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PubMed1981

Idiotypic analysis of anti-GAT antibodies. VIII. Comparison of interstrain and allotype-associated idiotypic specificities.

A guinea pig anti-idiotypic antiserum made against pooled specifically purified A/J anti-GAT antibodies was characterized. This antiserum contains anti-idiotypic antibodies specific to interspecies, interstrain, and allotype-linked idiotypic determinants. These idiotypic determinants are associated with the combining sites of idiotypic antibodies that are induced by GT-related but not GA-related antigenic moieties. Genetic and strain distribution studies indicated that the shared allotype-linked idiotypic determinants are controlled by Igh-1e- or Igh-1b-linked genes. The interrelationships of the allotype-linked and interstrain CGAT idiotypic specificities are described using monoclonal anti-GAT hybridoma antibodies. Four of 7 hybridoma anti-GAT antibodies of C57BL/6 origin expressed a major fraction of the idiotypic specificities of A/J anti-GAT antibodies. These 4 hybridoma antibodies also carried the common interstrain idiotype, termed CGAT, but not all CGAT-bearing anti-GAT hybridoma antibodies expressed the allotype-linked idiotypic specificities. The Ig-1b-positive, F17-167.1 hybridoma anti-GAT antibody was used as a ligand to selectively identify the major allotype-linked idiotypic specificities, which were designated Gte idiotype.

Animals↗
PubMed1982

Immunoelectron microscopic localization of idiotypes and allotypes on immunoglobulin molecules.

We have developed a novel approach to the analysis of antigenic (allotypic and idiotypic) determinants on intact immunoglobulin molecules. Immune complexes composed of IgG in combination with anti-idiotype or anti-allotype antibody were "visualized" by transmission electron microscopy. Individual Fab fragments of anti-idiotype or anti-allotype antibody, when bound to the IgG, altered the "Y" configuration in a reproducible and interpretable manner. Anti-idiotype antibody (either as Fab or IgG) bound to the terminus of the presumed V region of the IgG molecule, thus extending the apparent length of the Fab arms. Analysis of a rabbit VH framework allotype (a1) revealed that the determinant(s) is (are) located on the lateral portion of the V region of IgG. Binding of the anti-a1 Fab fragments was always at approximately right angles to the axis of the Fab arms of IgG. Fab antibody to the rabbit kappa light chain (b4) allotype bound to the lateral portion of the terminal half of the IgG Fab arms. This technique should be of value in localizing less well defined immunoglobulin determinants.

Animals↗
PubMed1980

Production of antibodies to host IgG after transfer of histocompatible cells primed to host allotype.

A method is described to bring about endogenous production of antibodies to the Fc region of IgG. Mice of one allotype (Igb) were immunized against immunoglobulin from a congenic strain of mice bearing another allotype (Iga). The Iga-primed cells were transferred to congenic recipients bearing the Iga allotype and the production of anti-host allotype antibodies by the donor cells measured. Low levels of anti-host allotype antibodies were found in the sera of normal recipients but much greater amounts in recipients pretreated with cyclophosphamide. On ultracentrifugation some of these IgG antibodies sedimented at more than 7S probably because they were complexed with the IgG antigen. It is considered that thismodel may be of use in testing the effect of anti-Fc antibodies on joint inflammation.

Animals↗
PubMed1984

Complete sequence of a cloned cDNA encoding rabbit secreted mu-chain of VHa2 allotype: comparisons with VHa1 and membrane mu sequences.

