1
|
Gao J, Wu XJ, Zheng XN, Li TT, Kou YJ, Wang XC, Wang M, Zhu XQ. Functional Characterization of Eight Zinc Finger Motif-Containing Proteins in Toxoplasma gondii Type I RH Strain Using the CRISPR-Cas9 System. Pathogens 2023; 12:1232. [PMID: 37887748 PMCID: PMC10609756 DOI: 10.3390/pathogens12101232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/03/2023] [Accepted: 10/06/2023] [Indexed: 10/28/2023] Open
Abstract
The Zinc finger protein (ZFP) family is widely distributed in eukaryotes and interacts with DNA, RNA, and various proteins to participate in many molecular processes. In the present study, the biological functions of eight ZFP genes in the lytic cycle and the pathogenicity of Toxoplasma gondii were examined using the CRISPR-Cas9 system. Immunofluorescence showed that four ZFPs (RH248270-HA, RH255310-HA, RH309200-HA, and RH236640-HA) were localized in the cytoplasm, and one ZFP (RH273150-HA) was located in the nucleus, while the expression level of RH285190-HA, RH260870-HA, and RH248450-HA was undetectable. No significant differences were detected between seven RHΔzfp strains (RHΔ285190, RHΔ248270, RHΔ260870, RHΔ255310, RHΔ309200, RHΔ248450, and RHΔ236640) and the wild-type (WT) strain in the T. gondii lytic cycle, including plaque formation, invasion, intracellular replication, and egress, as well as in vitro virulence (p > 0.05). However, the RHΔ273150 strain exhibited significantly lower replication efficiency compared to the other seven RHΔzfp strains and the WT strain, while in vivo virulence in mice was not significantly affected. Comparative expression analysis of the eight zfp genes indicates that certain genes may have essential functions in the sexual reproductive stage of T. gondii. Taken together, these findings expand our current understanding of the roles of ZFPs in T. gondii.
Collapse
Affiliation(s)
- Jin Gao
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong 030801, China; (J.G.); (X.-J.W.); (X.-N.Z.); (Y.-J.K.)
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (T.-T.L.); (X.-C.W.)
| | - Xiao-Jing Wu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong 030801, China; (J.G.); (X.-J.W.); (X.-N.Z.); (Y.-J.K.)
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (T.-T.L.); (X.-C.W.)
| | - Xiao-Nan Zheng
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong 030801, China; (J.G.); (X.-J.W.); (X.-N.Z.); (Y.-J.K.)
| | - Ting-Ting Li
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (T.-T.L.); (X.-C.W.)
| | - Yong-Jie Kou
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong 030801, China; (J.G.); (X.-J.W.); (X.-N.Z.); (Y.-J.K.)
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (T.-T.L.); (X.-C.W.)
| | - Xin-Cheng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (T.-T.L.); (X.-C.W.)
| | - Meng Wang
- State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China; (T.-T.L.); (X.-C.W.)
| | - Xing-Quan Zhu
- Laboratory of Parasitic Diseases, College of Veterinary Medicine, Shanxi Agricultural University, Taigu, Jinzhong 030801, China; (J.G.); (X.-J.W.); (X.-N.Z.); (Y.-J.K.)
- Key Laboratory of Veterinary Public Health of Higher Education of Yunnan Province, College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
| |
Collapse
|
2
|
Functional Characterization of 15 Novel Dense Granule Proteins in Toxoplasma gondii Using the CRISPR-Cas9 System. Microbiol Spectr 2023; 11:e0307822. [PMID: 36515555 PMCID: PMC9927372 DOI: 10.1128/spectrum.03078-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The analysis of the subcellular localization and function of dense granule proteins (GRAs) is of central importance for the understanding of host-parasite interaction and pathogenesis of Toxoplasma gondii infection. Here, we identified 15 novel GRAs and used C-terminal endogenous gene tagging to determine their localization at the intravacuolar network (IVN), parasitophorous vacuole (PV), or PV membrane (PVM) in the tachyzoites and at the periphery of the bradyzoites-containing cysts. The functions of the 15 gra genes were examined in type I RH strain and 5 of these gra genes were also evaluated in the cyst-forming type II Pru strain. The 15 novel gra genes were successfully disrupted by using CRISPR-Cas9 mediated homologous recombination and the results showed that 13 gra genes were not individually essential for T. gondii replication in vitro or virulence in mice during acute and chronic infection. Intriguingly, deletion of TGME49_266410 and TGME49_315910 in both RH and Pru strains decreased the parasite replication in vitro and attenuated its virulence, and also reduced the cyst-forming ability of the Pru strain in mice during chronic infection. Comparison of the transcriptomic profiles of the 15 gra genes suggests that they may play roles in other life cycle stages and genotypes of T. gondii. Taken together, our findings improve the understanding of T. gondii pathogenesis and demonstrate the involvement of two novel GRAs, TGME49_266410 and TGME49_315910, in the parasite replication and virulence. IMPORTANCE Dense granule proteins (GRAs) play important roles in Toxoplasma gondii pathogenicity. However, the functions of many putative GRAs have not been elucidated. Here, we found that 15 novel GRAs are secreted into intravacuolar network (IVN), parasitophorous vacuole (PV), or PV membrane (PVM) in tachyzoites and are located at the periphery of the bradyzoite-containing cysts. TGME49_266410 and TGME49_315910 were crucial to the growth of RH and Pru strains in vitro. Deletion of TGME49_266410 and TGME49_315910 attenuated the parasite virulence in mice. However, disruption of other 13 gra genes did not have a significant impact on the proliferation and pathogenicity of T. gondii in vitro or in vivo. The marked effects of the two novel GRAs (TGME49_266410 and TGME49_315910) on the in vitro growth and virulence of T. gondii are notable and warrant further elucidation of the temporal and spatial dynamics of translocation of these two novel GRAs and how do they interfere with host cell functions.
Collapse
|
3
|
Ma Z, Li Z, Jiang R, Li X, Yan K, Zhang N, Lu B, Huang Y, Dibo N, Wu X. Virulence-related gene wx2 of Toxoplasma gondii regulated host immune response via classic pyroptosis pathway. Parasit Vectors 2022; 15:454. [PMID: 36471417 PMCID: PMC9724370 DOI: 10.1186/s13071-022-05502-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/16/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Toxoplasma gondii is known as the most successful parasite, which can regulate the host immune response through a variety of ways to achieve immune escape. We previously reported that a novel gene wx2 of T. gondii may be a virulence-related molecule. The objective of this study was to explore the mechanism of wx2 regulating host immune response. METHODS The wx2 knockout strain (RHwx2-/- strain) and complementary strain (RHwx2+/+ strain) were constructed by the CRISPR/Cas9 technique, and the virulence of the wx2 gene was detected and changes in pyroptosis-related molecules were observed. RESULTS Compared with the wild RH and RHwx2+/+ strain groups, the survival time for mice infected with the RHwx2-/- strain was prolonged to a certain extent. The mRNA levels of pyroptosis-related molecules of caspase-1, NLRP3, and GSDMD and et al. in mouse lymphocytes in vivo and RAW267.4 cells in vitro infected with RHwx2-/- strain increased to different degrees, compared with infected with wild RH strain and RHwx2+/+ strain. As with the mRNA level, the protein level of caspase-1, caspase-1 p20, IL-1β, NLRP3, GSDMD-FL, GSDMD-N, and phosphorylation level of NF-κB (p65) were also significantly increased. These data suggest that wx2 may regulate the host immune response through the pyroptosis pathway. In infected RAW264.7 cells at 48 h post-infection, the levels of Th1-type cytokines of IFN-γ, Th2-type cytokines such as IL-13, Th17-type cytokine of IL-17 in cells infected with RHwx2-/- were significantly higher than those of RH and RHwx2+/+ strains, suggesting that the wx2 may inhibit the host's immune response. CONCLUSION wx2 is a virulence related gene of T. gondii, and may be involved in host immune regulation by inhibiting the pyroptosis pathway.
