Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “allotype”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10Linked to original sources
PubMed1989

Serological survey of complement factor H in common laboratory and wild mice: a new third allotype.

Antigenic specificities of complement factor H from mice were studied serologically. In addition to previously reported allotypes, referred to as H.1 and H.2, a new allotype of complement factor H, H.3, was identified in the BFM/2Ms strain derived from European wild mice. Using three different alloantisera raised against the various mouse factor H allotype, a serological survey of the common laboratory strains and wild-derived strains of Mus musculus and its relatives, Mus spretus, Mus spretoides, and Mus spicilegus was carried out. All of the common laboratory strains examined in this survey had the H.1 allotype except for STR/N which had H.2. The geographical distributions of factor H allotypes in M. musculus were specific to the subspecies. Mice derived from Mus musculus domesticus and Mus musculus castaneus had the H.1 allotype. Mice derived from M. m. musculus, Mus musculus bactrianus, and Mus musculus molossinus had the H.2 allotype. Only BFM/2Ms and BFM/1Mpl strains derived from M. m. domesticus had the novel H.3 allotype. Sera of mice from strains derived from M. spretoides and M. spicilegus cross-reacted with H.2-specific antiserum, and those from M. spretus cross-reacted with H.3-specific antiserum.

Alleles↗
PubMed1995

Overlap in the repertoires of peptides bound in vivo by a group of related class I HLA-B allotypes.

BACKGROUND: Polymorphism among class I molecules of the major histocompatibility complex (MHC) confers allotypic specificity on the peptides that these molecules bind and present to cytotoxic T lymphocytes. Evolution of new human HLA class I alleles usually involves gene recombination events that replace a segment of one allele with the homologous region of another. In this study, the impact of these evolutionary changes has been assessed by comparison of the peptide-binding specificities of six related HLA-B allotypes. RESULTS: Endogenous peptides bound by HLA-B*5401, HLA-B*5501, HLA-B*5502, HLA-B*5601, HLA-B*6701 and HLA-B*0702 were characterized. Despite differing by 1-9 of the amino-acid residues comprising their peptide-binding sites, all these allotypes share a dominant preference for peptides that have proline at position 2. Polymorphism results in differing selection of carboxy-terminal and secondary anchor residues, but the peptide-binding specificities are sufficiently similar that there is overlap in the repertoires of peptides bound by these allotypes. Complete sequence determination of individual peptides revealed four that could be isolated from two or more allotypes. Members of the closely related HLA-B22 family--HLA-B*5401, HLA-B*5501, HLA-B*5502 and HLA-B*5601--show only minor differences in their peptide-binding specificities. This marked similarity is reflected at the functional level, as alloreactive cytotoxic T lymphocytes generated against HLA-B*5401 and HLA-B*5501 exhibited cross-reactive recognition. CONCLUSION: The isolation of identical endogenously bound peptides from six HLA-B allotypes demonstrates overlap in the repertoires of peptides bound in vivo by different allotypes. We speculate that the shared preference for binding peptides with proline at position 2 reflects a selective pressure to retain this specificity, which may be based upon peptide availability in vivo. Characterization of the overlap between the repertoires of peptides bound by HLA-B allotypes could simplify the development of peptide-based vaccines that are targeted to cytotoxic T cells, as single peptides would be effective for humans of different HLA types.

Amino Acid Sequence↗
PubMed1968

Allotype-related sequence variation of the heavy chain of rabbit immunoglobulin G.

The heavy chain of rabbit immunoglobulin G exists in three major allotypic patterns, Aa1-Aa3. A comparison of the amino acid compositions of the heavy chains isolated from immunoglobulin IgG homozygous for each allotypic determinant revealed the presence of an additional methionine residue per chain in the Aa3 allotype relative to the Aa1 and Aa2 allotypes. The position of the additional methionine residue was determined by cyanogen bromide cleavage and by tryptic digestion of the gamma-chains; it coincided with the inter-Fd-Fc area of the chain. Isolation and characterization of the corresponding tryptic peptides of 31 amino acid residues from each of the allotypes showed the presence of a methionine-for-threonine replacement in the Aa3 allotype, but only in about 70-80% of the molecules. No other allotypic variations were seen in this tryptic peptide. Allotypically related variations in composition were also detected in the N-terminal cyanogen bromide-cleavage peptide.

