Cytokine Patterns Associated with a Serotype 8 Fowl Adenovirus Infection

Abstract

This study examined cytokine gene expression patterns associated with fowl adenovirus (FAdV) infection. The selected cytokine mRNA was quantified by quantitative real-time reverse transcription-PCR in spleen, liver, and cecal tonsil during the course of infection of chickens with a serotype 8 FAdV (FAdV-8). Compared to uninfected chickens, infected birds had higher mRNA expression of interleukin (IL)-18 and IL-10 in spleen and liver, respectively. Interferon gamma (IFN-γ) mRNA expressed in spleen and liver of infected chickens was significantly upregulated, while the expression of IL-8 mRNA in spleen and liver of infected chickens was significantly downregulated. There was no significant difference between infected and uninfected groups in terms of cytokine gene expression in cecal tonsil. These results indicate that these four cytokines might play an important role in driving the immune responses following FAdV-8 infection.

Pathogenicity and Cytokine Gene Expression Pattern of a Serotype 4 Fowl Adenovirus Isolate

“…in the infected group, when compared to that of the negative control birds. Our finding that IL-10 was up-regulated following FAdV-4 infection is in agreement with a previous report [15], and may indicate an immune evasive mechanism used by the virus to skew the immune response, supporting persistence of the virus [17]. IL-10 has both immunosuppressive and immunostimulating effects on cells of the adaptive immune system [20].…”

“…The expression of cytokines has been studied following FAdV-8 infection [15], however, this is the first report on the cytokine repertoire associated with FAdV-4 infection. Enhanced expression of IFN-γ in the liver was noted, with a significant increase in expression at 3 d.p.i.…”

“…Since the most variability in cytokine gene expression following FAdV-8 infection was in the liver [15], mRNA expression in liver was determined for IFN-γ, IL-18, IL-10, and IL-8, while for cecal tonsil and spleen, mRNA expression was determined only for IFN-γ and IL-18.…”

Oral Inoculation of Chickens with a Candidate Fowl Adenovirus 9 Vector

“…), but it became statistically significant at days 3, 5, and 7 p.i. These data were similar to the results of our study on FAdV-8 (27). FAdV-9⌬4 infection also upregulated the expression of IFN-␣ and IFN-␥ mostly in the liver and bursa of Fabricius samples.…”

“…Liver, cecal tonsil, spleen, and bursa of Fabricius samples were collected and sectioned into two portions: one was placed in a sample bag and stored at Ϫ80°C for viral genome copy number determination, as described previously (24), and the other was collected in a 1.5-ml sterile Eppendorf tube containing RNAlater (Invitrogen Canada, Inc., Burlington, Ontario, Canada) and stored at Ϫ80°C. The expression levels of the IFN-␣, IFN-␥, IL-10, and IL-12 p40 cytokine genes were evaluated by real-time quantitative PCR (RT-qPCR), with ␤-actin as a reference gene, as described previously (25)(26)(27).…”