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R Jefferis

Publications and source records attributed to R Jefferis.

At least 145 records · Page 8Linked to original sources
PubMed1984

The separation of human serum IgG into subclass fractions by immunoaffinity chromatography and assessment of specific antibody activity.

Murine monoclonal antibodies ( McAbs ) with specificity for subclass-specific or subclass-restricted determinants on human IgG have been coupled to Sepharose to generate affinity columns. The judicial use of positive and negative chromatography and the exploitation of the special properties of individual McAb affinity columns has allowed the preparation of individual IgG subclasses from polyclonal IgG containing less than 1% contamination by any other IgG subclass. The specificity of the antibodies present in each polyclonal IgG subclass preparation has been assayed against a bacterial toxoid (tetanus), 2 bacterial cell wall antigens (E. coli and pneumococcal) and coat antigen(s) of a DNA virus (CMV). Antibodies were predominantly IgG1 to tetanus toxoid, IgG2 to pneumovax and E. coli cell walls, and IgG1, 2 and 3 to CMV coat antigens.

Adult↗
PubMed1984

The monocyte binding domain(s) on human immunoglobulin G.

Monocyte binding has previously been assigned to the C gamma 3 domain of human immunoglobulin G (IgG) largely on the ability of the pFc' fragment to inhibit the monocyte-IgG interaction. This ability is markedly reduced compared to the intact parent IgG. We find this result with a conventional pFc' preparation but this preparation is found to contain trace contamination of parent IgG as demonstrated by reactivity with monoclonal antibodies directed against C gamma 2 domain and light-chain epitopes of human IgG. Extensive immunoaffinity purification of the pFc' preparation removes its inhibitory ability indicating that this originates in the trace contamination of parent IgG (or Fc). Neither of the human IgG1 paraproteins TIM, lacking the C gamma 2 domain, or SIZ, lacking the C gamma 3 domain, are found to inhibit the monocyte-IgG interaction. The hinge-deleted IgG1 Dob protein shows little or no inhibitory ability. Indirect evidence for the involvement of the C gamma 2 domain in monocyte binding is considered. We suggest finally that the site of interaction is found either on the C gamma 2 domain alone or between the C gamma 2 and C gamma 3 domains.

Antibodies, Anti-Idiotypic↗
PubMed1984

Immunogenic and antigenic epitopes of immunoglobulins--VII. The topographical distribution of Fc gamma epitopes and the relationship of an iso-allotypic specificity to the presence of histidine 435.

Epitopes recognised by a panel of 23 anti-Fc gamma monoclonal antibodies (McAbs) have been subdivided into three groups each having a distinct topographical distribution. One group of mutually inhibitory McAbs are reactive with epitopes expressed on the fy "surface" of the C gamma 2 domain. A second group recognises epitopes in the region of arginine 355 of the C gamma 3 domain whilst the third group recognises epitopes expressed in the inter C gamma 2/C gamma 3 domain region--as evidenced by inhibition of Staphylococcus aureus protein A binding. An antibody of the latter group reactive with IgG1, 2, 4 and IgG3m(15,16) proteins but not IgG3m(5) or IgG3m(21) proteins allows histidine 435 to be identified as a critical residue for expression of the epitope recognised by this antibody.

Animals↗
PubMed1984

Immunogenic and antigenic epitopes of immunoglobulins. VIII. A human monoclonal rheumatoid factor having specificity for a discontinuous epitope determined by histidine/arginine interchange as residue 435 of immunoglobulin G.

A monoclonal human rheumatoid factor (RF-AN) reactive with human Fc gamma is shown to recognise a discontinuous epitope dependent on the presence of histidine (His) at residue 435. RF-AN is not reactive with IgG1 paraproteins having C gamma 2 or C gamma 3 domain deletions or IgG3m (5) or Ig3m (21) proteins having arginine (Arg) at residue 435. RF-AN is reactive with IgG1, 2, 4 and IgG3m (15,16) proteins having histidine at 435.

Amino Acid Sequence↗
PubMed1984

Monoclonal antibodies to an immunoglobulin allotype marker G1m(f).

The properties of a group of mouse monoclonal antibodies (McAbs) specific for the human G1m(f) allotype marker on immunoglobulin G are described. The specificity of all 5 McAbs was anti-Gm(f) in haemagglutination assays detecting the G1m(f) determinant on 6 ng of purified G1m(f) paraproteins. A high dilution (greater than or equal to 1/10(4)) could be used for the majority of McAbs in this assay. In Elisa the G1m(f) marker could be detected in homozygote G1m(f+z-) sera at a serum dilution of greater than or equal to 1/10(4). In Elisa assays the G1m(f) specificity was lost when IgG was bound directly to polystyrene but was restored when IgG was bound via anti-human IgG to the polystyrene plate. A possible conformational change in IgG to account for this loss of specificity is discussed. It is expected that these McAbs with their high titre and increased sensitivity over conventional Gm antisera will allow more detailed analysis of the Gm marker system.

Animals↗
PubMed1984

IgG subclass distribution of autoantibodies to DNA and to nuclear ribonucleoproteins in autoimmune diseases.

