Expression of cross-reactive, shared idiotypes on anti-SEA antibodies from humans and mice with schistosomiasis

Immunoaffinity-purified antibodies against Schistosoma mansoni soluble egg Ag (SEA) from infected patients' sera differ idiotypically according to the donor's clinical form of the disease. The Id differ both by their ability to stimulate proliferation of anti-Id T cells and their recognition by anti-Id-specific sera. Also, mice infected with S. mansoni develop anti-Id T and B cell responses against mouse anti-SEA antibodies. We now show that anti-SEA antibodies from serum pools of chronic, but asymptomatic patients (AM1 and AM5) stimulate proliferation of spleen cells from mice infected with S. mansoni. However, AM8, anti-SEA antibodies from hepatosplenic patients, did not stimulate these spleen cells. The murine responses directly parallel patient studies where AM1 and AM5 Id-stimulated human PBMC, but AM8 Id did not. In competitive ELISA, using AM1 or AM-5-specific rabbit antisera or human anti-SEA mAb E5-specific rabbit antiserum, sera from mice infected for 8 and 16 wk (but not from uninfected mice) compete with AM1, AM5, or E5. These sera do not compete in the AM8/anti-AM8 competitive ELISA. Sera from 8-wk-infected mice inhibit more against AM1, AM5, and E5 than do sera from later infections, and anti-SEA immunoaffinity-purified antibodies from 8-wk-infected mice stimulate spleen cells from infected mice more than anti-SEA antibodies from sera of mice late in infection. However, spleen cells from more chronically infected mice are more responsive to either the murine or human anti-SEA antibody preparations than cells from mice with earlier infections. Both the ELISA data and lymphocyte responses indicate that anti-SEA antibodies from mice infected with S. mansoni for 8 wk bear Id cross-reactive with those expressed on anti-SEA antibodies from humans with chronic, asymptomatic schistosomiasis, but not those from hepatosplenic patients.     

Immune responses during human Schistosoma mansoni. XVII. Recognition by monoclonal anti-idiotypic antibodies of several idiotopes on a monoclonal anti-soluble schistosomal egg antigen antibody and anti-soluble schistosomal egg antigen antibodies from patients with different clinical forms of infection

A monoclonal human anti-soluble schistosomal egg Ag(SEA) antibody (E5) that stimulates anti-Id T cells and is idiotypically represented in pools of immunoaffinity-purified human anti-SEA antibodies from chronic, generally asymptomatic, intestinal (INT) patients (AM1 and AM5) was used to raise several monoclonal anti-Id: 1C2, 1C6, 4A8, 4F9, and 2A7. Cross-inhibition between these anti-Id identified distinct idiotopes on E5. Anti-SEA preparations from schistosomiasis patients (AM1, AM5, and others) were tested for their inhibition of the E5/monoclonal anti-Id reactions, in competitive ELISA. In either the E5/4A8 or E5/1C6 ELISA system, anti-SEA from INT (AM1 or AM5) or hepatointestinal (HI) (AM7) patients were able to inhibit these reactions. However, anti-SEA antibodies from acute (AM9) or hepatosplenic (HS) (AM3 or AM8) patients did not express Id that were inhibitory in these systems. These results suggest that a relatively high proportion of INT and HI anti-SEA antibodies express a dominant cross-reactive idiotope (CRI) recognized by 1C6/4A8. This CRI is also easily detected in plasmas from individual INT patients. Anti-Id 1C2 reacted strongly with an Id in AM1, AM5, or AM7, but one which also occurred, to a lesser extent, in AM3, AM8, and AM9. Monoclonal anti-Id 4F9 and 2A7 reacted weakly with idiotopes expressed by antibodies from all patients, regardless of the clinical form of their infection. These observations indicate that anti-SEA antibodies from INT and HI, but not acute or HS patients express dominant, CRI that are identified by 1C6, 4A8, or 1C2 and are also expressed on the INT-derived anti-SEA mAb E5.     

Immune responses during human schistosomiasis mansoni. XV. Anti-idiotypic T cells can recognize and respond to anti-SEA idiotypes directly

We previously have shown that former patients and patients with active cases of schistosomiasis mansoni have T lymphocytes in their PBMC that proliferate when exposed to immunoaffinity-purified antibodies against Schistosoma mansoni soluble egg antigens (SEA). These T cell anti-idiotypic responses required the participation of adherent cells, but the role of these cells in the response to the Id has been unclear. We now show that chloroquine does not interfere with Id-elicited stimulation of cells from former patients but completely inhibits their response to the SEA. F(ab')2 fragments of anti-SEA Id are stimulatory, and excess normal human IgG does not alter anti-Id responses. Soluble Id F(ab) fragments are not stimulatory, but rather inhibit stimulation by the intact Id from which they were made. Either intact Id or their F(ab')2 fragments can stimulate non-adherent T cells in the absence of adherent cells if an exogenous source of purified or recombinant human IL-1 is supplied. Nonstimulatory F(ab) fragments can stimulate nonadherent cells if they are bound first to Sepharose 4B and presented in conjunction with IL-1. Thus, T cells from former schistosomiasis patients can react with polyclonal anti-SEA-related Id directly. Under these conditions T cell proliferation requires receptor cross-linking and a source of IL-1 but does not require either "processing" of Id or MHC co-presentation.     

