Profile of cutaneous innate lymphoid cells after exposure to the bite of the Aedes aegypti mosquito in naive and sensitized hosts

Abstract

Aedes aegypti is an arthropod from the Culicidae family, distributedworldwide. This mosquito is the vector of arboviruses that cause yellow fever,Zika, chikungunya and dengue, which together are responsible for the deaths ofthousands of individuals every year. The Ae. aegypti uses glucose obtainedfrom plant nectar as the main energy source for its metabolism. However,females of the species need other nutrients to mature their eggs, obtainedthrough hematophagy, that consists on the blood feeding of vertebrate hosts.Following exposure to the mosquito, the vertebrate host develops a cutaneousinflammatory reaction, characterized by the migration of cells to the bite site, aswell as a systemic adaptive immune response to the mosquito's salivarycomponents. Among the cells of the immune system present in the skin, areinnate lymphoid cells (ILCs). These cells arise from lymphoid progenitors thatact on innate immunity with a role analogous to T lymphocytes, however,without the need for antigen recognition carried out by interaction with antigenpresenting cells (APCs) and with a rapid response. ILCs are currently classifiedin 5 subpopulations: NK cells (natural killer), LTi (lymphoid tissue inducer) cells,and ILC1, ILC2, and ILC3, presenting corresponding responses to CD4 + T cells(helper): Th1, Th2 and Th17, respectively. The literature on cutaneous ILCs isstill scarce and no article has addressed their role in response to exposure tohematophagous arthropods. Therefore, the present study aims to characterizethe phenotype of ILCs in response to the Ae. aegypti mosquito biting usingnaïve and antigen-sensitized mice as a study model.