Teaching:

Current Research:

Ticks continue to be a threat to animal and human health, and new and novel control strategies are needed for ticks and tick-borne pathogens. Our long-term goal is to exploit the tick-host interaction during the early feeding interval to develop effective dual-target vaccine strategies against vector ticks, and the tick-borne infections they transmit. Our ultimate goal will be to vaccinate host populations with unique tick- and pathogen-specific products for the purpose of reducing vectorial capacity and/or basic reproduction rate.

Currently, we are developing a tick feeding and transmission model in white-tailed deer through which we can evaluate peptides, proteins and DNA molecules for vaccination against ticks and tick pathogens where the endpoints include disturbance of tick feeding and/or inhibition of pathogen transmission. Initial studies comprise discovering the cellular and molecular mechanisms involved in transmission of the intracellular bacteria, Ehrlichia chaffeensis through the lone star tick, Amblyomma americanum (L.).

In addition, we are also characterizing tick innate immunity to bacterial infections. Our hypothesis for this area of research is that the tick immune system manages the maintenance of pathogenic bacteria. Therefore, discovery of tick immune response genes may provide targets for novel control strategies directed toward reducing vector competency and pathogen transmission. Using a high-throughput genomic sequencing method (p454 sequencing), we have surveyed tick genes expressed in response to bacterial and fungal infections. Expressed sequence tags (ESTs) were analyzed from Dermacentor variabilis ticks that had been injected with bacteria (Escherichia coli, Bacillus subtilis, Micrococcus luteus) or fungi (Saccharomyces cerevisiae and Candida albicans) and ticks that were naturally infected with the intracellular bacterium, Anaplasma marginale. By this approach, 38,000 ESTs were assembled into 5995 contigs (catalog of tick immune responsive genes). Currently, we have identified more than 30 genes that are likely to encode for proteins involved in tick immune function.

Selected Publications:

Jaworski, D.C., Bowen, C.J. and Wasala, N.B. In Press. Vector-Borne and Zoonotic Diseases. A white tailed deer /lone star tick model for studying transmission of Ehrlichia chaffeensis.

Wasala, N.B., Bowen, C.J., and Jaworski, D.C. In Press. Expression and regulation of macrophage migration inhibitory factor (MIF) in feeding American dog ticks (Dermacentor variabilis Say). Experimental and Applied Acarology.

Wasala, N.B. and Jaworski, D.C. 2012. Dermacentor variabilis: Characterization and modeling of macrophage migration inhibitory factor with phylogenetic comparisons to other ticks, insects and parasitic nematodes. Experimental Parasitology, 130: 232-238. http://dx.doi.org/10.1016/j.exppara.2011.12.010

Jaworski, D.C., N.B. Wasala, and N.R. Walker. 2010. Evaluation of Aloft LC SC, Aloft LC G, and ARY 0486-02 SC for management of ticks in turfgrass, 2009. Arthropod Management Tests. Vol. 35: G1.

Bowen, C.J., D.C. Jaworski, N.B. Wasala and L.B. Coons. 2010. Macrophage migration inhibitory factor expression and localization in Amblyomma americanum (Ixodidae). Exp. and Appl. Acarol. 50:343-359.

Jaworski, D.C., Z. Zou, C.J. Bowen, R. Madden, N.B. Wasala, Y. Wang, K. Kocan, H. Jiang and J.W. Dillwith. 2010. Pyrosequencing and characterization of immune response genes from the American dog tick, Dermacentor variabilis (L.). Insect Molecular Biology,19: 617-630.

Jaworski, D.C., C.J. Bowen and N.B. Wasala. 2009. Amblyomma americanum (L): Tick Macrophage Migration Inhibitory Factor Peptide immunization lengthens lone star tick feeding intervals in vivo. Exp. Parasitol. 121:384-387.

Jaworski, D.C. 2003. 'Tick talk': Current view on protein release from tick salivary cells. Trends in Parasitology, 19:427-429.

Jaworski, D.C., A. Jasinskas, C.N. Metz, R. Bucala and A.G. Barbour. 2001. Identification and functional characterization of a homologue of the proinflammatory cytokine Macrophage Migration Inhibitory Factor in the tick vector, Amblyomma americanum. Insect Mol. Biol., Aug;10(4):323-331.

Jasinskas, A., D.C. Jaworski and A.G. Barbour. 2000. Amblyomma americanum: Specific uptake of immunoglobulins into tick hemolymph during feeding. Exp. Parasitol., 96:213-221.

Sanders, M.L., D.C. Jaworski, J.L. Sanchez, R.F. DeFraites, A.L. Scott, G.E. Glass, S. Raha, B. Ritchie, G.R. Needham and B.S. Schwartz. 1998. Antibody to a cDNA-derived calreticulin protein from Amblyomma americanum is a biomarker of tick exposure in humans. Am. J. Trop. Med. Hyg. 59, 279-285.

Jaworski, D.C., F.A. Simmen, W. Lamoreaux, L.B. Coons, M.T. Muller and G.R. Needham. 1995. A secreted calreticulin protein in ixodid tick saliva. J. Ins. Physiol. 41, 369-375.

Jaworski, D.C., R. Rosell, L.B. Coons and G.R. Needham. 1992. Tick (Acari: Ixodidae) attachment cement and salivary gland cells contain similar immunoreactive polypeptides. J. Med. Entomol. 29:305-309.

Jaworski, D.C., M.T. Muller, F.A. Simmen and G. R. Needham. 1990. Amblyomma americanum: Identification of tick salivary gland antigens from unfed and early feeding females with comparisons to Ixodes dammini and Dermacentor variabilis. Exp. Parasitol. 70:217-226.

Jaworski, D.C., J.R. Sauer, J.P. Williams, R.W. McNew and J.A. Hair. 1984. Age-related effects on water, lipid, hemoglobin, and critical equilibrium humidity in unfed adult lone star ticks (Acari: Ixodidae). J. Med. Entomol. 21 (1) 100-104.

Jaworski, D.C., D.M. Barker, J.P. Williams, J.R. Sauer, C.L. Ownby and J.A. Hair. 1983. Age-related changes in midgut ultrastructure and surface tegument of unfed adult lone star ticks. J. Parasitol. 69 (4) 701-708.

Invited Book Chapters:

Jaworski, D.C. 2005. Gene Expression in Acarines. In: The Biology of Disease Vectors, 2nd Ed. Beatty, B.J. and Marquardt, W.C. Eds. Elsevier Academic Press. pp. 587-599.

Jaworski, D.C. and G.R. Needham. 1996. Calreticulin in Vector Arthropods--The Secreted Calreticulin. In: Calreticulin ed. M. Michalak pp. 171-182. R.G. Landes Company, Austin, TX.