Interactions at the vector-host interface are likely to be most critical to transmission of arthropod transmitted infections. Our studies have demonstrated that through the action of their saliva, black-legged ticks (Ixodes scapularis) manipulate the host immune response in a manner that both assures bloodfeeding success, and favors survival and transmission of Lyme disease spirochetes (Borrelia burgdorferi). We have learned that these bacteria receive cues from tick saliva to regulate their protein expression, perhaps leading to enhanced invasiveness or survival in the host. We have discovered several novel molecules, including I. scapularis' salivary anti-complement protein (Isac) and a Factor Xa-inhibiting anticoagulant (Ixolaris), and recombinant proteins are in production. Taken together, this progress now allows us to test our hypothesis, that an effective prevention strategy for Lyme disease, and other I. scapularis-transmitted infections, can be developed by manipulating host immune responses to components of vector saliva or saliva-induced microbial products. In continuing this project, we will identify and isolate molecules from the saliva of vector ticks and from B. burgdorferi that provide protection against Lyme disease and other infections transmitted by I. scapularis. A comprehensive protocol integrating vector salivary gland genomics and proteomics is expected to accelerate both discovery and recovery of potentially important protective molecules. Massive cDNA sequencing of an I. scapularis salivary gland cDNA library containing full-length clones has revealed nearly 1,200 sequences and at least 476 genes. We will begin cloning these into plasmids using high-throughput technology to generate candidate DNA vaccines. In addition, recent advances in B. burgdorferi genomics will allow rapid progress on studies examining B. burgdorferi gene and protein expression in the presence and absence of tick saliva, or under other starvation-stress conditions. We will test whether whole genome analysis by DNA arrays and 2-D gel electrophoresis can facilitate discovery of potential protective molecules. Candidate vaccines will be screened for their ability to interrupt tick feeding or block pathogen transmission in a white-footed mouse (Peromyscus leucopus) model. We expect these studies to lead to new vaccination strategies that combine tick and bacterial elements for preventing Lyme disease, and possibly a broader range of tick-transmitted infections.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI037230-11
Application #
7032253
Study Section
Special Emphasis Panel (ZRG1-VACC (01))
Program Officer
Breen, Joseph J
Project Start
1994-09-30
Project End
2009-03-31
Budget Start
2006-04-15
Budget End
2009-03-31
Support Year
11
Fiscal Year
2006
Total Cost
$469,248
Indirect Cost
Name
University of Rhode Island
Department
Type
Organized Research Units
DUNS #
144017188
City
Kingston
State
RI
Country
United States
Zip Code
02881
Pichu, Sivakamasundari; Ribeiro, José M C; Mather, Thomas N et al. (2014) Purification of a serine protease and evidence for a protein C activator from the saliva of the tick, Ixodes scapularis. Toxicon 77:32-9
Pichu, Sivakamasundari; Yalcin, Emine B; Ribeiro, José Mc et al. (2011) Molecular characterization of novel sulfotransferases from the tick, Ixodes scapularis. BMC Biochem 12:32
Yalcin, Emine Bihter; Stangl, Hubert; Pichu, Sivakamasundari et al. (2011) Monoamine neurotransmitters as substrates for novel tick sulfotransferases, homology modeling, molecular docking, and enzyme kinetics. ACS Chem Biol 6:176-84
Karim, Shahid; Troiano, Emily; Mather, Thomas N (2010) Functional genomics tool: gene silencing in Ixodes scapularis eggs and nymphs by electroporated dsRNA. BMC Biotechnol 10:1
Pichu, Sivakamasundari; Ribeiro, José M C; Mather, Thomas N (2009) Purification and characterization of a novel salivary antimicrobial peptide from the tick, Ixodes scapularis. Biochem Biophys Res Commun 390:511-5
Kotsyfakis, Michalis; Anderson, Jennifer M; Andersen, John F et al. (2008) Cutting edge: Immunity against a ""silent"" salivary antigen of the Lyme vector Ixodes scapularis impairs its ability to feed. J Immunol 181:5209-12
Karim, Shahid; Kenny, Bronwyn; Troiano, Emily et al. (2008) RNAi-mediated gene silencing in tick synganglia: a proof of concept study. BMC Biotechnol 8:30
Sa-Nunes, Anderson; Bafica, Andre; Lucas, David A et al. (2007) Prostaglandin E2 is a major inhibitor of dendritic cell maturation and function in Ixodes scapularis saliva. J Immunol 179:1497-505
Kotsyfakis, Michalis; Karim, Shahid; Andersen, John F et al. (2007) Selective cysteine protease inhibition contributes to blood-feeding success of the tick Ixodes scapularis. J Biol Chem 282:29256-63
Karim, Shahid; Miller, Nathan J; Valenzuela, Jesus et al. (2005) RNAi-mediated gene silencing to assess the role of synaptobrevin and cystatin in tick blood feeding. Biochem Biophys Res Commun 334:1336-42

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