21 research outputs found
Polymorphisms in the α4 Integrin of Neotropical Primates: Insights for Binding of Natural Ligands and HIV-1 gp120 to the Human α4β7
The α4 integrin subunit associates with β7 and β1 and plays important roles in immune function and cell trafficking. The gut-homing receptor α4β7 has been recently described as a new receptor for HIV. Here, we describe polymorphisms of ITGA4 gene in New World primates (NWP), and tested their impact on the binding to monoclonal antibodies, natural ligands (MAdCAM and VCAM), and several gp120 HIV-1 envelope proteins. Genomic DNA of NWP specimens comprising all genera of the group had their exons 5 and 6 (encoding the region of binding to the ligands studied) analyzed. The polymorphisms found were introduced into an ITGA4 cDNA clone encoding the human α4 subunit. Mutant α4 proteins were co-expressed with β7 and were tested for binding of mAbs, MAdCAM, VCAM and gp120 of HIV-1, which was compared to the wild-type (human) α4. Mutant α4 proteins harboring the K201E/I/N substitution had reduced binding of all ligands tested, including HIV-1 gp120 envelopes. The mAbs found with reduced biding included one from which a clinically-approved drug for the treatment of neurological disorders has been derived. α4 polymorphisms in other primate species may influence outcomes in the development and treatment of infectious and autoimmune diseases in humans and in non-human primates
Genome-wide <i>in vivo</i> screen identifies novel host regulators of metastatic colonisation
Metastasis is the leading cause of death for cancer patients. This multi-stage process requires tumour cells to survive in the circulation, extravasate at distant sites, then proliferate; it involves contributions from both the tumour cell and tumour microenvironment ('host', which includes stromal cells and the immune system). Studies suggest the early steps of the metastatic process are relatively efficient, with the post-extravasation regulation of tumour growth ('colonization') being critical in determining metastatic outcome. Here we show the results of screening 810 mutant mouse lines using an in vivo assay to identify microenvironmental regulators of metastatic colonization. We identify 23 genes that, when disrupted in mouse, modify the ability of tumour cells to establish metastatic foci, with 19 of these genes not previously demonstrated to play a role in host control of metastasis. The largest reduction in pulmonary metastasis was observed in sphingosine-1-phosphate (S1P) transporter spinster homologue 2 (Spns2)-deficient mice. We demonstrate a novel outcome of S1P-mediated regulation of lymphocyte trafficking, whereby deletion of Spns2, either globally or in a lymphatic endothelial-specific manner, creates a circulating lymphopenia and a higher percentage of effector T cells and natural killer (NK) cells present in the lung. This allows for potent tumour cell killing, and an overall decreased metastatic burden.status: publishe
Distinct Microbiome in Pouchitis Compared to Healthy Pouches in Ulcerative Colitis and Familial Adenomatous Polyposis
Background: Pouchitis occurs in up to 50% of patients with ulcerative colitis (UC) undergoing ileal pouch anal anastomosis (IPAA). Pouchitis rarely occurs in patients with familial adenomatous polyposis (FAP) who undergo IPAA. Our aim was to compare mucosal and luminal flora in patients with UC-associated pouchitis (UCP), healthy UC pouches (HUC), and healthy FAP pouches (FAP).
Methods: Nineteen patients were enrolled in thi s cross-sectional study (nine UCP, tl1ree HUC, seven FAP). Patie nts with active pouchitis were identified using the Pouchitis Disease Activity Index (PDAI). Ileal pouch mucosal biopsies and fecal samples were analyzed with a 16S rDNA-based terminal restriction fr agment length polymorphism (TRFLP) approach. Pooled fecal DNA from four UCP and four FAP pouches were sequenced for further speciation.
