Virulent Lena strain induced an earlier and stronger downregulation of CD163 in bronchoalveolar lavage cells

Activation of pro- and anti-inflammatory responses in lung tissue injury during the acute phase of PRRSV-1 infection with the virulent strain Lena

“…Interestingly, both the number of PRRSV-N-protein + cells and lung viral load showed a solid negative correlation with the frequency of CD163 + cells, the essential host receptor for PRRSV infection (Burkard et al, 2017;Van Gorp et al, 2008;Whitworth et al, 2016). The dramatical depletion in the frequency of pulmonary CD163 + cells in Lenainfected animals has been already reported in live PAMs from the BALF of Lena-infected piglets (Renson et al, 2017;Rodríguez-Gómez et al, 2019) as well as from lung tissue sections of piglets infected with virulent SU1-bel strain (Sánchez-Carvajal et al, 2019). This finding could be due to the direct cytopathic effect of the virus in its target cell but also to an indirect induction of regulated cell death in infected and non-infected cells, which has been broadly described in the lung and lymphoid organs of pigs infected with virulent PRRSV-1 strains (Morgan et al, 2013;Ruedas-Torres et al, 2020;Sánchez-Carvajal et al, 2019).…”

“…3.1. Acute suppurative bronchopneumonia and the highest rectal temperature and clinical signs score were observed in Lena-infected pigs Clinical observations and gross pathology of lung were described thoroughly by Rodríguez-Gómez et al (2019). In brief, piglets inoculated with virulent Lena strain had a long period of hyperthermia (mean rectal temperature above 40.5°C) with marked clinical signs score from 4 dpi onwards, both peaking at 6 dpi ( Fig.…”

“…PRRSV plays a pivotal role in PRDC, modulating the host immune response and favouring secondary bacterial infections (Gómez-Laguna et al, 2013;Van Gucht et al, 2004). Virulent PRRSV-1 strains cause more severe clinical signs, higher mortality rates as well as marked lung injury with a higher incidence of bronchopneumonia as opposed to low virulent strains (Amarilla et al, 2015;Canelli et al, 2017;Frydas et al, 2013;Gómez-Laguna et al, 2010;Morgan et al, 2013;Renson et al, 2017;Rodríguez-Gómez et al, 2019;Stadejek et al, 2017;Weesendorp et al, 2013). Accordingly, we hypothesise that severe pulmonary lesions observed along infection with virulent PRRSV-1 strains might be associated with a higher decrease in the amount of PAMs as well as an imbalance between anti-and pro-inflammatory responses with different molecules potentially involved in this process.…”

“…The animals and samples used in this study were part of a project to investigate the pathogenesis of the infection with PRRSV-1 strains of different virulence (Rodríguez-Gómez et al, 2019). Briefly, fifty-two 4week-old male and female piglets (Landrace x Large White crossbred) were obtained from a historically PRRSV-negative farm.…”

Activation of regulated cell death in the lung of piglets infected with virulent PRRSV-1 Lena strain occurs earlier and mediated by cleaved Caspase-8

“…Animals and samples used in this study belong to a large project carried out in order to investigate the pathogenesis of PRRSV-1 strains of different virulence [42]. Briefly, a total of sixty-five 4-week-old piglets (Landrace x Large White) were assigned to three different experimental groups: (i) control group (n = 15), (ii) 3249-infected group (n = 25) and (iii) Lena-infected group (n = 25).…”