We previously identified a rearrangement of mixed-lineage leukemia (MLL) gene (also known as ALL-1, HRX, and HTRX1), consisting of an in-frame partial tandem duplication (PTD) of exons 5 through 11 in the absence of a partner gene, occurring in approximately 4%-7% of patients with acute myeloid leukemia (AML) and normal cytogenetics, and associated with a poor prognosis. The mechanism by which the MLL PTD contributes to aberrant hematopoiesis and/or leukemia is unknown. To examine this, we generated a mouse knockin model in which exons 5 through 11 of the murine Mll gene were targeted to intron 4 of the endogenous Mll locus. Mll PTD/WT mice exhibit an alteration in the boundaries of normal homeobox (Hox) gene expression during embryogenesis, resulting in axial skeletal defects and increased numbers of hematopoietic progenitor cells. Mll PTD/WT mice overexpress Hoxa7, Hoxa9, and Hoxa10 in spleen, BM, and blood. An increase in histone H3/H4 acetylation and histone H3 lysine 4 (Lys4) methylation within the Hoxa7 and Hoxa9 promoters provides an epigenetic mechanism by which this overexpression occurs in vivo and an etiologic role for MLL PTD gain of function in the genesis of AML.

Patients with severe chronic obstructive pulmonary disease (COPD) are at higher risk of developing invasive pulmonary aspergillosis (IPA). However, there are limited data for this disease. To evaluate risk factors and the clinical characteristics of IPA in COPD patients, we conducted a hospital-based, retrospective case-control study of 30 COPD patients with IPA and 60 COPD control patients without IPA. Patients in the case group were significantly more likely to have concurrent co-morbidities than controls. Of the IPA patients, 65.4% had worsening radiological findings vs. 11.4% in the control group (p<0.001). IPA in COPD was associated with a higher proportion of mechanical ventilation (43.3% vs. 5%; p<0.001), a longer hospital stay duration (45.8±39.1 days vs. 18.4±11.8 days; p<0.001), and higher mortality (43.3% vs. 11.4%; p<0.001). Systemic use of steroids in the stable phase, treatment with three or more antibiotics during hospitalization and antibiotic treatment longer than 10 days were independent risk factors associated with IPA. COPD patients with obvious dyspnoea, antibiotic-resistant lower respiratory tract infection and repeated detection of Aspergillus in sputum should be considered for the possibility of IPA.

Interleukin-15 (IL-15) is a pleiotropic proinflammatory cytokine with inefficient posttranscriptional processing. We hypothesized that endogenous IL-15 could affect disease progression in the well-described C57Bl/6 (B6) 3 (C57Bl/6 ؋ DBA/2) F1 hybrid ( IntroductionBone marrow transplantation (BMT) is a potentially curative therapy for patients with heritable immunodeficiencies and malignant diseases including leukemia, lymphoma, and myeloma. 1 While the conditioning regimen for BMT leads to direct tumor destruction, donor-derived allogeneic T cells can exert an important graft-versus-tumor (GVT) effect: recipients of allogeneic transplants have a decreased probability of relapse compared with recipients of autologous, syngeneic, or T-cell-depleted bone marrow transplants. 2,3 However, allogeneic BMT also carries a significant risk for graft-versus-host disease (GVHD), an immunologic attack of allogeneic donor T lymphocytes against normal recipient tissues, the magnitude of which depends in large part on the degree of HLA incompatibility between donor and recipient. Even with appropriate prophylaxis, the incidence of acute GVHD ranges from 30% in HLA-identical donor-recipient pairs to 70% for donorrecipient pairs HLA-incompatible at 2 loci. 1,4 Thus, GVHD remains the most significant obstacle to the wider application of BMT for the treatment of malignancy.GVHD is characterized by a cycle of tissue destruction and inflammation initiated by the preparative regimen for transplantation and propagated by alloreactive donor T cells. 5 Transplant recipients are prepared for BMT with a regimen that obliterates their current bone marrow stores and potentially their residual leukemia. However, this regimen is also highly toxic to the gastrointestinal system and allows release of gram-negative bacterial lipopolysaccharide (LPS) across the intestinal mucosa. 6 LPS is a potent stimulator for the production of tumor necrosis factor ␣ (TNF-␣), interleukin-1 (IL-1), and IL-12. 6,7 IL-12 polarizes donorderived T cells toward a proinflammatory Th1/Tc1 phenotype, producing interferon ␥ (IFN-␥) and TNF-␣; 8,9 IFN-␥ and TNF-␣ induce major histocompatibility complex (MHC) expression by host-derived antigen-presenting cells (APCs), which results in efficient presentation of alloantigen to donor-derived T cells. 10,11 These donor-derived Th1/Tc1-polarized T cells in turn produce IL-2, expand, and infiltrate host epithelial tissues. Thus, the inflammation of acute GVHD is influenced in large part by the cytokine cascade within the host after transplantation.The role of IL-15, a T-and natural killer (NK) cell growth factor, in allogeneic GVHD has not been addressed. Originally isolated because of its ability to restore T-cell growth in the presence of IL-2-neutralizing antibodies, 12,13 IL-15 mRNA is widely and abundantly expressed in multiple tissues. However, IL-15 is inefficiently translated and secreted with multiple posttranscriptional checkpoints. [14][15][16] 36,37 We therefore hypothesized that alteration of endogenous IL-15 produ...

