Characterization of segmented-filamentous bacterium intestinal colonization and its impact on skin graft outcome

Studies from the Alegre lab show that the microbiota can modulate allograft rejection in transplantation and that its perturbation reduces type I IFN signaling in APCs, which leads to reduced priming of alloreactive T cells. Specifically, simultaneous colonization of both skin and gut microbiota casually affects graft outcomes. Intestinal colonization with segmented-filamentous bacteria (SFB) is sufficient to accelerate skin graft rejection. This current study assesses the intestinal colonization pattern of SFB. We compared the relative abundance and bacterial load of feces, cecal content, ileal scrapings, ileal content of specific pathogen-free (SPF), SFB gavaged SPF, SFB-mono colonized (positive control), and germ-free (negative control) mice. By using qPCR, I analyzed bacterial load and relative abundance with pan-16S and SFB- specific primers. SFB gavage treatment shows trends of increasing the relative abundance of SFB, although this is variable and not statistically significant. These results suggest that to study the impact of SFB on graft rejection, we should use GF and SFB-monocolonized mice as a transplant model. This will contribute to the interpretation of findings in future experiments identifying the effects of SFB gavage treatment. Further research will help us develop possible therapeutic approaches to enhance graft acceptance