Disease relevance of C1R

• All NK clones killed the prototypic HLA-negative erythroleukemia K562 and most lysed the MHC class I-deficient C1R and 721.221 B-LCL [1].
• In contrast, tumors of alternate histologies were not lysed, including lung cancer, squamous cell cancer, as well as the natural/lymphocyte-activated killer cell-sensitive hematopoietic cell lines T2, C1R, or Daudi [2].
• Human NK cells were unable to preferentially lyse class I-deficient C1R cells after infection with herpes simplex virus (HSV) [3].
• During the course of extensive mutagenesis of HLA-A2.1, we examined influenza A matrix peptide (FMP)-specific CTL recognition of HMy2.C1R (C1R) cells expressing mutant HLA-A2.1 molecules, sensitized with synthetic peptide, FMP 58-66, (exogenous peptide), or infected with influenza A virus (endogenous peptide) [4].
• To investigate whether there might be exclusive roles for LCa and LCb in clathrin function, the expression of LCa was manipulated in C1R lymphoid cells and PC12 pheochromocytoma cells by transfection with light chain cDNA [5].

High impact information on C1R

• The cloned cDNA was transfected into HLA-A- and B-negative HMy/C1R cells, and the B2702 molecules generated in this environment rendered these cells, after incubation with peptide, susceptible to lysis by peptide-specific CTL [6].
• To control for MHC class I expression on target cells, we used either HLA class I-deficient C1R cells or C1R sublines expressing transfected HLA class I gene products [3].
• Site-directed mutation of the His-74 residue in HLA-A2 to the Asp-74 (HLA-A3, -Aw68, -Aw69, -B7) residue generates a mutant that provides C1R cell line transfectants an NK-resistant phenotype [7].
• Several mutant HLA-A2 molecules have been constructed and expressed in the mutant human B-cell line C1R, which lacks HLA-A and HLA-B antigens, and examined for presentation of a previously defined peptide epitope derived from the influenza matrix protein to appropriate human cytotoxic T-lymphocyte lines [8].
• Isoelectric focusing and immunoblotting reveals considerable biochemical and genetic variation in the C1R subcomponent of the first complement component [9].

Biological context of C1R

• This occurred for HSV-infected C1R cells expressing any of the three HLA class I gene products tested (i.e., HLA-B27, HLA-A3, or HLA-Aw68), indicating that NK cell recognition in this system does not require "self" MHC and is not unique for a single haplotype [3].
• Genetic studies of low-abundance human plasma proteins. XIII. Population genetics of C1R complement subcomponent and description of new variants [9].
• The Vdelta1 T lymphocytes studied were able to lyse the ULBP3(+) C1R B-cell line upon transfection with MIC-A [10].
• The HLA-A,B "negative" mutant cell line C1R expresses a novel HLA-B35 allele, which also has a point mutation in the translation initiation codon [11].
• The C1R transfectants with reduced levels of LCa and the LCa-negative PC12 transfectant grow normally and show no change in clathrin distribution, clathrin assembly level, or impairment of endocytosis or secretion compared with wild-type cells and cells transfected with vectors lacking light chain cDNA [5].

Anatomical context of C1R

• Nuclear SpSHR2 in blastula extracts binds to the C1R hormone response element in the upstream promoter region of the CyIIIb actin gene indicating that the latter may be a target of this nuclear receptor in the sea urchin embryo [12].
• Gastric cancer-specific CTLs specifically lysed autologous and allogeneic HLA-A2.1+, HER2/neu+ gastric cancer cells, HER2/neu-transfected C1R/A2 cell lines (HLA-A2.1+, HER2+) and HLA-A2.1-transfected SW626 tumor cell lines (HLA-A2.1+, HER2+) [13].
• The effectors lysed C1RA24 cells (p53(+), HLA-A*2402 transfectant), but not their parental cell lines C1R (p53(+), HLA-A,B null cell) [14].
• The C1R element, binding site of the nuclear receptors SpCOUP-TF and SpSHR2, is by itself sufficient to restrict expression in the ectoderm, whereas the aboral ectoderm restricted expression requires in addition the presence of both C1L and E1 [15].
• SEB-stimulated peripheral blood (PB) CD8+ T cells lysed similar numbers of C1R cells but fewer HT-29 cells (53+/-13% and 8+/-5%, respectively) [16].

Associations of C1R with other chemical compounds

• Genetic variation in the C1R subcomponent of the first complement component C1 was investigated in U.S. whites by isoelectric focusing and immunoblotting [17].
• The separation of the drug and internal standard (methyldopa) was achieved using a 4 microns particle size C1R cartridge (10 cm x 8 mm i.d.) in conjunction with a radial compression system and a C18 precolumn module [18].

Gene context of C1R

• Acidic treatment of the C1R (Cw4+) target cells or 81.22 (Cw3+, Cw4+) at pH 2.2 resulted in loss of reactivity with 6A4, A6-136 and W6-32 mAb (known to react with the assembled form of class I molecules) and in the de novo reactivity with L31 mAb (specific for the HLA-C free chain) [19].
• The cDNAs encoding both wild type and mutant CD1A were cloned in the expression vector pSRalphaNeo and transfected into C1R and L721.221 cells [20].
• IEL killing of C1R cells involved interaction of major histocompatibility complex (MHC) class II with TCR, CD2 with CD58, and CD11a with CD54, and was perforin mediated [16].
• In the presence of SEB, IEL became potently cytotoxic against C1R cells and interferon-gamma (IFN-gamma)-precultured HT-29 cells, causing 55+/-10% and 31+/-6% lysis, respectively, greater than that by phytohaemagglutinin (PHA)-, interleukin-2 (IL-2)-, or anti-T-cell receptor (TCR)-activated IEL [16].
• In the present study, we characterize new MUC1 transfected human lymphoblastoid cell lines C1R and T2, and a pig kidney epithelial line LLC-PKI, that express MUC1 with either two repeats (MUC1-2R) or 22 repeats (MUC1-22R), and use them as stimulators and targets for cytotoxic T cells (CTL) in vitro [21].

Analytical, diagnostic and therapeutic context of C1R

• Endogenous peptides from the human C1R line transfected by B*2705 or B*2703 were acid-eluted and separated by HPLC [22].
• Jejunal IEL, from morbidly obese individuals undergoing gastric bypass operations, were tested for SEB-induced cytotoxicity against C1R B-lymphoblastoid cells, HT-29 adenocarcinoma cells, or CD1d-transfected cells using the 51Cr-release assay [16].
• The polymorphism of C1R was investigated in 570 unrelated Japanese individuals using isoelectric focusing and immunoblotting [23].
• Immunoprecipitation analysis of surface-biotinylated C1R transfectants revealed heterodimeric association for both HLA-A2.1:DAF-L and HLA-A2.1:DAF-S heavy chains with beta 2m [24].
• The highest lodscore was 1.04 in females at theta 0.00 to the system C1R, thus supplying a clue for continued gene-mapping investigations on the short arm of chromosome No. 12 [25].

References