Infection dynamics of Japanese encephalitis virus in porcine cell lines

Authors: ADETUNJI, SHAKIRAT - Kansas State University; Smolensky, Dmitriy; Mitzel, Dana; Chitko-Mckown, Carol; CERNICCHIARO, NATALIA - Kansas State University; Noronha, Leela

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/5/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary: Interpretive Summary not required in accordance with ARS-115 Publications P & P 152.1 v.5 (10/19/2019)chapter 5 page 31 Matrix for Data Entry Determinations.kmm

Technical Abstract: Japanese encephalitis virus (JEV) is an arbovirus that causes severe neurological disease in humans in Southeast Asia and the western Pacific region. Pigs are the main amplifying hosts of JEV and can transmit the virus through both vector-borne and vector-free routes. To develop an in vitro system for studying aspects of JEV pathogenesis in pigs, we examined several porcine cell lines for susceptibility to the attenuated JEV strain SA-14-14-2. Monolayers of porcine nasal turbinate (PT-K75), kidney (SK-RST), testis (ST), and monocyte-derived macrophage-like (Cdelta2+) cells were infected with SA-14-14-2 for up to 5 days at a multiplicity of infection (MOI) of 0.1. Culture supernatants were collected between 0 and 120 hours post infection (hpi), and monolayers were observed for cytopathic effects (CPE) using brightfield microscopy. Infectious virus was quantified by plaque assay and cell viability was determined using trypan blue staining. An indirect immunofluorescence assay was used to detect the presence of JEV NS1 antigens. The hamster kidney cell line BHK-21, known to be susceptible to SA-14-14-2, was used as a positive control. All four porcine cell lines demonstrated susceptibility to SA-14-14-2 and produced infectious virus by 12hpi. Virus titers peaked at 48hpi in Cdelta2+, BHK-21, and SK-RST cells, and at 72hpi in PT-K75 and ST cells. At the 48hpi timepoint, JEV NS1 was observed in all cell lines. CPE was visible in infected Cdelta2+ and BHK-21 cells, but not the other three cell lines. The proportion of viable cells, as measure by trypan blue exclusion, declined after 24hpi in BHK-21, 48hpi in Cdelta2++ cells, 72hpi in SK-RST cells, and did not substantially decline in PT-K75 or ST cells. These findings demonstrate the relevance of several porcine cell lines that may be useful for understanding JEV infection dynamics and host cell mechanisms critical for viral replication in a natural host species.