Tick-Pathogen Interactions and Vector Competence: Identification of Molecular Drivers for Tick-Borne Diseases.

José De La Fuente,Alejandro Cabezas-Cruz,Santo Caracappa,Katherine M Kocan,Anna Papa,Alessandra Torina,Nataliia Rudenko,Sandra Antunes,Margarita Villar,Pilar Alberdi,Sarah Bonnet,Anthony R Fooks,Karen L Mansfield,Nieves Ayllón,Maryna Golovchenko,Nicholas Johnson,Ard M Nijhof,Ryan O M Rego,Libor Grubhoffer,Agustı́n Estrada-Peña ,Ana Domingos ,Christian Gortázar ,Marie Vancová

doi:10.3389/fcimb.2017.00114

Abstract

Ticks and the pathogens they transmit constitute a growing burden for human and animal health worldwide. Vector competence is a component of vectorial capacity and depends on genetic determinants affecting the ability of a vector to transmit a pathogen. These determinants affect traits such as tick-host-pathogen and susceptibility to pathogen infection. Therefore, the elucidation of the mechanisms involved in tick-pathogen interactions that affect vector competence is essential for the identification of molecular drivers for tick-borne diseases. In this review, we provide a comprehensive overview of tick-pathogen molecular interactions for bacteria, viruses, and protozoa affecting human and animal health. Additionally, the impact of tick microbiome on these interactions was considered. Results show that different pathogens evolved similar strategies such as manipulation of the immune response to infect vectors and facilitate multiplication and transmission. Furthermore, some of these strategies may be used by pathogens to infect both tick and mammalian hosts. Identification of interactions that promote tick survival, spread, and pathogen transmission provides the opportunity to disrupt these interactions and lead to a reduction in tick burden and the prevalence of tick-borne diseases. Targeting some of the similar mechanisms used by the pathogens for infection and transmission by ticks may assist in development of preventative strategies against multiple tick-borne diseases.

Highlights

Ectoparasites that derive nutrition through blood feeding are efficient vectors of disease
Host-tick and host-pathogen molecular interactions affect vector competence, this review focuses on tick-pathogen interactions for the identification of molecular drivers affecting vector competence that may result in the identification of tick-derived and pathogen-derived antigens for the development of novel control and prevention strategies for tick-borne diseases
Arthropod vectors have co-evolved with a variety of microorganisms including bacteria, viruses, and protozoa to the point where they appear to co-exist with little impact on the vector (Beerntsen et al, 2000; Estrada-Peña et al, 2015; de la Fuente et al, 2015)

Summary

Introduction

Ectoparasites that derive nutrition through blood feeding (haematophagy) are efficient vectors of disease. While vectorial capacity is influenced by behavioral and environmental determinants affecting variables such as vector density, longevity, and competence, vector competence is a component of vectorial capacity that depends on genetic factors affecting the ability of a vector to transmit a pathogen (Beerntsen et al, 2000, Box 1) These genetic determinants affect traits such as tick host preferences, duration of tick attachment, tick-host-pathogen and microbiome-pathogen interactions, and susceptibility to pathogen infection (Ramamoorthi et al, 2005; Hajdušek et al, 2013; Narasimhan et al, 2014; Nuttall, 2014; Rynkiewicz et al, 2015; Vayssier-Taussat et al, 2015). The elucidation of the mechanisms involved in tick-pathogen interactions that affect vector competence is essential for the identification of molecular drivers for tick-borne diseases, and exposes paradigms for controlling and preventing these diseases

Objectives

Findings

Conclusion