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PubMed1987

[Immunogenetics of immunoglobulins of the American mink. VI. Deviation from Mendelian segregation for Cgamma-allotypes H2, H3 and H4].

The non-expression of parental allotype among mink F1 offsprings of monohybrid analyzing crosses was established for C gamma-allotypes. A phenotype ratio 0:1, instead of the expected Mendelian 1:1, was observed in some families. The non-expression of allotype may occur in the progeny of mink with normal allotypic specificity. Deviations of allotypic expression had both qualitative and quantitative nature and did not depend on the direction of crossings. Sometimes, the appearance of allotype in a mink could not be expected on the basis of its pedigree. Instability of expression and inheritance of H2, H3 and H4 in many families may have masked the allelic or linkage relationships of these genetic markers.

Animals↗
PubMed1985

Cosuppression of latent and nominal allotypes in individual rabbit lymphocytes.

Endogenous synthesis of latent and nominal allotype was observed in vitro in rabbit peripheral blood lymphocytes (PBL). PBL from rabbits displaying the nominal b4 specificity, as well as the latent b5 and b6 either on the cell surface or in the serum or both, were treated with pronase to remove surface latent and nominal allotypes and cultured in serum-free medium to regenerate the nominal and latent markers. Rosette formation using the mixed anti-globulin assay demonstrated that the nominal b4 and latent b5 and b6 specificities were displayed in the same cell. Cells were seen bearing the b4 + b5, b4 + b6, or b4 + b5 + b6, as double or triple expressors. No latent allotype-bearing cells were detectable in the absence of the nominal allotype. In vitro suppression of nominal surface b4 with anti-b4 antibodies resulted in the cosuppression of the latent b5 and b6. In contrast, in vitro suppression of latent b5 and b6 with anti-b5 and anti-b6 antibodies, respectively, did not cause the cosuppression of the nominal b4 allotype. Cosuppression of latent and nominal markers in the same cell confirms that the biosynthetic machinery for latent and nominal allotypes lies within the same cell.

Animals↗
PubMed1984

Induction of "latent a2" allotype in a1a1 homozygous rabbits as the major part of a bidirectional immune response to immunization with anti-a2 antibody.

Previously, we induced Ab to a common idiotypic specificity (IdC) of rabbit anti-a2 VH Ab. We observed then that some of the putative anti-IdC Ab molecules induced by immunizing a1a1 rabbits with anti-a2 Ab did not have the expected nominal allotypic markers (a1, x32, or y33) characteristic of the genotype of the immunized rabbits. Thus, immunization of a1 a1 rabbits with a1 anti-a2 Ab induced population of molecules that reacted with anti-a2 Ab but bore an unidentified (unknown) VH region marker. The following observations indicate that these molecules bear a "latent a2" allotypic marker: (a) when the unknown VH molecules were used to immunize a1 a1 and a3 a3 rabbits, anti-a2 Ab was produced; (b) when an a2 a2 rabbit was immunized with the same preparation of unknown VH molecules, an anti-idiotypic Ab was produced; and (c) when the unknown VH molecules were used to inhibit the binding of labeled a2 IgG to anti-a2 Ab, the inhibition curve obtained was essentially the same as that obtained by using normal a2 IgG. Thus, immunization of a1 a1 rabbits with a1 anti-a2 Ab provided a bidirectional stimulus to produce both nominal "a1" anti-IdC Ab and a "latent a2" allotype. The distribution of nominal to latent allotypes induced ranged from 3% nominal/92% latent to 57% nominal/23% latent. In absolute terms, the maximum amount of "latent a2" molecules was 1.18 mg/ml of serum, which far exceeds the amount of latent allotype described by others (0.3 mg/ml of serum). The effective induction of large amounts of "latent a2" allotype may have resulted from a simultaneous stimulation of an idiotope and a paratope on the surface of the "latent a2"-producing cells.

Animals↗
PubMed1980

Evidence for linked expression of latent allotypes of the heavy chain constant and variable regions.

CH allotypes were determined for rabbit IgG and antibody molecules identified and isolated on the basis of their expression of latent group a (VH) allotypic determinants. Serologic and chemical typing of the purified molecules revealed that five out of 10 individual preparations studied expressed d allotypes not present in the rabbit as a nominal allotype. None of the latent VH-CH combinations represented products of a new or unusual arrangement of VH and CH structural genes. This result indicates that the molecules with latent allotypes express their VH and CH allotypes in the same combinations as do their nominal counterparts and do not result from misspairing of separate genes involved in H chain synthesis.