Collapse
Affiliation(s)
- Zhenrong Ma
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Zhuolin Li
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Ruolan Jiang
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China ,grid.284723.80000 0000 8877 7471School of Public Health, Southern Medical University, Guangzhou, China
| | - Xuanwu Li
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Kang Yan
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Ni Zhang
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Bin Lu
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Yehong Huang
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Nouhoum Dibo
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Xiang Wu
- grid.216417.70000 0001 0379 7164Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China ,Hunan Provincial Key Lab of Immunology and Transmission Control On Schistosomiasis, Changsha, China
| |
Collapse
|
4
|
Live-attenuated ME49Δcdpk3 strain of Toxoplasma gondii protects against acute and chronic toxoplasmosis. NPJ Vaccines 2022; 7:98. [PMID: 35986017 PMCID: PMC9391373 DOI: 10.1038/s41541-022-00518-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/20/2022] [Indexed: 11/09/2022] Open
Abstract
Toxoplasmosis, a common parasitic disease, is caused by Toxoplasma gondii, which infects approximately 30% of the world’s population. This obligate intracellular protozoan causes significant economic losses and poses serious public health challenges worldwide. However, the development of an effective toxoplasmosis vaccine in humans remains a challenge to date. In this study, we observed that the knockout of calcium-dependent protein kinase 3 (CDPK3) in the type II ME49 strain greatly attenuated virulence in mice and significantly reduced cyst formation. Hence, we evaluated the protective immunity of ME49Δcdpk3 as a live attenuated vaccine against toxoplasmosis. Our results showed that ME49Δcdpk3 vaccination triggered a strong immune response marked by significantly elevated proinflammatory cytokine levels, such as IFN-γ, IL-12, and TNF-α, and increased the percentage of CD4+ and CD8+ T-lymphocytes. The high level of Toxoplasma-specific IgG was maintained, with mixed IgG1/IgG2a levels. Mice vaccinated with ME49Δcdpk3 were efficiently protected against the tachyzoites of a variety of wild-type strains, including type I RH, type II ME49, Chinese 1 WH3 and Chinese 1 WH6, as well as the cysts of wild-type strains ME49 and WH6. These data demonstrated that ME49Δcdpk3 inoculation induced effective cellular and humoral immune responses against acute and chronic Toxoplasma infections with various strains and was a potential candidate to develop a vaccine against toxoplasmosis.
Collapse
|
5
|
CRISPR-Cas Technology: Emerging Applications in Clinical Microbiology and Infectious Diseases. Pharmaceuticals (Basel) 2021; 14:ph14111171. [PMID: 34832953 PMCID: PMC8625472 DOI: 10.3390/ph14111171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 11/06/2021] [Accepted: 11/09/2021] [Indexed: 12/26/2022] Open
Abstract
Through the years, many promising tools for gene editing have been developed including zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), CRISPR-associated protein 9 (Cas9), and homing endonucleases (HEs). These novel technologies are now leading new scientific advancements and practical applications at an inimitable speed. While most work has been performed in eukaryotes, CRISPR systems also enable tools to understand and engineer bacteria. The increase in the number of multi-drug resistant strains highlights a necessity for more innovative approaches to the diagnosis and treatment of infections. CRISPR has given scientists a glimmer of hope in this area that can provide a novel tool to fight against antimicrobial resistance. This system can provide useful information about the functions of genes and aid us to find potential targets for antimicrobials. This paper discusses the emerging use of CRISPR-Cas systems in the fields of clinical microbiology and infectious diseases with a particular emphasis on future prospects.
Collapse
|
6
|
Characterization of functions in parasite growth and virulence of four Toxoplasma gondii genes involved in lipid synthesis by CRISPR-Cas9 system. Parasitol Res 2021; 120:3749-3759. [PMID: 34499198 DOI: 10.1007/s00436-021-07308-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 08/29/2021] [Indexed: 10/20/2022]
Abstract
Fatty acid uptake is extremely important for the survival and growth of the intracellular parasite Toxoplasma gondii. In this study, CRISPR-Cas9 gene editing technology was used to investigate the role of four lipid synthesis enzymes, namely, glycerol-3-phosphate dehydrogenase (G3PDH), malonyl CoA-acyl carrier protein transacylase (FabD), acyl-ACP thiolesterase (TE), and diacylglycerol acyltransferase (DGAT), in the virulence and infectivity of Type I RH and Type II Prugniaud (Pru) strains of T. gondii. Immunofluorescence analysis of the tachyzoite stage showed that FabD protein was located in the apicoplast; however, the expression level of the other three proteins was undetectable. Compared with wild-type (WT) strains, the growth of RHΔG3PDH, RHΔTE, and RHΔDGAT in vitro and their virulence in vivo were not significantly different. However, RHΔFabD exhibited a significantly reduced growth rate, compared with the WT strain. The deletion of FabD attenuated the virulence of Type II Pru strain and reduced the formation of cysts in vivo. These data improved our understanding of the role of lipid synthesis enzymes in the pathogenesis of T. gondii.
Collapse
|
7
|
Liu Q, Jiang W, Chen Y, Zhang M, Geng X, Wang Q. Study on Circulating Antigens in Serum of Mice With Experimental Acute Toxoplasmosis. Front Microbiol 2021; 11:612252. [PMID: 33537014 PMCID: PMC7848078 DOI: 10.3389/fmicb.2020.612252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/23/2020] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is a ubiquitous apicomplexan protozoan parasite that can infect all warm-blooded animals, causing toxoplasmosis. Thus, efficient diagnosis methods for acute T. gondii infection are essential for its management. Circulating antigens (CAgs) are reliable diagnostic indicators of acute infection. In this study, we established a mouse model of acute T. gondii infection and explored new potential diagnostic factors. CAgs levels peaked 60 h after T. gondii inoculation and 31 CAgs were identified by immunoprecipitation-liquid chromatography-tandem mass spectrometry, among which RuvB-like helicase (TgRuvBL1), ribonuclease (TgRNaseH1), and ribosomal protein RPS2 (TgRPS2) were selected for prokaryotic expression. Polyclonal antibodies against these three proteins were prepared. Results from indirect enzyme-linked immunosorbent assay indicated that anti-rTgRuvBL1, anti-rTgRNase H1, and anti-rTgRPS2 mouse sera were recognized by natural excretory-secretory antigens from T. gondii tachyzoites. Moreover, immunofluorescence assays revealed that TgRuvBL1 was localized in the nucleus, while TgRNase H1 and TgRPS2 were in the apical end. Western blotting data confirmed the presence of the three proteins in the sera of the infected mice. Moreover, mice immunized with rTgRuvBL1 (10.0 ± 0.30 days), TgRNaseH1 (9.67 ± 0.14 days), or rTgRPS2 (11.5 ± 0.34 days) had slightly longer lifespan when challenged with a virulent T. gondii RH strain. Altogether, these findings indicate that these three proteins can potentially be diagnostic candidates for acute toxoplasmosis. However, they hold poor protective potential against highly virulent T. gondii infection.
Collapse
Affiliation(s)
- Qi Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Wei Jiang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yun Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Manyu Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiaoling Geng
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Quan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| |
Collapse
|
8
|
Zhang ZW, Li TT, Wang JL, Liang QL, Zhang HS, Sun LX, Zhu XQ. Functional Characterization of Two Thioredoxin Proteins of Toxoplasma gondii Using the CRISPR-Cas9 System. Front Vet Sci 2021; 7:614759. [PMID: 33521087 PMCID: PMC7841047 DOI: 10.3389/fvets.2020.614759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/16/2020] [Indexed: 01/01/2023] Open
Abstract
Toxoplasmosis caused by infection with Toxoplasma gondii is an important parasitic zoonosis with a worldwide distribution. In this study, we examined the functions of two thioredoxins (namely CTrp26 and CTrx1) of T. gondii tachyzoites by generation of HA tag strains or gene deficient parasites in Type I RH strain (ToxoDB#10). Immunofluorescence analysis (IFA) was used to investigate the subcellular localization of the thioredoxins (Trxs). Results of IFA showed that both CTrp26 and CTrx1 were located in the cytoplasm of T. gondii. Functional characterizations of CTrp26 and CTrx1-deficient parasites were performed by plaque assay, intracellular replication, egress, H2O2 resistance, detection of reactive oxygen species (ROS) level and total antioxidant capacity (T-AOC) assays in vitro, as well as mouse infection in vivo. Our results showed that deletion of CTrp26 or CTrx1 did not influence the ability of T. gondii RH strain to replicate, egress, form plaque, resist H2O2 exposure, maintain the ROS level, and T-AOC, and also did not serve as virulence factors in Kunming mice. Taken together, these results provide new properties of the two Trxs. Although they are not essential for RH strain, they may have roles in other strains of this parasite due to their different expression patterns, which warrants future research.
