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Browsing by Author "Kelich, Stephanie L."
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Item AluY-mediated germline deletion, duplication and somatic stem cell reversion in UBE2T defines a new subtype of Fanconi anemia(Oxford University Press, 2015-09-15) Virts, Elizabeth L.; Jankowska, Anna; Mackay, Craig; Glaas, Marcel F.; Wiek, Constanze; Kelich, Stephanie L.; Lottmann, Nadine; Kennedy, Felicia M.; Marchal, Christophe; Lehnert, Erik; Scharf, Rüdiger E.; Dufour, Carlo; Lanciotti, Marina; Farruggia, Piero; Santoro, Alessandra; Savasan, Süreyya; Scheckenbach, Kathrin; Schipper, Jörg; Wagenmann, Martin; Lewis, Todd; Leffak, Michael; Farlow, Janice L.; Foroud, Tatiana M.; Honisch, Ellen; Niederacher, Dieter; Chakraborty, Sujata C.; Vance, Gail H.; Pruss, Dmitry; Timms, Kirsten M.; Lanchbury, Jerry S.; Alpi, Arno F.; Hanenberg, Helmut; Department of Pediatrics, IU School of MedicineFanconi anemia (FA) is a rare inherited disorder clinically characterized by congenital malformations, progressive bone marrow failure and cancer susceptibility. At the cellular level, FA is associated with hypersensitivity to DNA-crosslinking genotoxins. Eight of 17 known FA genes assemble the FA E3 ligase complex, which catalyzes monoubiquitination of FANCD2 and is essential for replicative DNA crosslink repair. Here, we identify the first FA patient with biallelic germline mutations in the ubiquitin E2 conjugase UBE2T. Both mutations were aluY-mediated: a paternal deletion and maternal duplication of exons 2–6. These loss-of-function mutations in UBE2T induced a cellular phenotype similar to biallelic defects in early FA genes with the absence of FANCD2 monoubiquitination. The maternal duplication produced a mutant mRNA that could encode a functional protein but was degraded by nonsense-mediated mRNA decay. In the patient's hematopoietic stem cells, the maternal allele with the duplication of exons 2–6 spontaneously reverted to a wild-type allele by monoallelic recombination at the duplicated aluY repeat, thereby preventing bone marrow failure. Analysis of germline DNA of 814 normal individuals and 850 breast cancer patients for deletion or duplication of UBE2T exons 2–6 identified the deletion in only two controls, suggesting aluY-mediated recombinations within the UBE2T locus are rare and not associated with an increased breast cancer risk. Finally, a loss-of-function germline mutation in UBE2T was detected in a high-risk breast cancer patient with wild-type BRCA1/2. Cumulatively, we identified UBE2T as a bona fide FA gene (FANCT) that also may be a rare cancer susceptibility gene.Item Proteomics analysis reveals a Th17-prone cell population in presymptomatic graft-versus-host disease(American Society for Clinical Investigation, 2016-05-05) Li, Wei; Liu, Liangyi; Gomez, Aurelie; Zhang, Jilu; Ramadan, Abdulraouf; Zhang, Qing; Choi, Sung W.; Zhang, Peng; Greenson, Joel K.; Liu, Chen; Jiang, Di; Virts, Elizabeth; Kelich, Stephanie L.; Chu, Hong Wei; Flynn, Ryan; Blazar, Bruce R.; Hanenberg, Helmut; Hanash, Samir; Paczesny, Sophie; Department of Microbiology & Immunology, IU School of MedicineGastrointestinal graft-versus-host-disease (GI-GVHD) is a life-threatening complication occurring after allogeneic hematopoietic cell transplantation (HCT), and a blood biomarker that permits stratification of HCT patients according to their risk of developing GI-GVHD would greatly aid treatment planning. Through in-depth, large-scale proteomic profiling of presymptomatic samples, we identified a T cell population expressing both CD146, a cell adhesion molecule, and CCR5, a chemokine receptor that is upregulated as early as 14 days after transplantation in patients who develop GI-GVHD. The CD4+CD146+CCR5+ T cell population is Th17 prone and increased by ICOS stimulation. shRNA knockdown of CD146 in T cells reduced their transmigration through endothelial cells, and maraviroc, a CCR5 inhibitor, reduced chemotaxis of the CD4+CD146+CCR5+ T cell population toward CCL14. Mice that received CD146 shRNA-transduced human T cells did not lose weight, showed better survival, and had fewer CD4+CD146+CCR5+ T cells and less pathogenic Th17 infiltration in the intestine, even compared with mice receiving maraviroc with control shRNA- transduced human T cells. Furthermore, the frequency of CD4+CD146+CCR5+ Tregs was increased in GI-GVHD patients, and these cells showed increased plasticity toward Th17 upon ICOS stimulation. Our findings can be applied to early risk stratification, as well as specific preventative therapeutic strategies following HCT.