Cytokine responses to EHV-1 infection in immune and non-immune ponies

Induction of a Th-1-Biased IgG Subclass Response against Equine Herpesvirus Type 1 in Horses Previously Infected with Type 4 Virus

“…On the other hand, low-level, or no, IgG(T) responses were observed after EHV-1 infection in horses previously infected with EHV-4, suggesting a Th-1-like immune response. This is similar to the findings of a study by Coombs et al [5], which showed that horses repeatedly infected with EHV-1 mounted a Th-1-type immune response with high interferon-gamma levels in the peripheral blood mononuclear cells, whereas horses infected for the first time generated a non-polarized cytokine response. Our results taken together with those of other groups [5,10,20,22,23], indicated that pre-infection of horses with EHV-4 induced a Th-1-biased IgG subclass response against subsequent EHV-1 infection.…”

“…This is similar to the findings of a study by Coombs et al [5], which showed that horses repeatedly infected with EHV-1 mounted a Th-1-type immune response with high interferon-gamma levels in the peripheral blood mononuclear cells, whereas horses infected for the first time generated a non-polarized cytokine response. Our results taken together with those of other groups [5,10,20,22,23], indicated that pre-infection of horses with EHV-4 induced a Th-1-biased IgG subclass response against subsequent EHV-1 infection. This immune modulation may be effective for inducing cytotoxic T cell-mediated killing of virus-infected cells and thus reducing clinical signs during EHV-1 infection in horses with histories of EHV-4 exposure.…”

Clinical effect of three important cytokines on the pathogenesis of equine herpes virus 9 (EHV-9), equine herpes virus 1 (EHV-1) and Zebra borne EHV-1

“…In acquired immune responses, T lymphocytes are the major source of IFN-γ [7]. IFN-γ induction is increased after EHV-1 infection especially in non vaccinated ponies as protective immunity to infection [16], this report is in accordance to our results for the three groups of infected animals. IFN-γ augments TNF-α synthesis and both mediate many aspects of the disease, both TNF-α and IFN-γ are directly toxic to oligodendrocytes and can stimulate others local inflammatory cytokine production [17 -19].…”

Evaluation of immune responses following infection of ponies with an EHV-1 ORF1/2 deletion mutant

“…Whether immunosuppressive effects of the virus caused these "weak" memory responses or whether our methodology was not adequate to enumerate EHV-1 specific memory responses remains to be determined. There are several studies in the literature that were able to detect significant CTL or IFN-γ responses post EHV-1 infection, however, responses were mostly significant in horses with prior exposure or vaccination for EHV-1 [2,28,36-39]. …”