Collapse
Affiliation(s)
- Zhi-Wei Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hai-Sheng Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Li-Xiu Sun
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China.,Key Laboratory of Veterinary Public Health of Higher Education of Yunnan Province, College of Veterinary Medicine, Yunnan Agricultural University, Kunming, China
| |
Collapse
|
9
|
Zhang Q, Shao Q, Guo Y, Li N, Li Y, Su J, Xu R, Zhang Z, Xiao L, Feng Y. Characterization of Three Calcium-Dependent Protein Kinases of Cryptosporidium parvum. Front Microbiol 2021; 11:622203. [PMID: 33510735 PMCID: PMC7835281 DOI: 10.3389/fmicb.2020.622203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/14/2020] [Indexed: 12/02/2022] Open
Abstract
In Cryptosporidium spp., calcium-dependent protein kinases (CDPKs) are considered promising targets for the development of pharmaceutical interventions. Whole-genome sequencing has revealed the presence of 11 CDPKs in Cryptosporidium parvum (CpCDPKs). In this study, we expressed recombinant CpCDPK4, CpCDPK5, and CpCDPK6 in Escherichia coli. The biological characteristics and functions of these CpCDPKs were examined by using quantitative reverse transcription PCR (qRT-PCR), immunofluorescence microscopy, and an in vitro neutralization assay. The expression of the CpCDPK4 gene peaked at 12 h post-infection, the CpCDPK5 gene peaked at 12 and 48 h, and the CpCDPK6 gene peaked at 2–6 h. CpCDPK4 protein was located in the anterior and mid-anterior regions of sporozoites, and CpCDPK5 protein was located over the entire sporozoites, while CpCDPK6 protein was expressed in a spotty pattern. Immune sera of CpCDPK4 and CpCDPK6 exhibited significant inhibitory effects on host cell invasion, while the immune sera of CpCDPK5 had no effects. These differences in protein localization, gene expressions, and neutralizing capacities indicated that the CpCDPK proteins may have different roles during the lifecycle of Cryptosporidium spp.
Collapse
Affiliation(s)
- Qiang Zhang
- State Key Laboratory of Bioreactor Engineering, School of Resource and Environmental, East China University of Science and Technology, Shanghai, China
| | - Qian Shao
- State Key Laboratory of Bioreactor Engineering, School of Resource and Environmental, East China University of Science and Technology, Shanghai, China
| | - Yaqiong Guo
- Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Na Li
- Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yu Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jiayuan Su
- State Key Laboratory of Bioreactor Engineering, School of Resource and Environmental, East China University of Science and Technology, Shanghai, China
| | - Rui Xu
- State Key Laboratory of Bioreactor Engineering, School of Resource and Environmental, East China University of Science and Technology, Shanghai, China
| | - Ziding Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Lihua Xiao
- Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Yaoyu Feng
- State Key Laboratory of Bioreactor Engineering, School of Resource and Environmental, East China University of Science and Technology, Shanghai, China.,Center for Emerging and Zoonotic Diseases, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| |
Collapse
|
10
|
Li TT, Wang JL, Liang QL, Sun LX, Zhang HS, Zhang ZW, Zhu XQ, Elsheikha HM. Effect of deletion of gra17 and gra23 genes on the growth, virulence, and immunogenicity of type II Toxoplasma gondii. Parasitol Res 2020; 119:2907-2916. [PMID: 32686022 DOI: 10.1007/s00436-020-06815-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022]
Abstract
The protozoan parasite Toxoplasma gondii secretes a number of dense granule proteins (GRAs) from the dense granule organelle to manipulate the host cell. Two of these effector proteins (GRA17 and GRA23) are involved in the trafficking of molecules between the parasitophorous vacuole (PV) and the host cell cytoplasm. However, their roles in establishing chronic infection remain obscured. In this study, CRISPR-Cas9 was used to delete gra17 or gra23 gene in T. gondii Pru strain (type II). The growth, the virulence, the ability to establish chronic infection, and the immunogenicity of the constructed mutant strains were investigated in Kunming mice. Pru:Δgra17 and Pru:Δgra23 mutants developed PVs with abnormal morphology and exhibited reduced growth rate, compared with the wild-type Pru strain. Deletion of gra17 abrogated acute infection and blocked cyst formation. Although the deletion of gra23 caused slight attenuation of the parasite virulence in mice, it caused a significant reduction in cyst formation. Immunization with Pru:Δgra17 induced high levels of IgG (IgG1 and IgG2a) antibodies and cytokines (interleukin-2 [IL-2], IL-10, IL-12, and interferon gamma [IFN-γ]), which conferred significant protection in mice challenged with virulent type I (RH), ToxoDB#9 (PYS) strains, or less virulent type II (Pru) strain of T. gondii. These findings show that GRA17 and GRA23 play important roles in T. gondii chronic infection and that irreversible deletion of gra17 in T. gondii type II Pru strain can be a viable option for stimulating protective immunity to T. gondii infection.
Collapse
Affiliation(s)
- Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China.
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China
| | - Li-Xiu Sun
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China
| | - Hai-Sheng Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China
| | - Zhi-Wei Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, Gansu Province, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, LE12 5RD, UK.
| |
Collapse
|
11
|
Ma Z, Yan K, Jiang R, Guan J, Yang L, Huang Y, Lu B, Li X, Zhang J, Chang Y, Wu X. A Novel wx2 Gene of Toxoplasma gondii Inhibits the Parasitic Invasion and Proliferation in vitro and Attenuates Virulence in vivo via Immune Response Modulation. Front Microbiol 2020; 11:399. [PMID: 32318029 PMCID: PMC7154108 DOI: 10.3389/fmicb.2020.00399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 02/26/2020] [Indexed: 11/25/2022] Open
Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular apicomplexan protozoan that can parasitize most warm-blooded animals and cause severe diseases in immunocompromised individuals or fetal abnormalities in pregnant woman. The treatment of toxoplamosis has been limited by effective drugs. Our previous work indicated that the novel gene wx2 of T. gondii may serve as a vaccine antigen candidate. To further investigate the molecular functions of wx2 in highly virulent T. gondii (RH strain), a wx2 gene deletion mutant RH strain (KO-wx2) was established using CRISPR-Cas9. The phynotype of KO-wx2 was analyzed by plaque, invasion, and replication assays in vitro as well as in vivo virulence assays. The results indicated that the targeted deletion of the wx2 gene significantly inhibited in vitro parasite growth and replication in the host cells as well as attenuated parasite virulence in the mouse model. Notably, the percentage of pro-inflammatory factors of interferon gamma (IFN-γ) and interlukin-17A (IL-17A) and anti-inflammatory factor of interlukin-10 (IL-10) in the lymph nodes were upregulated in mice infected with the KO-wx2 strain. Our data suggested that the wx2 gene plays an important role in the process of the parasite’s life cycle and virulence in mice. In addition, it also plays an important role in the host’s immunity reaction, mainly via Th1 and Th17 cellular immunity, not Th2.
