New variations of human CC-chemokine receptors CCR3 and CCR4

Abstract

CCR3 and CCR4 are the members of CC chemokine receptor family expressed on Th2 type CD4 + T cells. In this study, variation screening of the entire coding regions of CCR3 and CCR4 was performed, and possible association with several autoimmune diseases was tested, using the genomic DNA from 304 Japanese healthy individuals and 272 Japanese patients with rheumatic diseases. One non-synonymous substitution was identified in CCR3 gene, whereas in CCR4 gene, two non-synonymous and two synonymous substitutions were detected. Among the synonymous substitutions, CCR4 1014(C→T) was observed in 7.2% of the healthy individuals and 6.6% of the patients, and was considered as a single nucleotide polymorphism. All other variations were observed in only one or two individuals. No significant association was observed between any of the variations and any of the rheumatic diseases. Among these variations, CCR3-C218S substitution coded by 652(T→A) substitution was localized in the region conserved among the G protein coupled receptor family. Reactivity of eosinophils to the monoclonal antibody against CCR3 and the chemotaxis to eotaxin were slightly reduced in this patient as compared with healthy controls or a patient with Behçet disease homozygous for the common allele, while CCR3 mRNA level was not different. These findings suggest that CCR3-C218S substitution may lead to the reduced function of CCR3 at the protein level. Further study will be of interest to test whether CCR3-C218S variation or any of the CCR4 variations has a significant role in rendering susceptibility to immunological diseases or resistance to HIV infection.

Single nucleotide polymorphisms in the coding regions of human CXC-chemokine receptors CXCR1, CXCR2 and CXCR3

“…SSCP analysis was performed essentially according to the method described previously. 21 One microliter of solution containing the PCR product was mixed with 7 l of denaturing solution (95% formamide, 20 mm EDTA, 0.05% bromphenol blue, 0.05% xylene cyanol FF). The mixtures were thermally denatured at 96°C for 5 min and immediately cooled on ice.…”

“…21 Since the imbalance of Th1/Th2 cells had been implicated in autoimmune rheumatic diseases, it was possible that genetic variations of CCR3 or CCR4 might cause the imbalance and might influence the susceptibility to the diseases. 22 However, although several new variations were detected, no association was observed between the susceptibility to rheumatic diseases and any of the variations.…”

New polymorphisms of human CD80 and CD86: lack of association with rheumatoid arthritis and systemic lupus erythematosus

“…19,20 We have been trying to detect susceptibility genes to human rheumatic or autoimmune diseases through extensive polymorphism screening of the candidate genes. [21][22][23][24][25][26] Based on the functional importance and chromosomal locations, genes coding for the costimulatory molecules were considered as strong candidates for the susceptibility gene to rheumatic diseases. We recently reported that CTLA-4 exon 1 polymorphism does not substantially contribute to the susceptibility to RA and SLE in Japanese.…”

A single nucleotide polymorphism in the CCR3 gene ablates receptor export to the plasma membrane

“…[34][35][36] The point mutations conferred on the primary sequence of CCR3 were distributed throughout the protein (Fig E1, B). Plasmids encoding the CCR3 SNPs were generated and used to transfect L1.2 cells transiently to determine the functional consequences of mutation.…”

“…The majority of constructs were expressed at levels comparable to WT-CCR3 with the exception of the C218S-CCR3 and L324P-CCR3 constructs, which were expressed at considerably lower levels (Fig 1, A and B). 36 A lack of extracellular expression may be envisaged to be a result of a defect in mRNA transcription or protein translation. To determine that the L324P-CCR3 and C218S-CCR3 protein products were expressed, we carried out intracellular staining for the HA tag in transfectants by using flow cytometry.…”