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K H Roux

Publications and source records attributed to K H Roux.

At least 55 records · Page 3Linked to original sources
PubMed1985

Dynamic gene interactions in the evolution of rabbit VH genes: a four codon duplication and block homologies provide evidence for intergenic exchange.

Two rabbit VHa-negative genes, RVH831 and RVH832, were isolated from a single genomic fragment selected by hybridization with the mouse VHIII gene S107V1. RVH831 is a pseudogene with a frameshift mutation in FR3 and a 19 bp deletion within the VH-D splice site. In contrast, RVH832 has an open reading frame and an intact VH-D splice site and thus may be functional. However, RVH832 displays a unique 4 codon duplication/insertion in FR1 that may be the result of an unequal exchange event between two ancestral VH genes. Sequence comparisons between these and other rabbit VH genes reveal patterns of shared blocks of nucleotide substitutions, suggestive of gene conversion. A high overall homology (greater than or equal to 73%) between the compared VH nucleotide sequences suggests that rabbit VH genes may not be organized in clearly divergent families or subgroups.

Animals↗
PubMed1985

A reevaluation of rabbit anti-allotype antibody for the presence of cross-reactive idiotypes. I. A species-specific idiotype on rabbit anti-a1 antibody is recognized by guinea pig anti-IdX antibody.

Rabbit reagents previously thought to display specificity for a cross-reactive idiotype on anti-VHa allotype antibody from all tested rabbits have recently been shown to be contaminated with an induced (latent) molecule similar or identical to the original antigen (rabbit a1 or a2 allotype). In an attempt to circumvent this problem, we have immunized guinea pigs with rabbit anti-a1 allotype antibody to produce heterologous anti-idiotype antibody. The resulting guinea pig antibody (GP anti-R IdX) recognizes anti-a1 antibody from each of 17 immunized rabbits, and in four tested samples reacts with 22 to 100% of the molecules. Neither goat nor guinea pig anti-a1 reacts with the guinea pig anti-R IdX antibody, even though the goat, guinea pig, and rabbit anti-a1 Ab all recognize a similar set of a1 determinants. The reaction between IdX-bearing rabbit anti-a1 and guinea pig anti-R IdX is inhibited by the original antigen (a1 IgG), demonstrating that the IdX is at or near the antigen combining site of anti-a1 antibody. Immunoelectron microscopy of immune complexes supports this conclusion and demonstrates that the reactive site on the GP anti-R IdX is at or near its antigen combining site.

Animals↗
PubMed1985

A reevaluation of rabbit anti-allotype antibody for the presence of cross-reactive idiotypes. II. Expression of rabbit a1-like images on goat antibody after immunization with anti-a1 antibody.

In an effort to generate heterologous anti-idiotype (Ab2) molecules to a suspected IdX on rabbit anti-a1 antibody (Ab1), goats were immunized with either rabbit or guinea pig Ab1. The goat Ab2 preparations reacted with each of 13 rabbit Ab1, as well as two goat Ab1 samples in serologic assays. From 8 to 50% of the molecules in purified rabbit Ab1 preparations reacted with each goat Ab2. Electron microscopy of immune complexes composed of rabbit Fab anti-a1 and goat Ab2 reveals that the Fab anti-a1 binds to the side of the variable region of most goat Ab2 molecules, rather than at the tip (i.e. in the CDR) as expected. This configuration indicates that the goat Ab2 actually represents a population of induced or enhanced Ig molecules expressing a1-like allotypic or isotypic determinants, rather than an anti-IdX Ab or a paratope-associated internal image of a1.

Animals↗
PubMed1984

Direct demonstration of multiple VH allotopes on rabbit Ig molecules: allotope characteristics and Fab arm rotational flexibility revealed by immunoelectron microscopy.