The complete sequence of a cDNA clone (pmu3) encoding a secreted IgM heavy chain from a rabbit of VHa2 allotype has been determined. Comparison of the nucleic acid and amino acid sequences with a comparable mouse mu-chain shows unusually high homologies of the sequences of the fourth domains and secretory portions of the molecules (80 to 90% vs 56 to 73% for the other domains). This high degree of homology is also seen with the sequences of the fourth domain and secreted terminus of human mu-chain. The DNA sequence of a second cDNA clone encoding the membrane form of rabbit IgM is approximately 90% homologous with the mouse and human coding sequences for the membrane terminus, and there is 98 and 97% amino acid sequence homology. We found an unusually long (156 base pair) 5' untranslated region in clone pmu3 and discovered that 105 bases at the 5' end were complementary to the terminal portion of the CH4 domain of our mu sequence. Southern blotting analyses and the finding of a 13 base pair segment in rabbit genomic V region DNA that is homologous to the complementary strand of a segment of the CH4 of rabbit mu strongly suggests that this extended sequence resulted from a reverse transcriptase "hooking error". We have also obtained and sequenced another cDNA clone from a VHa1 cDNA library. Comparison of the V region of clone pmu3 from VHa2 with the 117 available positions of a1 DNA sequence shows 25 differences, nine of which are in allotype-associated codons. There is also a two-codon deletion in the VHa1 compared to VHa2 in the third framework region that may contribute to allotypic differences. Development of VHa allotype-specific probes, now in progress, is complicated by the fact that most of the allotype-associated amino acids of a1, a2, and a3 can be derived from each other by single base changes.

Amino Acid Sequence↗
PubMed1993

Low concentrations of Gm allotypic subsets G3 mg and G1 mf in homozygotes and heterozygotes.

Serum concentrations of IgG3, IgG1, and of the Gm allotypic subsets of these two isotypes were measured in adult homozygotes and heterozygotes. Alleles G3 mb and G3 mst of the IgG3 locus, and alleles G1 ma and G1 max of the IgG1 locus were found to associate with a high concentration of the allotypic product. Alleles G3 mg (IgG3) and G1 mf (IgG1) were associated with a low concentration of the product. This was true regardless of the haplotype; for example, allele G3 mb was associated with a high concentration of the product in all haplotypes f;n+;b f;n-;b and fa;n+;b. One dose of allele G3 mg was associated with a characteristic mean concentration of the product (g-type IgG3). This rule was valid regardless of the other allele of the subject, thus, heterozygotes and G3 mg/g homozygotes had mean concentrations of 0.10 and 0.20 g/liter, respectively, of g-type IgG3. Products of the IgG1 alleles were also simply additive: one dose of allele G1 ma(x) or G1 mf was associated with mean concentrations of 3.63 and 2.84 g/liter, respectively, and two doses with twice these amounts. Only allele G3 mb did not completely follow this rule. We also studied the serum concentrations and the allotype distribution of 41 IgG1 and 31 IgG3 myeloma proteins. The results suggested that the allotype-associated differences in serum concentrations are caused by different numbers of B cells producing allotypic subsets of IgG1 or IgG3, not by different rates of synthesis per B cell.

Adult↗
PubMed1989

Application of immunoglobulin heavy chain (GM, AM) and light chain (KM) allotypes to cases of disputed paternity.

To evaluate the usefulness of extended immunoglobulin allotyping compared to the conventional number of reagents in general use, 1,896 cases of disputed paternity tested for HLA, immunoglobulin allotypes (IGH, [GM, AM] and KM) and red blood cell markers (RBC) (ABO, RH, MNS, Kidd, Duffy, Kell, Colton, Lutheran, and Lewis) were analyzed. There were 1,289 cases in which both the mother and alleged father were Black, 548 cases in which the mother and alleged father were White and 59 cases that were either mixed or of different ethnic groups. A total of 691 exclusions were observed (533 Black, 143 White and 15 other). The observed exclusion rates for the HLA system in Blacks (93.9%) and in Whites (94.9%) were similar to previous estimates of the HLA exclusion rates, indicating that these cases appear to be consistent with other studies. The observed exclusion rates for the IGH haplotypes (alleles) were the highest single system exclusion rates beside the HLA system (54.08% in Blacks and 31.47% in Whites). Further, the values were higher than any single blood group system, or electrophoretic system in common usage. The combined IGH and KM observed exclusion rates were 57.50% for Black cases and 37.06% for White cases. The value of the combined immunoglobulin allotypes in Blacks almost exceeds the combined exclusion rate for all RBC antigens tested. The importance of doing extended immunoglobulin allotyping in Black cases is demonstrated by the fact that 76.5% of the exclusions would have been missed if only G1M A, F and X and G3M B0 and G had been used in the Black cases. The inclusion of additional markers in the White cases increased the observed IGH exclusion rate from 23.78 to 31.47%. The increase was primarily due to the addition of G2M N.

