Inducible nitric oxide synthase is expressed in joints of goats in the late stage of infection with caprine arthritis encephalitis virus

Abstract

SUMMARYWe have studied the expression of the inducible form of nitric oxide synthase (iNOS) in joints of goats infected with the caprine arthritis encephalitis virus (CAEV). Nitric oxide generated by iNOS is thought to play an important role in the pathogenesis of various types of arthritis, especially rheumatoid arthritis (RA) in humans. Surprisingly, iNOS immunoreactivity was found only in joints of long-term infected goats with severe clinical arthritis, whereas-despite the presence of high numbers of inflammatory cells in the synovial tissue-no iNOS immunoreactivity was detected in mildly arthritic and in shortterm experimentally infected goats. Most iNOS-positive cells expressed neither MHC class II nor CD68, which suggests that they were fibroblast-like synoviocytes. In situ hybridization studies showed that there was no correlation between iNOS immunoreactivity and detectable virus expression in the joint. In addition, infection of macrophages in vitro-the major host cells of CAEV in vivo-did not lead to increased iNOS mRNA expression. In response to stimulation, similar levels of iNOS expression were observed in infected and in uninfected macrophages. These findings suggest that the expression of iNOS is a feature of late-stage chronic arthritis and is not involved in the development of the inflammatory lesions. Both the lack of co-localization of iNOS protein and viral transcripts in the joint and the finding that CAEV does not stimulate the expression of iNOS in vitro further suggest that iNOS is not directly induced by the virus or the anti-viral immune response in the joint, that it may well, however, be involved in tissue remodelling or scar formation.

Lesion Development and Immunohistochemical Changes in Granulomas from Cattle Experimentally Infected withMycobacterium bovis

“…23 Moreover, in affected joints of goats with arthritis, iNOS-expressing cells were CD68-and major histocompatibility complex II (MHCII) -negative and thought to be fibroblast-like synoviocytes. 23 It is possible that the spindloid cells exhibiting iNOS immunoreactivity in the present study were fibroblasts. Cells with similar morphology have been described in a recent report of iNOS immunoreactivity in bovine granulomas.…”

Expanding Possibilities for Intervention against Small Ruminant Lentiviruses through Genetic Marker-Assisted Selective Breeding

“…There have been several important studies demonstrating involvement of many gene products in SRLV infection and disease [137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162], but these do not specifically relate to individual genetic variants present in sheep. In addition to building understanding of infection and disease, such valuable results prepare the way for further work to address whether such genetic variants exist in small ruminants, and if so, begin developing genetic marker tests.…”

Isolation and characterization of mesenchymal progenitors derived from the bone marrow of goats native from northeastern Brazil

“…In addition, the goat model finds a particular acceptance in Orthopedic Medicine fields 23,24 . Lechner et al 25 reported that goat joint injuries showed similarities to those observed in rheumatoid arthritis in humans.…”