Animals↗
PubMed1977

Allotype suppression at the CHn locus of IgM in heterozygous rabbits with concomitant suppression at the VHa locus of all Ig classes.

Doubly heterozygous offspring, malen83alpha1/femalen82alpha2 or malen81alpha1/femalen82alpha2, of doubly homozygous dams, n82alpha2/n82alpha2, were injected neonatally with anti-n83 or anti-n81 antibody directed to the paternal n locus allotype. In each injected rabbit, the paternal n83 or n81 allotypes were suppressed and increased amounts of the maternal n82 allotype accounted for almost all of the serum IgM. This is the first report of allotype suppression in the rabbit mediated by antibody directed toward the CH region of any Ig class. A concomitant decrease in the paternal a1 Ig allotype and a compensatory increase in the maternal a2 allotype were also found. This finding supports the concept that IgM-bearing cells are the precursors of IgG-secreting cells.

Animals↗
PubMed1997

Bovine IgG2a antibodies to Haemophilus somnus and allotype expression.

Bovine IgG2a has been implicated in protection against pyogenic infections, including those caused by Haemophilus somnus. To further investigate the role of IgG2a in defense against H. somnus, IgG1 and IgG2a antibodies were purified from antiserum against an immunodominant 40 kDa outer membrane protein (p40) of H. somnus, which was previously shown to passively protect calves against H. somnus pneumonia. The passive protective capacity of anti-p40 IgG1 or IgG2a was evaluated in vivo in calves. Purified anti-p40 IgG1 or IgG2a was incubated with H. somnus for 15 min before intrabronchial inoculation of calves. Bacteria incubated with anti-p40 IgG1 or IgG2a were inoculated into one caudal lung lobe and bacteria incubated with IgG1 or IgG2a from the respective preimmunization serum were inoculated into the contralateral lobe. The volumes of pneumonia in the right and left lungs were determined 24 h later. The difference in volume of pneumonia with H. somnus preincubated in IgG1 pre- and postimmunization anti p40 was less (16 cm3, P = 0.298) than the difference in volume of pneumonia with H. somnus preincubated in IgG2a pre- and postimmunization anti p40 (30 cm3, P = 0.146). Although the differences in lesion size between pre- and postimmunization serum were not statistically significant, the trend suggests IgG2a may be more protective than IgG1. To examine this further, the peptide specificity of these IgG1 and IgG2a antibodies to p40 was examined. After limited proteolysis of p40, IgG2a antibodies reacted with 2 peptides not recognized by IgG1 antibodies. Other peptides were recognized by both isotypes. Since these studies suggested that IgG2a may be important in protection against infection, we then investigated some aspects of the role of the 2 IgG2a allotypes, A1 and A2. In retrospective studies of age differences in expression of IgG2a allotypes, no heterozygotes were detected in calves of 60 d old or less, and fewer heterozygotes were detected in calves 61-120 d old than in cattle older than 270 d (P < 0.01). In a subsequent prospective study of the time course of allotype expression, Holstein calves shown to be heterozygotes expressed the IgG2aA1 allotype early but the IgG2aA2 allotype was not usually detected until 3 to 4 mo of age. Thus, both the retrospective and the prospective studies showed age related differences in expression of the IgG2aA1 and A2 allotypes. This could have implication in protection.

Age Factors↗
PubMed1989

Application of immunoglobulin allotyping in forensic stain analysis: reliability and sensitivity of Gm and Km typing.

The detection of immunoglobulin alloantigens in bloodstains was studied. Commercially available allotyping reagents are suited for immunoglobulin allotyping in forensic bloodstain identification. The value and reliability of immunoglobulin allotyping in blood-stain extracts is greatly enhanced by testing for a wide scope of different allotypes. Particular reference is made to the application of a sensitive semiquantitative IgG estimation in relation to the detectability of the respective allotypes. The relative performance of the individual antigens in serum and extracts of fresh and aged bloodstains were obtained. On the basis of these results it was often possible to interpret negative reactions of the bloodstain extract in the hemagglutination-inhibition method with confidence. There is no evidence for the preferential loss of any of the alloantigens after drying and after aging of the blood.

Blood Grouping and Crossmatching↗
PubMed1992

Properdin factor B and complement factor C4 allotypes in rheumatoid arthritis: results of a follow-up study.