Immune complexes composed of rabbit IgG and Fab fragments of antibody specific for the VH framework allotypes were analyzed by molecular immunoelectron microscopy. In this manner, the number of allotypic epitopes ( allotopes ) and their approximate topological location could be determined. A monoclonal anti-allotype Fab was used to show that relatively fine details of allotope location and orientation are demonstrable with this technique. Each of the three VH allotypes (a1, a2 and a3) was found to express at least two spacially separated allotopes . The locations of the allotopes varied for each of the three allotypes. Some allotopes were observed near the VH-CH1 switch region while others were in close proximity to the complementarity-determining region or were at intermediate positions. In addition to the information concerning allotope topology, the variety of configurations resulting from the interaction of monoclonal antibody Fab with IgG suggest considerable rotational flexibility (twisting) of the Fab arm of IgG about its long axis.

Animals↗
PubMed1984

Induced latent allotypes within rabbit anti-cross-reactive idiotype reagents. Direct immunoelectron microscopic evidence.

Immunization of rabbits with anti-VHa allotype antibody leads to the production of an "anti-cross-reactive idiotype (IdX)" reagent which appears to recognize a highly conserved IdX on anti-allotype antibodies. In many rabbits, a large percentage of this "anti-IdX" reagent does not express the nominal VHa framework allotype of the rabbit from which it was derived and is otherwise serologically indistinguishable from the original antigen, i.e. a1 or a2 allotype. To determine whether these anti-IdX molecules were in fact anti-IdX (or internal images) or were induced immunoglobulins bearing latent VHa allotypes, immunoelectron microscopic analysis of the molecules in complex with Fab anti-allotype antibody was conducted. The results show that the complexes do not resemble idiotype-anti-idiotype interactions but are essentially indistinguishable from allotype-anti-allotype complexes. We conclude that a major component of the "anti-idiotype" response of these anti-VHa-immunized rabbits is the production of Ig molecules bearing latent VHa allotypes.

Animals↗
PubMed1984

Cross-reactive idiotypes on heterologous anti-allotype antibody.

Specific anti-a1 Ab was isolated from rabbits, guinea pigs, mice, chickens, and a goat. Each of these preparations was able to inhibit the reaction between a1 IgG and rabbit anti-a1 Ab as well as the reaction between rabbit IdX (anti-a1 Ab) and rabbit anti-IdX (anti-anti-a1 Ab). Maximal levels of inhibition ranged from 75 to 100% in the latter assay. Although the relative binding efficiencies of each preparation varied widely, there was generally a positive correlation between the ability of an anti-allotype reagent to bind to a1 IgG and to anti-IdX Ab. Each of the heterologous anti-a1 Ab samples was able to form precipitin bands with rabbit anti-Id Ab. These bands fused with each other and with rabbit anti-a1 Ab. These results weaken the interpretation that the ubiquitous expression of IdX previously observed in the rabbit reflects shared conserved genes. We suggest that either 1) the anti-Id Ab represents high fidelity internal images of the a1 epitopes, or 2) latent a1 allotype Ig is present in the anti-IdX preparation. In either case, any anti-a1 Ab would be potentially reactive with the anti-IdX preparation.

Animals↗
PubMed1983

Monoclonal antibodies specific for the b5 allotype of rabbit kappa light chains.

The mouse monoclonal antibodies (mAb), 3B5 and 4B5, which recognize rabbit kappa light chains bearing the b5 allotype, were produced from separate fusions. The specificity of the mAbs was determined by solid-phase inhibition radioimmunoassay. Nonimmune sera of 15 b5b5 rabbits of various heavy chain haplotypes inhibited the binding of both mAbs to b5 IgG, whereas 20 sera from rabbits not expressing the b5 allotype were not inhibitory. In addition, the binding of both mAbs was inhibited by purified b5 light chains, but not by b4 light chains. The b5 epitope recognized by the mAbs was shown by sequential precipitation to be present on all b5-bearing molecules that are defined by an alloantiserum produced in a b4b4 rabbit. Antibody 4B5 forms strong precipitin bands with b5 serum and Ig in gel diffusion assays. An anomalous reaction of nonidentity was observed when mAb was compared to rabbit anti-b5 antiserum and a hypothesis to explain this phenomenon is proposed.