Results: TRFLP data revealed statistically significant diffe rences in the mucosal and fecal microbiota between each group of patients. UCP samples exhibited significantly more TRFLP peaks matching Clostridium and Eubacterium genera compared to HUC and FAP pouches and fewer peaks matching Lactobacillus and Streptococcus genera compared to FAP. DNA Sanger sequencing of a subset of luminal samples revealed UCP having more identifiable sequences of Firmicutes (51.2% versus 2 1.2%) and Verrucomicrobia (20.2% versus 3.2%), and fewer Bacteroidetes (1 7.9% versus 60.5%) and Proteobacteria (9.8% versus 14.7%) compared to FAP.
Conclusions: The pouch microbial environment appears to be distinctly different in the settings of UC pouchitis, healthy UC, and FAP. These findings suggest that a dysbiosis may exist in pouchitis which may be central to understanding the disease
Distinct microbiome in pouchitis compared to healthy pouches in ulcerative colitis and familial adenomatous polyposis
Background: Pouchitis occurs in up to 50% of patients with ulcerative colitis (UC) undergoing ileal pouch anal anastomosis (IPAA). Pouchitis rarely occurs in patients with familial adenomatous polyposis (FAP) who undergo IPAA. Our aim was to compare mucosal and luminal flora in patients with UC-associated pouchitis (UCP), healthy UC pouches (HUC), and healthy FAP pouches (FAP).
Methods: Nineteen patients were enrolled in this cross-sectional study (nine UCP, three HUC, seven FAP). Patients with active pouchitis were identified using the Pouchitis Disease Activity Index (PDAI). Ileal pouch mucosal biopsies and fecal samples were analyzed with a 16S rDNA-based terminal restriction fragment length polymorphism (TRFLP) approach. Pooled fecal DNA from four UCP and four FAP pouches were sequenced for further speciation.
Results: TRFLP data revealed statistically significant differences in the mucosal and fecal microbiota between each group of patients. UCP samples exhibited significantly more TRFLP peaks matching Clostridium and Eubacterium genera compared to HUC and FAP pouches and fewer peaks matching Lactobacillus and Streptococcus genera compared to FAP. DNA Sanger sequencing of a subset of luminal samples revealed UCP having more identifiable sequences of Firmicutes (51.2% versus 21.2%) and Verrucomicrobia (20.2% versus 3.2%), and fewer Bacteroidetes (17.9% versus 60.5%) and Proteobacteria (9.8% versus 14.7%) compared to FAP.
Conclusions: The pouch microbial environment appears to be distinctly different in the settings of UC pouchitis, healthy UC, and FAP. These findings suggest that a dysbiosis may exist in pouchitis which may be central to understanding the disease. (Inflamm Bowel Dis 2011;17:1092-1100
Transition of adolescents with inflammatory bowel disease from pediatric to adult care: a survey of adult gastroenterologists
Transition of patients with inflammatory bowel disease (IBD) from pediatric to adult providers requires preparation. Gastroenterologists for adult patients ("adult gastroenterologists") may have expectations of patients that are different from those of pediatric patients. We sought to explore the perspectives of adult gastroenterologists caring for adolescents and young adults with IBD, to improve preparation for transition. A survey sent to 1132 adult gastroenterologists caring for patients with IBD asked physicians to rank the importance of patient competencies thought necessary in successful transition to an adult practice. Providers reported which problems occurred in patients with IBD transitioning to their own practice. Adult gastroenterologists were asked about medical and developmental issues that are unique to adolescence. A response rate of 34% was achieved. Adult gastroenterologists reported that young adults with IBD often demonstrated deficits in knowledge of their medical history (55%) and medication regimens (69%). In addition, 51% of adult gastroenterologists reported receiving inadequate medical history from pediatric providers. Adult providers were less concerned about the ability of patients to identify previous and current health care providers (19%), or attend office visits by themselves (15%). Knowledge of adolescent medical and developmental issues was perceived as important by adult gastroenterologists; however, only 46% felt competent addressing the developmental aspects of adolescents. For successful transition, adolescents and young adults with IBD need improved education about their medical history and medications. Pediatric providers need to improve communication with the receiving physicians. In addition, adult providers may benefit from further training in adolescent issues. Formal transition checklists and programs may improve the transition of patients with IBD from pediatric to adult car
