Variation in cellular tropism between isolates of Equine herpesvirus-1 in Foals

Abstract

Subtype-1 isolates of Equine herpesvirus-1 (EHV-1) from a quadriplegic horse and from an aborted foetus were compared with each other and with a subtype-2 respiratory isolate. All 3 isolates were detected in the epithelium and macrophages of the respiratory tract. Both the paresis and foetal subtype-1 isolates replicated in the epithelium of the ileum and this correlated with the recovery of virus from faeces in vivo. The paresis subtype-1 isolate also had a predelection for vascular endothelial cells, particularly in the nasal mucosa, but also in the lungs, central nervous system, adrenal and thyroid. In the 9 foals inoculated with the paresis isolate two developed hind limb dysfunction, four developed diarrhoea, and one of these 4 died with an intussusception. The differences between these isolates are discussed in relation to other herpesviruses.

In vitro reactivation of latent equid herpesvirus-1 from CD5+/CD8+ leukocytes indirectly by IL-2 or chorionic gonadotrophin.

“…The primary antibodies included anti-EHV-1 polyclonal (rabbit) (Patel et al, 1982) and anti-CG polyclonal (rabbit) (Sigma), each used at 1 : 20 ; the remaining antisera were all monoclonal antibodies (MAbs) and used as neat tissue culture supernatants. They were anti-EHV-1 gB , anti-equine CD5 and anti-equine CD4 (Lunn & Duffys, 1992), anti-equine CD8 (RVC3) (McCulloch et al, 1992), anti-equine CD3 (Blanchard-Chanell et al, 1994) and anti-human recombinant IL-2 (R&D Systems).…”

“…At 2 h intervals for up to 12 h, and at 24 h, and thereafter daily for up to 5 days, cells were taken and cytospins made. Virus isolation was made by co-cultivation on monolayers of EEKs and RK13 as described previously (Patel et al, 1982). The cell surface markers of cells harbouring virus were detected using two-colour IIF or by secondary staining with alkaline phosphatase-labelled antibody on cytospins of 2i10& cells from each time-point.…”

“…During the viraemia EHV-1 has been isolated for up to 3 weeks postinfection from peripheral blood mononuclear cells, predominantly from T lymphocytes and to a lesser extent monocytes (Bumgardner et al, 1982 ;Kydd et al, 1994). This cell-associated viraemia in an acute infection has been shown to be a prerequisite for abortion and paresis by initiating replication of EHV-1 in endothelial cells in the pregnant uterus and CNS (Patel et al, 1982 ;Edington et al, 1986Edington et al, , 1991.…”

Genetic diversity of equine herpesvirus 1 isolated from neurological, abortigenic and respiratory disease outbreaks

“…Numerous studies have demonstrated that differences in pathogenicity correlate with the ability to disseminate to and infect vascular endothelial cells in the uterus and central nervous system (Edington, Bridges, & Patel, 1986; Mumford et al., 1994; Patel, Edington, & Mumford, 1982; Platt, Singh, & Whitwell, 1980). Viruses carrying the A2254G neurological marker are thought to replicate to a higher level and induce a longer‐lasting viraemia than those lacking it (Allen & Breathnach, 2006).…”

Equid herpesvirus 1 is neurotropic in mice, but latency from which infectious virus can be reactivated does not occur

“…EHV-1 strain Ab4, passage 11 was propagated in RK13 cells in 10% fetal calf serum (FCS), 2 mM L-glutamine and non-essential amino acids (Patel et al, 1982). Penicillin (100 units/ml), streptomycin (100 µg/ml) and fungizone (20 µg/ml) were added to the medium.…”