Journal Article↗
PubMed1975

Structure and regulation of immunoglobulins: kappa allotypes in the rat have multiple amino-acid differences in the constant region.

Immunoglobulin kappa chains from various inbred strains of rats have two serologically detectable forms that segregate in a Mendelian fashion (allotypes a and b of the RI-I locus). Partial amino-acid sequences from the constant regions of these two forms have been compared. Of the 81 residues of the constant region studied, 10 amino-acid substitutions as well as one size difference (sequence gap) were found. This large number of sequence differences among alternative forms of the kappa allotype raises provocative questions as to the genetic and evolutionary implications of these light chain allotypes. We designate allotypes whose alternative forms differ at multiple residue positions as complex allotypes. There are basically two genetic models that might explain complex allotypes. First, these allotypes are alleles of a single structural gene with an unusual evolutionary history. Second, all rats have genes that code for each of the light chain allotypes and a control mechanism that permits them to be expressed so that they mimic a Mendelian pattern of segregation. We discuss evidence from other immunoglobulin systems that is compatible with this second model.

Alleles↗
PubMed1965

Cellular localization of immunoglobulins with different allotypic specificities in rabbit lymphoid tissues.

The cellular localization of allotypes in rabbit lymphoid tissues has been studied by immunofluorescence. In heterozygous animals the double staining for two allotypes controlled by allelic genes (A1 and A2; A4 and A5; A4 and A6) has shown the existence of two populations of plasma cells, one containing one allotype and the other the alternative one. The localization in different cells of immunoglobulins marked by allelic allotypic specificities has been confirmed by microspectrography of single cells. An exception to this rule was given by the presence in the germinal centers of lymphoid follicles of apparently uniform mixtures of products of the two allelic genes. Double staining for two allotypes controlled by genes at different loci showed, instead, the presence of many cells containing both allotypes; the number of these cells was highest in doubly homozygotes, in the other it was consistent with random association of non-allelic specificities. In addition double staining for one allotype and gamma G globulins in the lymphoid tissues of rabbits homozygous at the a or at the b locus, has shown the presence of cells containing immunoglobulins that lack one allotype.

Animals↗
PubMed1975

Investigation of NZB mice born to BALB/c immunized against NZB allotype.

Allotype suppression is held to be an example of T-cell suppressor function. Failure of generalized suppressor T-cell function is considered to be responsible for the chronic and progressive disease of the NZB. The possible association of allotype suppression and autoimmune disease has been investigated here in a group of NZB mice, transplanted and born from BALB/c recipients whilst producing anti-NZB allotype. In this situation it was anticipated that if allotype suppression should fail this would coincide with the development of autoimmune disease; both processes reflecting failure of T-cell suppressor function. However, in spite of the fact that allotype suppression was not achieved, certain observations seem important. The fact that NZB born the BALB/c were in no way different from normally derived NZB confirms that the cause of the NZB disease is established prior to the stage of implantation. Maternal influence at or beyond this stage appears of little consequence in terms of effecting the development or progression of the NZB disease. The failure to induce allotype suppression in the NZB is important. In this context this strain appears to be no different from the majority of other strains that have been tested as homozygotes. The suppression obtained with (BALB/c X SJL/J)F1 hybrids in which chronic suppression has been achieved therefore seems to represent an exceptional situation and this suggests that it is perhaps unwise to base general assumptions as to the universal adaptability of T-cell control mechanisms upon unusual findings. It must be remembered that only homozygotes were examined here. Earlier attempts to induce allotype suppression in homozygotes also failed, even in the SJL/J. Since allotype suppression has only been demonstrated in heterozygote mice there is a distinct possibility that this phenomenon never occurs in the homozygote situation. The significance of this possibility is discussed.

Age Factors↗
PubMed1976

Study of A100 allotypic specificity of rabbit immunoglobulins: the cross-reactivity between A100, a1 and a3.

