Neospora caninum; recombinant antigens; cytotoxicity; mouse model; calcium dependent kinase inhibitors; Apicomplexa; sheep model; immunity
Basto Afonso P., Anghel Nicoleta, Rubbiani Riccardo, Müller Joachim, Stibal David, Giannini Federico, Süss-Fink Georg, Balmer Vreni, Gasser Gilles, Furrer Julien, Hemphill Andrew (2019), Targeting of the mitochondrion by dinuclear thiolato-bridged arene ruthenium complexes in cancer cells and in the apicomplexan parasite Neospora caninum, in Metallomics
, 11(2), 462-474.
García-Lunar P., Schares G., Sanz-Fernández A., Jiménez-Meléndez A., García-Soto I., Regidor-Cerrillo J., Pastor-Fernández I., Hemphill A., Fernández-Álvarez M., Ortega-Mora L. M., Álvarez-García G. (2019), Development and characterization of monoclonal antibodies against Besnoitia besnoiti tachyzoites, in Parasitology
, 146(02), 187-196.
Müller Joachim, Manser Vera, Hemphill Andrew (2019), In vitro treatment of Besnoitia besnoiti with the naphto-quinone buparvaquone results in marked inhibition of tachyzoite proliferation, mitochondrial alterations and rapid adaptation of tachyzoites to increased drug concentrations, in Parasitology
, 146(1), 112-120.
Sánchez-Sánchez Roberto, Ferre Ignacio, Regidor-Cerrillo Javier, Gutiérrez-Expósito Daniel, Ferrer Luis Miguel, Arteche-Villasol Noive, Moreno-Gonzalo Javier, Müller Joachim, Aguado-Martínez Adriana, Pérez Valentín, Hemphill Andrew, Ortega-Mora Luis Miguel, Benavides Julio (2019), Virulence in Mice of a Toxoplasma gondii Type II Isolate Does Not Correlate With the Outcome of Experimental Infection in Pregnant Sheep, in Frontiers in Cellular and Infection Microbiology
, 8, 1-18.
Aguado-Martínez Adriana, Basto Afonso P., Tanaka Shun, Ryser Lorenz T., Nunes Telmo P., Ortega-Mora Luis-Miguel, Arranz-Solís David, Leitão Alexandre, Hemphill Andrew (2019), Immunization with a cocktail of antigens fused with OprI reduces Neospora caninum vertical transmission and postnatal mortality in mice, in Vaccine
, 37(3), 473-483.
Beteck Richard M., Seldon Ronnett, Coertzen Dina, van der Watt Mariëtte E., Reader Janette, Mackenzie Jared S., Lamprecht Dirk A., Abraham Matthew, Eribez Korina, Müller Joachim, Rui Feng, Zhu Guang, de Grano Ruel Valerio, Williams Ian D., Smit Frans J., Steyn Adrie J. C., Winzeler Elizabeth A., Hemphill Andrew, Birkholtz Lyn-Marie, Warner Digby F., N’Da David D., Haynes Richard K. (2018), Accessible and distinct decoquinate derivatives active against Mycobacterium tuberculosis and apicomplexan parasites, in Communications Chemistry
, 1(1), 62-62.
Anghel Nicoleta, Balmer Vreni, Müller Joachim, Winzer Pablo, Aguado-Martinez Adriana, Roozbehani Mona, Pou Sovitj, Nilsen Aaron, Riscoe Michael, Doggett J. Stone, Hemphill Andrew (2018), Endochin-Like Quinolones Exhibit Promising Efficacy Against Neospora Caninum in vitro and in Experimentally Infected Pregnant Mice, in Frontiers in Veterinary Science
, 5, 1-15.
Roozbehani Mona, Falak Reza, Mohammadi Mohsen, Hemphill Andrew, Razmjou Elham, Meamar Ahmad reza, Masoori Leila, Khoshmirsafa Majid, Moradi Maryam, Gharavi Mohammad Javad (2018), Characterization of a multi-epitope peptide with selective MHC-binding capabilities encapsulated in PLGA nanoparticles as a novel vaccine candidate against Toxoplasma gondii infection, in Vaccine
, 36(41), 6124-6132.
Jiménez-Meléndez Alejandro, Rico-San Román Laura, Hemphill Andrew, Balmer Vreni, Ortega-Mora Luis Miguel, Álvarez-García Gema (2018), Repurposing of commercially available anti-coccidials identifies diclazuril and decoquinate as potential therapeutic candidates against Besnoitia besnoiti infection, in Veterinary Parasitology
, 261, 77-85.