Black People↗
PubMed1969

Variation in the N-terminal sequence of heavy chains of immunoglobulin G from rabbits of different allotype.

The sequences of the N-terminal peptides prepared by Pronase digestion of the heavy chain of rabbit immunoglobulin G of allotype Aa1, Aa2 and Aa3 were determined and were shown to be related to the allotype. An N-terminal fragment of about 34 residues was also prepared from the allotype heavy chains, by cleavage with cyanogen bromide; the yield varied with the allotype. The sequences of the cyanogen bromide fragments from the Aa1 and Aa3 heavy chains contain allotype-related variations similar to those found in the N-terminal Pronase peptides, and these sequences are thought to be representative of the whole heavy-chain populations. There is about 60% homology between the two sequences, and superimposed on the differences between them there are a number of positions within each sequence at which at least two amino acids are present.

Amino Acid Sequence↗
PubMed1972

Active suppression of immunoglobulin allotype synthesis. II. Transfer of suppressing factor with spleen cells.

The mechanism of chronic allotype suppression in (SJL x BALB/c)F(1) mice has been investigated by means of cell transfer studies. These mice are phenotypically negative for serum Ig-1b, the paternal allotype determinant on gammaG(2a) immunoglubulin, as a result of perinatal exposure to maternal anti-Ig-1b. When spleen or bone marrow (B) cells from suppressed mice were injected into irradiated BALB/c "indicator" hosts, detectable levels of Ig-1b were demonstrated in the sera of a majority of the recipients early after transfer. These results indicate that Ig-1b-producing cells or their precursors are present in the lymphoid tissues of suppressed mice, even though they are not expressed. Within 5-7 wk, it was no longer possible to detect Ig-1b in the sera of these hosts, although cells producing another paternal allotype (Ig-4b) were shown to persist. Control BALB/c mice, injected with spleen and B cells from normal mice, continued to produce high levels of immunoglobulin carrying this allotype. The disappearance of serum, Ig-1b occurred most frequently in the recipients of suppressed spleen cells. Similar results were obtained using a mixture of spleen cells from normal and suppressed mice. Ig-1b production in the recipient mice ceased within a few weeks, even though the majority of cells in the mixture were obtained from normal (nonsuppressed) donors. The data are interpreted as evidence that chronic allotype suppression in mice is actively maintained by cells which are resident in the lymphoid tissues, splenic cells being the most effective. These cells are capable of proliferating in a new host and exerting their suppressive influence on Ig-1b-producing cells and/or their precursors.

Animals↗
PubMed1997

Molecular characterization and functional analysis of murine interleukin 4 receptor allotypes.

The murine interleukin 4 receptor (IL-4R) exists as a transmembrane protein transducing pleiotropic IL-4 functions, or as soluble (s)IL-4-binding molecule with potent immunoregulatory effects. In this study we identified and characterized a murine IL-4R allotype. Sequence analysis of the IL-4R cDNA of BALB/c mice revealed 18 base substitutions leading to three extracellular and five cytoplasmic amino acid changes when compared with the published IL-4R sequence of C57BL/6 mice. Analyses with allotype-specific mAbs revealed that AKR/J and SJL/J mice possess the newly identified BALB/c IL-4R allotype whereas the IL-4Rs of C3H, CBA, DBA-2, and FVB/N mice are identical to that of the C57BL/6 mouse. The extracellular Thr49 to Ile substitution abrogates one N-glycosylation site in the naturally occurring BALB/c IL-4R as well as in the experimentally point mutated C57BL/6-T49I sIL-4R, and both molecules display a nearly threefold reduction in IL-4-neutralizing activity compared to the C57BL/6 sIL-4R. In line with this, a significantly enhanced dissociation rate of IL-4 was detected for the BALB/c IL-4R allotype by surface plasmon resonance and in radioligand binding studies with IL-4R-transfected cell lines. These findings suggest that the altered ligand binding behavior of the newly described IL-4R allotype may influence the IL-4 responsiveness, thus contributing to the diverse phenotypes of inbred mouse strains in IL-4-dependent diseases.