Animals↗
PubMed1983

Localization of the phosphocholine-binding sites on C-reactive protein by immunoelectron microscopy.

C-reactive protein (CRP) was reacted with monoclonal IgG antibody or Fab antibody fragments directed against the phosphocholine- (PC) binding site or a second unrelated site. The resulting immune complexes were viewed by a negative stain immunoelectron microscopy technique. Monoclonal anti-PC-binding site antibody bound to a single epitope on each of the five CRP subunits. The orientation of the PC-binding sites was determined to be slightly medial to one of the planar faces (A-face) of the molecule. The second monoclonal antibody, which was not PC-binding site related, bound to epitopes (one per CRP subunit) that were located slightly lateral to the other planar face (B-face) of the CRP molecule, i.e., opposite of the PC-binding site. Thus, the PC-binding site and the non-PC-binding site are oriented nearly perpendicular but on opposite sides with respect to the plane of the CRP molecule. The functional significance of this configuration is discussed.

Animals↗
PubMed1983

Response of the rabbit VH subgroups a and y following antigenic stimulation.

In order to test the relative immune competence of a minor VH subgroup (y), the concentrations of rabbit Ig bearing the VH subgroups a and y were determined in experimentally immunized rabbits. Three groups of three rabbits each were immunized with either Micrococcus luteus, bovine serum albumin or an alloantigenic determinant (b4) of the rabbit kappa light chain. The ratios of VHy to VHa Ig in the pre-immune sera ranged from 1:8 to 1:283. In five of the nine rabbits, the VHy to VHa ratios in affinity purified antibody (Ab) closely reflected the ratios of VHy to VHa in pre-immune serum. Of the remaining four rabbits, three produced disproportionately low amounts of VHy Ab, when compared to pre-immune values, while one rabbit produced virtually no VHy Ab. Regardless of the levels of VHy and VHa Ab detected, the kinetics of Ab production by each subgroup during the course of the immune response were similar to each other. When total serum levels of the subgroups were analysed, all rabbits displayed increases (6-450%) in total serum levels of both VHa Ig and total IgG following immunization, while in eight out of nine rabbits the level of VHy Ig remained unchanged. Our observations suggest that the immune repertoire of the minor VHy subgroup is sufficiently diverse to generate VH regions which react with a variety of antigens, and in five out of nine rabbits, VHy Ab-producing clones compete well with VHa Ab-producing clones. In addition, it appears that clones of the major and minor VH subgroups, once triggered, are under similar regulatory controls with respect to specific Ab, but differ with respect to non-specific Ig production.

Animals↗
PubMed1982

An increase in the number of recombinant molecules and other effects of the simultaneous allotype suppression of trans-chromosomal a VH and n Cmu Ig gene products.

The concomitant effects of trans-chromosomal allotype suppression of both an a VH and an n Cmu locus allotype in multiheterozygous rabbits were investigated. For example of the expression of the a2 VH and n81 Cmu allotypes were suppressed in a multiheterozygous rabbit having the a1 chi-y-n81de12,15f73g74/a2 chi 32y33n80de12.14f69g77 genotype. This trans-chromosomal allotype suppression led to the concomitant suppression of other CH allotypes in the same parental haplotype as the suppressed-n81 allotype (i.e. the e15, f73 and g74 allotype) and the partial suppression of the a1 VH allotype (from the normal level of 70% of the total Ig to 10%), and also led to compensation by other VH allotypes from the same parental haplotype as the suppressed-a2 allotype (i.e. the x32 and y33 allotypes). The x32 and y33 allotypes were expressed on Ig molecules with the CH allotypes coded by the same haplotype (i.e. the cis molecules). In a further analysis of the IgG molecules having the partially-suppressed-a1 allotype, one-half (5%) of these molecules were trans-chromosomal recombinant molecules (i.e. a1e14 IgG) and the other half (5%) were cis-chromosomal molecules (i.e. a1e15 IgG). The trans-chromosomal a1e14 IgG molecules probably were derived from the expansion of a limited number of lymphoid clones that normally produce only 1.5% trans-chromosomal recombinant molecules. The cis-chromosomal a1e15 IgG molecules were probably derived either from lymphoid clones that survived the suppression by the anti-n81 Ab, or from lymphoid clones that bore a different subclass of IgM (i.e. n-negative IgM).

