Three Chido determinants detected on the B5Rg+ allotype of human C4: Their expression in Ch-typed donors and families

Giles, Carolyn M.

doi:10.1016/0198-8859(87)90009-7

Cited by 40 publications

(30 citation statements)

References 18 publications

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“…C4B5 is much more common among the Japanese population (8.8%) (44) than among the Caucasians, in which C4B5 is most often found in the haplotype HLA-B55, C4A4 (45). A C4B5 with Rg 1, 2, 3 and Ch -1, -2, -3, 4, -5, -6, identical to our case, has been reported but not confirmed from sequence data (46), and would be called C4B*0508 (47). The C4B5Rg ϩ subtype associates also with HLA-B60 (40).…”

Section: Discussionsupporting

confidence: 60%

Characterization of a De Novo Conversion in Human Complement C4 Gene Producing a C4B5-Like Protein

Jaatinen

Eholuoto

Laitinen

et al. 2002

The Journal of Immunology

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Complement C4 is a highly polymorphic protein essential for the activation of the classical complement pathway. Most of the allelic variation of C4 resides in the C4d region. Four polymorphic amino acid residues specify the isotype and an additional four specify the Rodgers and Chido determinants of the protein. Rare C4 allotypes have been postulated to originate from recombination between highly homologous C4 genes through gene conversions. Here we describe the development of a de novo C4 hybrid protein with allotypic and antigenic diversity resulting from nonhomologous intra or interchromosomal recombination of the maternal chromosomes. A conversion was observed between maternal C4A3a and C4B1b genes producing a functional hybrid gene in one of the children. The codons determining the isotype, Asp1054, Leu1101, Ser1102, Ile1105 and His1106, were characteristic of C4B gene, whereas the polymorphic sites in exon and intron 28 were indicative of C4A3a sequence. The protein produced by this hybrid gene was electrophoretically similar to C4B5 allotype. It also possesses reversed antigenicity being Rodgers 1, 2, 3 and Chido-1, -2, -3, 4, -5, and -6. Our case describes the development of a rare bimodular C4B-C4B haplotype containing a functional de novo C4 hybrid gene arisen through gene conversion from C4A to C4B. Overall the data supports the hypothesis of gene conversions as an ongoing process increasing allelic diversity in the C4 locus.

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Section: Discussionsupporting

confidence: 60%

Characterization of a De Novo Conversion in Human Complement C4 Gene Producing a C4B5-Like Protein

Jaatinen

Eholuoto

Laitinen

et al. 2002

The Journal of Immunology

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“…RIT-AB (C4A*6) is associ ated with HLA-B57. A special comment shall be given to the reference variant C4B 5 (RIT-KHH) [4,26,27]; migrating slightly cathodal of the first minor band of A 3 it should have been des ignated as 'B 6' according to the Nomencla ture Statement of 1983. In consequence of the circulation of an uncorrected preprint of the statement this allele was later published as C4B 5 by some groups, as 'B 6' by others.…”

Section: Typing Criteriamentioning

confidence: 99%

“…Further criteria are used to support or subdivide allotype characterization. These are determination of (1) Rodgers and Chido epitopes on the C4d fragment [4], (2) the detection of the two C4 a-chain types after dénaturation of the pro tein [5], (3) Western blotting with mono clonal antibodies [6][7][8], and (4) prolonged agarose gel electrophoresis [9,10]; (5)C4 ß-chain allotypes on the denaturated protein do not directly contribute to the C4A or B allo type recognition but mostly support C4 hap lotype segregation patterns and have been found to be in linkage disequilibrium with some of the C4A and C4B alleles [11,12],…”

Section: Introductionmentioning

confidence: 99%

C4 Reference Typing Report

Mauff

Brenden²,

Braun-Stilwell³

et al. 1990

Complement Inflamm

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Human C4 is most polymorphic at the protein level, distinction between allotypes of the C4A and C4B proteins resting on electrophoretic migration patterns and difference in hemolytic activity. The aim of the C4 reference typing has been the definition of reference variants, the assignment of rare variants, and the investigation of duplicated, deleted, or non-expressed and hybrid genes. Samples from 136 individuals, predominantly with known segregation, from 16 laboratories were investigated by standard electrophoretic techniques, for their relative hemolytic activity, reactivity with monoclonal antibodies and Rg/Ch reagents, a-, and ß-chain types, relative electrophoretic migration distance, as well as the C4/21-OH-TaqI RFLPs. The results were evaluated in three groups; they consisted in the definition of the eight most common C4 alleles, and the ten Rg/Ch standard phenotypes in group I. In group II twelve C4A and fourteen C4B duplications among 96 complotypes, as well as eighteen deleted/non-expressed C4A and twenty-two C4B alleles, and hybrid alleles were seen by correlation of lytic activity, electrophoretic mobility, and monoclonal and/or Rg/Ch reactivity. Group III consisted of the newly defined allotypes A 8, A 7, A 58, A 55, A 45, B 45, B 35, and B 22, furthermore of alleles subdividing the A 1/A 91, and the B 13/ B 12/B 11 regions. The reference typing has allowed reclassification of the majority of described C4 allotypes and resulted in a revision of the C4 nomenclature.

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“…Samples were desialated by incubation with neuraminidase at 10 mU/gl of plasma or scrum for 15 h at 4°C with continuous dialysis C4B 5 Rg+ individuals so far studied possess Ch4 and 6 or Ch4,5, and 6, but lack Ch 1,2, and 3 [ 17], the failure of our C4B 5 Rg+ variants to react with the M.L.E. anti-Chl,3 reagent corresponds to previous findings.…”

Section: Methodsmentioning

confidence: 97%

“…Partial inhibition is now known to reflect the presence of multiple antigenic deter minants of Rodgers and of Chido reactivity. There are six Chido (Chl-6) and two Rodgers (Rgl and 2) specificities [17]. The recent detection of alloanti-Ch in a Chido-…”

Section: Introductionmentioning

confidence: 99%

An Immunoblotting Technique for Direct Visualization of Chido and Rodgers Reactivity on C4 Variants after Electrophoresis

Sklarin¹,

Awdeh²,

Alper³

1988

Vox Sanguinis

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An immunoblotting technique allows direct visualization of Chido and Rodgers antigenic determinants on intact C4 proteins. C4 molecules separated by electrophoresis are selectively transferred to nitrocellulose membranes saturated with goat antiserum to human C4. The membranes are then incubated in alloanti-Chido or anti-Rodgers followed by enzyme-conjugated goat antihuman IgG. Molecules with Chido or Rodgers reactivity are visualized by incubation with an indicator substrate for the bound enzyme.

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Three Chido determinants detected on the B5Rg+ allotype of human C4: Their expression in Ch-typed donors and families

Cited by 40 publications

References 18 publications

Characterization of a De Novo Conversion in Human Complement C4 Gene Producing a C4B5-Like Protein

Characterization of a De Novo Conversion in Human Complement C4 Gene Producing a C4B5-Like Protein

C4 Reference Typing Report

An Immunoblotting Technique for Direct Visualization of Chido and Rodgers Reactivity on C4 Variants after Electrophoresis

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