Alleles↗
PubMed1966

Immunoglobulin M allotypes of the rabbit: identification of a second specificity.

Rabbit antiserums, originally prepared to react specifically with rabbit immunoglobulin allotypes Ab5 and Ab6, also react with some normal rabbit serums that clearly do not contain Ab5 or Ab6 allotypes. This reaction is due to antigenic specificity present on rabbit immunoglobulin M(IgM) and not on rabbit immunoglobulin G. Serums that contain this IgM allotype do not react with an antiserum that reacts with the known rabbit IgM allotype, Ms1. This specificity may therefore be identified as a second rabbit IgM allotype, Ms2.

Animals↗
PubMed1991

Complement allotypes in Japanese patients with pemphigus and bullous pemphigoid.

The allotypes of C6, C7, factor B (BF) and factor I (IF) of the human complement system were studied in 11 Japanese patients with pemphigus (5 with pemphigus vulgaris and 6 with pemphigus foliaceus) and 17 with bullous pemphigoid (BP) to investigate the genetic background of these diseases. The allotypes were detected by using isoelectric focusing and immunoblotting. The frequency for IF*A allele in the pemphigus patients was significantly higher (p = 0.009) than that in healthy controls (n = 60). A significant association of IF A allotype with pemphigus was also observed (p = 0.027), with a relative risk of 6.3. There was no association between the C6, C7, BF or IF allotypes and BP. These data suggest that IF A allotype may be an etiological genetic factor in the development of pemphigus.

Alleles↗
PubMed2004

Involvement of C4 allotypes in the pathogenesis of human diseases.

The complement system is an important humoral defense mechanism that plays a relevant role against microbial agents, inflammatory response control, and immunocomplex clearance. Classical complement pathway activation is antibody-dependent. The C4 component participates in the initial step of activation, and C4 expression is determined by 2 pairs of allotypes: C4A and C4B. Deficiencies in C4 allotypes have been associated with several diseases. The aim of the present review is evaluate the reported data in the literature regarding specific C4A and C4B deficiencies and characterize their clinical relevance. We searched the MEDLINE and LILACS databases. Papers referring to total C4 deficiency without allotype evaluation and case reports of primary C4 deficiency were not included. Deficiencies in C4 allotypes have been associated with Mycobacterium leprae infection, erythema nodosum, systemic sclerosis with anti-topoisomerase I antibodies, intermediate congenital adrenal hyperplasia with DR5 genotype, diabetes mellitus type 1 with DR3,4 genotype, and diabetes mellitus with antibodies against islet cells. C4 allotype deficiency is also related to C4B deficiency and autoimmune-associated diseases, such as systemic lupus erythematosus, or diseases with an autoimmune component, such as autism. Some reports associate C4A with thyroiditis after delivery as well as limited and systemic sclerosis without anti-topoisomerase I antibodies. However, the studies with C4A and C4B have been concentrated in isolated populations, and some of the studies could not be reproduced by other authors.

Alleles↗
PubMed1992

The coding sequence of the hemolytically inactive C4A6 allotype of human complement component C4 reveals that a single arginine to tryptophan substitution at beta-chain residue 458 is the likely cause of the defect.

