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Bouchery T, Moyat M, Sotillo J, Silverstein S, Volpe B, Coakley G, Tsourouktsoglou TD, Becker L, Shah K, Kulagin M, Guiet R, Camberis M, Schmidt A, Seitz A, Giacomin P, Le Gros G, Papayannopoulos V, Loukas A, Harris NL. Hookworms Evade Host Immunity by Secreting a Deoxyribonuclease to Degrade Neutrophil Extracellular Traps. Cell Host Microbe 2020; 27:277-289.e6. [PMID: 32053791 DOI: 10.1016/j.chom.2020.01.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/15/2019] [Accepted: 01/17/2020] [Indexed: 12/11/2022]
Abstract
Hookworms cause a major neglected tropical disease, occurring after larvae penetrate the host skin. Neutrophils are phagocytes that kill large pathogens by releasing neutrophil extracellular traps (NETs), but whether they target hookworms during skin infection is unknown. Using a murine hookworm, Nippostrongylus brasiliensis, we observed neutrophils being rapidly recruited and deploying NETs around skin-penetrating larvae. Neutrophils depletion or NET inhibition altered larvae behavior and enhanced the number of adult worms following murine infection. Nevertheless, larvae were able to mitigate the effect of NETs by secreting a deoxyribonuclease (Nb-DNase II) to degrade the DNA backbone. Critically, neutrophils were able to kill larvae in vitro, which was enhanced by neutralizing Nb-DNase II. Homologs of Nb-DNase II are present in other nematodes, including the human hookworm, Necator americanus, which also evaded NETs in vitro. These findings highlight the importance of neutrophils in hookworm infection and a potential conserved mechanism of immune evasion.
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Affiliation(s)
- Tiffany Bouchery
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia; Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Mati Moyat
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia; Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Javier Sotillo
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia; Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid 28222, Spain
| | - Solomon Silverstein
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia
| | - Beatrice Volpe
- Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Gillian Coakley
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia
| | | | - Luke Becker
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia
| | - Kathleen Shah
- Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Manuel Kulagin
- Laboratory of Intestinal Immunology, SV, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne CH-1015 Switzerland
| | - Romain Guiet
- Bioimaging and Optics Core Facility, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Mali Camberis
- Malaghan Institute of Medical Research, Wellington 6242, New Zealand
| | - Alfonso Schmidt
- Hugh Green Cytometry Centre, Malaghan Institute of Medical Research, Wellington 6242, New Zealand
| | - Arne Seitz
- Bioimaging and Optics Core Facility, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne CH-1015, Switzerland
| | - Paul Giacomin
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia
| | - Graham Le Gros
- Malaghan Institute of Medical Research, Wellington 6242, New Zealand
| | | | - Alex Loukas
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4814, Australia
| | - Nicola L Harris
- Laboratory of Intestinal Immunology, Department of Immunology and Pathology, Monash University, Melbourne, VIC 3004, Australia.
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Iqbal J, Panjwani S, Siddiqui R, Khan NA. Partial characterization of Acanthamoeba castellanii (T4 genotype) DNase activity. Parasitol Res 2014; 114:457-63. [PMID: 25358239 DOI: 10.1007/s00436-014-4203-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 10/22/2014] [Indexed: 11/28/2022]
Abstract
The deoxyribonuclease (DNase) activities of Acanthamoeba castellanii belonging to the T4 genotype were investigated. Using zymographic assays, the DNase activities had approximate molecular masses of 25 and 35 kDa. A. castellanii DNases exhibited activity at wide-ranging temperature of up to 60 °C and at pH ranging from 4 to 9. The DNases activities were unaffected by proteinase-K treatment, divalent cations such as Ca(++), Cu(++), Mg(++), and Zn(++), or divalent cation chelating agent ethylenediaminetetraacetic acid (EDTA) or sodium dodecyl sulfate (SDS). The non-reliance on divalent cations and homology data suggests that A. castellanii DNases belong to the class of eukaryotic lysosomal DNase II but exhibit robust properties. The DNases activity in A. castellanii interfered with the genomic DNA extraction. Extraction methods involving EDTA, SDS, and proteinase-K resulted in low yield of genomic DNA. On the other hand, these methods resulted in high yield of genomic DNA from human cells suggesting the robust nature of A. castellanii DNases that are unaffected by reagents normally used in blocking eukaryotic DNases. In contrast, the use of chaotropic agent such as guanidine thiocyanate improved the yield of genomic DNA from A. castellanii cells significantly. Further purification and characterization of Acanthamoeba DNases is needed to study their non-classic distinct properties and to determine their role in the biology, cellular differentiation, cell cycle progression, and arrest of Acanthamoeba.
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Affiliation(s)
- Junaid Iqbal
- Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan
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