Dawoody Nejad Ladan, Serricchio Mauro, Jelk Jennifer, Hemphill Andrew, Bütikofer Peter (2018), TbLpn, a key enzyme in lipid droplet formation and phospholipid metabolism, is essential for mitochondrial integrity and growth of Trypanosoma brucei Role of lipin in T. brucei growth, in Molecular Microbiology
, 109(1), 105-120.
Olias P, Dettwiler I, Hemphill A, Deplazes P, Steiner A, Meylan M (2018), The significance of cryptosporidiosis for the health of calves in SwitzerlandDie Bedeutung der Cryptosporidiose für die Kälbergesundheit in der Schweiz, in Schweiz Arch Tierheilkd
, 160(6), 363-374.
Cardoso Rita, Wang Junhua, Müller Joachim, Rupp Sebastian, Leitão Alexandre, Hemphill Andrew (2018), Modulation of cis- and trans- Golgi and the Rab9A-GTPase during infection by Besnoitia besnoiti , Toxoplasma gondii and Neospora caninum, in Experimental Parasitology
, 187, 75-85.
Sánchez-Sánchez Roberto, Ferre Ignacio, Re Michela, Vázquez Patricia, Ferrer Luis Miguel, Blanco-Murcia Javier, Regidor-Cerrillo Javier, Pizarro Díaz Manuel, González-Huecas Marta, Tabanera Enrique, García-Lunar Paula, Benavides Julio, Castaño Pablo, Hemphill Andrew, Hulverson Matthew A., Whitman Grant R., Rivas Kasey L., Choi Ryan, Ojo Kayode K., Barrett Lynn K., Van Voorhis Wesley C., Ortega-Mora Luis Miguel (2018), Safety and efficacy of the bumped kinase inhibitor BKI-1553 in pregnant sheep experimentally infected with Neospora caninum tachyzoites, in International Journal for Parasitology: Drugs and Drug Resistance
, 8(1), 112-124.
Harmse Rozanne, Wong Ho Ning, Smit Frans J., Müller Joachim, Hemphill Andrew, N'Da David D., Haynes Richard K. (2017), Activities of 11-Azaartemisinin and N -Sulfonyl Derivatives against Neospora caninum and Comparative Cytotoxicities, in ChemMedChem
, 12(24), 2094-2098.
Hulverson Matthew A., Choi Ryan, Arnold Samuel L.M., Schaefer Deborah A., Hemphill Andrew, McCloskey Molly C., Betzer Dana P., Müller Joachim, Vidadala Rama S.R., Whitman Grant R., Rivas Kasey L., Barrett Lynn K., Hackman Robert C., Love Melissa S., McNamara Case W., Shaughnessy Thomas K., Kondratiuk Alison, Kurnick Matthew, Banfor Patricia N., Lynch James J., Freiberg Gail M., Kempf Dale J., Maly Dustin J., Riggs Michael W., et al. (2017), Advances in bumped kinase inhibitors for human and animal therapy for cryptosporidiosis, in International Journal for Parasitology
, 47(12), 753-763.
Hemphill Andrew, Leitão Alexandre, Ortega-Mora Luis-Miguel, Cooke Brian M. (2017), ApiCOWplexa 2017 – 4th International Meeting on Apicomplexan Parasites in Farm Animals, in International Journal for Parasitology
, 47(12), 697-699.
Jiménez-Meléndez Alejandro, Ojo Kayode K., Wallace Alexandra M., Smith Tess R., Hemphill Andrew, Balmer Vreni, Regidor-Cerrillo Javier, Ortega-Mora Luis M., Hehl Adrian B., Fan Erkang, Maly Dustin J., Van Voorhis Wesley C., Álvarez-García Gema (2017), In vitro efficacy of bumped kinase inhibitors against Besnoitia besnoiti tachyzoites, in International Journal for Parasitology
, 47(12), 811-821.
Müller Joachim, Aguado Adriana, Laleu Benoît, Balmer Vreni, Ritler Dominic, Hemphill Andrew (2017), In vitro screening of the open source Pathogen Box identifies novel compounds with profound activities against Neospora caninum, in International Journal for Parasitology
, 47(12), 801-809.
Aguado-Martínez Adriana, Basto Afonso P., Leitão Alexandre, Hemphill Andrew (2017), Neospora caninum in non-pregnant and pregnant mouse models: cross-talk between infection and immunity, in International Journal for Parasitology
, 47(12), 723-735.
Kunz Stefan, Balmer Vreni, Sterk Geert Jan, Pollastri Michael P., Leurs Rob, Müller Norbert, Hemphill Andrew, Spycher Cornelia (2017), The single cyclic nucleotide-specific phosphodiesterase of the intestinal parasite Giardia lamblia represents a potential drug target, in PLOS Neglected Tropical Diseases
, 11(9), e0005891-e0005891.