The association between allotypes of properdin factor B (Bf), the fourth component of complement (C4A and C4B), and rheumatoid arthritis (RA), was investigated in a well-characterized cohort of RA patients who were followed from an early phase of the disease for a mean duration of 6 years. The frequencies of probable heterozygous C4AQ0 and of C4A3 were lower in RA patients compared to controls, irrespective of the presence of DR4 [relative risk (RR): 0.52 and 0.49, respectively, 95% confidence intervals (95% CI): 0.34-0.80 and 0.29-0.82]. The frequency of C4A4 was higher in RA patients compared to controls (RR: 1.86, 95% CI: 1.03-3.35), especially in DR4 positive RA patients compared to DR4 positive controls (RR: 2.58, 95% CI: 1.07-6.25), indicating a positive association of this allotype with RA additional to DR4. Bf and C4B allotypes were comparable in RA patients and controls. We did not find significant differences in Bf and C4 allotype frequencies in RA patients subdivided according to severity of the disease into a mild group and a progressive group. Because of inconsistent results in all studies on Bf and C4 allotypes, we conclude that C4 and Bf allotypes do not seem to have an important independent effect on determining disease susceptibility.

Adult↗
PubMed1971

Allotypically related sequences in the Fd fragment of rabbit immunoglobulin heavy chains.

The sequence has been completed of the N-terminal 94 residues of the variable section of the Fd fragment of heavy chains from rabbit immunoglobulin G (IgG) of allotype As1. Most of the sequence of the same section from IgG of allotype Aa3 is also reported. These results, in conjunction with a substantial sequence of the variable region of allotype Aa2 reported elsewhere (Fleischman, 1971), show the presence of 16 positions (including six consecutive positions) in which the residue present correlates with the allotype. No allotype-related sequence variation has been found in the constant section of the Fd fragment. This evidence supports the view that two genes code for the heavy chain and it can be used as evidence in favour of somatic mutation as the origin of the variability in the sequence of the N-terminal section. The evolutionary origin of the ;a' locus allotypes of rabbit immunoglobulins remains obscure.

Amino Acid Sequence↗
PubMed1974

Congenic mouse strains: the expression of a hidden immunoglobulin allotype in a congenic partner strain of BALB-c mice.

This paper derives from the unexpected observations of the "wrong immunoglobulin allotype" in a congenic partner strain of BALB/c mice from the Institute of Cancer Research (ICR CB-17). These mice were specially bred so as not to differ from BALB/c mice in any known way except to carry immunoglobulin structural genes of the C57BL/Ka allotype. In this respect, ICR CB-17 mice were defined as allotypically homozygous according to the Mendelian inheritance of mouse allotype markers. The homozygosity of these mice was challenged, however, when in certain instances immunoglobulins of the BALB/c allotype appeared in the serum of some ICR CB-17 mice. The appearance of this hidden allotype was usually transient and only associated with immunoglobulins of the IgG (IgG2a) class. The implications of these findings for the inheritance and expression of immunoglobulin structural genes are discussed.

Animals↗
PubMed1975

Nonallelic behavior of rabbit variable-region allotypes.

Group a allotypes not detected by qualitative typing or anticipated from breeding data (latent allotypes) were detected at low levels in 50% of normal rabbit sera tested. The latent allotypes, which were serologically identical to allotypes of pooled IgG, were detected in sera from rabbits with all possible combinations of group a allotypes and their occurrence in individual rabbits was transitory and sporadic. These findings give reason to question the assumption that the synthesis of immunoglobulin allotypes is directed by allelic structural genes.

Animals↗
PubMedDate not supplied

The antigenic determinants, Rg/Ch/WH, expressed by Japanese C4 allotypes.

The expression of antigenic determinants, Rg/Ch/WH, on Japanese C4 allotypes has been studied. Although the Japanese C4 allotype frequencies are known to differ from Europeans, the antigenic expression of their C4 allotypes correlates with associations described previously. All 89 random donors and 17 selected donors were Rg:1,2 so neither Rg:1,-2 nor Rg:1,-2 was found. The frequency of Ch:1,-2,3 was elevated while that of Ch:1,2,3 was reduced, which was seen as a direct result of the higher frequency of B2 and B5 allotypes. None of the Japanese were Ch:1,2,-3, but this can be accounted for by the absence of the A*6,B*1 haplotype. The WH determinant, which has been associated completely with Rg:1,-2 in Caucasians, was found at a higher frequency, 32%, in association with an A*3,2,B*QO haplotype expressing Rg:1,2, which has not been described previously. Detailed investigation showed that the A3 allotype was Rg:1,2 whereas the A2 allotype only expressed Rg1 (Rg:1,-2 WH+).