Animals↗
PubMed1982

A predominant idiotype on rabbit anti-VH a1 allotype antibodies: sharing by both major and minor VH subgroups.

In every rabbit examined, greater than or equal to 80% of antibodies directed against the VH allotypic marker, a1, bears a predominant idiotype (IdX-a1). The IdX-a1 marker is site-associated and expressed on H chains, but not L chains, of anti-a1 antibody. Experiments using rabbits suppressed for the VH a subgroup demonstrated that IdX-a1 can be associated with both major (a+) and minor (a-) VH subgroup gene products and that a1 rabbits contain IdX-a1 within their genetic repertoire. The genetic and regulatory implications of our results are discussed.

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↗
PubMed1981

A fourth heavy chain variable region subgroup, w, with 2 variants defined by an induced auto-antiserum in the rabbit.

An antiserum recognizing previously undescribed antigenic determinants (designated subgroup w) of the heavy chain VH region was produced by immunizing a rabbit, homozygous for the VH haplotype a1x-y- with IgG from another a1x-y- rabbit, suppressed for a1. The antiserum gives a single fused precipitin band against sera from homozygous rabbits suppressed for the a1, a2, or a3 allotypes. By gel diffusion analysis, the determinant was found to be distinct from previously described a, x, and y allotypes, and was detectable on IgG, F(ab')2 gamma and the gamma-heavy chain. Radioinhibition analysis revealed 2 patterns of inhibition suggesting 2 variants of w that are closely linked to VH allotypes. Variant w34 was detected at very low levels (0.042 to 5.6 micrograms/mg IgG) in normal rabbits expressing the a1x-y-, a1-y33,30, and a3x32y- VH haplotypes. Variant w35 was detectable in a 2x32y33,- rabbits. Sera from homozygous a allotype-suppressed rabbits representing each of the 4 VH haplotypes similarly exhibited either w34 or w35 patterns of inhibition as described above. The level of w34 in a1- and a3-suppressed rabbits exhibited a dramatic 230-fold median increase. In contrast, w35 levels for a2-suppressed rabbits fell within the normal range. In addition to reacting with essentially all normal and suppressed sera, the antiserum reacted with preimmune serum from the same rabbit. Thus, anti-w represents an induced auto-antibody. These observations are further discussed with regard to rabbit and mouse VH populations.

Animals↗
PubMed1980

Idiotypic specificities which arise naturally in rabbits following allotype suppression of the major VH subgroup.

In contrast to normal IgG, some of the IgG molecules, which appear in compensation as a result of allotype suppression of IgG molecules of the major VH subgroup (a locus), were found to have an easily identifiable idiotypic specificity. For each of three donors' IgG, a different idiotypic specificity was present, and each idiotypic specificity was found on the Fab, as expected, but not on the Fc fragments. Further analysis of the IgG of one donor revealed that the idiotypic specificity was present on 15% of the Fab gamma fragments. The idiotypic specificity was expressed on IgG which also bor an allotypic specificity of the y locus VH subgroup of IgG which comprised most (72%) of the total compensatory IgG. This suggests that suppression of clones synthesizing the a locus major VH subgroup results in compensation by minor VH subgroup clones more limited in variability. These clones may then proliferate to synthesize larger amounts of IgG bearing the same idiotypic specificity which thereby becomes more easily detectable by immunization of rabbits.

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