Evidence for the genetic determination of A100 allotypic specificity suggests that it is the product of an allele at the alpha locus. The A100 allotypic specificity was detected in a wild rabbit lacking all the known specificities of the a series. None of the 8 rabbits possessing the A100 allotypic specificity possessed two allotypic specificities of the a series. The concentration of A100+ molecules is larger in the serum of a presumably homozygous rabbit than in that of a presumably heterozygous rabbit. In the sera of heterozygous A100+ rabbits, the A100 allotypic specificity and the known specificity of the a series are carried by different molecules. The determinants responsible for the A100 allotypic specificity are present both on IgG and IgM. They are located on the heavy chain and the Fab fragment of IgG. A family of variants of A100 specificity has been detected and cross-reactivity between A100, a1 and a3 specificities has been found. This was detected and studied with anti-a3 antisera. It seems that A100 allotypic specificity is closer to a3 specificity than a1 is to a3 specificity.

Animals↗
PubMed1977

Surface immunolglobulin on rabbit lymphoid cells. VI. Failure to detect d and e group immunoglobulin allotypes on lymphocytes by immunoelectron microscopic labeling.

Surface immunoglobulin allotypes on rabbit peripheral blood lymphocytes (PBL) and spleen lymphocytes are detected by an immunoferritin labeling technique for electron microscopy. Human red blood cells, chemically coated with purified rabbit IgG of specific allotypes, served as test cells to assess the labeling specificity and efficiency. Immunoelectron microscopic labeling reveals that groups a, b, d and e allotypic specificities are readily detectable on passively coated test cells. However, only a and b group markers are detectable on lymphocytes. On rabbit PBL both a (VH of Fd region) and b (kappa chain constant region) group allotypes are detectable (73-78% and 68-77%, respectively); on spleen cells, 46% and 52-55% are positive for a and b locus allotypes, respectively. The d and e allotypes (i. e. gamma chain-specific) are undetectable on PBL or on spleen lymphocytes using this method. We conclude that the d and e group allotypes are either not present on the lymphocyte surface or are buried in the surface membrane and unacessible to the antisera used in this immunoferritin labeling technique.

Animals↗
PubMed1981

Allotype suppression in the chicken. III. Analysis of the recovery form suppression by neonatally injected or maternal antibodies.

Injection of M-1 (Cmu), G-1 (Cgamma) heterozygous chickens on the day of hatch with anti-IgM-1 antiserum induced allotype suppression from which chickens recovered over a period of approximately 4 months. The suppression of the serum IgM-1 levels was matched by a decrease in the number of splenic and peripheral blood B cells bearing the relevant IgM-1 allotype, and a compensatory increase in the number of cells bearing the alternative nonsuppressed IgM-1 allotype. However, the proportion of IgM-1 bearing bursal cells was only marginally altered. The recovery from suppression was due to B cell recruitment and could be abrogated by bursectomy. Allotype suppression induced in ovo or maintained by repeated injection of anti-IgM-1 anti-serum resulted in chronic suppression and depletion of the relevant peripheral as well as bursal IgM-1-bearing cells. Antibody titers of the relevant allotype in partially suppressed chickens generally correlated with serum allotype levels without clonal restriction in antibody response of the suppressed allotype.

Animals↗
PubMed1984

Heterogeneity of Igh-linked allotypic determinants expressed on functional T cell subsets as detected by monoclonal antibodies.