Collapse
Affiliation(s)
- Zhenrong Ma
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Kang Yan
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Ruolan Jiang
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Jie Guan
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Linfei Yang
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Yehong Huang
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Bin Lu
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Xuanwu Li
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Jie Zhang
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| | - Yunfeng Chang
- Department of Forensic Medicine Science, Central South University, Changsha, China
| | - Xiang Wu
- Department of Parasitology, Xiangya School of Basic Medicine, Central South University, Changsha, China
| |
Collapse
|
12
|
Wang JL, Bai MJ, Elsheikha HM, Liang QL, Li TT, Cao XZ, Zhu XQ. Novel roles of dense granule protein 12 (GRA12) in Toxoplasma gondii infection. FASEB J 2020; 34:3165-3178. [PMID: 31908049 DOI: 10.1096/fj.201901416rr] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 12/18/2019] [Accepted: 12/19/2019] [Indexed: 01/09/2023]
Abstract
Dense granule protein 12 (GRA12) is implicated in a range of processes related to the establishment of Toxoplasma gondii infection, such as the formation of the intravacuolar network (IVN) within the parasitophorous vacuole (PV). This protein is also thought to be important for T. gondii-host interaction, pathogenesis, and immune evasion, but their exact roles remain unknown. In this study, the contributions of GRA12 to the molecular pathogenesis of T. gondii infection were examined in vitro and in vivo. Deletion of GRA12 in type I RH and type II Pru T. gondii strains did not affect the parasite growth and replication in vitro, however, it caused a significant reduction in the parasite virulence and tissue cyst burden in vivo. T. gondii Δgra12 mutants were more vulnerable to be eliminated by host immunity, without the accumulation of immunity-related GTPase a6 (Irga6) onto the PV membrane. The ultrastructure of IVN in Δgra12 mutants appeared normal, suggesting that GRA12 is not required for biogenesis of the IVN. Combined deletion of GRA12 and ROP18 induced more severe attenuation of virulence compared to single Δgra12 or Δrop18 mutant strains. These data suggest a functional association between GRA12 and ROP18 that is revealed by the severe attenuation of virulence in a double mutant relative to the single individual mutations. Future studies are needed to define the molecular basis of this putative association. Collectively these findings indicate that although GRA12 is not essential for the parasite growth and replication in vitro, it contributes to the virulence and growth of T. gondii in mice.
Collapse
Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Meng-Jie Bai
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, UK
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| | - Xue-Zhen Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, P.R. China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, P.R. China
| |
Collapse
|
13
|
Cao XZ, Wang JL, Elsheikha HM, Li TT, Sun LX, Liang QL, Zhang ZW, Lin RQ. Characterization of the Role of Amylo-Alpha-1,6-Glucosidase Protein in the Infectivity of Toxoplasma gondii. Front Cell Infect Microbiol 2019; 9:418. [PMID: 31867292 PMCID: PMC6908810 DOI: 10.3389/fcimb.2019.00418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/22/2019] [Indexed: 11/13/2022] Open
Abstract
In this study, we characterized the role of amylo-alpha-1,6-glucosidase (Aa16GL) in the biology and infectivity of Toxoplasma gondii, using Aa16GL-deficient parasites of type I RH and type II Prugniaud (Pru) strains. The subcellular localization of Aa16GL protein was characterized by tagging a 3 × HA to the 3′ end of the Aa16GL gene endogenous locus. Immunostaining of the expressed Aa16GL protein revealed that it is located in several small cytoplasmic puncta. Functional characterization of ΔAa16GL mutants using plaque assay, egress assay and intracellular replication assay showed that parasites lacking Aa16GL exhibit a slight reduction in the growth rate, but remained virulent to mice. Although PruΔAa16GL tachyzoites retained the ability to differentiate into bradyzoites in vitro, they exhibited slight reduction in their ability to form cysts in mice. These findings reveal new properties of Aa16GL and suggest that while it does not have a substantial role in mediating T. gondii infectivity, this protein can influence the formation of parasite cysts in mice.
Collapse
Affiliation(s)
- Xue-Zhen Cao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| | - Jin-Lei Wang
- Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Ting-Ting Li
- Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Li-Xiu Sun
- Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qin-Li Liang
- Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Zhi-Wei Zhang
- Key Laboratory of Veterinary Parasitology of Gansu Province, State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Rui-Qing Lin
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.,Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou, China
| |
Collapse
|
14
|
Wang JL, Li TT, Elsheikha HM, Chen K, Cong W, Yang WB, Bai MJ, Huang SY, Zhu XQ. Live Attenuated Pru:Δcdpk2 Strain of Toxoplasma gondii Protects Against Acute, Chronic, and Congenital Toxoplasmosis. J Infect Dis 2019; 218:768-777. [PMID: 29669003 DOI: 10.1093/infdis/jiy211] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 04/11/2018] [Indexed: 11/14/2022] Open
Abstract
Background The threat of Toxoplasma gondii infection in immunocompromised individuals and pregnant women necessitates the development of a safe and effective vaccine. Here, we examined the immune protection conferred by a live attenuated strain of T. gondii. Methods We tested the efficacy of intraperitoneal vaccination using 500 Ca2+-dependent protein kinase 2 (cdpk2)-deficient tachyzoites of T. gondii Pru strain against acute, chronic, and congenital toxoplasmosis in mice. The kinetics of antibody response, cytokines, and other quantifiable correlates of protection against T. gondii infection were determined. Results Vaccination with Pru:Δcdpk2 induced a high level of anti-T. gondii immunoglobulin G titer, type 1 T-helper (Th1) response at 28 days postvaccination, and a mixed Th1/type 2 T-helper response at 70 days postvaccination. All vaccinated mice survived a heterologous challenge with 1000 tachyzoites of RH or ToxoDB#9 (PYS or TgC7) strains. Also, vaccination protected against homologous infection with 20 T. gondii Pru cysts, and improved pregnancy outcome by reducing parasite cyst load in the brain, maintaining litter size and body weight of pups born to vaccinated dams challenged with 10 Pru cysts compared to pups born to unvaccinated dams. Conclusions The use of T. gondii Pru:Δcdpk2 mutant strain represents a promising approach to protection against acute, chronic, and congenital toxoplasmosis in mice.
Collapse
Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China
| | - Wei Cong
- College of Marine Science, Shandong University at Weihai, Weihai, Shandong Province, People's Republic of China
| | - Wen-Bin Yang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China.,College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province, People's Republic of China
| | - Meng-Jie Bai
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province, People's Republic of China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, People's Republic of China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province, People's Republic of China
| |
Collapse
|
15
|
Yang WB, Wang JL, Gui Q, Zou Y, Chen K, Liu Q, Liang QL, Zhu XQ, Zhou DH. Immunization With a Live-Attenuated RH:Δ NPT1 Strain of Toxoplasma gondii Induces Strong Protective Immunity Against Toxoplasmosis in Mice. Front Microbiol 2019; 10:1875. [PMID: 31456786 PMCID: PMC6701201 DOI: 10.3389/fmicb.2019.01875] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/29/2019] [Indexed: 12/14/2022] Open
Abstract
Toxoplasmosis, one of the most important health-threatening diseases worldwide, is caused by Toxoplasma gondii, which infects a wide range of warm-blooded animals and humans, leading to enormous health and socioeconomic concerns. T. gondii can establish chronic infection to evade the immune response in hosts. Once a chronic infection has been established, the available treatments cannot efficiently control this stage of T. gondii efficiently. Moreover, the available treatments rely only on a few drugs, such as sulfapyridine and pyrimethamine, that tend to have severe side effects. Given these factors, vaccination has been considered to be the most efficient method to prevent and control this disease. However, there is currently lack of effective vaccine available for use to prevent toxoplasmosis apart form Toxovax®, the only available vaccine, which is used in sheep to prevent abortion. To address this problem, we knocked out the NPT1 gene of the type I T. gondii strain using the CRISPR-Cas9 system, constructed a live-attenuated vaccine and evaluated its protective efficacy in a mouse model. Immunization of mice with RH:ΔNPT1 induced a high level of Toxoplasma-specific IgG1, IgG2a and total IgG 42 days after immunization. There was a significant increase in the levels of cytokines in the splenocyte suspensions of RH:ΔNPT1-infected mice, and a mixed Th1/Th2 response was induced in the mice. Remarkably, after heterologous challenges with tachyzoites of the RH, PYS and Pru strains and cysts of the Pru strain by different infection routes, the immunized animals were protected from toxoplasmosis with a 100% survival rate, in both acute and chronic infection. In addition, compared with control mice, the Pru cyst load was clearly reduced in the brains of RH:ΔNPT1-infected immunization-mice. Our study demonstrated that the RH:ΔNPT1 strain was able to evoke strong anti-Toxoplasma immune responses and provide effective protection against parasite strains with different levels of virulence, suggesting that the RH:ΔNPT1 strain may represent a promising live-attenuated vaccine against toxoplasmosis, which is worthy of further evaluation in food-producing animals and in definitive feline host.
