Harry W. Dickerson
BVSc, MS, PhD
Associate Dean for Research and Graduate Affairs
- BVSc (1977), Onderstepoort Faculty of Veterinary Science, University of Pretoria, South Africa
- MS (1982), Medical Microbiology, University of Georgia
- PhD (1985), Medical Microbiology, University of Georgia
About Harry W. Dickerson
Dr. Dickerson studies the immune response of bony fishes (teleosts) to the common protozoan parasite Ichthyophthirius multifiliis. This virulent ciliate is well known among aquaculturists as the etiological agent of “white spot,” a disease that afflicts a wide range of freshwater fishes. While I. multifiliis is highly pathogenic, animals exposed to controlled infections develop a strong acquired resistance to the parasite. I. multifiliis and channel catfish provide a good host-parasite experimental system for research on the mechanisms of mucosal immunity. Ichthyophthirius is confined to the epidermal layers of the skin and gills, and therefore can be visualized by light microscopy from the time it invades the host until the time it exits. It provides a unique system for the in vivo study of host-parasite interactions.
Studies in the Dickerson laboratory suggest that acquired protection of the host following exposure to the parasite involves a novel mechanism of humoral immunity affecting parasite behavior. Rather than being killed, parasites are forced to exit fish prematurely in response to antibody binding. The target antigens involved in this response are a class of highly abundant glycosylphosphatidly-inositol (GPI)-anchored coat proteins referred to as immobilization antigens (i-antigens). Antibodies against surface i-antigens have been used to serotype isolates of the parasite, which in turn has contributed to new knowledge regarding the epizootiology of disease outbreaks and virulence between and among isolates.
I. multifiliis. His laboratory also investigates the mechanisms of teleost B cell induction and antibody production at mucosal surfaces. His laboratory has been funded since 1987 through grants from the USDA National Research Competitive Grants Program, NIH, NSF, and private contracts.
- Molecular basis of microbial pathogenesis immunoparasitology and fish vaccinology
- Craig Findly R, Zhao X, Noe J, Camus AC, Dickerson HW. B cell memory following infection and challenge of channel catfish with Ichthyophthirius multifiliis. Dev Comp Immunol. 2013 Mar;39(3):302-11.
- Coyne RS, Hannick L, Shanmugam D, Hostetler JB, Brami D, Joardar VS, Johnson J, Radune D, Singh I, Badger JH, Kumar U, Saier M, Wang Y, Cai H, Gu J, Mather MW, Vaidya AB, Wilkes DE, Rajagopalan V, Asai DJ, Pearson CG, Findly RC, Dickerson HW, Wu M, Martens C, Van de Peer Y, Roos DS, Cassidy-Hanley DM, Clark TG. Comparative genomics of the pathogenic ciliate Ichthyophthirius multifiliis, its free-living relatives and a host species provide insights into adoption of a parasitic lifestyle and prospects for disease control. Genome Biol. 2011 Oct 17;12(10):R100.
- Cassidy-Hanley DM, Cordonnier-Pratt MM, Pratt LH, Devine C, Mozammal Hossain M, Dickerson HW, Clark TG. Transcriptional profiling of stage specific gene expression in the parasitic ciliate Ichthyophthirius multifiliis. Mol Biochem Parasitol. 2011 Jul-Aug;178(1-2):29-39. Diseases of Aquatic Organisms, 69(2-3):227-32.
- Sun HY, Noe J, Barber J, Coyne RS, Cassidy-Hanley D, Clark TG, Findly RC, Dickerson HW. Endosymbiotic bacteria in the parasitic ciliate Ichthyophthirius multifiliis. Appl Environ Microbiol. 2009 Dec;75(23):7445-52.
- Zhao X, Findly RC, Dickerson HW. Cutaneous antibody-secreting cells and B cells in a teleost fish. Dev Comp Immunol. 2008;32(5):500-8. Epub 2007 Nov 5.
- Swennes AG, Findly RC, Dickerson HW. Cross-immunity and antibody responses to different immobilisation serotypes of Ichthyophthirius multifiliis. Fish Shellfish Immunol. 2007 Jun;22(6):589-97. Epub 2006 Aug 1.
- Swennes AG, Noe JG, Findly RC, Dickerson HW. Differences in virulence between two serotypes of Ichthyophthirius multifiliis. Dis Aquat Organ. 2006 Apr 6;69(2-3):227-32.
- Clark TG, Dickerson HW. Antibody-mediated effects on parasite behavior: nEvidence of a novel mechanism of immunity against a parasitic protist. Parasitol Today. 1997 Dec;13(12):477-80.
- Maki JL, Dickerson HW. Systemic and cutaneous mucus antibody responses of channel catfish immunized against the protozoan parasite Ichthyophthirius multifiliis. Clin Diagn Lab Immunol. 2003 Sep;10(5):876-81.
- Everett KD, Dickerson HW. Ichthyophthirius multifiliis and Tetrahymena thermophila tolerate glyphosate but not a commercial herbicidal formulation. Bull Environ Contam Toxicol. 2003 Apr;70(4):731-8.