CollagenVI-Cre mice: A new tool to target stromal cells in secondary lymphoid organs.

Alejandro Prados,George Kollias,Vasiliki Koliaraki

doi:10.1038/srep33027

Abstract

Stromal cells in secondary lymphoid organs (SLOs) are non-hematopoietic cells involved in the regulation of adaptive immune responses. Three major stromal populations have been identified in adult SLOs: fibroblastic reticular cells (FRCs), follicular dendritic cells (FDCs) and marginal reticular cells (MRCs). The properties of these individual populations are not clearly defined, mainly due to the lack of appropriate genetic tools, especially for MRCs. Here, we analyzed stromal cell targeting in SLOs from a transgenic mouse strain that expresses Cre recombinase under the CollagenVI promoter, using lineage tracing approaches. We show that these mice target specifically MRCs and FDCs, but not FRCs in Peyer’s patches and isolated lymphoid follicles in the intestine. In contrast, stromal cells in lymph nodes and the spleen do not express the transgene, which renders ColVI-cre mice ideal for the specific targeting of stromal cells in the gut-associated lymphoid tissue (GALT). This funding further supports the hypothesis of organ-specific stromal precursors in SLOs. Interestingly, in all tissues analyzed, there was also high specificity for perivascular cells, which have been proposed to act as FDC precursors. Taken together, ColVI-Cre mice are a useful new tool for the dissection of MRC- and FDC-specific functions and plasticity in the GALT.

Highlights

Morphogenesis, hemostasis, and lymph propulsion[20,21]
Co-staining with stromal specific markers and analysis by confocal microscopy showed lack of GFP expression by FDCs, MRCs or FRCs. These results suggest that, in contrast to Peyer’s patches (PPs), other SLOs, including peripheral lymph nodes (pLNs), mesenteric LNs (mLNs) and the spleen, are not targeted by the ColVI-Cre mouse strain (Table 1), which may allow for the analysis of local SLO stromal cell functions in the intestine, Figure 2
We analyzed the cell-specificity of the ColVI-Cre transgenic mouse strain in SLOs, including the spleen, pLNs, mLNs and PPs in the intestine, in addition to the known specificities for mesenchymal cells in the intestine, synovium and skin[28,29]

Summary

Introduction

Morphogenesis, hemostasis, and lymph propulsion[20,21]. The precise origin of these cells, as well as the relationship between them and other stromal cell types in SLOs is not clearly defined. The development of the Cre-LoxP system has provided such a powerful tool in combination with genetic targeting and cell lineage tracing approaches. This technology is based on the expression of the bacteriophage P1 Cre-recombinase under the control of cell type-specific promoters[22]. In the case of SLOs, the most common genetic tools used for the study of SLO stromal cells include the CD21-Cre mice that target FDCs in all SLOs, the PDPN-Cre mice that target FRCs in LNs and CCL19-Cre mice that target FRCs in all SLOs23–26. ColVI-cre mice could facilitate the analysis of MRC- and FDC-specific functions and plasticity in the gut-associated lymphoid tissue (GALT)

Methods

Results

Conclusion