Collapse
Affiliation(s)
- Wen-Bin Yang
- Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qian Gui
- Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yang Zou
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Qing Liu
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Dong-Hui Zhou
- Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| |
Collapse
|
16
|
Huang SY, Chen K, Wang JL, Yang B, Zhu XQ. Evaluation of protective immunity induced by recombinant calcium-dependent protein kinase 1 (TgCDPK1) protein against acute toxoplasmosis in mice. Microb Pathog 2019; 133:103560. [PMID: 31145981 DOI: 10.1016/j.micpath.2019.103560] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/23/2019] [Accepted: 05/25/2019] [Indexed: 12/23/2022]
Abstract
Toxoplasma gondii is an intracellular zoonotic parasite that causes toxoplasmosis, which can cause economic losses and serious public health problems worldwide. A member of the T. gondii calcium-dependent protein kinases family, TgCDPK1 was recently identified as an essential regulator of exocytosis in T. gondii, and participated in direct parasite motility, host-cell invasion and egress. In the present study, the protective immunity of recombinant TgCDPK1 protein (rTgCDPK1) was evaluated against acute toxoplasmosis in mice. rTgCDPK1 were expressed and purified, BABL/c mice were intraperitoneally immunized with rTgCDPK1 and challenged with the highly virulent RH strain of T. gondii. The specific immune responses were analyzed by measuring the cytokine and serum antibody, and lymphocyte proliferation assays, flow cytometry of lymphocytes and the survival curve were employed to evaluate the protective efficacy. From the results we found that special humoral and cellular responses could be elicited in vaccine mice, and higher level of IgG antibody, and the significant increased levels of Th1-type cytokines IFN-γ, IL-12 (p70), IL10 and CD3+CD4+CD8- and CD3+CD8+CD4- T cells could also be detected comparing to control mice (P < 0.05). All vaccinated mice prolonged survival time (14.90 ± 2.89 days) challenge with 1000 tachyzoites of RH, while the control mice died within 8 days. These results indicated that TgCDPK1 protein was a potential vaccine candidate against acute toxoplasmosis.
Collapse
MESH Headings
- Animals
- Antibodies, Protozoan/blood
- Antigens, Protozoan/genetics
- Antigens, Protozoan/immunology
- Cloning, Molecular
- Cytokines/metabolism
- Female
- Genes, Protozoan/genetics
- Immunity, Cellular
- Immunity, Humoral
- Immunization
- Immunoglobulin G/blood
- Lymphocytes/immunology
- Mice
- Protein Kinases/genetics
- Protein Kinases/immunology
- Protozoan Proteins/genetics
- Protozoan Proteins/immunology
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Spleen/immunology
- Survival Analysis
- Toxoplasma/genetics
- Toxoplasma/immunology
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/prevention & control
- Vaccines, DNA/immunology
Collapse
Affiliation(s)
- Si-Yang Huang
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province, 225009, PR China.
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| | - Bin Yang
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province, 225009, PR China
| | - Xing-Quan Zhu
- College of Veterinary Medicine, Yangzhou University, and Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Jiangsu Key Laboratory of Zoonosis, Yangzhou, Jiangsu Province, 225009, PR China; State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, PR China
| |
Collapse
|
17
|
Sánchez-Sánchez R, Vázquez P, Ferre I, Ortega-Mora LM. Treatment of Toxoplasmosis and Neosporosis in Farm Ruminants: State of Knowledge and Future Trends. Curr Top Med Chem 2019; 18:1304-1323. [PMID: 30277158 PMCID: PMC6340160 DOI: 10.2174/1568026618666181002113617] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/03/2018] [Accepted: 09/13/2018] [Indexed: 12/17/2022]
Abstract
Toxoplasmosis and neosporosis are closely related protozoan diseases that lead to important economic impacts in farm ruminants. Toxoplasma gondii infection mainly causes reproductive failure in small ruminants and is a widespread zoonosis, whereas Neospora caninum infection is one of the most important causes of abortion in cattle worldwide. Vaccination has been considered the most economic measure for controlling these diseases. However, despite vaccine development efforts, only a live-attenuated T. gondii vaccine has been licensed for veterinary use, and no promising vaccines against ne-osporosis have been developed; therefore, vaccine development remains a key goal. Additionally, drug therapy could be a valuable strategy for disease control in farm ruminants, as several drugs that limit T. gondii and N. caninum proliferation and dissemination have been evaluated. This approach may also be relevant to performing an initial drug screening for potential human therapy for zoonotic parasites. Treat-ments can be applied against infections in adult ruminants to minimize the outcomes of a primo-infection or the reactivation of a chronic infection during gestation or in newborn ruminants to avoid infection chronification. In this review, the current status of drug development against toxoplasmosis and neosporo-sis in farm ruminants is presented, and in an effort to promote additional treatment options, prospective drugs that have shown efficacy in vitro and in laboratory animal models of toxoplasmosis and neosporosis are examined
Collapse
Affiliation(s)
- Roberto Sánchez-Sánchez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Patricia Vázquez
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Ignacio Ferre
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| | - Luis Miguel Ortega-Mora
- SALUVET, Animal Health Department, Faculty of Veterinary Sciences, Complutense University of Madrid, Ciudad Universitaria s/n, 28040, Madrid, Spain
| |
Collapse
|
18
|
Tu V, Yakubu R, Weiss LM. Observations on bradyzoite biology. Microbes Infect 2018; 20:466-476. [PMID: 29287987 PMCID: PMC6019562 DOI: 10.1016/j.micinf.2017.12.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 02/06/2023]
Abstract
Tachyzoites of the Apicomplexan Toxoplasma gondii cause acute infection, disseminate widely in their host, and eventually differentiate into a latent encysted form called bradyzoites that are found within tissue cysts. During latent infection, whenever transformation to tachyzoites occurs, any tachyzoites that develop are removed by the immune system. In contrast, cysts containing bradyzoites are sequestered from the immune system. In the absence of an effective immune response released organisms that differentiate into tachyzoites cause acute infection. Tissue cysts, therefore, serve as a reservoir for the reactivation of toxoplasmosis when the host becomes immunocompromised by conditions such as HIV infection, organ transplantation, or due to the impaired immune response that occurs when pathogens are acquired in utero. While tachyzoites and bradyzoites are well defined morphologically, there is no clear consensus on how interconversion occurs or what exact signal(s) mediate this transformation. Advances in research methods have facilitated studies on T. gondii bradyzoites providing important new insights into the biology of latent infection.
Collapse
Affiliation(s)
- Vincent Tu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Rama Yakubu
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Louis M Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| |
Collapse
|
19
|
Bai MJ, Wang JL, Elsheikha HM, Liang QL, Chen K, Nie LB, Zhu XQ. Functional Characterization of Dense Granule Proteins in Toxoplasma gondii RH Strain Using CRISPR-Cas9 System. Front Cell Infect Microbiol 2018; 8:300. [PMID: 30211128 PMCID: PMC6121064 DOI: 10.3389/fcimb.2018.00300] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 08/07/2018] [Indexed: 11/13/2022] Open
Abstract
Infection with the apicomplexan protozoan parasite Toxoplasma gondii is an ongoing public health problem. The parasite's ability to invade and replicate within the host cell is dependent on many effectors, such as dense granule proteins (GRAs) released from the specialized organelle dense granules, into host cells. GRAs have emerged as important determinants of T. gondii pathogenesis. However, the functions of some GRAs remain undefined. In this study, we used CRISPR-Cas9 technique to disrupt 17 GRA genes (GRA11, GRA12 bis, GRA13, GRA14, GRA20, GRA21, GRA28-31, GRA33-38, and GRA40) in the virulent T. gondii RH strain. The CRISPR-Cas9 constructs abolished the expression of the 17 GRA genes. Functional characterization of single ΔGRA mutants was achieved in vitro using cell-based plaque assay and egress assay, and in vivo in BALB/c mice. Targeted deletion of these 17 GRA genes had no significant effect neither on the in vitro growth and egress of the mutant strains from the host cells nor on the parasite virulence in the mouse model of infection. Comparative analysis of the transcriptomics data of the 17 GRA genes suggest that GRAs may serve different functions in different genotypes and life cycle stages of the parasite. In sum, although these 17 GRAs might not be essential for RH strain growth in vitro or virulence in mice, they may have roles in other strains or parasite stages, which warrants further investigations.