Fifty-seven serum samples positive for antibodies to double-stranded DNA (dsDNA), single-stranded DNA (ssDNA) or small nuclear ribonucleoproteins (snRNP) selected from patients with systemic lupus erythematosus and mixed connective tissue disease, were examined for the IgG subclass distribution of these autoantibodies. It was shown that antibodies to dsDNA were relatively restricted to IgG1 and IgG3 subclasses whilst antibodies to ssDNA were equally distributed throughout the four subclasses. Antibodies to snRNP were essentially restricted to the IgG2 isotype. These isotype distribution patterns contrasted with that observed for total serum IgG.

Antibodies, Antinuclear↗
PubMed1984

Surface IgG subclasses in human B cell lymphomas as revealed by monoclonal antibodies.

IgG subclass expression on cells from lymph node biopsies of 17 sIgG positive B cell lymphomas has been studied. Subclass specific monoclonal antibodies were used in an immunoradiometric assay. Ten were also tested by immunofluorescence using a biotin-avidin system. Thirteen of the lymphomas expressed IgG only, while four co-expressed other Ig isotypes. Morphological investigations revealed that 14 lymphomas originated from germinal centre cells. IgG1 was found to be dominant subclass in 10 lymphomas, IgG3 in seven, IgG2 in one, while none expressed IgG4. Multiple IgG subclasses could not be detected in any of the lymphomas tested.

Antibodies, Monoclonal↗
PubMed1984

Subclasses of IgG on the surface of human lymphocytes: a study with monoclonal antibodies.

Cells from sIgG+ B lymphoblastoid cell lines, sIgG+ B cell neoplasms and from tonsils, adult and cord blood and fetal spleen were tested for IgG subclass expression using a panel of monoclonal antibodies. IgG1 was in all cases the commonest subclass except on blood lymphocytes, when approximately equal numbers of cells expressing IgG1 and IgG2 were found. No evidence for multiple subclass isotype expression was found.

Adult↗
PubMed1983

Immunogenic and antigenic epitopes of immunoglobulins--V. Reactivity of a panel of monoclonal antibodies with sub-fragments of human Fc gamma and abnormal paraproteins having deletions.

The specificity of a panel of 27 monoclonal antibodies reactive with human Fc gamma has been further defined through reactivity profiles with sub-fragments of Fc gamma and IgG paraproteins having deletions within C gamma 2 or C gamma 3. Antibodies are identified that are directed to discontinuous epitopes requiring native Fc gamma for expression. Other antibodies are reactive with isolated C gamma 2 or C gamma 3 domains. Sub-class specific and sub-class restricted antibodies allow correlation of epitope expression with primary structure.

Animals↗
PubMed1983

Detection of free kappa chains in human serum and urine using pairs of monoclonal antibodies reacting with C kappa epitopes not available on whole immunoglobulins.

The properties of five monoclonal antibodies (McAbs) which react with free kappa chains but not with IgG kappa, IgM kappa or IgA kappa have been studied. IgG preparations stored for long periods sometimes contained low and high molecular weight material reacting as free kappa. This could be removed by passing the preparation through an affinity column to which two of the McAbs had been coupled, but reactive material reappeared when the purified IgG was heated at 65 degrees C. Two of the McAbs from one fusion reacted with F(ab')2 fragments of IgG whereas two from another fusion did not. Pairs of McAbs (one from each fusion) were much more sensitive in the detection of free kappa, particularly monomer, than a single McAb. This provided the basis for a very sensitive method of detection of free kappa chains in human body fluids and culture supernates.

Antibodies, Monoclonal↗
PubMed1983

Triggering of monoclonal human lymphoma B cells with antibodies to IgM heavy chains: differences of response obtained with monoclonal as compared to polyclonal antibodies.

A comparative study of human B lymphoma cells activation by monoclonal (murine hybridoma) antibodies to mu heavy chains (Ma-mu) as compared to polyclonal (rabbit) antibodies to mu heavy chains (Ra-mu) has been carried out. Early events related to calmodulin activation such as 86Rb influx and changes in cell volume at 4 h could be induced by Ma-mu. One antibody (AF6) approached Ra-mu with regard to the strength of response obtained. However, Ma-mus including AF6 were deficient in inducing DNA synthesis under conditions where this was achieved with Ra-mu. Studies in one lymphoma, where stimulation of re-expressed surface IgM could be studied, revealed that Ma-mu was deficient in stimulating re-expressed sIgM. These findings raise questions with regard to polyclonal antibody to surface Ig as a model for B cell triggering by antigen and suggest that antigen-induced B cell triggering may be more complex than indicated by previous studies with polyclonal antibody.

Antibodies, Monoclonal↗
PubMed1982

Immunogenic and antigenic epitopes of immunoglobulins. II. Antigenic differences between secreted and membrane IgG demonstrated using monoclonal antibodies.

