Charles River altered Schaedler flora (CRASF®) remained stable for four years in a mouse colony housed in individually ventilated cages

Abstract

As recommendations for specific pathogen-free housing change, mouse facilities need to re-derive their colonies repeatedly in order to eliminate specified bacteria or viruses. This paper describes the establishment of a new mouse facility using as starting point a small colony of CD-1 mice colonized with the Charles River altered Schaedler flora (CRASF w ) housed in individually ventilated cages (IVCs). The import of new strains was performed exclusively via embryo transfer using CD-1 mice as recipients. The integrity of the CRASF w in caecum samples of the original CD-1 colony and of three inbred mouse lines imported into the colony was proven by a quantitative realtime polymerase chain reaction approach. Furthermore, we searched for bacterial contaminants in the gut flora using non-specific 16S rRNA primers. The bacterial sequences found were closely related to but not exclusively sequences of altered Schaedler flora (ASF) members, suggesting that the ASF is heterogeneous rather than restricted to the eight defined bacteria. Moreover, no pathogens were found, neither using the non-specific 16S rRNA primers nor in routine quarterly health monitoring. As one effect of this defined gut flora, interleukin-10 knockout mice are devoid of colitis in our facility. In conclusion, our approach building up a mouse facility using foster mothers and embryo transfer as well as a strict barrier system and IVCs is suitable to maintain a colony free from contaminating bacteria over the long term. CRASF w remained stable for seven mouse generations and was efficiently transferred to the imported mouse strains.

Foxp3+ T cells expressing RORγt represent a stable regulatory T-cell effector lineage with enhanced suppressive capacity during intestinal inflammation

“…In mice containing a complex microflora, 24 the proportion of RORgt-expressing cells within the Foxp3 þ T-cell pool was B10% in lymphoid organs, such as the spleen or peripheral lymph nodes (pLNs). However, in contrast to mice that harbor only a minimal flora, 25 the frequency of Foxp3 þ RORgt þ T cells was clearly elevated in the gut-draining mesenteric lymph nodes (mLNs), Peyer's patches, and especially the intestinal colonic LP, where B80% of all Foxp3 þ T cells expressed RORgt (Figure 1a,b). Thus, our data confirm that in the presence of a complex microbiota, a high proportion of Foxp3 þ T cells in the intestinal organs, and especially in the LP of the colon, simultaneously express RORgt.…”

“…24 Where indicated, mice with a minimal microflora with close similarity to the altered Schaedler flora were used. 25 All animal experiments were performed in compliance with the German animal protection law (TierSchG BGBl. I S. 1105; 25.05.1998).…”

Monocytes/macrophages and/or neutrophils are the target of IL‐10 in the LPS endotoxemia model

“…Deletion was found to be more than 90% efficient in T cells of IL-10R [13]. In our SPF mouse facility, neither conventional IL-10 [14] nor IL-10R1 knock-out mice were found to develop significant signs of inflammatory bowel disease when examined up to 12 months of age (data not shown). However, a similarly increased susceptibility to dextran sulphate sodium (DSS)-induced colitis and to LPS was found in both strains ( Fig Table 1).…”

“…Animals were bred and maintained at the Helmholtz Centre for Infection Research under specific pathogen free conditions [14]. All experiments were performed in accordance to federal guidelines and institutional policies (permission number: …”

<b>Rederivação de linhagens de camundongos por transferência embrionária para obtenção de colônias livres de patógenos específicos (SPF)</b>

“…(CARTHEW; WOOD; . Além disso, a rederivação associada com barreiras sanitárias estritas, mantém colônias de camundongos livres de contaminações por agentes infecciosos por um longo período de tempo (STEHR et al, 2009;.…”