Development of Onchocerca volvulus in humanized NSG mice and detection of parasite biomarkers in urine and serum.

Background The study of Onchocerca volvulus has been limited by its host range, with only humans and non-human primates shown to be susceptible to the full life cycle infection. Small animal models that support the development of adult parasites have not been identified. Methodology/principal findin...

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Bibliographic Details
Published in:PLOS Neglected Tropical Diseases
Main Authors: John B Patton, Sasisekhar Bennuru, Mark L Eberhard, Jessica A Hess, April Torigian, Sara Lustigman, Thomas B Nutman, David Abraham
Format: Article in Journal/Newspaper
Language:English
Published: Public Library of Science (PLoS) 2018
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Online Access:https://doi.org/10.1371/journal.pntd.0006977
https://doaj.org/article/d5eefc01f5184522a2b2fc4f3dadff49
Description
Summary:Background The study of Onchocerca volvulus has been limited by its host range, with only humans and non-human primates shown to be susceptible to the full life cycle infection. Small animal models that support the development of adult parasites have not been identified. Methodology/principal findings We hypothesized that highly immunodeficient NSG mice would support the survival and maturation of O. volvulus and alteration of the host microenvironment through the addition of various human cells and tissues would further enhance the level of parasite maturation. NSG mice were humanized with: (1) umbilical cord derived CD34+ stem cells, (2) fetal derived liver, thymus and CD34+ stem cells or (3) primary human skeletal muscle cells. NSG and humanized NSG mice were infected with 100 O. volvulus infective larvae (L3) for 4 to 12 weeks. When necropsies of infected animals were performed, it was observed that parasites survived and developed throughout the infection time course. In each of the different humanized mouse models, worms matured from L3 to advanced fourth stage larvae, with both male and female organ development. In addition, worms increased in length by up to 4-fold. Serum and urine, collected from humanized mice for identification of potential biomarkers of infection, allowed for the identification of 10 O. volvulus-derived proteins found specifically in either the urine or the serum of the humanized O. volvulus-infected NSG mice. Conclusions/significance The newly identified mouse models for onchocerciasis will enable the development of O. volvulus specific biomarkers, screening for new therapeutic approaches and potentially studying the human immune response to infection with O. volvulus.