Collapse
Affiliation(s)
- Meng-Jie Bai
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - Qin-Li Liang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Lan-Bi Nie
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| |
Collapse
|
20
|
Chang L, Dykes EJ, Li J, Moreno SNJ, Hortua Triana MA. Characterization of Two EF-hand Domain-containing Proteins from Toxoplasma gondii. J Eukaryot Microbiol 2018; 66:343-353. [PMID: 30063275 DOI: 10.1111/jeu.12675] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 07/25/2018] [Accepted: 07/26/2018] [Indexed: 12/01/2022]
Abstract
The universal role of calcium (Ca2+ ) as a second messenger in cells depends on a large number of Ca2+ -binding proteins (CBP), which are able to bind Ca2+ through specific domains. Many CBPs share a type of Ca2+ -binding domain known as the EF-hand. The EF-hand motif has been well studied and consists of a helix-loop-helix structural domain with specific amino acids in the loop region that interact with Ca2+ . In Toxoplasma gondii a large number of genes (approximately 68) are predicted to have at least one EF-hand motif. The majority of these genes have not been characterized. We report the characterization of two EF-hand motif-containing proteins, TgGT1_216620 and TgGT1_280480, which localize to the plasma membrane and to the rhoptry bulb, respectively. Genetic disruption of these genes by CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) resulted in mutant parasite clones (Δtg216620 and Δtg280480) that grew at a slower rate than control cells. Ca2+ measurements showed that Δtg216620 cells did not respond to extracellular Ca2+ as the parental controls while Δtg280480 cells appeared to respond as the parental cells. Our hypothesis is that TgGT1_216620 is important for Ca2+ influx while TgGT1_280480 may be playing a different role in the rhoptries.
Collapse
Affiliation(s)
- Le Chang
- College of Veterinary Medicine, Jilin University, Changchun, 130062, China.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, 30602
| | - Eric J Dykes
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, 30602
| | - Jianhua Li
- College of Veterinary Medicine, Jilin University, Changchun, 130062, China
| | - Silvia N J Moreno
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, 30602.,Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602
| | | |
Collapse
|
21
|
Grzybek M, Golonko A, Górska A, Szczepaniak K, Strachecka A, Lass A, Lisowski P. The CRISPR/Cas9 system sheds new lights on the biology of protozoan parasites. Appl Microbiol Biotechnol 2018; 102:4629-4640. [PMID: 29626235 PMCID: PMC5954013 DOI: 10.1007/s00253-018-8927-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 03/06/2018] [Indexed: 01/04/2023]
Abstract
The CRISPR/Cas9 system, a natural defence system of bacterial organisms, has recently been used to modify genomes of the most important protozoa parasites. Successful genome manipulations with the CRISPR/Cas9 system are changing the present view of genetics in parasitology. The application of this system offers a major chance to overcome the current restriction in culturing, maintaining and analysing protozoan parasites, and allows dynamic analysis of parasite genes functions, leading to a better understanding of pathogenesis. CRISPR/Cas9 system will have a significant influence on the process of developing novel drugs and treatment strategies against protozoa parasites.
Collapse
Affiliation(s)
- Maciej Grzybek
- Department of Tropical Parasitology, Medical University of Gdansk, Powstania Styczniowego 9b, 81-519 Gdynia, Poland
| | - Aleksandra Golonko
- Department of Biotechnology, Bialystok University of Technology, Wiejska 45E, 15-351, Bialystok, Poland
| | - Aleksandra Górska
- Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland
| | - Klaudiusz Szczepaniak
- Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland
| | - Aneta Strachecka
- Faculty of Biology, Animal Sciences and Bioeconomy, University of Life Sciences in Lublin, Akademicka 13, 20-950 Lublin, Poland
| | - Anna Lass
- Department of Tropical Parasitology, Medical University of Gdansk, Powstania Styczniowego 9b, 81-519 Gdynia, Poland
| | - Paweł Lisowski
- Department of Molecular Biology, Institute of Genetics and Animal Breeding PAS, Postepu 36A, 05-552 Jastrzebiec, Poland
- iPS Cell-Based Disease Modeling Group, Max-Delbrück-Center for Molecular Medicine (MDC) in the Helmholtz Association, Robert-Rössle-Str. 10, 13092 Berlin, Germany
| |
Collapse
|
22
|
Abstract
Although the application of CRISPR/Cas9 genome engineering approaches was first reported in apicomplexan parasites only 3 years ago, this technology has rapidly become an essential component of research on apicomplexan parasites. This review briefly describes the history of CRISPR/Cas9 and the principles behind its use along with documenting its implementation in apicomplexan parasites, especially Plasmodium spp. and Toxoplasma gondii. We also discuss the recent use of CRISPR/Cas9 for whole genome screening of gene knockout mutants in T. gondii and highlight its use for seminal genetic manipulations of Cryptosporidium spp. Finally, we consider new variations of CRISPR/Cas9 that have yet to be implemented in apicomplexans. Whereas CRISPR/Cas9 has already accelerated rapid interrogation of gene function in apicomplexans, the full potential of this technology is yet to be realized as new variations and innovations are integrated into the field.
Collapse
|
23
|
Denny PW. Microbial protein targets: towards understanding and intervention. Parasitology 2018; 145:111-115. [PMID: 29143719 PMCID: PMC5817423 DOI: 10.1017/s0031182017002037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/06/2017] [Accepted: 10/06/2017] [Indexed: 12/11/2022]
Abstract
The rise of antimicrobial resistance, coupled with a lack of industrial focus on antimicrobial discovery over preceding decades, has brought the world to a crisis point. With both human and animal health set to decline due to increased disease burdens caused by near untreatable microbial pathogens, there is an urgent need to identify new antimicrobials. Central to this is the elucidation of new, robustly validated, drug targets. Informed by industrial practice and concerns, the use of both biological and chemical tools in validation is key. In parallel, repurposing approved drugs for use as antimicrobials may provide both new treatments and identify new targets, whilst improved understanding of pharmacology will help develop and progress good 'hits' with the required rapidity. In recognition of the need to increase research efforts in these areas, in 14-16 September 2017, the British Society for Parasitology (BSP) Autumn Symposium was hosted at Durham University with the title: Microbial Protein Targets: towards understanding and intervention. Staged in collaboration with the Royal Society of Chemistry (RSC) Chemistry Biology Interface Division (CBID), the core aim was to bring together leading researchers working across disciplines to imagine novel approaches towards combating infection and antimicrobial resistance. Sessions were held on: 'Anti-infective discovery, an overview'; 'Omic approaches to target validation'; 'Genetic approaches to target validation'; 'Drug target structure and drug discovery'; 'Fragment-based approaches to drug discovery'; and 'Chemical approaches to target validation'. Here, we introduce a series of review and primary research articles from selected contributors to the Symposium, giving an overview of progress in understanding antimicrobial targets and developing new drugs. The Symposium was organized by Paul Denny (Durham) for the BSP and Patrick Steel (Durham) for RSC CBID.
Collapse
Affiliation(s)
- Paul W Denny
- Department of Biosciences,Durham University,Lower Mountjoy, Stockton Road, Durham DH1 3LE,UK
| |
Collapse
|
24
|
Foroutan M, Ghaffarifar F. Calcium-dependent protein kinases are potential targets for Toxoplasma gondii vaccine. Clin Exp Vaccine Res 2018; 7:24-36. [PMID: 29399577 PMCID: PMC5795042 DOI: 10.7774/cevr.2018.7.1.24] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 01/03/2018] [Accepted: 01/06/2018] [Indexed: 01/30/2023] Open
Abstract
Toxoplasma gondii belongs to the Apicomplexa phylum that caused a widespread zoonotic infection in wide range of intermediate hosts. Over one-third of the world's population are latently infected with T. gondii and carry it. The complex life cycle of T. gondii indicates the presence of a plurality of antigenic epitopes. During the recent years, continuous efforts of scientists have made precious advances to elucidate the different aspects of the cell and molecular biology of T. gondii. Despite of great progresses, the development of vaccine candidates for preventing of T. gondii infection in men and animals is still remains a challenge. The calcium-dependent protein kinases (CDPKs) belongs to the superfamily of kinases, which restricted to the apicomplexans, ciliates, and plants. It has been documented that they contribute several functions in the life cycle of T. gondii such as gliding motility, cell invasion, and egress as well as some other critical developmental processes. In current paper, we reviewed the recent progress concerning the development of CDPK-based vaccines against acute and chronic T. gondii.
