Project description:Alpha-gal syndrome (AGS) is a delayed allergic response to red meat caused by the production of alpha-gal-specific IgE following certain tick bites. We designed this study to characterize the underlying immune response to tick bites associated with AGS. Our results suggest that Amblyomma americanum bites direct mouse immunity toward Th2 following the initial burst of proinflammatory response and facilitate host sensitization to the α-gal antigen.
Project description:Transcriptional profiling of lymph nodes of three cattle breeds (Bonsmara, Brahman, Holstein-Friesian) in response to the cattle tick (Rhipicephalus microplus) larvae and adult infestation. Emphasis is placed on firstly, comparing transcriptional responses within a cattle breed, before and after infestation, and secondly, comparing differentially expressed genes common between the breeds.
Project description:Understanding the molecular basis of how the tick adapts to feed on different animal hosts is central to understanding tick and tick-borne disease (TBD) epidemiology. Tick adaptation to feed on vertebrate hosts is regulated by tick secretion of multiple tick saliva proteins (TSPs) and other molecules that regulate tick feeding. This study was initiated to determine if ticks such as Ixodes scapularis and Amblyomma americanum that are adapted to feed on multiple hosts utilized the same sets of proteins to accomplish feeding on all hosts. Our data suggest that ticks of the same species differentially express proteins when feeding on diffent hosts. SDS-PAGE and silver staining analysis revealed unique protein eletrophoretic profile in saliva of Ixodes scapularis and Amblyomma americanum that were stimulated to start feeding on different hosts: rabbits, humans, and dogs. LC-MS/MS sequencing and pairwise analysis of proteins in saliva of I. scapularis and A. americanum ticks that were non-stimulated and those that were stimulated to feed on rabbits, dogs, or humans identified TSPs that were unique to each treatment and those that were common. Overal, we identified a total of 276 and 340 non-redundant I. scapularis and A. americanum TSPs, which we have classified into 28 functional classes that include secreted conserved proteins (unknown functions), proteinase inhibitors, lipocalins, extracellular matrix/cell adhesion, heme/iron metabolism, signal transduction and immunity-related proteins being the most predominant in saliva of unfed ticks. With exception of Rhipicephalus microplus, anti-tick vaccine research relies on feeding lab animals. Data here suggest that lab animal data could result in prioritizing irrelevant targets as some tick genes are unique to ticks fed on lab animals. This study provides the platform that could be utilized to identify relevant target anti-tick vaccine antigens, and will facilitate early stage tick feeding research.
Project description:Anti-tick vaccines represent a promising alternative to chemical acaricides for the management of ticks on wildlife; however little progress has been made to produce an effective vaccine in hosts relevant to tick reproduction. Further, most of the antigens described are expressed during feeding in domesticated hosts and may not activate the immune system in wild hosts. We recently tested Amblyomma americanum salivary (SG) and midgut (MG) extracellular vesicles (EVs) as vaccine candidates in white-tailed deer (Odocoileus virginianus; WTD), which resulted in on-host female tick mortality. Herein, we describe our efforts to identify the antigenic proteins found within these vesicles. Within both SG- and MG-EVs, an enriched “core- cargo” was identified within both SG- and MG-EVs, including chaperones, small GTPases, and other proteins previously reported in small EVs was discovered. Label-free quantitative proteomics showed significant differences in protein cargo between MG and SG-EVs (333 proteins out of 516). Serum from three vaccinated WTD (pre-vaccinated and day 57 post vaccination) and one control WTD was used to immunoprecipitated antigenic proteins from SG- and MG-EV preparations. Proteomic analysis of immunoprecipitated proteins identified seven antigenic proteins in SG-EVs and one in MG-EVs that were statistically significantly different from the pre-vaccinated serum. Moreover, these proteins were unique to vaccinated animals (not precipitated by control serums). Additionally, two MG-EVs and 24 SG-EV proteins show antigenic potential. These proteins represent promising candidates for anti-tick vaccine design in WTD and other wildlife.
Project description:Tick infestations by Rhipicephalus microplus, the cattle tick, cause enormous losses to health and animal production. Ticks induce immune response in their hosts; therefore their immunobiological control is feasible. The available anti-tick vaccines display variable efficacy and short-lived, encouraging the search for new protective antigens. The identification of important genes in tick parasitism may indicate protective antigens useful to compose an anti-tick vaccine. We have developed and tested so far four recombinant salivary antigens as a multicomponent anti-tick vaccine in tick-susceptible bovines (Holstein breed). The challenge with R. microplus larvae displayed that tick infestation in vaccinated bovines was significantly reduced. In order to elucidate the molecular mechanisms trigged after immunisation and during infestation, RNA-seq data of peripheral blood from vaccinated and control animals were obtained in different periods of the immunisation trial. A total of 24 mRNA-seq Illumina libraries (single-end, 100 bp) were analysed to identify differential gene expression according to the experimental condition.