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Márquez LM, Roossinck MJ. Do persistent RNA viruses fit the trade-off hypothesis of virulence evolution? Curr Opin Virol 2012; 2:556-60. [DOI: 10.1016/j.coviro.2012.06.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 06/26/2012] [Accepted: 06/27/2012] [Indexed: 01/08/2023]
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Pan Q, Chen H, Wang F, Jeza VT, Hou W, Zhao Y, Xiang T, Zhu Y, Endo Y, Fujita T, Zhang XL. L-ficolin binds to the glycoproteins hemagglutinin and neuraminidase and inhibits influenza A virus infection both in vitro and in vivo. J Innate Immun 2012; 4:312-24. [PMID: 22399010 PMCID: PMC6741490 DOI: 10.1159/000335670] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 12/08/2011] [Accepted: 12/08/2011] [Indexed: 12/28/2022] Open
Abstract
L-ficolin, one of the complement lectins found in human serum, is a novel pattern recognition molecule that can specifically bind to microbial carbohydrates, thereby activating the lectin complement pathway and mounting a protective innate immune response. However, little is known about the role of L-ficolin during viral infections in vivo. In the present study, we used a mouse model of influenza A virus infection to demonstrate that the administration of exogenous L-ficolin or ficolin A (FCNA - an L-ficolin-like molecule in the mouse) is protective against the virus. Furthermore, FCNA-null mice have a greatly increased susceptibility to infection with the influenza A virus. Moreover, we found recombinant human L-ficolin inhibited influenza A virus entry into Madin-Darby canine kidney cells. More importantly, L-ficolin can recognize and bind hemagglutinin (HA) and neuraminidase (NA) glycoproteins and different subtypes of influenza A virus, and these interactions can be competitively inhibited by N-acetyl-D-glucosamine. In addition, the binding of L-ficolin and FCNA may lead to the activation of the lectin complement pathway. To our knowledge, this is the first report demonstrating that L-ficolin can block influenza virus infections both in vitro and in vivo using FCNA-knockout mice, possibly by interacting with the carbohydrates of HA and NA. Therefore, these data may provide new immunotherapeutic strategies based on the innate immune molecule L-ficolin against the influenza A virus.
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Affiliation(s)
- Qin Pan
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
| | - Haidan Chen
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
| | - Feng Wang
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
| | - Victor Tunje Jeza
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
| | - Wei Hou
- Institute of Virology, Wuhan University School of Medicine China, Wuhan, PR China
| | - Yinglan Zhao
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
| | - Tian Xiang
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
| | - Ying Zhu
- State Key Laboratory of Virology, Wuhan University College of Life Sciences, Wuhan, PR China
| | - Yuchi Endo
- Department of Biochemistry II, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Teizo Fujita
- Department of Biochemistry II, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Xiao-Lian Zhang
- State Key Laboratory of Virology, Department of Immunology and Hubei Province, Key Laboratory of Allergy and Immune-Related Diseases China, Wuhan University School of Medicine China, Wuhan, PR China
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Yang YS, Murciano B, Moubri K, Cibrelus P, Schetters T, Gorenflot A, Delbecq S, Roumestand C. Structural and functional characterization of Bc28.1, major erythrocyte-binding protein from Babesia canis merozoite surface. J Biol Chem 2012; 287:9495-508. [PMID: 22294693 DOI: 10.1074/jbc.m111.260745] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Babesiosis (formerly known as piroplasmosis) is a tick-borne disease caused by the intraerythrocytic development of protozoa parasites from the genus Babesia. Like Plasmodium falciparum, the agent of malaria, or Toxoplasma gondii, responsible for human toxoplasmosis, Babesia belongs to the Apicomplexa family. Babesia canis is the agent of the canine babesiosis in Europe. Clinical manifestations of this disease range from mild to severe and possibly lead to death by multiple organ failure. The identification and characterization of parasite surface proteins represent major goals, both for the understanding of the Apicomplexa invasion process and for the vaccine potential of such antigens. Indeed, we have already shown that Bd37, the major antigenic adhesion protein from Babesia divergens, the agent of bovine babesiosis, was able to induce complete protection against various parasite strains. The major merozoite surface antigens of Babesia canis have been described as a 28-kDa membrane protein family, anchored at the surface of the merozoite. Here, we demonstrate that Bc28.1, a major member of this multigenic family, is expressed at high levels at the surface of the merozoite. This protein is also found in the parasite in vitro culture supernatants, which are the basis of effective vaccines against canine babesiosis. We defined the erythrocyte binding function of Bc28.1 and determined its high resolution solution structure using NMR spectroscopy. Surprisingly, although these proteins are thought to play a similar role in the adhesion process, the structure of Bc28.1 from B. canis appears unrelated to the previously published structure of Bd37 from B. divergens. Site-directed mutagenesis experiments also suggest that the mechanism of the interaction with the erythrocyte membrane could be different for the two proteins. The resolution of the structure of Bc28 represents a milestone for the characterization of the parasite erythrocyte binding and its interaction with the host immune system.
