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].
• 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 [4].
• CTL generated by stimulating C57BL/6 (H-2b) responder cells with H-2Dd or H-2Ld transfectants of the human B cell line C1R or the murine T cell lymphoma EL4 were assayed for their ability to recognize alloantigenic determinants on these transfectants [5].

High impact information on C1R

• Transfection of HLA-Aw66.2, and of a mutant of this gene with serine 4 substituted for tryptophan, into a human B cell line (C1R) both resulted in expression of the LA45 epitope [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].
• 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 [7].
• 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 [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

• A maximum lod score of 1.505 at theta = 0.00 was found in a two-point analysis between C1R and C1S [10].
• 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 polymorphism of the C1R subcomponent of human complement component C1 has been detected in normal plasma samples using the high resolving power of isoelectric focusing in 6 M urea followed by immunoblotting [11].
• Genetic studies of low-abundance human plasma proteins. XIII. Population genetics of C1R complement subcomponent and description of new variants [9].
• 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 [12].

Anatomical context of C1R

• To characterize the factors limiting surface expression, the processes of assembly and intracellular transport of HLA-Cw4 molecules were investigated in the C1R cell line [13].
• 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 [14].
• The effectors lysed C1RA24 cells (p53(+), HLA-A*2402 transfectant), but not their parental cell lines C1R (p53(+), HLA-A,B null cell) [15].
• 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 [16].
• B-cells including mouse hybridoma cells, human multiple myeloma cells C1R and DIG, as well as an immortalized T-cell line (Jurkat cells) were cloned using this approach [17].

Associations of C1R with chemical compounds

• The nature of the intraindividual biochemical variation can be explained by differences in sialic acid content because after digestion with neuraminidase the terminal sialic acids are removed to yield a single major band corresponding to the C1R polypeptide [9].
• The HLA-B35 allele from C1R and Hmy2 represents a novel subtype, B*3503, differing from B*3501 by replacement of serine by phenylalanine at the peptide binding position 116 [12].
• Sera deficient in C1R, C2,4D, C4, C3-C9 did not increase the calcium uptake response to antibody whereas augmentation did occur with C6-deficient serum [18].
• 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 [19].

Regulatory relationships of C1R

• The NK susceptibility of C1R target cells expressing no HLA-A, B class I molecules or the nonprotective HLA-A2.1 or HLA-A2M70 mutant class I molecules was unaffected by pretreatment with HLA-A2-binding peptides [20].

Other interactions of C1R

• In this study we investigated the exon-intron organization of the human C1R gene, which spans 11 kb from the initiation codon to the stop codon, and is very similar in exon-intron structure to the C1S gene [21].
• Here strong cytotoxicity was found to be directed against MHC class I mutant cell lines, such as 721.221 and C1R, as well as against some allogeneic target cells [22].
• The use of the method is illustrated on distantly related domains shared by complement components C1S and C1R, calcium-dependent serine proteinase and bone morphogenetic protein 1 [23].

Analytical, diagnostic and therapeutic context of C1R

• The polymorphism of C1R was investigated in 570 unrelated Japanese individuals using isoelectric focusing and immunoblotting [24].
• 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 [25].
• 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 [26].

References