title: An integrated in vitro imaging platform for characterizing filarial parasite behavior within a multicellular microenvironment.
abstract: Lymphatic Filariasis, a Neglected Tropical Disease, is caused by thread-like parasitic worms, including B. malayi, which migrate to the human lymphatic system following transmission. The parasites reside in collecting lymphatic vessels and lymph nodes for years, often resulting in lymphedema, elephantiasis or hydrocele. The mechanisms driving worm migration and retention within the lymphatics are currently unknown. We have developed an integrated in vitro imaging platform capable of quantifying B. malayi migration and behavior in a multicellular microenvironment relevant to the initial site of worm injection by incorporating the worm in a Polydimethylsiloxane (PDMS) microchannel in the presence of human dermal lymphatic endothelial cells (LECs) and human dermal fibroblasts (HDFs). The platform utilizes a motorized controllable microscope with CO2 and temperature regulation to allow for worm tracking experiments with high resolution over large length and time scales. Using post-acquisition algorithms, we quantified four parameters: 1) speed, 2) thrashing intensity, 3) percentage of time spent in a given cell region and 4) persistence ratio. We demonstrated the utility of our system by quantifying these parameters for L3 B. malayi in the presence of LECs and HDFs. Speed and thrashing increased in the presence of both cell types and were altered within minutes upon exposure to the anthelmintic drug, tetramisole. The worms displayed no targeted migration towards either cell type for the time course of this study (3 hours). When cells were not present in the chamber, worm thrashing correlated directly with worm speed. However, this correlation was lost in the presence of cells. The described platform provides the ability to further study B. malayi migration and behavior.
authors.affiliation: Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America; School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: Timothy
authors.initials: T
authors.lastname: Kassis
authors.affiliation: Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: Henry M
authors.initials: HM
authors.lastname: Skelton
authors.affiliation: Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: Iris M
authors.initials: IM
authors.lastname: Lu
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Moorhead
authors.affiliation: Parker H. Petit Institute for Bioengineering & Bioscience, Georgia Institute of Technology, Atlanta, Georgia, United States of America; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America.
authors.forename: J Brandon
authors.initials: JB
authors.lastname: Dixon
mesh_terms: D000465:Algorithms; D000818:Animals; D017178:Brugia malayi / Q000502:physiology*; D002478:Cells, Cultured; D060833:Cellular Microenvironment / Q000502:physiology; D004605:Elephantiasis, Filarial / Q000469:parasitology*; D042783:Endothelial Cells / Q000166:cytology; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D008208:Lymphatic System / Q000166:cytology; D018715:Microscopy, Video / Q000379:methods*; D010274:Parasitology / Q000295:instrumentation / Q000379:methods