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Affiliation(s)
- Yin-Shan Yang
- Centre de Biochimie Structurale, CNRS UMR 5048, Université Montpellier 1 et 2, Montpellier, France
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Pradhan A, Tuteja R. Bipolar, Dual Plasmodium falciparum helicase 45 expressed in the intraerythrocytic developmental cycle is required for parasite growth. J Mol Biol 2007; 373:268-81. [PMID: 17822710 DOI: 10.1016/j.jmb.2007.07.056] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2007] [Revised: 07/12/2007] [Accepted: 07/16/2007] [Indexed: 11/21/2022]
Abstract
Helicases are ubiquitous molecular motor proteins that have an important role in the metabolism of nucleic acids. The gene encoding a helicase was cloned from the human malaria parasite Plasmodium falciparum. The polypeptide of 398 amino acid residues has a molecular mass of 45 kDa, contains striking homology to eukaryotic translation initiation factor 4A (eIF4A) and all the conserved domains of the DEAD-box family. The recombinantly expressed and homogeneous P. falciparum protein PfH45 is an ATP-dependent DNA and RNA helicase, with ATPase and ATP-binding activities. PfH45 is a unique bipolar helicase that contains both the 3' to 5' and 5' to 3' directional helicase activities and anti-PfH45 antibodies curtail all its activities. PfH45 is expressed in all the intraerythrocytic developmental stages of the parasite and has a role in translation. Parasite cultures treated with PfH45 double-stranded RNA or purified immunoglobulins against PfH45 exhibited approximately 60% and approximately 55% growth inhibition, respectively. This inhibitory effect was due to interference with expression of the cognate messenger and down-regulation of synthesis of PfH45 protein in the parasite culture and was associated with morphologic deformation of the parasite. These studies indicate that PfH45 is an indispensable enzyme that is essential for growth, and probably survival, of P. falciparum.
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Affiliation(s)
- Arun Pradhan
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, PO Box 10504, Aruna Asaf Ali Marg, New Delhi-110067, India
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Hilpert K, Winkler DFH, Hancock REW. Cellulose-bound Peptide Arrays: Preparation and Applications. Biotechnol Genet Eng Rev 2007; 24:31-106. [DOI: 10.1080/02648725.2007.10648093] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Pradhan A, Tuteja R. Plasmodium falciparum DNA helicase 60. dsRNA- and antibody-mediated inhibition of malaria parasite growth and downregulation of its enzyme activities by DNA-interacting compounds. FEBS J 2006; 273:3545-56. [PMID: 16884495 DOI: 10.1111/j.1742-4658.2006.05362.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Helicases are ubiquitous enzymes that play important roles in all types of DNA transaction in the cells. Recently we have reported the characterization of the first DEAD-box helicase [Plasmodium falciparum DNA helicase 60 (PfDH60)] from Plasmodium falciparum and have shown that it is a unique, dual bipolar helicase expressed in a stage-specific manner. In this study, we show the further characterization of PfDH60. For analyzing the significance of this enzyme in parasite growth, we studied the effect of dsRNA and specific antibodies on growth of the parasite. The studies indicate that the parasite cultures treated with PfDH60 dsRNA exhibited approximately 50% growth inhibition when compared with either untreated cultures or cultures treated with unrelated dsRNA. It was interesting to note that purified immunoglobulins against PfDH60 induced approximately 62% inhibition of in vitro growth of P. falciparum and that this inhibitory effect was associated with morphologic damage to the parasite. DNA-interacting compounds inhibit DNA helicase and ssDNA-dependent ATPase activities of PfDH60. Of various compounds tested, only actinomycin, daunorubicin, ethidium bromide, netropsin and nogalamycin were able to inhibit the enzyme activities of PfDH60, with apparent IC50 values for helicase inhibition of 0.8, 0.3, 2.0, 1.2 and 1.5 microm, respectively. It may be proposed that these compounds form a complex with DNA and specifically inhibit helicases due to obstruction in the translocation of the enzyme. These compounds also inhibited parasite growth in culture. This is the first study to show inhibition of growth of the parasite by the dsRNA of a helicase, and most probably this is due to interference with cognate mRNA expression.
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Affiliation(s)
- Arun Pradhan
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
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