Cattle remain immunocompetent during the acute phase of foot-and-mouth disease virus infection

Abstract

Infection of cattle with foot-and-mouth disease virus (FMDV) results in the development of long-term protective antibody responses. In contrast, inactivated antigen vaccines fail to induce long-term protective immunity. Differences between susceptible species have also been observed during infection with FMDV, with cattle often developing persistent infections whilst pigs develop more severe symptoms and excrete higher levels of virus. This study examined the early immune response to FMDV in naïve cattle after in-contact challenge. Cattle exposed to FMDV were found to be viraemic and produced neutralising antibody, consistent with previous reports. In contrast to previous studies in pigs these cattle did not develop leucopenia, and the proliferative responses of peripheral blood mononuclear cells to either mitogen or third party antigen were not suppressed. Low levels of type 1 interferon and IL-10 were detected in the circulation. Taken together, these results suggest that there was no generalised immunosuppression during the acute phase of FMDV infection in cattle.

Differential Persistence of Foot-and-Mouth Disease Virus in African Buffalo Is Related to Virus Virulence

“…Circulating IFN (Ͼ1 IU/ml) lasted at least 5 days in the majority of buffaloes and up to 6 days in challenged cattle (n ϭ 2; peak titers of 21.6 and 26.6 IU/ml, respectively). Similar to data reported previously for cattle (43), FMDV-challenged buffaloes did not develop leucopenia during acute infection (data not shown).…”

Global Foot-and-Mouth Disease Research Update and Gap Analysis: 6 - Immunology

“…This could represent an immune evasion strategy, as the immune complexes formed by FMDV and host antibodies early in the response have the potential to destroy any DC attempting to take up the complexes and use the digested viral proteins to stimulate FMDV‐specific T cells. Such a mechanism is consistent with in vivo observations in cattle, where there is little or no induction of the FMDV‐specific T‐cell response during infection, while the initiation of responses to other antigens is unaffected (Windsor et al., ).…”

“…High levels of IFN‐α were linked with early T‐cell inhibition during FMD infection in mice (Langellotti et al., ), and a similar mechanism may operate in swine, at least during classical swine fever virus infection (Summerfield et al., ). In contrast, in cattle, only low levels of Type I IFNs are detected (Windsor et al., ), again consistent with the lack of immunosuppression that is evident in this species.…”

Global Foot-and-Mouth Disease Research Update and Gap Analysis: 5 - Biotherapeutics and Disinfectants

“…Data showing protection of swine from multiple serotypes of FMDV as early as 1 day post‐administration of the Ad5 bearing porcine IFN‐α (Dias et al., ) have been supported and extended to describe the ability of Ad5 encoding type III IFN to either prevent or substantially protect from FMDV in both pigs (Perez‐Martin et al., ) and cattle (Perez‐Martin et al., ). The lack of protection of cattle by Ad5 encoding bovine type I IFN is perhaps consistent with the finding that only low levels of IFN‐α are seen in this species during FMDV infection (Windsor et al., ), which remains to be fully understood in terms of species‐specific mechanisms of immunity. This finding is supported by previous work in which, unlike swine, antiviral activity could not be detected in cattle inoculated with Ad5‐expressing bovine IFN‐α, although Ad5‐expressing porcine IFN‐α did inhibit FMDV replication in cattle cells and also provided limited protection in live cattle challenged with FMDV (Wu et al., ).…”