The C4A6 allotype of the human complement component C4 is known to be defective in C5 binding within the C5 convertase. To characterize the position and nature of the molecular defect in the C4A6 allotype we have isolated the C4A6 gene from a cosmid genomic DNA library. Direct sequencing of a 4.4-kb region of the gene covering exons 17 to 31 and encoding the C4d fragment and most of the rest of the alpha chain of C4 revealed that the C4A6 allele encodes the A isotypic residues Pro Cys-Leu Asp at positions 1101, 1102, 1105, and 1106 and the same residues as the C4A3 alpha gene at the polymorphic positions 1054 (Asp), 1157 (Asn), 1182 (Thr), 1188 (Val), 1191 (Leu) and 1267 (Ala). In addition the C4A6 allele was shown to encode a Pro at the previously characterized polymorphic position 707 in the C4a peptide where the C4A3 alpha allele encodes a Leu. The remaining 26 exons of the C4A6 gene were analyzed by detecting nucleotide mismatches in C4A6/C4A3 and C4A6/C4B1 DNA heteroduplexes using the chemical cleavage of mismatch technique. The regions around detected mismatches were sequenced. In total seven nucleotide differences were defined on comparison of the C4A6 and other C4 sequences, of which three were present in exons. Two of these resulted in amino acid changes. One of the amino acid differences is a known polymorphism in C4, a Tyr/Ser substitution at position 328 in the beta-chain. The second amino acid difference caused by a C to T transition in the first base of the codon for amino acid residue 458 was the only one shown to be specific to the C4A6 allotype. The C4A6 allotype contains a Trp residue at this position in the beta-chain instead of the Arg residue found in all other C4A and C4B allotypes so far characterized. We propose that this Arg to Trp substitution at beta-chain residue 458 is responsible for the inability of C4A6 to bind C5 in the C5 convertase.

Alleles↗
PubMed1988

Immunoglobulin (GM and KM) allotypes in the Sikh population of India.

The populations of India are genetically diverse, both within and between geographic regions; immunoglobulin (GM) allotypes provide important information on genetic differences between populations, since the frequencies of combinations of allotypes (termed "haplotypes") vary dramatically among ethnic groups. As part of a project to assess genetic diversity among defined Indian populations, we have examined eight GM allotypes in a sample of 101 unrelated Sikhs who have migrated to Toronto, Canada: Glm(1, 2, 3, 17) and G3m (5, 15, 16, 21). Sikhs are a religious group that arose in the Punjab about 1500 A.D.; most of the original converts are believed to have been middle to upper-middle caste Hindus. Gm allotyping showed that six Gm haplotypes occurred at polymorphic frequencies (greater than 0.01) in Sikhs: Gm3;5, Gm1,17;21, Gm1,2,17;21, Gm1,17;5, Gm1,17;15,16, and Gm1,3;5. These haplotypes have all been previously reported in Indian populations. The frequencies of the first four haplotypes resembled the published frequencies for lower-caste Hindus of NW India more than upper-caste Hindus. However, the last two haplotypes have been found only in upper-caste Hindus. The frequency of one of these, Gm1,17;15,16 was higher in Sikhs (0.09) than has been reported in any Indian population with the exception of Parsis (who are descended from Iranians). We speculate that the high frequency of this haplotype may have been characteristic of some of the Hindu castes in the Punjab from which Sikhs are descended.

Ethnicity↗
PubMed1999

Immunoglobulin allotypes among the Bicolanos of Sorsogon province, Luzon, Philippines: implications of phenotypes for filariasis.

Immunoglobulin (Ig) allotypes are polymorphic genetic systems that show distinct racial arrays, thus making them powerful tools for studies of genetic admixture and biological relationships. In the province of Sorsogon, southern Luzon, Philippines, allotyping was completed on 252 persons residing in two neighboring villages. The people demonstrated 14 GM and 3 KM phenotypes. The frequency of homozygous KM3, KM1 and heterozygous KM1,3 was identical in these villages; however, half of the GM phenotypes present in one village were significantly less frequent in the other village. The frequency of KM and GM haplotypes was different from those reported in Filipino aboriginal groups, but similar to a population on Samar Island, the only other Filipino group for which Ig allotype data exist. Variability in the prevalence of parasitic disease such as lymphatic filariasis may in part reflect differences in genetic susceptibility, resulting from allotypic heterogeneity between villages.