Hybridomas producing monoclonal antibodies (mAb) specific for immunoglobulin heavy chain (Igh) allotype-linked gene products expressed only on functional T cells but not on B cells and macrophages were established by fusion of allotype congenic SJL (Igh-1b) and SJA /9 (Igh-1a) B cells immunized reciprocally with partner spleen cells with a myeloma P3-X63-Ag8-653 of BALB/c origin. Nine mAb have been selected on the criteria that they can specifically block various antigen-dependent functions of known T cell subsets in in vitro immune responses of mouse strains having the corresponding Igh allotype, but not the other one. These included (a) four mAb that augment the in vitro secondary antibody response of either Igh-1a or Igh-1b strains and thus are considered to react with the Igh-linked allotypic determinant expressed on suppressor T cells, (b) one mAb that inhibits the helper T cell activity of Igh-1b but not of Igh-1a strains, (c) two mAb that inhibit the antigen-induced proliferative response of Igh-1a but not Igh-1b strains, and (d) two mAb that block the cytotoxicity of alloreactive cytotoxic T cells of Igh-1a strains. The linkage to Igh-1 allotype of the T cell products was established by testing with Igh-1-congenic strains with different backgrounds including the H-2 complex. Some of the mAb were able to react with cloned hybridomas and a continuous cell line of the given allotype and functions. Each mAb was able to block one of the known functions of T cell subsets, but not others, indicating the existence of the heterogeneity and multiplicity of the Igh allotype-linked products on T cells.

Animals↗
PubMed1984

Antibody-mediated allotype suppression in adult mice: the role of antigen, effector isotype and regulatory T cells.

It has been reported (Contemp. Top. Immunobiol. 1974. 3:41) that allotype-specific T suppressor cells can be induced after monoclonal anti-allotype treatment of neonatal (BALB/c X SJL)F1 (Igha/b) mice. Here we show that (BALB/c X CB20)F1 adult-derived spleen cells (SC) are, by contrast, potently suppressed by monoclonal allotype-specific reagents, (when transferred into irradiated BALB/c recipients) in the absence of primary T suppressor cell induction. Such suppression is only induced in activated B cells [exposed to lipopolysaccharide or sheep red blood cells (SRBC)], and is probably dependent on the isotype of the anti-allotype sera administered. For example, two independently produced IgG1 monoclonal reagents raised against the Igh-1b allotype were poorly suppressive or nonsuppressive, whereas an IgG3 and an IgG2a monoclonal antibody induced a 90% suppression of the target allotype in transferred adult SC. It was found that suppression was not due to a depletion of antigen-specific T cell help since: (a) the addition of SRBC-educated T cells did not break suppression and (b) suppressed SC were as good a source of T cell help as normal SC, in the response of virgin or memory B cell (Thy-1-depleted) responses to SRBC in vivo. Suppression was maintained in suppressed cells which had been rechallenged with SRBC after transfer into a second irradiated recipient, but was not induced in normal SC when these were admixed with an equal number from this suppressed SC population. These findings point to a possible mechanism for the regulation of B cell expression, through the formation of an antibody-Ig receptor complex at the surface of the B lymphocyte. After complexing the target cell is either deleted or inactivated. The response to SRBC was reduced or ablated for at least 70 days after treatment with a single dose of anti-allotype serum.

Animals↗
PubMed1982

Microdetermination of rabbit immunoglobulin allotypes by ELISA using specific antibodies conjugated with peroxidase or with biotin.

Enzyme-linked immunoadsorbent assays (ELISA) specific for the allotypes of rabbit heavy chain variable region (group a) and light chain constant region (group b) have been developed. These assays utilize affinity-purified allogeneic anti-allotype antibodies to coat polyvinyl microtiter plates. After test samples are added to the plates, the same affinity-purified antibody, coupled to the enzyme peroxidase, is used to detect binding of allotype-positive IgG samples to the coated plate. These assays can detect as little as 40 ng/ml of IgG of the appropriate allotype; the assays are highly specific and allow quantitative determination of allotype-defined IgG samples. In addition, the procedure can be modified by coupling of the antibody with biotin followed by development with avidin-peroxidase; this adaptation avoids the difficulties encountered in antibody-peroxidase conjugations. The ELISA assay is not influenced by the presence of anti-allotype antibody in the test sample, giving a distinct advantage over solid-phase radioimmunoassay procedures conventionally used for the quantitative determination of rabbit allotypes.

Animals↗
PubMed1984

The structural and genetic basis for expression of normal and latent VHa allotypes of the rabbit.

