IId subtype.
Project description:It has been reported that Cryptosporidium parvum, a species of a protozoan frequently isolated from humans and animals, is able to induce digestive adenocarcinoma in a rodent model. Consistently, some epidemiological studies have reported an association with cryptosporidiosis in patients with colorectal adenocarcinoma. However, the correlation between cryptosporidiosis and human digestive cancer remains unclear at this time, and it is not known whether this intracellular parasite, considered an opportunistic agent, is able to induce gastrointestinal malignancies in humans. In order to add new arguments for a probable association between cryptosporidiosis and digestive human cancer, the main aim of this study is to determine prevalence and to identify species of Cryptosporidium among a French digestive cancer population.
Project description:Purpose: Transcriptome profiling of Crytosporidium parvum infected lung and small intestinal organoids was performed to access the response of epithelial cells upon parasitic infection and to do a temporal analysis of the transcriptome of the parasite inside the organoid lumen. We isolated RNA from infected human lung and small intestinal organoids at 24 and 72 hour post infection. Methods: Organoids were grown in expansion or differentiation media and microinjected with equal amounts of Cryptosporidium oocysts. Media-injected organoids were used as a control .Expanding SI organoids were microinjected at 5-6 days after seeding, differentiated SI organoids were injected at 5 days after inducing differentiation. Lung organoids were incubated for 2 weeks after seeding for microinjection. RNA was extracted from 1-2 matrigel drops containing organoids. RNA was converted to cDNA and libraries were prepared using the CelSeq2 method and sequenced. Samples were sequenced on Illumina NextSeq500 by using 75-bp paired-end sequencing. Methods: Paired-end reads from Illumina sequencing were aligned to the human transcriptome genome and C. parvum transcriptome genome (Iowa strain) by BWA. DeSeq (v1.18.0) was used for read normalization and differential expression analysis (p-value adjustment 0.05 by method Benjamini-Hochberg). Gene set enrichment analysis (GSEA) was performed using gene lists for type I interferon response and regulation against normalized RNA-seq reads of injected SI and lung organoids using GSEA software v3.0 beta2. Results: At 24 hr post-infection,GO (gene ontology)-term analysis revealed that a substantial number of genes related to ‘cytoskeleton’ and ‘cell mobility’ were up-regulated in lung organoids. This suggests that infection by the parasites and subsequent formation of the intracellular stages within 24 hrs might affects cytoskeleton structures of host cells. After 72 hrs, many genes associated with the type I interferon pathway increased dramatically in lung and intestinal organoids. Results: After 72 hrs, many genes associated with the type I interferon pathway increased dramatically in lung and intestinal organoids. Multiple C. parvum genes were differentially expressed with a large fold change between 24 and 72 hr post-injection.At 24 hr post-infection, most of the enriched genes represented ribosomal proteins and ribosomal RNA subunits in both intestinal organoids and lung organoids. By contrast, at 72 hr post-infection, multiple oocyst-wall protein genes were up-regulated, confirming that the parasites formed new oocysts within the organoids. Conclusions: RNA sequencing of injected organoids revealed host epithelial responses upon parasite infection in differentiated SI organoids as well as in lung organoids.Upregulation of genes associated with type I interferon immunity in both SI and lung organoids.
Project description:BackgroundHundreds of millions of people are infected with cryptosporidiosis annually, with immunocompromised individuals suffering debilitating symptoms and children in socioeconomically challenged regions at risk of repeated infections. There is currently no effective drug available. In order to facilitate the pursuit of anti-cryptosporidiosis targets and compounds, our study spans the classification of the Cryptosporidium parvum kinome and the structural and biochemical characterization of representatives from the CDPK family and a MAP kinase.ResultsThe C. parvum kinome comprises over 70 members, some of which may be promising drug targets. These C. parvum protein kinases include members in the AGC, Atypical, CaMK, CK1, CMGC, and TKL groups; however, almost 35% could only be classified as OPK (other protein kinases). In addition, about 25% of the kinases identified did not have any known orthologues outside of Cryptosporidium spp. Comparison of specific kinases with their Plasmodium falciparum and Toxoplasma gondii orthologues revealed some distinct characteristics within the C. parvum kinome, including potential targets and opportunities for drug design. Structural and biochemical analysis of 4 representatives of the CaMK group and a MAP kinase confirms features that may be exploited in inhibitor design. Indeed, screening CpCDPK1 against a library of kinase inhibitors yielded a set of the pyrazolopyrimidine derivatives (PP1-derivatives) with IC₅₀ values of < 10 nM. The binding of a PP1-derivative is further described by an inhibitor-bound crystal structure of CpCDPK1. In addition, structural analysis of CpCDPK4 identified an unprecedented Zn-finger within the CDPK kinase domain that may have implications for its regulation.ConclusionsIdentification and comparison of the C. parvum protein kinases against other parasitic kinases shows how orthologue- and family-based research can be used to facilitate characterization of promising drug targets and the search for new drugs.
Project description:The apicomplexan parasite Cryptosporidium is a leading global cause of severe diarrheal disease and an important contributor to early childhood mortality. Currently there are no fully effective treatments or vaccines available. Transmission of the disease occurs through ingestion of oocysts, through direct contact or contaminated water or food. Oocysts are meiotic spores and the product of parasite sex. Cryptosporidium has a single host lifecycle where both asexual and sexual processes unfold in the intestine of infected hosts. Here we use the new-found ability to genetically engineer Cryptosporidium to make life cycle progression and parasite sex tractable. We derive reporter strains to follow parasite development in culture and infected mice and define the genes that orchestrate sex and oocyst formation through mRNA sequencing of sorted cells. After two days, parasites in cell culture show pronounced sexualization, but productive fertilization does not occur and infection falters. In contrast in infected mice, male gametes successfully fertilize females, leading to meiotic division and sporulation. To rigorously test for fertilization, we devised a two-component genetic crossing assay employing a Cre recombinase activated reporter. Our findings suggest obligate developmental progression towards sex in Cryptosporidium, which has important implications for the treatment and prevention of the infection.
Project description:Cryptosporidiosis in an enteric infection caused by Cryptosporidium parasites and is a major cause of acute infant diarrhea in the developing world. A major bottleneck to research progress is the lack of methods to cryopreserve Cryptosporidium oocysts, thus requiring routine propagation in laboratory animals. Here, we report a method to cryopreserve C. parvum oocysts by ultra-fast cooling. Cryopreserved oocysts exhibit high viability and robust in vitro excystation, and are infectious to interferon-? knockout mice. The course of the infection is comparable to what we observe with unfrozen oocysts. Oocyst viability and infectivity is not visibly changed after several weeks of cryogenic storage. Cryopreservation will facilitate the sharing of oocysts from well-characterized isolates and transgenic strains among different laboratories.