Asian People↗
PubMed1986

Distribution of immunoglobulin allotypes among local populations of Kenya olive baboons.

In this paper we report on the distributions of immunoglobulin allotypes among 564 olive baboons collected at six localities in Kenya. The sample localities and sizes are 1) Lake Magadi, N = 107; 2) Nanyuki, N = 77; 3) Lake Baringo, N = 55; 4) Mosiro, N = 132; 5) Isiolo, N = 36; 6) Gilgil, N = 157. Gm allotypes 1, 10, 13, 15, and 17 are polymorphic among these samples. Gm(11) and Km(3) were present in all samples, and Gm(2,3,5,6,14,16,21,24,26) and Km(1) were absent from all samples. The proportions of individuals positive for polymorphic allotypes varied substantially between different local samples, as did the arrays and estimated frequencies of haplotypes. Allotype frequencies in local samples do not appear to be simply related to either geographic location or habitat characteristics of the localities. Our data suggest that much of the geographic variability in Kenya olive baboon populations occurs between populations separated by small geographic distances.

Alleles↗
PubMed1978

Maternal allotype dominance and allelic exclusion in the B lineage cells of the newborn rabbit.

Newborn rabbits from parents which differ at the b allotype locus (kappa chain), show a strong maternal allotype dominance, especially in the bone marrow. This concerns not only the membrane but also the cytoplasm, and it cannot be simply due to a passive uptake of maternal immunoglobulins. The spleen precedes the bone marrow for a high level of expression of the paternal allotype. In the thymus, cells which contain cytoplasmic immunoglobulin are found at low frequency, but their absolute number represent a substantial contribution to the B lineage cell pool. A small proportion of such thymus cells do not show allelic exclusion of kappa chain allotypes.

Alleles↗
PubMed1991

Preferrential rearrangement in normal rabbits of the 3' VHa allotype gene that is deleted in Alicia mutants; somatic hypermutation/conversion may play a major role in generating the heterogeneity of rabbit heavy chain variable region sequences.

The rabbit is unique in having well-defined allotypes in the variable region of the heavy chain. Products of the VHa locus, (with alleles a1, a2, and a3), account for the majority of the serum immunoglobulins. A small percentage of the serum immunoglobulins are a-negative. In 1986, Kelus and Weiss described a mutation that depressed the expression of the Ig VH a2 genes in an a1/a2 rabbit. From this animal the Alicia rabbit strain was developed and the mutation was termed ali. We previously showed, using Southern analysis and the transverse alternating field electrophoresis technique, that the difference between the ali rabbit and normal is a relatively small deletion including some of the most 3' VH genes. The most JH proximal 3' VH1 genes in DNA from normal rabbits of a1, a2 and a3 haplotypes encode a1, a2 and a3 molecules respectively, and it has been suggested that these genes are responsible for allelic inheritance of VHa allotypes. The present study suggests that the 3' end of the VH locus probably plays a key role in regulation of VH gene expression in rabbits because VH gene(s) in this region are the target(s) of preferential VDJ rearrangements. This raises the possibility that mechanisms such as somatic gene conversion and hypermutation are at work to generate the antibody repertoire in this species. Our data support the view that the 3' VH1 gene may be the preferred target for rearrangement in normal rabbits, and for the normal chromosome in heterozygous ali animals. However, homozygous ali rabbits with a deletion that removed the a2-encoding VH1 on both chromosomes do survive, rearrange other VH genes and produce normal levels of immunoglobulins as well as a significant percentage of B cells which bear the a2 allotype. This challenges the view that one VH gene, VH1, is solely responsible for the inheritance pattern of VHa allotypes.

Animals↗