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Martinez, K.

Publications and source records attributed to Martinez, K..

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Longitudinal profiling of the macaque vaginal microbiome reveals similarities to diverse human vaginal communities: implications for use as a pre-clinical model for bacterial vaginosis

The vaginal microbiota plays an important role in womens reproductive and urogenital health. Disturbances in this microbial community can lead to several adverse outcomes including pelvic inflammatory disease, bacterial vaginosis (BV) as well as increased susceptibility to sexually transmitted infections, miscarriage, and pre-term births. It is now well accepted that while the microbiome of healthy women in the developed world is dominated by Lactobacillus species, vaginal communities in asymptomatic women, especially those in the developing world, can be comprised of a diverse set of micro-organisms. The presence of a diverse vaginal microbiome has been associated with increased susceptibility to HIV infection but their implications for womens health remain poorly understood. Rhesus macaques are an excellent translational animal model due to significant physiological and genetic homology with humans. In this study, we performed a longitudinal analysis of clinical and microbiome data from 16 reproductive age female rhesus macaques. Many animals showed hallmarks of BV, including Nugent scores above 7 and high vaginal pH. At both the taxonomic and functional level, the rhesus macaque vaginal microbiome was most similar to that of women who harbor a diverse vaginal community associated with asymptomatic/symptomatic bacterial vaginosis. Specifically, rhesus macaque vaginal microbiomes harbored a diverse set of anaerobic gram-negative bacteria, including; Snethia, Prevotella, Porphyromonas, and Mobilluncus. Interestingly, some animals were transiently colonized by Lactobacillus and some with Gardnerella. Our in-depth and comprehensive analysis highlights the importance of the model to test interventions for manipulating the vaginal microbiome. IMPORTANCEIt is widely accepted that the "healthy" vaginal microbiome of the majority of women in the developed world is dominated by Lactobacillus species. However, in the developing world, a majority of women are colonized by diverse microbial communities, typically associated with bacterial vaginosis, but remain asymptomatic. Many questions remain about the drivers of this disparity and potential interventions to alter the vaginal microbiome. Rhesus macaques provide an excellent translational model due to significant physiological and genetic homology with humans. In this study, we performed a longitudinal analysis of clinical and microbiome data from a large cohort of reproductive age rhesus macaques. At the taxonomic, genomic, and functional level, the rhesus macaque vaginal microbiome was most similar to that of humans who harbor a diverse vaginal community associated with asymptomatic/symptomatic bacterial vaginosis. Our in-depth and comprehensive analysis highlights the utility of macaques to test interventions for manipulating the vaginal microbiome.

microbiology

Development of early-stage type 1 diabetes in germ-free interleukin-10 deficient mice

Several experimental models demonstrate a role for gut microbiota in the progression of type 1 diabetes (T1D) in genetically prone hosts. While the association between disturbances in gut microbiota, or microbial dysbiosis, and complex immune diseases such as inflammatory bowel diseases (IBD) are well established, less is known about its role in T1D pathogenesis. In IBD-prone interleukin-10 deficient (IL-10 KO) mice, the absence of gut microbiota under germ-free (GF) conditions prevents IBD development. However, in aged GF IL-10 KO mice (>6-months of age), polyuria and pancreatic lymphocytic infiltration resembling T1D lesions was observed. Approximately 50% of male and female mice above 6-months of age develop pancreatic immune cell infiltration, as compared to none in conventionally-raised and fecal microbiota transplanted (FMT) IL-10 KO counterparts. Immunofluorescence staining of islet infiltrates was positive for adaptive and innate immunological markers, including lymphoid and myeloid cell markers, which typically characterize autoimmune T1D lesions. A subset of GF IL-10 KO mice was also positive for insulin autoantibodies (IAA), but the majority of mice did not become diabetic. Our findings of early stage lymphocytic infiltrates in the pancreas and IAA in the absence of overt diabetes in GF IL-10 KO mice embody the early stages of T1D pathogenesis. As such, we propose that the presence of gut microbiota play a protective role against immune infiltration in the pancreas of genetically prone hosts. Moreover, our model provides an opportunity to better understand the role of the microbiota in the early stages of immune pathogenesis and perhaps conceive the development of microbe-mediated prophylactic strategies to treat or even prevent T1D.

physiology