The immunoglobulin heavy chain variable regions of the rabbit are unusual in having genetically controlled, serologically detectable alternative forms, the VHa allotypes, as well as minor VH allotypes of the x, y and w groups. New insights into the probable structural basis for the VHa allotypes have come from re-examination of earlier protein sequence data in the light of newly deduced protein sequences derived from sequencing cloned cDNAs and genomic DNAs encoding VH regions. Here we review this sequence information, and define the allotype-correlated differences at seven positions in framework region 1 and 10 positions in framework region 3 that may lead to the serologically detectable allotypic determinants (allotopes). Most alternative amino acids at allotype-correlated positions can be derived from each other by single-base changes. Thus somatic mutations and/or gene conversion-like events must be considered along with other serological and genetic explanations for various reported observations of the production of latent VHa allotypes. The proximity of rabbit VH genes (approximately 3 kb apart) might enhance the likelihood of conversion-like events in both germline and somatic cells.

Amino Acid Sequence↗
PubMed1985

Allotypic and isotypic specificities of rabbit IgM: localization to the Fab mu or Fc mu fragments.

IgM from trypanosome-infected rabbits was digested with trypsin under different conditions to obtain Fab mu or Fc5 mu fragments suitable for analysis with anti-allotype and anti-isotype antibodies. The Fab mu but not the Fc5 mu fragment was shown to have the n-locus allotypic specificities, n80, n81, n82, n83 and n87, characteristic of the IgM class of immunoglobulins. Thus, the n82 and n83 allotypic specificities, conformationally dependent on the a VH locus for expression, and the n80, n81 and n87 allotypic specificities, independent of the a VH locus for expression, are in either the CH1 or CH2 domain of IgM heavy chains. In addition, two high-affinity mouse monoclonal antibodies (MoAbs) specific for IgM and able to bind IgM in direct-binding radioimmunoassays were produced and characterized. One MoAb (3C1) was specific for an isotypic determinant (epitope) in the Fab mu fragment, presumably in the CH1 or CH2 domain, whereas another MoAb (8C2) was specific for an isotypic epitope in the Fc5 mu fragment, presumably in the CH3 or CH4 domain. The proximity of the n-locus allotypic specificities (CH1 or CH2 domain) to the VH domain is consistent with the finding that some IgM allotypic specificities are expressed only in conjunction with certain a VH locus allotypic specificities.

Animals↗
PubMedDate not supplied

Genetic polymorphism of rabbit VHa region: a new allotype, a108.

We report a new rabbit IgVH allotype, designated a108, which was detected following studies of the progeny of a wild rabbit (Oryctolagus cuniculus) from Zembra Island (Tunisia). This allotype seems to be specific of this island, since it has not been detected in other wild rabbit populations (in Spain, Portugal or France). Its determinants are located on the Fd fragment of the immunoglobulin (Ig) heavy chain and it behaves like the product of an allele at the alpha locus. Allotype a108 was strongly related serologically to a1 and a107, and to a lesser extent to a101, a109 and a3 allotypes. We also detected determinants shared among the a1, a107, a108, a101 and a109 allotypes. These determinants were expressed by a large fraction of Ig molecules from rabbits of allotype a1, a107 and a108 and by a very small fraction of Ig from rabbits of allotype a101 and a109.

Animals↗
PubMed1999

Binding of bovine IgG2a and IgG2b allotypes to protein A, protein G, and Haemophilus somnus IgBPs.

Immunoglobulin binding proteins (IgBPs) are thought to be virulence factors which enable pathogens to evade the host's immune response. Since bovine IgG2 is important in protection against pyogenic infections, the binding characteristics of Staphylococcus aureus protein A (PrA), streptococcal protein G (PrG), or Haemophilus somnus high molecular weight IgBPs to the two bovine IgG2 allotypes were examined. For PrA or PrG binding of IgG2, guinea pig red blood cells coated with specific IgG2a or IgG2b antibodies were used in a competitive binding inhibition assay with unlabeled and horseradish peroxidase-labeled PrA or PrG. To determine which sizes of H. somnus. IgBPs bind to the two IgG2 allotypes, immunoblots with H. somnus culture supernatant were probed with anti-DNP IgG2a and IgG2b. This detects only Fc binding because anti-DNP does not cross-react with H. somnus antigens. Both IgG2 allotypes bound equally well to PrA and PrG. However, IgG2b but not IgG2a bound to H. somnus high molecular weight IgBPs. The lack of differential binding of bovine IgG2 allotypes to PrA and PrG means that these IgBPs can be considered to be unbiased reagents in assays for detection of bovine IgG2 or for immunoaffinity purification. The differential binding of H. somnus IgBPs to the IgG2 allotypes indicates that animals having one allotype may be more resistant to H. somnus infection than animals having the other allotype.