Transforming Cancer Prevention through Precision Medicine and Immune-oncology
We have entered a transformative period in cancer prevention (including early detection). Remarkable progress in precision medicine and immune-oncology, driven by extraordinary recent advances in genome-wide sequencing, big-data analytics, blood-based technologies, and deep understanding of the tumor immune microenvironment (TME), has provided unprecedented possibilities to study the biology of premalignancy. The pace of research and discovery in precision medicine and immunoprevention has been astonishing and includes the following clinical firsts reported in 2015: driver mutations detected in circulating cell-free DNA in patients with premalignant lesions (lung); clonal hematopoiesis shown to be a premalignant state; molecular selection in chemoprevention randomized controlled trial (RCT; oral); striking efficacy in RCT of combination chemoprevention targeting signaling pathway alterations mechanistically linked to germline mutation (duodenum); molecular markers for early detection validated for lung cancer and showing promise for pancreatic, liver, and ovarian cancer. Identification of HPV as the essential cause of a major global cancer burden, including HPV16 as the single driver of an epidemic of oropharyngeal cancer in men, provides unique opportunities for the dissemination and implementation of public health interventions. Important to immunoprevention beyond viral vaccines, genetic drivers of premalignant progression were associated with increasing immunosuppressive TME; and Kras vaccine efficacy in pancreas genetically engineered mouse (GEM) model required an inhibitory adjuvant (Treg depletion). In addition to developing new (e.g., epigenetic) TME regulators, recent mechanistic studies of repurposed drugs (aspirin, metformin, and tamoxifen) have identified potent immune activity. Just as precision medicine and immune-oncology are revolutionizing cancer therapy, these approaches are transforming cancer prevention. Here, we set out a brief agenda for the immediate future of cancer prevention research (including a "Pre-Cancer Genome Atlas" or "PCGA"), which will involve the inter-related fields of precision medicine and immunoprevention - pivotal elements of a broader domain of personalized public health
A crossover-crossback prospective study of dibutyl-phthalate exposure from mesalamine medications and semen quality in men with inflammatory bowel disease
BACKGROUND: Phthalates are widely used chemicals with ubiquitous exposure. Dibutyl-phthalate (DBP), a male reproductive toxicant in animals, is understudied in humans. Some mesalamine medications used to treat inflammatory bowel disease (IBD) have DBP in their coating, whereas other mesalamine formulations do not. OBJECTIVES: Taking advantage of differences in mesalamine formulations, we investigated whether high-DBP exposure from mesalamine medications was associated with decreased semen parameters. METHODS: 73 men with IBD taking mesalamine participated in a crossover-crossback prospective study. Men taking non-DBP containing mesalamine at baseline i.e., background exposure, crossed-over for four months to high-DBP mesalamine and then crossed-back for four months to their non-DBP mesalamine (B(1)HB(2)-arm;Background(1)-High-Background(2)) and vice versa for men taking high-DBP mesalamine at baseline (H(1)BH(2)-arm;High(1)-Background-High(2)). Men provided up to six semen samples (2: baseline, 2: crossover and 2: crossback). RESULTS: We estimated crossover, crossback and carryover effects using linear mixed models adjusted for abstinence time, age, season and duration on high-DBP mesalamine at baseline. Semen parameters in B(1)HB(2)-arm (26 men, 133 samples) decreased after high-DBP mesalamine exposure (crossover versus baseline), especially motility parameters, and continued to decrease further even after crossback to non-DBP mesalamine (crossback versus crossover).The cumulative carryover effect of high-DBP (crossback versus baseline) was a decrease of % total sperm motility by 7.61(CI:-13.1, -2.15), % progressive sperm motility by 4.23(CI:-8.05, -0.4) and motile sperm count by 26.0% (CI:-46.2%, 1.7%). However, H(1)BH(2)-arm (47 men, 199 samples) had no significant change during crossover or crossback. CONCLUSIONS: Men newly exposed to high-DBP mesalamine for four months had a cumulative reduction in several semen parameters, primarily sperm motility, that was more pronounced and statistically significant even after exposure ended for four months