Collapse
Affiliation(s)
- Masoud Foroutan
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Fatemeh Ghaffarifar
- Department of Parasitology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| |
Collapse
|
25
|
Abstract
The apicomplexan protozoan parasites include the causative agents of animal and human diseases ranging from malaria (Plasmodium spp.) to toxoplasmosis (Toxoplasma gondii). The complex life cycle of T. gondii is regulated by a unique family of calcium-dependent protein kinases (CDPKs) that have become the target of intensive efforts to develop new therapeutics. In this review, we will summarize structure-based strategies, recent successes and future directions in the pursuit of specific and selective inhibitors of T. gondii CDPK1.
Collapse
|
26
|
Pan M, Lyu C, Zhao J, Shen B. Sixty Years (1957-2017) of Research on Toxoplasmosis in China-An Overview. Front Microbiol 2017; 8:1825. [PMID: 28993763 PMCID: PMC5622193 DOI: 10.3389/fmicb.2017.01825] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/06/2017] [Indexed: 01/12/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous zoonotic pathogen belonging to apicomplexan parasites. Infection in humans and animals may cause abortion and other severe symptoms under certain circumstances, leading to great economical losses and public health problems. T. gondii was first discovered in China in 1955 and the corresponding work was published in 1957. Since then, a lot of work has been done on this parasite and the diseases it causes. This review summarizes the major progress made by Chinese scientists over the last 60 years, and gives our perspectives on what should be done in the near future. A wide variety of diagnostic approaches were designed, including the ones to detect T. gondii specific antibodies in host sera, and T. gondii specific antigens or DNA in tissue and environmental samples. Further work will be needed to translate some of the laboratory assays into reliable products for clinic uses. Epidemiological studies were extensively done in China and the sero-prevalence in humans increased over the years, but is still below the world average, likely due to the unique eating and cooking habits. Infection rates were shown to be fairly high in meat producing animals such as, pigs, sheep, and chickens, as well as in the definitive host cats. Numerous subunit vaccines in the form of recombinant proteins or DNA vaccines were developed, but none of them is satisfactory in the current form. Live attenuated parasites using genetically modified strains may be a better option for vaccine design. The strains isolated from China are dominated by the ToxoDB #9 genotype, but it likely contains multiple subtypes since different ToxoDB #9 strains exhibited phenotypic differences. Further studies are needed to understand the general biology, as well as the unique features of strains prevalent in China.
Collapse
Affiliation(s)
- Ming Pan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Congcong Lyu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
| | - Junlong Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
- Key Laboratory of Preventive Medicine in Hubei ProvinceWuhan, China
- Hubei Cooperative Innovation Center for Sustainable Pig ProductionWuhan, China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China
- Key Laboratory of Preventive Medicine in Hubei ProvinceWuhan, China
| |
Collapse
|
27
|
Wang JL, Elsheikha HM, Zhu WN, Chen K, Li TT, Yue DM, Zhang XX, Huang SY, Zhu XQ. Immunization with Toxoplasma gondii GRA17 Deletion Mutant Induces Partial Protection and Survival in Challenged Mice. Front Immunol 2017; 8:730. [PMID: 28706518 PMCID: PMC5489627 DOI: 10.3389/fimmu.2017.00730] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 06/09/2017] [Indexed: 01/10/2023] Open
Abstract
Toxoplasmosis remains a world-threatening disease largely because of the lack of a fully effective vaccine. Here, we created a ΔGRA17 mutant by disrupting the virulence factor GRA17 using CRISPR-Cas9 method. Then, we tested whether ΔGRA17 tachyzoites can be used as a live-attenuated vaccine against acute, chronic, and congenital Toxoplasma gondii infection in mice. Immune response evoked by ΔGRA17 immunization suggested a sequential Th1 and Th2 T cell response, indicated by high levels of Th1 and a mixed Th1/Th2 cytokines at 28 and 70 days after immunization, respectively. ΔGRA17-mediated immunity fully protected mice against lethal infection with wild-type (wt) RH strain, heterologous challenge with PYS, and TgC7 strains of the Chinese ToxoDB#9 genotype, and T. gondii Pru strain. Although parasite cysts were detected in 8 out of 10 immunized mice, cyst burden in the brain was significantly reduced (P < 0.05) in immunized mice (53 ± 15 cysts/brain) compared to non-immunized mice (4,296 ± 687 cysts/brain). In respect to congenital infection, the litter size, survival rate, and body weight (BW) of pups born to ΔGRA17-immunized dams were not different compared to pups born to naïve control dams (P = 0.24). However, a marked reduction in the litter size (P < 0.001), survival rate, and BW (P < 0.01) of pups born to non-immunized and infected dams was detected. Also, immunized dams infected with type II Pru strain had significantly (P < 0.001) less cyst burden in the brain compared with non-immunized and infected dams. These findings show that immunization with ΔGRA17 strain evokes cell-mediated and neutralizing antibody responses and confers some degree of protection against challenge with homologous and heterologous virulent T. gondii strains.
Collapse
Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, United Kingdom
| | - Wei-Ning Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.,College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, China
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Dong-Mei Yue
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xiao-Xuan Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| |
Collapse
|
28
|
McCoy JM, Stewart RJ, Uboldi AD, Li D, Schröder J, Scott NE, Papenfuss AT, Lehane AM, Foster LJ, Tonkin CJ. A forward genetic screen identifies a negative regulator of rapid Ca 2+-dependent cell egress (MS1) in the intracellular parasite Toxoplasma gondii. J Biol Chem 2017; 292:7662-7674. [PMID: 28258212 DOI: 10.1074/jbc.m117.775114] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/27/2017] [Indexed: 12/20/2022] Open
Abstract
Toxoplasma gondii, like all apicomplexan parasites, uses Ca2+ signaling pathways to activate gliding motility to power tissue dissemination and host cell invasion and egress. A group of "plant-like" Ca2+-dependent protein kinases (CDPKs) transduces cytosolic Ca2+ flux into enzymatic activity, but how they function is poorly understood. To investigate how Ca2+ signaling activates egress through CDPKs, we performed a forward genetic screen to isolate gain-of-function mutants from an egress-deficient cdpk3 knockout strain. We recovered mutants that regained the ability to egress from host cells that harbored mutations in the gene Suppressor of Ca2+-dependent Egress 1 (SCE1). Global phosphoproteomic analysis showed that SCE1 deletion restored many Δcdpk3-dependent phosphorylation events to near wild-type levels. We also show that CDPK3-dependent SCE1 phosphorylation is required to relieve its suppressive activity to potentiate egress. In summary, our work has uncovered a novel component and suppressor of Ca2+-dependent cell egress during Toxoplasma lytic growth.
