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Abstract

Chaperonins have classically been thought of as intracellular molecules involved in the correct folding of proteins. Their expression is upregulated during times of stress such as heat (hence their common nomenclature as heat shock proteins [HSP]), anoxia, hypoglycaemia and reactive oxygen species [1]. These are conditions found in infected tissues or in tissues with chronic inflammation such as the rheumatoid synovium. In their intracellular location they protect the cell from apoptotic death due to stress. Increasingly chaperonins have been recognised to subserve extracellular functions for which they have received the name 'chaperokines' since they bind to specific receptors on the cell surface and activate cells of the innate immune system to secrete inflammatory cytokines, chemokines and small molecular weight mediators such as prostaglandins [2]. Indeed, an early event in inflammation is cell stress/necrosis leading to the release of HSP60 and HSP70 that binds via a CD14-mediated mechanism to Toll-like receptors 2 and 4 [2] as part of the 'danger' signal [3]. The secretion of tumour necrosis factor alpha, IL-1, IL-12 and other chemokines prepares the environment for a TH1 adaptive immune response. It is now recognised that some chaperonins, such as BiP and HSP27, may activate the innate immune system to secrete anti-inflammatory cytokines, such as IL-10 [4,5] that may skew the adaptive immune response to TH2. Recent work by our group has shown that BiP can not only prevent but also treat ongoing collagen-induced arthritis in DBA/1 mice [6], suggesting that chaperonins may down modulate ongoing TH1 responses. Thus, it may be possible to suppress rheumatoid inflammation by administration of appropriate chaperonins such as BiP. Finally, chaperonins may be important system regulators determining the outcome between TH1 and Th2 immune responses. References 1. Pockley AG: Heat shock proteins as regulators of the immune response. Lancet 2003, 362:469-476. 2. Asea A: Chaperokine-induced signal transduction pathways. Exerc Immunol Rev 2003, 9:25-33. 3. Matzinger P: The danger model: a renewed sense of self. Science 2002, 296:301-305. 4. De AK, Kodys KM, Yeh BS, Miller-Graziano C: Exaggerated human monocyte IL-10 concomitant to minimal TNF-alpha induction by heatshock protein 27 (Hsp27) suggests Hsp27 is primarily an antiinflammatory stimulus.

­Immunohistochemistry for the detection of neural and inflammatory cells in equine brain tissue

“…Identification of equine-reactive antibodies can be challenging due to limited knowledge of commercial antibodies' reactivity with veterinary tissues and lack of development of multiple species-specific reagents. Evaluation of cross-species reactivity of commercially available antibodies, particularly CD antigens, has been largely performed in equine tissues prepared for whole-cell analysis like flow-cytometry (Johne et al, 1997, Mérant et al, 2003, Terio et al, 2003, Kunisch et al, 2004, and Ibrahim et al, 2007 or on fresh or frozen specimens (Bilzer et al, 1995, Zeng et al, 1996, Lemos et al, 2008, and Härtig et al, 2009. Large screenings of non-equine derived antibodies have often resulted in limited identification of equine reactive reagents (Ibrahim et al, 2007, Schnabel et al, 2013, and Szabo and Gulya, 2013.…”

“…Commercial macrophage antibodies are non-specific to macrophages and often cross react with monocytes, granulocytes, dendritic cells, and fibroblasts (Johne et al, 1997, Kunisch et al, 2004, Shaw et al, 2005, and Sellner et al, 2014. Multiple macrophage-directed antibodies with different target antigens were tested so that a distinction could be made between tissue macrophage populations and cells that may cross-react with those antibodies.…”