BackgroundIn China, large-scale outbreaks of severe diarrhea caused by viruses have occurred in pigs since late 2010. To investigate the prevalence and genetic evolution of diarrhea-associated viruses responsible for the outbreaks, a total of 2987 field diarrheal samples collected from 168 pig farms in five provinces in Southern China during 2012–2018 were tested.ResultsPorcine epidemic diarrhea virus (PEDV) was most frequently detected virus with prevalence rates between 50.21 and 62.10% in samples, and 96.43% (162/168) in premises, respectively. Porcine deltacoronavirus (PDCoV) was the second prevalent virus with prevalence rates ranging from 19.62 to 29.19% in samples, and 70.24% (118/168) in premises, respectively. Both transmissible gastroenteritis virus (TGEV) and porcine rotavirus (PoRV) were detected at low prevalence rates of < 3% in samples and 10.12% in premises. In this study, we identified a newly emerged swine acute diarrhea syndrome coronavirus (SADS-CoV) in diarrheal samples of piglets from Fujian province in Southern China, and the prevalence rate of SADS-CoV was 10.29% (7/68). Co-infections of these diarrhea-associated viruses were common. The most frequent co-infection was PEDV with PDCoV, with an average detection rate of 12.72% (380/2987, ranging from 8.26–17.33%). Phylogenetic analysis revealed that PEDVs circulating in Southern China during the last 7 years were clustered with the variant strains of PEDV in genotype IIa. The most frequent mutations were present in the collagenase equivalent (COE) and epitope regions of the spike gene of the PEDVs currently circulating in the field. Genetic relationships of PDCoVs were closely related with Chinese strains, other than those present in the USA, South Korea, Thailand and Lao’s public.ConclusionsThe findings of this study indicated that variant PEDV, PDCoV, and SADS-CoV were leading etiologic agents of porcine diarrhea, and either mono-infections or co-infections of pathogenic enteric CoVs were common in pigs in Southern China during 2012–2018. Thus, significant attention should be paid in order to effectively prevent and control porcine viral diarrhea.

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This study indicates that NF-κB plays an important role in the process of TNF-α-induced apoptosis in AECs, via regulation of the expression of Bcl-2 and Bax.