Van Voorhis Wesley C., Doggett J. Stone, Parsons Marilyn, Hulverson Matthew A., Choi Ryan, Arnold Samuel L.M., Riggs Michael W., Hemphill Andrew, Howe Daniel K., Mealey Robert H., Lau Audrey O.T., Merritt Ethan A., Maly Dustin J., Fan Erkang, Ojo Kayode K. (2017), Extended-spectrum antiprotozoal bumped kinase inhibitors: A review, in Experimental Parasitology
, 180, 71-83.
Basto Afonso P., Müller Joachim, Rubbiani Riccardo, Stibal David, Giannini Federico, Süss-Fink Georg, Balmer Vreni, Hemphill Andrew, Gasser Gilles, Furrer Julien (2017), Characterization of the Activities of Dinuclear Thiolato-Bridged Arene Ruthenium Complexes against Toxoplasma gondii, in Antimicrobial Agents and Chemotherapy
, 61(9), 1-10.
Müller Joachim, Aguado-Martínez Adriana, Ortega-Mora Luis-Miguel, Moreno-Gonzalo Javier, Ferre Ignacio, Hulverson Matthew A., Choi Ryan, McCloskey Molly C., Barrett Lynn K., Maly Dustin J., Ojo Kayode K., Van Voorhis Wes, Hemphill Andrew (2017), Development of a murine vertical transmission model for Toxoplasma gondii oocyst infection and studies on the efficacy of bumped kinase inhibitor (BKI)-1294 and the naphthoquinone buparvaquone against congenital toxoplasmosis, in Journal of Antimicrobial Chemotherapy
, 72(8), 2334-2341.
Müller Joachim, Aguado-Martínez Adriana, Balmer Vreni, Maly Dustin J., Fan Erkang, Ortega-Mora Luis-Miguel, Ojo Kayode K., Van Voorhis Wesley C., Hemphill Andrew (2017), Two Novel Calcium-Dependent Protein Kinase 1 Inhibitors Interfere with Vertical Transmission in Mice Infected with Neospora caninum Tachyzoites, in Antimicrobial Agents and Chemotherapy
, 61(4), 1-12.
Leineweber Margret, Spekker-Bosker Katrin, Ince Vanessa, Schares Gereon, Hemphill Andrew, Eller Silvia K., Däubener Walter (2017), First Characterization of the Neospora caninum Dense Granule Protein GRA9, in BioMed Research International
, 2017, 1-15.
DubeyJitender, HemphillAndrew, Calero-BernalRafael, ScharesGereon (2017), Neosporosis in animals
, CRC Press, Taylor & Francis Group, Boca Raton.
Horcajo P., Regidor-Cerrillo J., Aguado-Martínez A., Hemphill A., Ortega-Mora L. M. (2016), Vaccines for bovine neosporosis: current status and key aspects for development, in Parasite Immunology
, 38(12), 709-723.
Van Voorhis Wesley C., Adams John H., Adelfio Roberto, Ahyong Vida, Akabas Myles H., Alano Pietro, Alday Aintzane, Alemán Resto Yesmalie, Alsibaee Aishah, Alzualde Ainhoa, Andrews Katherine T., Avery Simon V., Avery Vicky M., Ayong Lawrence, Baker Mark, Baker Stephen, Ben Mamoun Choukri, Bhatia Sangeeta, Bickle Quentin, Bounaadja Lotfi, Bowling Tana, Bosch Jürgen, Boucher Lauren E., Boyom Fabrice F., et al. (2016), Open Source Drug Discovery with the Malaria Box Compound Collection for Neglected Diseases and Beyond, in PLOS Pathogens
, 12(7), e1005763-e1005763.
CARDOSO RITA, SOARES HELENA, HEMPHILL ANDREW, LEITÃO ALEXANDRE (2016), Apicomplexans pulling the strings: manipulation of the host cell cytoskeleton dynamics, in Parasitology
, 143(08), 957-970.
Müller Joachim, Hemphill Andrew (2016), Drug target identification in protozoan parasites, in Expert Opinion on Drug Discovery
, 11(8), 815-824.
Imhof Simon, Fragoso Cristina, Hemphill Andrew, von Schubert Conrad, Li Dong, Legant Wesley, Betzig Eric, Roditi Isabel (2016), Flagellar membrane fusion and protein exchange in trypanosomes; a new form of cell-cell communication?, in F1000Research
, 5, 682-682.
