Ngwafu Nancy Ngwasiri1, Norbert W Brattig2, Dieudonné Ndjonka1, Eva Liebau3, Archile Paguem1,4,5, Dustin Leusder3, Manchang Tanyi Kingsley5,6, Albert Eisenbarth4,7, Alfons Renz4,7, Achukwi Mbunkah Daniel8. 1. University of Ngaoundéré, Ngaoundéré, Cameroon. 2. Department Molecular Medicine, Bernhard Nocht Institute of Tropical Medicine, Hamburg, Germany. 3. University of Muenster, Münster, Germany. 4. Department Comparative Zoology, Eberhard Karls University, Institute of Evolution and Ecology, Tübingen, Germany. 5. Department of Veterinary Medicine, University of Buea, Buea, Cameroon. 6. Veterinary Research Laboratory, IRAD Wakwa Regional Centre, Ngaoundéré, Cameroon. 7. Programme Onchocercoses, Station of the University of Tübingen, Ngaoundéré, Cameroon. 8. TOZARD Research Laboratory, P.O. Box 59, Bambili-Tubah, Bamenda, Cameroon. dmbunkahachukwi@gmail.com.
Abstract
BACKGROUND: During the last two decades research on animal filarial parasites, especially Onchocerca ochengi, infecting cattle in savanna areas of Africa revealed that O. ochengi as an animal model has biological features that are similar to those of O. volvulus, the aetiological agent of human onchocerciasis. There is, however, a paucity of biochemical, immunological and pathological data for O. ochengi. Galectins can be generated by parasites and their hosts. They are multifunctional molecules affecting the interaction between filarial parasites and their mammalian hosts including immune responses. This study characterized O. ochengi galectin, verified its immunologenicity and established its immune reactivity and that of Onchocerca volvulus galectin. RESULTS: The phylogenetic analysis showed the high degree of identity between the identified O. ochengi and the O. volvulus galectin-1 (ß-galactoside-binding protein-1) consisting only in one exchange of alanine for serine. O. ochengi galectin induced IgG antibodies during 28 days after immunization of Wistar rats. IgG from O. ochengi-infected cattle and O. volvulus-infected humans cross-reacted with the corresponding galectins. Under the applied experimental conditions in a cell proliferation test, O. ochengi galectin failed to significantly stimulate peripheral blood mononuclear cells (PBMCs) from O. ochengi-infected cattle, regardless of their parasite load. CONCLUSION: An O. ochengi galectin gene was identified and the recombinantly expressed protein was immunogenic. IgG from Onchocerca-infected humans and cattle showed similar cross-reaction with both respective galectins. The present findings reflect the phylogenetic relationship between the two parasites and endorse the appropriateness of the cattle O. ochengi model for O. volvulus infection research.
BACKGROUND: During the last two decades research on animal filarial parasites, especially Onchocerca ochengi, infecting cattle in savanna areas of Africa revealed that O. ochengi as an animal model has biological features that are similar to those of O. volvulus, the aetiological agent of humanonchocerciasis. There is, however, a paucity of biochemical, immunological and pathological data for O. ochengi. Galectins can be generated by parasites and their hosts. They are multifunctional molecules affecting the interaction between filarial parasites and their mammalian hosts including immune responses. This study characterized O. ochengigalectin, verified its immunologenicity and established its immune reactivity and that of Onchocerca volvulusgalectin. RESULTS: The phylogenetic analysis showed the high degree of identity between the identified O. ochengi and the O. volvulusgalectin-1 (ß-galactoside-binding protein-1) consisting only in one exchange of alanine for serine. O. ochengigalectin induced IgG antibodies during 28 days after immunization of Wistar rats. IgG from O. ochengi-infected cattle and O. volvulus-infectedhumans cross-reacted with the corresponding galectins. Under the applied experimental conditions in a cell proliferation test, O. ochengigalectin failed to significantly stimulate peripheral blood mononuclear cells (PBMCs) from O. ochengi-infected cattle, regardless of their parasite load. CONCLUSION: An O. ochengigalectin gene was identified and the recombinantly expressed protein was immunogenic. IgG from Onchocerca-infectedhumans and cattle showed similar cross-reaction with both respective galectins. The present findings reflect the phylogenetic relationship between the two parasites and endorse the appropriateness of the cattleO. ochengi model for O. volvulus infection research.
Authors: Virginia L Tchakouté; Simon P Graham; Siv Aina Jensen; Benjamin L Makepeace; Charles K Nfon; Leo M Njongmeta; Sara Lustigman; Peter A Enyong; Vincent N Tanya; Albert E Bianco; Alexander J Trees Journal: Proc Natl Acad Sci U S A Date: 2006-04-03 Impact factor: 11.205