The effect of temperature on production and function of bovine interferons

Abstract

Subnormal temperatures were found to depress the production of interferon by bovid herpesvirus 2 (BHV-2)-infected bovine testicular cells, bovine peripheral blood leukocytes, and bovine monocytes, as well as by BHV-2 antigen-stimulated immune peripheral blood leukocytes. Interferon titers generated at 30 degrees C were approximately 10 percent of those at 40 degrees C. Also, subnormal temperatures depressed interferon function. Bovine testicular cells treated at 40 degrees C for 24 hours with high concentrations of BHV-2-induced bovine monocyte interferon or BHV-2 antigen-stimulated immune peripheral blood leukocyte interferon, and then infected with BHV-2 and retreated with interferon at 40 degrees C, had little or no viral growth or cytopathic effect after 72 hours. Cultures without interferon, or those treated with the same amount of interferon at 30 degrees C, had significantly more cytopathic effect and had viral titers up to 10(7) TCID50 higher than cultures at 40 degrees C. Earlier in vitro studies done without exogenous interferon showed that BHV-2 replicated to high titers at 30 degrees but not at 40 degrees C. Thus, at low temperatures (30 degrees C) in vitro, BHV-2 induced little interferon, was not highly suppressed by interferon, and replicated to high titers. At higher temperatures (40 degrees C), BHV-2 replication induced high interferon levels, was strongly suppressed by interferon, and replicated poorly. This may help explain the restriction of BHV-2 lesions to skin despite the presence of virus in both skin and internal organs in infected cattle.

The Efficacy of the Interferon Alpha/Beta Response versus Arboviruses Is Temperature Dependent

“…Historically, studies of the IFN-α/β response have largely relied on genetic knockout strategies to examine the roles of individual mediators and effectors in various infection and disease models. However, there is a growing body of literature focused on intact innate immune mechanisms within the variable physiological contexts in which they operate in vivo and how this variability may affect efficacy ( 15 , 16 , 19 , 20 , 23 , 46 – 49 ). The results presented here indicate that ambient temperature can have broad impacts on the effectiveness of the mammalian IFN-α/β antiviral response.…”

Bovine interferon: Its biology and application in veterinary medicine

“…The induction was achieved by infection of calf kidney cells in vitro with human influenza A virus. Since then a multitude of primary cell culture systems, established cell lines and organ cultures of bovine origin, and viruses, homologous as well as heterologous, have been employed for in vitro generation of IFN [1,50,51,52,53,73,78,85,95, see 92 for references prior to 1973].…”

“…In vitro systems for IFN-production are liable to many variables including temperature [78], the age of the cells or their passage level, serum-factors including contaminating endotoxins and contamination with other, non-cytopathic, viruses or with mycoplasma, as well as the host cell and inducer. The influence of some of these factors on bovine IFN production has been investigated by several groups; however, no consistent results have appeared [1,42,51,73,95].…”