TY - JOUR

T1 - Marked induction of IL-6, haptoglobin and IFNγ following experimental BRSV infection in young calves

AU - Grell, Susanne Nedergaard

AU - Tjørnehøj, Kirsten

AU - Larsen, Lars Erik

AU - Heegaard, Peter Mikael Helweg

PY - 2005/2/10

Y1 - 2005/2/10

N2 - Bovine respiratory syncytial virus (BRSV) has been identified worldwide as an important pathogen associated with acute respiratory disease in calves. An infection model has been developed reflecting accurately the clinical course and the development of pathological signs during a natural BRSV-infection. In the experiments described in the present study, calves were infected at 13-21 weeks of age and reinfected 14 weeks later. Blood samples from the entire infection period were analysed for acute phase protein (haptoglobin) by ELISA and for expression (mRNA level in peripheral blood mononuclear cells) of the cytokines interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6) and interferon-γ (IFNγ) by quantitative real-time reverse transcribed polymerase chain reaction (RT-PCR). IFNγ, interleukin-6 and haptoglobin were markedly induced together with development of clinical signs in response to the first infection with BRSV. The IFNγ response was biphasic, with an early peak at day 1-3 post infection (p.i.) and a later increase between day 5 and 8 p.i. Reinfection also resulted in an induction of IFNγ, but without induction of clinical signs, IL-6 and haptoglobin. These results indicate that early mediators connected with the innate responses are induced on a first encounter with the pathogen, but not on a second encounter (reinfection) where the adaptive immune system may act as the first line defence.

AB - Bovine respiratory syncytial virus (BRSV) has been identified worldwide as an important pathogen associated with acute respiratory disease in calves. An infection model has been developed reflecting accurately the clinical course and the development of pathological signs during a natural BRSV-infection. In the experiments described in the present study, calves were infected at 13-21 weeks of age and reinfected 14 weeks later. Blood samples from the entire infection period were analysed for acute phase protein (haptoglobin) by ELISA and for expression (mRNA level in peripheral blood mononuclear cells) of the cytokines interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6) and interferon-γ (IFNγ) by quantitative real-time reverse transcribed polymerase chain reaction (RT-PCR). IFNγ, interleukin-6 and haptoglobin were markedly induced together with development of clinical signs in response to the first infection with BRSV. The IFNγ response was biphasic, with an early peak at day 1-3 post infection (p.i.) and a later increase between day 5 and 8 p.i. Reinfection also resulted in an induction of IFNγ, but without induction of clinical signs, IL-6 and haptoglobin. These results indicate that early mediators connected with the innate responses are induced on a first encounter with the pathogen, but not on a second encounter (reinfection) where the adaptive immune system may act as the first line defence.

KW - Acute phase proteins

KW - Bovine respiratory syncytial virus

KW - Cytokines

KW - Experimental infection model

U2 - 10.1016/j.vetimm.2004.09.025

DO - 10.1016/j.vetimm.2004.09.025

M3 - Journal article

C2 - 15690587

AN - SCOPUS:11144280126

VL - 103

SP - 235

EP - 245

JO - Veterinary Immunology and Immunopathology

JF - Veterinary Immunology and Immunopathology

SN - 0165-2427

IS - 3-4

ER -