Collapse
Affiliation(s)
- James M McCoy
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,Computing and Information Systems,University of Melbourne, Victoria 3010, Australia
| | - Rebecca J Stewart
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,Computing and Information Systems,University of Melbourne, Victoria 3010, Australia
| | - Alessandro D Uboldi
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,Computing and Information Systems,University of Melbourne, Victoria 3010, Australia
| | - Dongdi Li
- the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Jan Schröder
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,the Peter MacCallum Cancer Institute, Victoria 3000, Australia, and
| | - Nicollas E Scott
- the University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Anthony T Papenfuss
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia.,the Departments of Medical Biology.,the Peter MacCallum Cancer Institute, Victoria 3000, Australia, and
| | - Adele M Lehane
- the Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Leonard J Foster
- the University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Christopher J Tonkin
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia, .,the Departments of Medical Biology
| |
Collapse
|
29
|
Wang JL, Li TT, Elsheikha HM, Chen K, Zhu WN, Yue DM, Zhu XQ, Huang SY. Functional Characterization of Rhoptry Kinome in the Virulent Toxoplasma gondii RH Strain. Front Microbiol 2017; 8:84. [PMID: 28174572 PMCID: PMC5258691 DOI: 10.3389/fmicb.2017.00084] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 01/12/2017] [Indexed: 11/13/2022] Open
Abstract
Toxoplasma gondii is an obligatory intracellular apicomplexan protozoan which can infect any warm-blooded animal and causes severe diseases in immunocompromised individuals or infants infected in utero. The survival and success of this parasite require that it colonizes the host cell, avoids host immune defenses, replicates within an appropriate niche, and exits the infected host cell to spread to neighboring non-infected cells. All of these processes depend on the parasite ability to synthesis and export secreted proteins. Amongst the secreted proteins, rhoptry organelle proteins (ROPs) are essential for the parasite invasion and host cell manipulation. Even though the functions of most ROPs have been elucidated in the less virulent T. gondii (type II), the roles of ROPs in the highly virulent type I strain remain largely un-characterized. Herein, we investigated the contributions of 15 ROPs (ROP10, ROP11, ROP15, ROP20, ROP23, ROP31, ROP32, ROP33, ROP34, ROP35, ROP36, ROP40, ROP41, ROP46, and ROP47) to the infectivity of the high virulent type I T. gondii (RH strain). Using CRISPR-Cas9, these 15 ROPs genes were successfully disrupted and the effects of gene knockout on the parasite's ability to infect cells in vitro and BALB/c mice in vivo were investigated. These results showed that deletions of these ROPs did not interfere with the parasite ability to grow in cultured human foreskin fibroblast cells and did not significantly alter parasite pathogenicity for BALB/c mice. Although these ROPs did not seem to be essential for the acute infectious stage of type I T. gondii in the mouse model, they might have different functions in other intermediate hosts or play different roles in other life cycle forms of this parasite due to the different expression patterns; this warrants further investigations.
Collapse
Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Ting-Ting Li
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus Loughborough, UK
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Wei-Ning Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural SciencesLanzhou, China; College of Animal Science and Veterinary Medicine, Shandong Agricultural UniversityTai'an, China
| | - Dong-Mei Yue
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural SciencesLanzhou, China; College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural UniversityDaqing, China
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences Lanzhou, China
| |
Collapse
|
30
|
Lander N, Chiurillo MA, Docampo R. Genome Editing by CRISPR/Cas9: A Game Change in the Genetic Manipulation of Protists. J Eukaryot Microbiol 2016; 63:679-90. [PMID: 27315329 DOI: 10.1111/jeu.12338] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 06/12/2016] [Accepted: 06/13/2016] [Indexed: 01/01/2023]
Abstract
Genome editing by CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated gene 9) system has been transformative in biology. Originally discovered as an adaptive prokaryotic immune system, CRISPR/Cas9 has been repurposed for genome editing in a broad range of model organisms, from yeast to mammalian cells. Protist parasites are unicellular organisms producing important human diseases that affect millions of people around the world. For many of these diseases, such as malaria, Chagas disease, leishmaniasis and cryptosporidiosis, there are no effective treatments or vaccines available. The recent adaptation of the CRISPR/Cas9 technology to several protist models will be playing a key role in the functional study of their proteins, in the characterization of their metabolic pathways, and in the understanding of their biology, and will facilitate the search for new chemotherapeutic targets. In this work we review recent studies where the CRISPR/Cas9 system was adapted to protist parasites, particularly to Apicomplexans and trypanosomatids, emphasizing the different molecular strategies used for genome editing of each organism, as well as their advantages. We also discuss the potential usefulness of this technology in the green alga Chlamydomonas reinhardtii.
Collapse
Affiliation(s)
- Noelia Lander
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, 13083, Brazil
| | - Miguel A Chiurillo
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, 13083, Brazil
| | - Roberto Docampo
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo, 13083, Brazil.,Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, Georgia, 30602, USA
| |
Collapse
|
31
|
Fernández C, Jaimes J, Ortiz MC, Ramírez JD. Host and Toxoplasma gondii genetic and non-genetic factors influencing the development of ocular toxoplasmosis: A systematic review. INFECTION GENETICS AND EVOLUTION 2016; 44:199-209. [PMID: 27389360 DOI: 10.1016/j.meegid.2016.06.053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 12/13/2022]
Abstract
Toxoplasmosis is a cosmopolitan infection caused by the apicomplexan parasite Toxoplasma gondii. This infectious disease is widely distributed across the world where cats play an important role in its spread. The symptomatology caused by this parasite is diverse but the ocular affectation emerges as the most important clinical phenotype. Therefore, we conducted a systematic review of the current knowledge of ocular toxoplasmosis from the genetic diversity of the pathogen towards the treatment available for this infection. This review represents an update to the scientific community regarding the genetic diversity of the parasite, the genetic factors of the host, the molecular pathogenesis and its association with disease, the available diagnostic tools and the available treatment of patients undergoing ocular toxoplamosis. This review will be an update for the scientific community in order to encourage researchers to deploy cutting-edge investigation across this field.
Collapse
Affiliation(s)
- Carolina Fernández
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Jesús Jaimes
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - María Camila Ortiz
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Juan David Ramírez
- Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia.
| |
Collapse
|
32
|
Wang JL, Huang SY, Behnke MS, Chen K, Shen B, Zhu XQ. The Past, Present, and Future of Genetic Manipulation in Toxoplasma gondii. Trends Parasitol 2016; 32:542-553. [PMID: 27184069 DOI: 10.1016/j.pt.2016.04.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 12/16/2022]
Abstract
Toxoplasma gondii is a classic model for studying obligate intracellular microorganisms as various genetic manipulation tools have been developed in T. gondii over the past 20 years. Here we summarize the major strategies for T. gondii genetic manipulation including genetic crosses, insertional mutagenesis, chemical mutagenesis, homologous gene replacement, conditional knockdown techniques, and the recently developed clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system. We evaluate the advantages and limitations of each of these tools in a historical perspective. We also discuss additional applications of modified CRISPR-Cas9 systems for use in T. gondii, such as regulation of gene expression, labeling of specific genomic loci, and epigenetic modifications. These approaches have the potential to revolutionize the analysis of T. gondii biology and help us to better develop new drugs and vaccines.
Collapse
Affiliation(s)
- Jin-Lei Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China
| | - Si-Yang Huang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province 225009, PR China
| | - Michael S Behnke
- Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Kai Chen
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei Province 430070, PR China.
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province 730046, PR China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu Province 225009, PR China.
| |
Collapse
|
33
|
Analysis of Noncanonical Calcium-Dependent Protein Kinases in Toxoplasma gondii by Targeted Gene Deletion Using CRISPR/Cas9. Infect Immun 2016; 84:1262-1273. [PMID: 26755159 DOI: 10.1128/iai.01173-15] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 01/04/2016] [Indexed: 12/31/2022] Open
Abstract
Calcium-dependent protein kinases (CDPKs) are expanded in apicomplexan parasites, especially in Toxoplasma gondii where 14 separate genes encoding these enzymes are found. Although previous studies have shown that several CDPKs play a role in controlling invasion, egress, and cell division in T. gondii, the roles of most of these genes are unexplored. Here we developed a more efficient method for gene disruption using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) that was modified to completely delete large, multiexonic genes from the genome and to allow serial replacement by recycling of the selectable marker using Cre-loxP. Using this system, we generated a total of 24 mutants in type 1 and 2 genetic backgrounds to ascertain the functions of noncanonical CDPKs. Remarkably, although we were able to confirm the essentiality of CDPK1 and CDPK7, the majority of CDPKs had no discernible phenotype for growth in vitro or infection in the mouse model. The exception to this was CDPK6, loss of which leads to reduced plaquing, fitness defect in a competition assay, and reduced tissue cyst formation in chronically infected mice. Our findings highlight the utility of CRISPR/Cas9 for rapid serial gene deletion and also suggest that additional models are needed to reveal the functions of many genes in T. gondii.
Collapse
|