Alleles↗
PubMed1990

C4 allotyping by prolonged gel electrophoresis and immunoblotting using monoclonal and polyclonal antibodies.

Out of the 136 individual samples mostly from HLA-typed family members which were submitted to the VIth Complement Genetics Workshop 1989, Mainz, FRG, for C4 allotyping, 129 were analyzed by prolonged gel electrophoresis followed by immunoblotting. The blotting was performed using either a Rodger (Rg):1,2 specific monoclonal, 99H7 (provided by G. Mauff, Cologne, FRG), and/or a Chido (Ch):1 specific monoclonal antibody (MoAb), 2B12 (provided by G.J. O'Neill, Miami, USA), and a polyclonal antihuman C4 antibody. In addition, 29 individuals from the workshop panel were tested with a third antibody, 1217, and 20 individuals with a fourth antibody, 1228 (both provided by D. Bitter-Suermann, Hannover, FRG). Due to the improved typing technique a total of 13 C4A and 16 C4B variants could be discriminated, of which some have not yet been described. Considering as a rule that all allotypes with great hemolytic activity are named C4B, the Ch:1 specific antibody 2B12 is reactive with all B allotypes except C4*B11, C4*B12, C4*B13, some C4*B3, C4*B4, one C4*B5, and weakly with one C4*B6 variant. The Rg:1,2 specific antibody 99H7 recognizes all C4A allotypes except for C4*A91, one C4*A1, and some C4*A12 variants. Therefore all these allotypes mentioned may, like C4*A91, express reversed antigenicity. The two additionally tested MoAbs 1217 and 1228 reacted similar to 2B12 with one exception for each. Correlations of HLA haplotypes with C4 allotypes especially with those of reversed antigenicity are discussed.

Antibodies↗
PubMed1988

Rabbit secretory components of different allotypes vary in their carbohydrate content and their sites of N-linked glycosylation.

The asparagine-linked glycosylation sites in rabbit high and low Mr secretory components (SC) have been determined for the three known allotypes, t61, t62, and t63. Purified SC polypeptides were subjected to mild periodate oxidation of terminal nonreducing sugars followed by selective reduction with [3H]sodium borohydride, SC polypeptides were further proteolytically cleaved, and the 3H-labeled peptides were isolated and characterized. Both high and low Mr SCs of the three allotypes possess a common glycosylation site at the asparagine residue position 400, whereas the second site, in the amino-terminal domain of SC, was found to be variable: the t61 and t63 allotypes contained a glycosylation site at positions 70 and 90, respectively. Moreover, although the t62 allotype was found to contain a triplet acceptor site (N-X-S) at positions 90-92, analyses showed that less than 30% of the t62 allotype peptides encompassing this region were glycosylated at residue 90. Furthermore, the amino acid sequence of the t61 SC in the region of residues 69-90 varies by 8 and 10 amino acid substitutions when compared with the t62 and t63 allotype sequences, respectively. However, neither the variation in amino acid sequence nor the variation in degree or site of glycosylation measurably affected the non-covalent binding of domain 1 to dimeric IgA.

Animals↗
PubMed1983

Allotypes associated with B apolipoproteins in rabbits.

Western blot analysis of the alloantisera (i.e., anti-Lpq1, anti-Lpq2, anti-Lpq3, and anti-Lpq4) which defined the three lpq genes of rabbit linkage group VIII showed that they reacted strongly with an apolipoprotein of molecular weight 320,000. They also cross-reacted with an apolipoprotein of molecular weight 220,000. The two apolipoproteins that reacted with the alloantisera were found by SDS-polyacrylamide gel electrophoresis to be present in very low density (VLDL), intermediate density (IDL), and low density (LDL) lipoprotein fractions and by Western blot analysis to react with an anti-apolipoprotein B antiserum. These results support the conclusion that the alloantisera react with allotypes associated with the B apolipoproteins. The distribution of the four allotypes among different lipoprotein fractions, however, differed. The quantitative competitive Enzyme Linked Immunosorbant Assay (ELISA) showed that the Lpq1, Lpq2, and Lpq4 allotypes were found in the highest concentration in VLDL, IDL, and LDL, and in significantly lower concentrations in plasma chylomicrons. The concentrations of these allotypes in high density lipoproteins (HDL) as measured in the ELISA were about 1% of the concentrations found in LDL. The Lpq3 allotype, on the other hand, was present in the highest concentrations only in IDL and LDL and in significantly lower concentrations in VLDL and plasma chylomicrons. Surprisingly, the concentration of the Lpq3 allotype in HDL was 20% of the level found in LDL.