Background: The apicomplexan Neospora caninum represents one of the major infectious causes of bovine abortion worldwide, and also causes fetal loss in sheep and other ruminants. Parasite proteins with invasive functions, released from rhoptries, micronemes and dense granules, are highly interesting vaccine targets, but information on parasite antigens specifically targeted by T cells is sparse. The development of subunit vaccines against neosporosis has been hampered by the fact that an immune response that is induced in a non-pregnant animal prior to pregnancy is generally not maintained, or when maintained, not appropriately, for pregnancy. Thus, alternative approaches for defining vaccine candidates are needed. Experience from other disease models shows that T cell antigens could constitute prime vaccine candidates. In addition, chemotherapy could offer an alternative and/or addition to vaccination. In this respect, inhibitors of calcium-dependent protein kinase 1, such as the bumped kinase inhibitor BKI-1294, exhibit outstanding efficacy in the non-pregnant and pregnant neosporosis mouse models, and BKI-1294 has emerged as a prime candidate to be further evaluated in a ruminant model. BKI-1294 does not kill the parasites instantly but interferes in the separation of daughter zoites. This leads to the formation of large intracellular multinucleated complexes, which remain viable for several days to weeks in vitro. Preliminary studies indicate that this could also impact on the immune response against the parasite in vivo, and this cross-talk between chemotherapy and immunity aspect will be further elaborated in this project. Working hypotheses: (1.) BKI-1294 treatment in mice enhances the immune response against infection, which in turn supports treatment efficacy.(2.) Antigens targeted by N. caninum-specific CD4+ and CD8+ T cells represent potential vaccine candidates. (3.) BKI-1294 limits neosporosis and also impacts on the immune response in sheep. Specific aims:(1.) Characterization of (i) the proteome of multinucleated complexes in N. caninum-infected host cells treated with BKI-1294 in vitro, and of (ii) the immune response in BKI-1294-treated and non-treated infected T cell deficient and wildtype mice. (2.) Identification and characterization of Neospora T-cell target antigens, assessment of their vaccine potential in pregnant mice, and preliminary evaluation of their antigenicity in N. caninum infected pregnant sheep.(3.) Assessment of BKI-1294 therapy in the pregnant neosporosis sheep model, and its impact on the ovine immune response.Experimental design and/or methods: (1.) BKI-1294-induced proteome changes will be analyzed in a time-course experiment by immunoblotting followed by LC-MS. Overexpressed proteins that are potentially targeted by the immune response will be identified by immunoblotting and recombinantly expressed. Innate and acquired immune responses in BKI-treated or non-treated Neospora-infected pregnant or non-pregnant mice are comparatively analyzed, and the effects of BKI-treatment on immunity assessed by re-challenge experiments. Experiments in athymic nude mice will be performed to study the role of T cells in compound efficacy.(2.) Generation of N. caninum-specific CD4+ and CD8+ T cell lines (NcTcs) from pregnant and non-pregnant mice with acute or chronic infection, which will be studied with regard to proliferation, phenotype (CD4+ and CD8+ populations), polarization and cytotoxicity. We will identify proteins targeted by T cells through screening antigens previously studied in the group as vaccine candidates, antigens shown to be upregulated in virulent isolates, and antigens upregulated in multinucleated complexes. The targeted antigens are then assessed for their immunoprotective potential in the pregnant neosporosis mouse model.(3.) BKI-1294 efficacy will be studied in the N. caninum-infected pregnant sheep model. Parameters in dams (clinical signs such as fever and abortion) and offspring (fetal death, stillbirth, birth of weak offspring, neurological disorders, congenital transmission in healthy lambs) will be assessed. Tissue samples of aborted offspring and/or newborn lambs will be analyzed by (immuno)histology and real time PCR for measuring parasite and lesion presence and infection intensity. Cellular and humoral peripheral responses and comparative detection of cytokines in placental tissues will be analyzed by real time PCR, ELISA and IHC to study the role of immunity during BKI-1294 treatment in sheep. Expected value of the project: This project aims to develop novel tools to prospectively limit economic losses due to neosporosis, but has a wider impact in that CDPK1 is an important drug target in other apicomplexan parasites such as Toxoplasma, Cryptosporidium, and Besnoitia among others. For the development of preventive or therapeutical measures against neosporosis, it is important to show whether and how BKI-1294 affects the immunogenicity of the parasite, and whether this change could be a relevant factor for improving protective immunity and contribute to compound efficacy. As the role of T cell immunity in neosporosis has not been widely explored, we aim to identify novel T-cell targets, and these can constitute novel vaccine candidates. This project aims to shed light on the relationship between immunity and BKI-1294 therapy, and provides important information on how vaccination could be coupled to a drug treatment strategy, both in mice but also in a ruminant model that largely mimics infection in cattle. Prospectively, a combined immune-chemotherapeutical approach could represent an interesting option for future development of effective measures against neosporosis, and possibly also related apicomplexans such as Toxoplasma, Besnoitia among others.