Cryphonectria parasitica hypovirus 3-Grand Haven 2 (CHV3-GH2) is the most recently characterized member of the Hypoviridae family of viruses associated with hypovirulence of the chestnut blight fungus. Isolates of CHV3-GH2 contain either three or four double-stranded (ds) RNAs that are visible on ethidium bromide-stained agarose or polyacrylamide gels. Only the largest dsRNA appears to be required for virus infectivity, and was characterized previously (C. D. Smart et al., 1999, Virology 265, 66-73). In this study, we report the cloning, sequencing, and analysis of the other three dsRNAs. Sizes of the accessory dsRNAs are 3.6 kb (dsRNA 2), 1.9 kb (dsRNA 3), and 0.9 kb (dsRNA 4), compared to 9.8 kb for the genomic dsRNA segment (dsRNA 1). All three accessory dsRNA species are polyadenylated on the 3'-end of one strand, as is genomic dsRNA. DsRNA 2 represents a defective form of dsRNA 1, with the 5'-terminal 1.4 kb derived from the 5'-end of dsRNA 1 and the 3'-terminal 2.2 kb from the 3'-end of dsRNA 1. A single major open reading frame (ORF) is evident from deduced translations of dsRNA 2. The deduced translation product is a 91-kDa protein that represents a fusion consisting of the entire N-terminal protease and the entire putative helicase domain. DsRNAs 3 and 4 represent satellite RNAs that share very little sequence with dsRNA 1 and 2. DsRNA 4 is 937 nucleotides, excluding the poly(A)(+). The first AUG of the polyadenylated strand of dsRNA 4 occurs eight residues in from the 5'-terminus and would initiate the largest ORF on dsRNA 4, with the coding capacity for a 9.4-kDa protein. Within the deduced ORF and approximately 100 nucleotides from the 5'-end of dsRNA 4 is a 22-base sequence that is identical to sequences found in the nontranslated leaders of dsRNAs 1 and 2. DsRNA 3 accumulation in infected cultures varied, but it was less abundant than dsRNA 4. DsRNA 3 was found to represent a head-to-tail dimer of dsRNA 4 linked by a poly(A)/(U) stretch of 40-70 residues.

The partial tandem duplication of MLL (MLL-PTD) is found in 5% to 10% of patients with acute myeloid leukemia (AML) and normal cytogenetics. Its expression in leukemic blasts is coincident with a silenced wild-type (WT) MLL allele. We therefore generated mice expressing the Mll-PTD in the absence of Mll-WT. These Mll PTD/؊ mice die at birth unlike the normal life expectancy of Mll PTD/WT , Mll IntroductionApproximately 5% to 10% of patients with acute myeloid leukemia (AML) and normal cytogenetics present with rearrangement of the mixed-lineage leukemia (MLL, also known as ALL1 or HRX) gene as the result of a partial tandem duplication (PTD) within a single MLL allele. 1,2 In AML blasts harboring the somatic MLL PTD mutation, the MLL wild-type (WT) allele is not expressed and, when reexpressed, leukemic cell death was observed. 3 We previously reported on the Mll PTD/WT knockin mice that are fully viable with modest developmental defects, have aberrant gene expression and altered hematopoiesis, but do not develop leukemia. 4 Methods Generation of Mll PTD/؊ miceMll WT/Ϫ mice 5 were generously provided by the late Dr Stanley Korsmeyer (Dana-Farber Cancer Institute, Boston, MA). These mice were maintained on a B6C3F1 background. To obtain Mll PTD/Ϫ mice, F1 offspring were obtained by crossing the Mll WT/Ϫ mice with the Mll PTD/WT mice 4 (maintained on a pure C57Bl/6J background). This work was performed with approval of The Ohio State University institution review board and under an Institutional Animal Care and Use Committee-approved proposal. Comparative real-time RT-PCRTotal RNA was extracted from E17.5 fetal liver cells (FLC) from Mll PTD/WT , Mll PTD/Ϫ , Mll WT/Ϫ , and Mll WT/WT embryos. Comparative realtime reverse transcription-polymerase chain reaction (RT-PCR) assays on whole fetal liver and c-kit ϩ -and CD11b ϩ -sorted populations were performed as previously described. 4,6 Chromatin immunoprecipitation H3 (Lys4) dimethylation has been shown to occur as a direct result of MLL's SET domain methyltransferase activity. 4,7 Therefore, chromatin immunoprecipitation (ChIP) assays were performed on 2 ϫ 10 6 FLC using the EZ ChIP Assay Kit with the anti-dimethyl Histone H3 (Lys4) antibody (Millipore, Billerica, MA) according to the manufacturer's standard protocol. DNA was quantified using PCR and nested real-time quantitative PCR with SYBR green incorporation (Applied Biosystems, Foster City, CA) using previously described methods. 4 Colony forming unit-progenitor assaysSingle cell suspensions were plated at a density of 50 000 cells/dish in M3434 methylcellulose (StemCell Technologies, Vancouver, BC), and were performed according to the manufacturer's protocol (StemCell Technologies) and methods as previously described. 4 StatisticsTo evaluate whether significant differences in pluripotent hemopoietic progenitors (colony forming unit [CFU]-GEMM), CFU-GM, or burst forming unit-erythroid (BFU-E) existed between mouse genotypes as indicated in the Figure 1 legend, paired t tests were carried out using siblings. ...