Animals↗
PubMed1998

Direct binding and functional transfer of NK cell inhibitory receptors reveal novel patterns of HLA-C allotype recognition.

Cytotoxicity of human NK cells is under negative control of killer cell Ig-like receptors (KIR) specific for HLA class I. To determine the specificity of five KIR containing two Ig domains (KIR2D), direct binding of soluble recombinant KIR2D to a panel of HLA class I transfectants was assayed. One soluble KIR2D, derived from an inhibitory receptor with a long cytoplasmic tail (KIR2DL1), bound to HLA-C allotypes containing asparagine 77 and lysine 80 in the heavy chain, as expected, since these allotypes inhibit lysis by NK cells expressing KIR2DL1. Surprisingly, another KIR2D (KIR2DL2), which inhibits NK lysis of cells expressing HLA-C molecules with serine 77 and asparagine 80, bound to HLA-C allotypes carrying either amino acid motif. Expression of the KIR2DL receptors in NK cells using recombinant vaccinia viruses confirmed these patterns of recognition, and identified KIR2DL3 as another KIR reacting with both groups of HLA-C allotypes. Mutagenesis of amino acid 44 in KIR2DL1 and KIR2DL2 suggested this residue controls the affinity of KIR for the 77/80 motif of HLA-C molecules. Two other soluble KIR2D, derived from noninhibitory receptors with short cytoplasmic tails (KIR2DS), did not bind to any of the HLA class I allotypes tested. One of these receptors (KIR2DS2) is closely related in sequence to KIR2DL2. Substitution of tyrosine 45 with the phenylalanine conserved in other KIR was sufficient to permit specific binding of KIR2DS2 to HLA-C. These results show that KIR2DL receptors are specific for HLA-C, but that recognition of HLA-C allotypes appears more permissive than indicated by previous functional experiments.

Alleles↗
PubMed1976

Structural and serological relationships among different antibodies from the same rabbit antiserum. I. Isolation, chemical and allotypic characterization of ten antibody components from one anti-streptococcal serum.

The relationships among antibodies produced by an individual rabbit were examined using multiple antibodies elicited by hyperimmunization with Group C streptococcal vaccine. Immunoadsorbent chromatography followed by agarose block electrophoresis yielded nine different antibody fractions, all directed against Group C carbohydrate, from the immune plasma of rabbit 4295 (allotype a1/b5). Electrophoresis of the antibody light chains gave single bands for most of the antibodies. Amino acid sequence analyses carried out on several of the antibody L-chains revealed that five of these had aspartic acid at the amino terminus. By quantitative allotypic analyses all antibodies were allotype a1/b5. One antibody fraction, homogeneous by all other criteria, contained antibodies with two distinct group a allotypic subspecificities. The two antibodies in this fraction could be separated on an anti-a1 column. The ten antibodies were placed into a minimum of three groups based on differences in a1 allotype subspecificity.

Amino Acid Sequence↗
PubMed1978

Prevention of immunoglobulin production by allotype-dependent T cells.

Adoptive lymphocyte transfers between Iga, Igb and Igd allotype-congenic mouse strains revealed host barriers against the production of certain donor allotypes. First, as recipients of Igb cells, Iga and Igd mice permitted the production of donor Ig-4b but not that of Ig-1 b. The apparent mediators of this Ig-1 b barrier were T cells specific for Ig- 1 b determinants on B cells. Additional cell transfers showed Iga mice to have a second barrier against allotype production by Igd donor cells. Reciprocal cell transfers showed Igb and Igd mice to have comparatively weak barriers against Iga-producing cells. As host barriers were absent in mice deficient for T cells (athymic nude mice), it appears that they are T cell-mediated. Further, the allotype-dependence of such barriers means that the antigens responsible must be under the control of allotype-linked genes. The regulatory implications of this for the immune system are discussed.

Animals↗