Production, quantitation, and infection of amazonian icoaraci phlebovirus (bunyaviridae)

Abstract

Phlebotomine vectors, sand flies of the order Diptera, are known to transmit Leishmania parasites as well as RNA viruses (arboviruses) to humans. The arbovirus, Icoaraci Phlebovirus (BeAN 24262 - ICOV), used in this study was isolated from Nectomys rodents, a mammalian species that is the same natural sylvatic reservoir of Leishmania (Leishmania) amazonensis. This Leishmania species is distributed in primary and secondary forests in Brazil and other countries in America and causes localized and diffuse anergic skin lesions. In our recent studies, we observed an aggravation of the protozoan infection by ICOV through the modulation of cytokine expression, such as IL-10 and IFN-β, enhancing the parasite load and possibly the pathogenesis. Efficient viral production and quantitation had to be developed and standardized to ensure that immuno-molecular assays provide consistent and reproducible viral infection results. The standardization of these procedures becomes a particularly useful tool in research, with several applications in understanding the interaction between the host cell and Phlebovirus, as well as co-infections, allowing the study of intracellular signaling pathways. Here, we detail a protocol that allows the production and quantitation of the Icoaraci Phlebovirus using BHK-21 cells (baby hamster kidney cells) and subsequent infection of peritoneal macrophages from C57BL/6 mice.