HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Gillespie, R. D. Articles by Titus, R. G. Search for Related Content PubMed PubMed Citation Articles by Gillespie, R. D. Articles by Titus, R. G.

Identification of an IL-2 Binding Protein in the Saliva of the Lyme Disease Vector Tick, Ixodes scapularis¹

R. Dean Gillespie^2,*, Marc C. Dolan, Joseph Piesman and Richard G. Titus^*

^* Department of Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523; and United States Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Center for Infectious Diseases, Division of Vector-Borne Infectious Diseases, Fort Collins, CO 80522

A potent inhibitor of mitogen-stimulated T cell proliferation exists in the saliva of several species of hard ticks, including the Lyme disease vector tick, Ixodes scapularis. Our characterization of this phenomenon has led to the identification of a possible mechanism for the T cell inhibitory activity of I. scapularis saliva. The T cell inhibitor can overcome stimulation of mouse spleen cells with anti-CD3 mAb; however, a direct and avid interaction with T cells does not appear to be necessary. Tick saliva inhibits a mouse IL-2 capture ELISA, suggesting that a soluble IL-2 binding factor is present in the saliva. This hypothesis was verified by using a direct binding assay in which plate-immobilized tick saliva was shown to bind both mouse and human IL-2. Elimination of the IL-2 binding capacity of saliva in the in vitro assays by trypsin digestion demonstrated that the IL-2 binding factor is a protein. These experiments comprise the first demonstration of the existence of such a secreted IL-2 binding protein from any parasite or pathogen. This arthropod salivary IL-2 binding capacity provides a simple mechanism for the suppression of T cell proliferation as well as for the activity of other immune effector cells that are responsive to IL-2 stimulation. Relevance of the tick T cell inhibitory activity to the human immune system is demonstrated by the ability of tick saliva to inhibit proliferation of human T cells and CTLL-2 cells grown in the presence of human IL-2.

This article has been cited by other articles:

				A. Sa-Nunes, A. Bafica, L. R. Antonelli, E. Y. Choi, I. M. B. Francischetti, J. F. Andersen, G.-P. Shi, T. Chavakis, J. M. Ribeiro, and M. Kotsyfakis The Immunomodulatory Action of Sialostatin L on Dendritic Cells Reveals Its Potential to Interfere with Autoimmunity J. Immunol., June 15, 2009; 182(12): 7422 - 7429. [Abstract] [Full Text] [PDF]

				X. Guo, C. J. Booth, M. A. Paley, X. Wang, K. DePonte, E. Fikrig, S. Narasimhan, and R. R. Montgomery Inhibition of Neutrophil Function by Two Tick Salivary Proteins Infect. Immun., June 1, 2009; 77(6): 2320 - 2329. [Abstract] [Full Text] [PDF]

				A. Sa-Nunes, A. Bafica, D. A. Lucas, T. P. Conrads, T. D. Veenstra, J. F. Andersen, T. N. Mather, J. M. C. Ribeiro, and I. M. B. Francischetti Prostaglandin E2 Is a Major Inhibitor of Dendritic Cell Maturation and Function in Ixodes scapularis Saliva J. Immunol., August 1, 2007; 179(3): 1497 - 1505. [Abstract] [Full Text] [PDF]

				M. R. Scheckelhoff, S. R. Telford, M. Wesley, and L. T. Hu Borrelia burgdorferi intercepts host hormonal signals to regulate expression of outer surface protein A PNAS, April 24, 2007; 104(17): 7247 - 7252. [Abstract] [Full Text] [PDF]

				R. R. Montgomery, D. Lusitani, A. de Boisfleury Chevance, and S. E. Malawista Tick Saliva Reduces Adherence and Area of Human Neutrophils Infect. Immun., May 1, 2004; 72(5): 2989 - 2994. [Abstract] [Full Text] [PDF]

				S. Narasimhan, R. R. Montgomery, K. DePonte, C. Tschudi, N. Marcantonio, J. F. Anderson, J. R. Sauer, M. Cappello, F. S. Kantor, and E. Fikrig Disruption of Ixodes scapularis anticoagulation by using RNA interference PNAS, February 3, 2004; 101(5): 1141 - 1146. [Abstract] [Full Text] [PDF]

				J. G. Valenzuela, I. M. B. Francischetti, V. M. Pham, M. K. Garfield, T. N. Mather, and J. M. C. Ribeiro Exploring the sialome of the tick Ixodes scapularis J. Exp. Biol., September 15, 2002; 205(18): 2843 - 2864. [Abstract] [Full Text] [PDF]