Cytokine mRNA expression in lesions in cats with chronic gingivostomatitis

Semiquantitative reverse transcription-PCR assays were developed to measure feline interleukin-2 (IL-2), IL-4, IL-5, IL-6, IL-10, and IL-12 (p35 & p40 ); gamma interferon (IFN-gamma); and glyceraldehyde-3-phosphate dehydrogena se mRNA concentrations in biopsies of feline oral mucosa, Biopsies were col lected from 30 cats with chronic gingivostomatitis (diseased) prior to each cat receiving one of four treatments. In 23 cases replicate biopsies were collected 3 months after treatment commenced. Biopsies were also analyzed f rom 11 cats without clinical disease (nondiseased), Expression of IL-2, IL- 10, IL-12 (p35 and p40), and IFN-gamma was detected in most nondiseased bio psies, while IL-6 was detected in a minority, and IL-4 and IL-5 were both u ndetectable. Compared to nondiseased cats, the diseased population showed a significant increase in the relative mRNA expression of IL-2, IL4, IL-6, I L-10, IL-12 (p35 and p40), and IFN-gamma, In contrast, IL-5 mRNA expression was unchanged and was only detected in one case, No significant relationsh ip was demonstrable between the change in relative expression of specific c ytokine mRNA and the change in clinical severity of the local mucosal lesio ns over the treatment period. The results demonstrate that the normal felin e oral mucosa is biased towards a predominantly (Th) type 1 profile of cyto kine expression and that during the development of lesions seen in feline c hronic gingivostomatitis there is a shift in the cytokine profile from a ty pe 1 to a mixed type 1 and type 2 response.