Type 17 helper T-cell cytokines have been implicated in the pathogenesis of inflammatory bowel disease, a chronic condition affecting the gastrointestinal tract, but information regarding their contribution to pathology in different regions of the gut is lacking. By using a murine model of bacteria-induced typhlocolitis, we investigated the role of IL-17A, IL-17F, and IL-22 in cecal versus colonic inflammation. Cecal, but not colonic, pathology in C57BL/6 mice inoculated with Helicobacter hepaticus plus anti-IL-10 receptor (IL-10R) monoclonal antibody was exacerbated by co-administration of anti-IL-17A monoclonal antibody, suggesting a disease-protective role for IL-17A in the cecum.
View Article and Find Full Text PDFAging is exemplified by progressive, deleterious changes that increase the probability of death. However, while the effects of age are easy to recognize, identification of the processes involved has proved to be much more difficult. Somewhat surprisingly, research using the budding yeast has had a profound impact on our current understanding of the mechanisms involved in aging.
View Article and Find Full Text PDFWhen is less more? A new study reveals that decreased mitochondrial gene expression and reduced lipid biosynthesis may actually increase cell growth.
View Article and Find Full Text PDFThe peptide-antibody (Ab) genetic fusion is a promising technology for targeting multiple antigens in a single Ab-like molecule. We have recently described generation and in vitro characterization of several such genetic fusions, using an interleukin (IL)-17A binding peptide and an anti-IL-22 Ab as a model system. In this study we assessed pharmacokinetic profiles of these model genetic fusions in mice.
View Article and Find Full Text PDFOver the lifespan of therapeutic proteins, from the point of biosynthesis to the complete clearance from tested subjects, they undergo various biological modifications. Therapeutic influences and molecular mechanisms of these modifications have been well appreciated for some while remained less understood for many. This paper has classified these modifications into multiple categories, according to their processing locations and enzymatic involvement during the trafficking events.
View Article and Find Full Text PDFCell size homeostasis is a conserved attribute in many eukaryotic species involving a tight regulation between the processes of growth and proliferation. In budding yeast S. cerevisiae, growth to a "critical cell size" must be achieved before a cell can progress past START and commit to cell division.
View Article and Find Full Text PDFProtein biosynthesis and extracellular secretion are essential biological processes for therapeutic protein production in mammalian cells, which offer the capacity for correct folding and proper post-translational modifications. In this study, we have generated bispecific therapeutic fusion proteins in mammalian cells by combining a peptide and an antibody into a single open reading frame. A neutralizing peptide directed against interleukin-17A (IL17A) was genetically fused to the N termini of an anti-IL22 antibody, through either the light chain, the heavy chain, or both chains.
View Article and Find Full Text PDFNumerous observations support the existence of senescence factors in yeast. Historically, the asymmetric propagation and accumulation of extra-chromosomal ribosomal DNA circles (ERCs) has been proposed to fulfill this function. On the other hand, several recent papers have re-invigorated the discussion of a potential role for cell size and/or hypertrophy in yeast senescence.
View Article and Find Full Text PDFThe T helper cell-derived cytokine interleukin-17A (IL-17A) is a variably glycosylated disulfide-linked homodimer of 34-38 kDa. Its polypeptide monomer contains one canonical N-glycosylation site at Asn68, and human recombinant IL-17A was partly N-glycosylated when expressed in human kidney (HEK293) cells as a fusion protein with a melittin signal sequence and an N-terminal hexahistidine tag. Orbitrap mass analyses of the tryptic N-glycopeptide 63-69 indicated that the N-glycosylation was of the GalNAc-terminated type characteristic of cultured kidney cells.
View Article and Find Full Text PDFBackground: Toll-like receptor 4 (TLR4) is activated by bacterial endotoxin, a prototypical pathogen-associated molecular pattern (PAMP). It has been suggested that TLR4 can also be activated by damage-associated molecular pattern (DAMP) proteins such as HSP70. It remains a challenge to provide unequivocal evidence that DAMP proteins themselves play a role in TLR4 activation, as the DAMP proteins used are often contaminated with endotoxin and other TLR ligands introduced during protein expression and/or purification.
View Article and Find Full Text PDFAm J Respir Cell Mol Biol
January 2012
The expression of acidic mammalian chitinase (AMCase) is associated with Th2-driven respiratory disorders. To investigate the potentially pathological role of AMCase in allergic airway disease (AAD), we sensitized and challenged mice with ovalbumin or a combination of house dust mite (HDM) plus cockroach allergen. These mice were treated or not treated with small molecule inhibitors of AMCase, which significantly reduced allergen-induced chitinolytic activity in the airways, but exerted no apparent effect on pulmonary inflammation per se.