Twenty-three monoclonal antibodies with specificity for epitopes in the Fc fragment of IgG have been used to investigate antigenic differences between secreted and membrane forms of IgG produced by 2 human B lymphoblastoid cell lines (LCL). All of the monoclonals reacted with IgG secreted by the cell lines, as demonstrated by their ability to agglutinate SRBC coated with immunoglobulin isolated from culture supernatants. Membrane IgG expression was studied using direct and indirect rosette assays with antibody-coated ORBC. A surprisingly high number of antibodies, 13 on EB2 and 9 on EB4, did not bind to the cell surface immunoglobulin. These included antibodies with specificities for both C gamma 3 and C gamma 2 domain determinants. Similar results were obtained with an indirect radiobinding assay, indicating that negative results with the rosette test were not due to steric hindrance by the red cell carrier. Their performance in indirect hemagglutination indicated that most of the antibodies that did not bind to membrane IgG were of high avidity. It is concluded that the epitopes for which these antibodies are specific are not available on the cell surface. Possible explanations for the apparent antigenic differences between secreted and membrane forms of IgG are discussed against the background of previous work on the structure and mode of insertion of cell surface immunoglobulin.

Animals↗
PubMed1982

Immunogenic and antigenic epitopes of immunoglobulins I. Cross-reactivity of murine monoclonal antibodies to human IgG with the immunoglobulins of certain animal species.

Antibody-producing hybridoma clones have been isolated following immunization of mice with human IgG. Twenty-five monoclonal antibodies (nine anti-C gamma 3, fourteen anti-C gamma 2, one anit-kappa and one anti-lambda) were selected for study of their cross-reactivity with the IgG of fifteen mammalian species and chicken immunoglobulin. Each antibody exhibited a unique reaction profile suggesting that human IgG expresses a very large repertoire of immunogenic epitopes. Whilst some antibodies showed a very restricted cross-reactivity profile for others a very wide reactivity profile was observed-including two clones producing autoantibodies. Antibodies demonstrating cross-reactivity between human Fc gamma and 7S chicken immunoglobulin allow its definitive assignment as a homologue of human IgG. Four clones demonstrated specificity for bovine IgG subclass gamma 1 and gamma 2 and the degree of reactivity allows their application to qualitative and quantitative assay systems. These studies suggest new perspectives for the characterization of immunoglobulins and the standardization of anti-immunoglobulin reagents.

Animals↗
PubMed1982

Monoclonal antibodies to the idiotypic determinants of a human IgG paraprotein: evidence for complexity of the anti-idiotype response.

BALB/c mice were immunized with a human gamma 2k paraprotein and hybridomas prepared by the Kohler & Milstein technique. Ten hybridoma clones producing high levels of antibody competed reacting specificity with the immunogen were isolated. Six of the monoclonal antibodies competed strongly with each other for sites on the antigen. In reverse passive haemagglutination tests immunoglobulins reacting with the antibodies were not detectable in normal or pathological sera. Polyclonal antisera to two of the monoclonal antibodies were prepared in rabbits; they were rendered specific by adsorption with Sepharose-normal mouse IgG and tested against the other monoclonal antibodies. A weak cross-reaction of one of the mouse antibodies with the immunogen was observed with one antiserum but none with the other. Furthermore, no repetition of the idiotypes of the two immunogens was observed in polyclonal responses of BALB/c mice immunized with the same paraprotein antigen. These results with monoclonal antibodies confirm those obtained with polyclonal antisera in showing that the antibody response of one species to the private idiotype determinants of an immunoglobulin of another species is highly heterogeneous.

Animals↗
PubMed1982

Theoretical and ultracentrifugal analysis of immune complex formation between monoclonal antibodies and human IgG.

Immune complex formation of four different mouse monoclonal antibodies against human IgG has been studied using analytical zonal centrifugation. A theoretical model has been used to depict thermodynamic ideal immune complex formation of monoclonal antibodies. It was found that the four monoclonal antibodies differed very much with respect to immune complex formation with human IgG. One of the monoclonal antibodies formed immune complexes in agreement with the theoretical model. Another was strongly related thereto. A third monoclonal antibody formed only a single complex and might exhibit a positive co-operativity between its two sites. A fourth formed as excess of a possibly cyclic complex. Thus monoclonal antibodies differ substantially with respect to physical properties adding a new aspect to the problems of antibody heterogeneity. It is moreover found that analytical zonal centrifugation can be used to estimate the number of antigenic determinants and antibody-binding sites thereby assuring whether or not a particular IgG monoclonal antibody has two binding sites.

Antibodies, Monoclonal↗
PubMed1982

Monoclonal antibodies (McAbs) to determinants on human gamma chains: properties of antibodies showing subclass restriction or subclass specificity.

Thirteen monoclonal antibodies (McAbs) showing subclass-specific and subclass-restricted reactivity to human IgG have been produced by the hybridoma technique. Their specificity has been defined by passive haemagglutination (HA) and haemagglutination-inhibition (HAI) assays using a large panel pf purified IgG paraproteins of known subclass. Their use in assaying human IgG subclasses in radial immunodiffusion (RID) and in purifying human subclasses by both positive and negative immunoabsorption chromatography is illustrated.

Animals↗