Immunohistochemical detection of pro-inflammatory and anti-inflammatory cytokines in granulomas in cattle with natural Mycobacterium bovis infection

CANAL ANA; PEZZONE N, ; CATALDI A, ; ZUMÁRRAGA MARTÍN JOSÉ; LARZABAL M, ; GARBACCIO S, ; FERNANDEZ A, ; DOMINGUEZ L, ; ARANAZ A, ; RODRIGUEZ-BERTOS A

RESEARCH IN VETERINARY SCIENCE

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2017 vol. 110 p. 34 - 39

0034-5288

Cellular immune response was evaluated in lymph nodes and lung with different granulomatous lesions fromcattle naturally infected with Mycobacterium bovis. For this purpose, we assessed pro-inflammatory and anti-inflammatorycytokines by immunohistochemical assays. Immunoreaction was observed for all the cytokines analyzed.Fourteen animals displayed advanced stage IV granulomas, with intense immunoreactivity to IFN-γand TGF-β in areas of caseous necrosis, macrophages and lymphocytes. Seven animals showed stage III granuloma,with high immunoreactivity to IFN-γ (average of 44.5% immunoreactive cells) and moderate to TNF-αand tothe anti-inflammatory cytokines IL-10 and TGF-β, in relation to the proliferation of fibroblasts in granuloma peripheryWe found satellite stage I granulomas in 4 bovines and stage II granulomas in 2 bovines, which exhibitedlow immunostaining response (‐13%). Cytokine expression in stage III and IV granulomas was significant, withpredominance of immunoreactivity to IFN-γ, thus suggesting a strong, longstanding local immune response mediatedby macrophages and epithelioid cells. In addition, these two stages displayed lower reactivity to IL-10;which suggests a deficit of anti-inflammatory cytokines, suppressed immunity and persistence of the infection.High expression of TGF-β could indicate a chronic processwith greater tissue damage and fibrosis. Numerous bacilliobserved in necrotic areas in stage III and IV granulomas with low expression of IL-1β suggest failure in theimmune response with bacterial multiplication. In this study, evidence of in situ presence of cytokines demonstratesthese cytokines are involved in the development and evolution of bovine tuberculosis granulomas.