Mucosal CD3ε+ cell proliferation and gut epithelial apoptosis: implications in rainbow trout gastroenteritis (RTGE)

Abstract

Rainbow trout gastroenteritis (RTGE) is an emerging disease that has acquired new relevance in European rainbow trout, Oncorhynchus mykiss (Walbaum), culture, because of the economic losses it causes. Disease aetiology and pathogenesis remain unclear. The lesions appear restricted to the gastrointestinal tract where extensive mucosal detachment associated with high numbers of segmented filamentous bacteria (SFB) can be detected. In this study, an RTGE outbreak in north-western Spain was investigated, and findings observed in diseased trout were compared with control fish. PAS stain and immunohistochemical assays with anti-CD3ε and anti-active caspase-3 antibodies were performed. The results showed that CD3ε+ inflammatory infiltrates were present in the intestine of diseased trout both in the lamina propria-submucosa and within the epithelium. Moreover, an increased number of caspase-3+ cells in the intestinal mucosa and also strong anti-caspase-3 immunoreactivity in desquamated cells in the gut lumen were observed. Changes in the number of goblet cells were also found, resulting in an increase or depletion of mucous cells depending on the severity of the intestinal lesions. These findings suggest that T cells and apoptosis play an important role in the development and pathogenesis of RTGE.

Bromodeoxyuridine DNA labelling reveals host and parasite proliferation in a fish‐myxozoan model

“…Fish intestinal remodelling can be affected by or can compensate the distress of the intestinal homoeostasis provoked by diet interventions (Bakke‐McKellep et al., ; Chikwati, Gu, Penn, Bakke, & Krogdahl, ; Yoshida, Maekawa, Bannai, & Yamamoto, ), radiation (Johnson, Nakatani, & Conte, ), intestinal resection (Schall et al., ), adaptation to salinity changes (Takahashi, Sakamoto, & Narita, ; Takahashi et al., ) or pathogens (Dezfuli et al., ; Dezfuli, Manera, et al., ; Hemmer, Steinhagen, Drommer, & Korting, ; Ronza, Bermúdez, Losada, Robles, & Quiroga, ). Inflammation is generally considered a beneficial response to tissue damage for its induction of a localized repair response.…”

Partial Replacement of Fishmeal with Soybean Meal and Soy Protein Concentrate in Diets of Atlantic Cod

“…Cod intestinal villi are also dominated by secretory goblet cells that synthesize and secrete mucin to protect the mucosal epithelium against shear stress and chemical damage (van der Flier and Clevers 2009), but inflammation can still occur (Figure 1). In teleost fishes, hyper-and hypoplasia of intestinal goblet cells have been associated with responses to various conditions of both infectious and noninfectious nature (Ronza et al 2011).…”