View Article and Find Full Text PDFA consortium of yeast geneticists have created -6000 individual ORF deletions, representing > 96% of the currently verified or predicted ORFs in S. cerevisiae. Importantly, molecular barcodes (each a unique 20 bp sequence termed either Uptag or Downtag) were used as identifiers for every ORF deletion.
View Article and Find Full Text PDFYeast cells, like mammalian cells, enlarge steadily as they age. Unabated cell growth can promote cellular senescence; however, the significance of the relationship between size and cellular lifespan is not well understood. Herein, we report a genetic link between cell size, growth rate and lifespan.
View Article and Find Full Text PDFThe receptor for advanced glycation end products (RAGE) is a multiligand transmembrane receptor implicated in a number of diseases including autoimmune diseases. To further understand the pathogenic mechanism of RAGE in these diseases, we searched for additional ligands. We discovered that C3a bound to RAGE with an EC(50) of 1.
View Article and Find Full Text PDFObjective: To assess the relative effectiveness of combining self-management and strength training for improving functional outcomes in patients with early knee osteoarthritis.
Methods: We conducted a randomized intervention trial lasting 24 months at an academic medical center. Community-dwelling middle-aged adults (n = 273) ages 35-64 years with knee osteoarthritis, pain, and self-reported physical disability completed a strength training program, a self-management program, or a combined program.
Alzheimer's disease (AD) is characterized by neuronal death; thus, identifying neurotoxic proteins and their source is central to understanding and treating AD. The multifunctional protease thrombin is neurotoxic and found in AD senile plaques. The objective of this study was to determine whether brain endothelial cells can synthesize thrombin and thus be a source of this neurotoxin in AD brains.
View Article and Find Full Text PDFVanin-1 is a pantetheinase that catalyzes the hydrolysis of pantetheine to produce pantothenic acid (vitamin B5) and cysteamine. Reported here is a highly sensitive fluorescent assay using a novel fluorescently labeled pantothenate derivative. The assay has been used for characterization of a soluble version of human vanin-1 recombinant protein, identification and characterization of hits from high-throughput screening (HTS), and quantification of vanin pantothenase activity in cell lines and tissues.
View Article and Find Full Text PDFT-helper 17 (Th17) cells are a new lineage of CD4(+) T cells that are characterized by their production of interleukin-17A (IL-17A). Recent studies show that these cells can also express IL-17F, IL-22, and IL-21. IL-17A and IL-17F can form a heterodimeric cytokine, which mediates biological activities, at least in part, through shared receptors with IL-17A and IL-17F homodimers.
View Article and Find Full Text PDFIL-17A and IL-17F, produced by the Th17 CD4(+) T cell lineage, have been linked to a variety of inflammatory and autoimmune conditions. We recently reported that activated human CD4(+) T cells produce not only IL-17A and IL-17F homodimers but also an IL-17F/IL-17A heterodimeric cytokine. All three cytokines can induce chemokine secretion from bronchial epithelial cells, albeit with different potencies.
View Article and Find Full Text PDFIL-17A and IL-17F are related homodimeric proteins of the IL-17 family produced by Th17 cells. In this study, we show that mouse Th17 cells also produce an IL-17F/A heterodimeric protein. Whereas naive CD4(+) T cells differentiating toward the Th17 cell lineage expressed IL-17F/A in higher amounts than IL-17A/A homodimer and in lower amounts than IL-17F/F homodimer, differentiated Th17 cells expressed IL-17F/A in higher amounts than either homodimer.
View Article and Find Full Text PDFIL-17F and IL-17A are members of the IL-17 pro-inflammatory cytokine family. IL-17A has been implicated in the pathogenesis of autoimmune diseases. IL-17F is a disulfide-linked dimer that contains a cysteine-knot motif.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2005
Myostatin is a secreted protein that normally functions as a negative regulator of muscle growth. Agents capable of blocking the myostatin signaling pathway could have important applications for treating human muscle degenerative diseases as well as for enhancing livestock production. Here we describe a potent myostatin inhibitor, a soluble form of the activin type IIB receptor (ACVR2B), which can cause dramatic increases in muscle mass (up to 60% in 2 weeks) when injected into wild-type mice.
View Article and Find Full Text PDFInterleukin 22 (IL-22) is a cytokine induced during both innate and adaptive immune responses. It can effect an acute phase response, implicating a role for IL-22 in mechanisms of inflammation. IL-22 requires the presence of the IL-22 receptor (IL-22R) and IL-10 receptor 2 (IL-10R2) chains, two members of the class II cytokine receptor family (CRF2), to effect signal transduction within a cell.
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