Animals↗
PubMed1999

Serum Gm allotype development during childhood.

Gm allotypes are genetic variants of the immunoglobulin heavy G chains (IGHG) of IgG molecules, coded from chromosome 14q32, characterized by differences in amino acid epitopes of the constant heavy G chains and inherited in the Mendelian manner. Gm allotypes have influence on IgG subclass levels, and serum Gm allotype levels have been given for different Gm genotypes in adults. Four hundred and thirty healthy children, aged 1-15 years, were examined for serum Gm allotypes and IgG subclasses from the six most common Gm genotypes and different age groups were measured using competitive enzyme-linked immunosorbant assay and radial immunodiffusion methods. Quantities (in g/l) of G1m(a) and G1m(f) of IgG1, G2m(n) and G2m(-n) of IgG2 and G3m(g), and G3m(b) of IgG3 are given. Different maturation rates of the alternative Gm allotypes within IgG1, IgG2 and IgG3 were shown. G2m(n) development was strikingly retarded compared with G2m(-n) from the gamma2 locus. This was found comparing IgG2 levels from homozygous G2m(-n-n) and G2m(nn) individuals, but was also seen in heterozygous G2m(n-n) genotypes. From the gamma1 locus G1m(f) levels dominated significantly, but inconstantly, over G1m(a) levels in heterozygous G1m(af) individuals. In homozygous G1m genotypes, G1m(aa) compared with G1m(ff) of the same age, one or the other dominated, sometimes significantly. Serum levels of G3m(b) from the gamma3 locus of homozygous G3m(bb) individuals were increased significantly compared with G3m(g) levels of homozygous G3m(gg) individuals, in ages over 3 years. However, in heterozygous G3m(gb) individuals G3m(b) dominance was not evident. There is a relatively rapid development of G1m(f) molecules and a retarded development of G2m(n) in the Gm(f;n;b) haplotype. In comparison, G1m(a) is retarded and G2m(-n) is enhanced in the Gm(a;-n;g) haplotype. The retarded serum G2m(n) development is comparable with serum IgA development during childhood. Different maturation rates of Gm allotypes within the same IgG subclass provide further explanation for the variation of the antibody response during childhood. Quantitative Gm allotype determinations give information of the activity from IGHG genes. The genetic variation constitutes an additional basis for evaluation of IgG antibodies in different diseases in childhood.

Adolescent↗
PubMed1984

A genomic gene encoding the b5 rabbit immunoglobulin kappa constant region: implications for latent allotype phenomenon.

We previously reported that domestic rabbits of five immunoglobulin kappa allotype strains (b4v, b4, b5, b6, and b9) harbor at least two DNA sequences that hybridize strongly to kappa constant region probes in Southern blots. One of these sequences ("type A") has been identified as encoding the constant region of the kappa 2 isotype, an immunoglobulin chain that most rabbits express only at low levels, if at all. We identified the second sequence--for rabbits of the b4 allotype--as encoding the nominal b4 kappa chain (or kappa 1 isotype), but for rabbits of other allotypes no definite identification for this "type B" sequence could be made. Here we suggest that the type B sequence in rabbits of the other domestic allotypes also encodes the nominal kappa 1 immunoglobulin chain. We show this directly for the b5 allotype; a type B sequence cloned from b5 DNA has been found to contain an apparently functional gene encoding the b5 constant region sequence. Indirect arguments suggest the corresponding conclusion for the b4v, b6, and b9 allotypes. We have considered the implications of these results for the phenomenon of "latent allotype" expression.

Animals↗