Search results for "primer"
showing 10 items of 530 documents
The Transcription Factor T-bet Regulates Mucosal T Cell Activation in Experimental Colitis and Crohn's Disease
2002
The balance between pro and antiinflammatory cytokines secreted by T cells regulates both the initiation and perpetuation of inflammatory bowel diseases (IBD). In particular, the balance between interferon (IFN)-gamma/interleukin (IL)-4 and transforming growth factor (TGF)-beta activity controls chronic intestinal inflammation. However, the molecular pathways that evoke these responses are not well understood. Here, we describe a critical role for the transcription factor T-bet in controlling the mucosal cytokine balance and clinical disease. We studied the expression and function of T-bet in patients with IBD and in mucosal T cells in various T helper (Th)1- and Th2-mediated animal models …
Differential expression of alternative H2-M isoforms in B cells, dendritic cells and macrophages by proinflammatory cytokines.
1999
Major histocompatibility (MHC) class II heterodimers bind peptides generated by degradation of endocytosed antigens and display them on the surface of antigen presenting cells (APCs) for recognition by CD4+ T cells. Efficient loading of MHC class II molecules with peptides is catalyzed by the MHC class II-like molecule H2-M. The coordinate regulation of MHC class II and H2-M expression is a prerequisite for efficient MHC class II/peptide assembly in APCs determining both the generation of the T cell repertoire in the thymus and cellular immune responses in the periphery. Here we show that expression of H2-M and MHC class II genes is coordinately and cell type-specific regulated in splenic B…
EcFLO, a FLORICAULA-like gene from Eschscholzia californica is expressed during organogenesis at the vegetative shoot apex.
2003
FLORICAULA/ LEAFY-like genes were initially characterized as flower meristem identity genes. In a range of angiosperms, expression occurs also in vegetative shoot apices and developing leaves, and in some species with dissected leaves expression is perpetuated during organogenesis at the leaf marginal blastozone. The evolution of these expression patterns and associated functions is not well understood. We have isolated and characterized a FLORICAULA-like gene from California Poppy, Eschscholzia californica Cham. (Papaveraceae), a species belonging to the basal eudicot clade Ranunculales. EcFLO encodes a putative 416-amino-acid protein with highest similarity to homologous genes from Trocho…
Deficient expression of components of the MHC class I antigen processing machinery in human cervical carcinoma.
2001
In cervical carcinomas abnormalities in the MHC class I surface expression are a frequent event, which are often associated with the deficient expression of the peptide transporter subunit TAP1 thereby resulting in impaired T cell response. In order to understand the role of other components of the MHC class I antigen processing machinery (APM) in the immune escape, 16 surgically removed primary cervical carcinoma lesions were analyzed for their mRNA expression of the heterodimeric peptide transporter TAP, the constitutive and interferon (IFN)-gamma inducible proteasome subunits and their activators PA28alpha/beta, various chaperones as well as MHC class I antigens. High expression levels o…
Role of glutathione in the induction of apoptosis and c-fos and c-jun mRNAs by oxidative stress in tumor cells.
2003
We have used two tumor cell clones (B9 and G2), derived from the methylcholanthrene-induced murine fibrosarcoma GR9 and normal BALB/c3T3 fibroblasts, to study the ability of t-BOOH derived reactive oxygen radicals to induce oxidative stress, apoptosis and c-fos and c-jun mRNA transcription. These clones differ in terms of their major histocompatibility complex (MHC) (H-2) class I genes expression, their tumor induction and metastatic potential and their reduced glutathione (GSH) levels. Incubation of both cell clones in the presence of t-BOOH results in the increase of 8-oxo-2'-deoxyguanosine (8-oxo-dG) and malondialdehyde and the decrease of GSH. The xenobiotic also induces the transcripti…
Antitumor effect of B16 melanoma cells genetically modified with the angiogenesis inhibitor rnasin.
2001
The growth of new blood vessels is an essential condition for the development of tumors with a diameter greater than 1-2 mm and also for their metastatic dissemination. RNasin, the placental ribonuclease inhibitor, is known to have antiangiogenic activity through the inhibition of angiogenin and basic fibroblast growth factor. Nevertheless, the administration of the recombinant form of a protein poses several limitations; as a result, we have studied the antitumor effect of RNasin in a murine gene therapy model. RNasin cDNA was subcloned into the pcDNA3 expression vector, and the resulting recombinant plasmid was used to transfect the B16 murine melanoma cell line. An RNasin inverted constr…
Enhanced expression of ELAM-1 on endothelium of renal cell carcinoma compared to the corresponding normal renal tissue
1999
Abstract Renal cell carcinoma (RCC) has been shown to respond to an immunological therapy with tumor infiltrating lymphocytes (TIL), which accumulate in RCC at a higher density than in normal renal tissue, suggesting that there is selective tumor invasion. Since invasion of TIL into the malignant tissue is mediated by adhesion molecules, we examined the different expression of the adhesion molecule endothelial-leukocyte-adhesion-molecule-1 (ELAM-1) on endothelial cells of RCC versus normal renal tissue. For a specific quantification, the level of ELAM-1 mRNA was investigated by both semi-quantitative reverse transcription–polymerase chain reaction (RT–PCR) and Northern blot analysis and ref…
Identification and validation of novel ERBB2 (HER2, NEU) targets including genes involved in angiogenesis.
2005
V-erb-b2 erythroblastic leukemia viral oncogene homolog 2 (ERBB2; synonyms HER2, NEU) encodes a transmembrane glycoprotein with tyrosine kinase-specific activity that acts as a major switch in different signal-transduction processes. ERBB2 amplification and overexpression have been found in a number of human cancers, including breast, ovary and kidney carcinoma. Our aim was to detect ERBB2-regulated target genes that contribute to its tumorigenic effect on a genomewide scale. The differential gene expression profile of ERBB2-transfected and wild-type mouse fibroblasts was monitored employing DNA microarrays. Regulated expression of selected genes was verified by RT-PCR and validated by West…
Regulation of CD1d expression by murine tumor cells: escape from immunosurveillance or alternate target molecules?
2002
alpha beta+ TCR T cells recognize peptide fragments displayed by MHC-class I or -class II molecules. Recently, additional mechanisms of antigen recognition by T cells have been identified, including CD1-mediated presentation of nonpeptide antigens. Only a limited number of CD1 antigens is retained in the mouse, i.e., the group II CD1 antigens, which are split into CD1D1 and CD1d2. Several T cell subsets have been shown to interact with murine CD1 antigens, including NK cells or "natural T cells" with the invariant V alpha 14 J alpha 281 TCR chain. Even if TAP defects may prevent classical endogenous antigen presentation in tumor cell lines, antigen presentation via CD1 is still functional. …
Differential MHC class II component expression in HPV-positive cervical cancer cells: implication for immune surveillance.
2005
Effective eradication of human papillomavirus (HPV)-positive tumors may require CD8+ and CD4+ T-cell-mediated immune responses. Ectopic expression of MHC class II surface molecules has been described in the context of cervical cancer, but coexpression with other components of the MHC class II antigen presentation pathway has not been addressed. We have evaluated the MHC class II antigen presentation pathway in malignant squamous epithelium of HPV+ cervical cancer lesions by in situ costaining HLA-DR with CLIP or DMA/DMB. Cervical cancer cells exhibit 3 MHC class II phenotypes: (i) DR+/CLIP+ or DM+; (ii) DR+/CLIP- or DM-; and (iii) DR-/CLIP+ or DM+. The identical profile has been identified …