Granulomatous hypersensitivity to Schistosoma mansoni egg antigens in human schistosomiasis. II. In vitro granuloma modulation induced by polyclonal idiotypic antibodies

We have previously reported on Id/anti-Id-receptor interactions in clinical human schistosomiasis. These findings support a hypothesis that anti-SEA cross-reactive Id develop in some patients during the course of a chronic infection and participate in regulation of anti-SEA cellular immune responses. We report here on experiments that extend those observations to the regulation of granulomatous hypersensitivity measured by an in vitro granuloma model. T cells from chronic intestinal schistosomiasis patients were stimulated in vitro with anti-SEA Id and assayed in an autologous in vitro granuloma assay for modulation of granuloma formation. These anti-SEA Id-reactive T cells were capable of regulating autologous in vitro granuloma formation. Both CD4 and CD8 T cells could be activated to regulate granuloma formation. This regulatory activity, initiated with stimulatory anti-SEA idiotypic antibodies, was antigenically specific and was dependent on the presence of intact F(ab')2 Ig molecules. The ability to elicit this regulatory activity appears to be dose dependent and is more easily demonstrated in chronically infected intestinal patients or SEA-sensitized individuals. These data support the hypothesis that anti-SEA cross-reactive Id are important in regulating granulomatous hypersensitivity in chronic intestinal schistosomiasis patients and these cross-reactive Id appear to play a major role in cell-cell interactions that result in the regulation of anti-SEA cellular immune responses.     

Anti-idiotypic T lymphocyte responsiveness in murine Schistosomiasis mansoni

Pooled sera from CBA/J mice infected for greater than or equal to 16 weeks with the blood fluke Schistosoma mansoni were immunoaffinity purified using soluble schistosome egg antigens (SEA) coupled to Sepharose 4B. The bound and then eluted fraction was shown to contain only immunoglobulins and to have anti-SEA activity. These anti-SEA antibodies stimulated proliferation of lymph node cells from mice infected with S. mansoni for 8, 12, or greater than or equal to 16 weeks but not from uninfected mice. The cells stimulated by anti-SEA antibodies were nylon wool adherent, Thy-1.2+, L3T4+, Lyt-2-lymphocytes. Immunoglobulins without anti-SEA activity isolated from the sera of syngeneic uninfected mice were not stimulatory for cells from normal or infected animals. Thus the responding T cells appear to be stimulated by the idiotypes expressed on the syngenic anti-SEA antibodies. These data present evidence for anti-idiotypic cellular reactions in murine schistosomiasis that could play important immunoregulatory roles in this disease.     

Neonatal exposure to idiotype induces Schistosoma mansoni egg antigen-specific cellular and humoral immune responses.

Exposure of neonatal mice to appropriate, cross-reactive Id (CRI) preparations alters immune responsiveness, ameliorates pathology, and prolongs survival of animals upon subsequent Schistosoma mansoni infection. However, because schistosome infections profoundly affect host immunobiology, which responses are effected by neonatal Id exposure alone and which responses are influenced by infection is unclear. To directly examine the schistosome soluble egg Ag (SEA)-specific immune responses altered by CRI exposure, neonatal mice were injected with CRI-expressing (CRI+) SEA-specific Ab preparations, SEA-specific Abs that did not express CRI (CRI-), or normal mouse Ig. At 9 wk of age, only mice that were neonatally exposed to CRI+ anti-SEA Abs displayed significant SEA-specific IgG serum levels and spleen cell proliferative responses. SEA-stimulated spleen cells from these CRI+-exposed mice also produced IFN-gamma, although not at significantly higher levels than mice receiving CRI- Id or normal mouse Ig. If CRI+-exposed mice were also injected with SEA at 8 wk of age, the 9-wk IFN-gamma responses were significantly higher than those of the other neonatal injection groups. The presence of both CRI and anti-CRI in the sera of animals neonatally injected with CRI, but receiving no exposure to S. mansoni Ags or infection, suggested a functional idiotypic network led to these responses. These data demonstrate that appropriate idiotypic exposure induces B and T cell responsiveness to the Ag recognized by the Id and support the hypothesis that neonatal idiotypic exposure can be an important immunoregulatory factor in schistosomiasis.     

Schistosome antigen gp50 is responsible for serological cross-reactivity with Trichinella spiralis.

The 50-kDa component (gp50) present in Schistosoma mansoni eggs and secretions of the various life stages of the parasite was recognized by experimentally infected mice and by humans with S. mansoni, Schistosoma haematobium, and Schistosoma japonicum infection. All sera reacting with crude S. mansoni-soluble egg antigens (SEA) also reacted strongly with gp50 in enzyme-linked immunosorbent assay. No reactivity against gp50 was seen with sera from individuals without schistosomiasis, with the exception of sera from patients with Trichinella spiralis infection. All of 10 sera from patients with trichinellosis also reacted with schistosomes by immunofluorescence essentially recognizing testes, ovaries, ootype epithelium and ducts of the reproductive system. Cross-reacting antigens were seen in T. spiralis hypodermis, stichocytes and possibly germinal primordia using anti-gp50 monoclonal antibodies and anti-gp50-positive schistosomiasis patient sera. The results suggest that the anti-gp50 antibody response constitutes a significant part of the anti-SEA antibody response in infected individuals and is a major reason for the previously recognized serological cross-reactivity between T. spiralis and schistosome species.     

Two major groups of neutralizing anti-gp120 antibodies exist in HIV-infected individuals. Evidence for epitope diversity around the CD4 attachment site.

The aim of this study was to dissect neutralizing anti-gp120 antibody populations in seropositive asymptomatic individuals. Murine anti-Id mAb were raised against polyclonal affinity-purified human anti-gp120 antibodies. These anti-Id mAb were used to fractionate anti-gp120 antibodies from a pool of HIV-positive sera into idiotypically distinct anti-gp120 antibody (Id+Ab) preparations. Immunochemical and neutralization studies indicated that all Id+Ab that neutralized HIV-1 in vitro interacted with either the V3 loop or the CD4 attachment site of gp120. The V3-specific Id+Ab neutralized HIV-1 in a strain-restricted manner. Id+Ab specific for the CD4 attachment site exhibited different spectra of neutralizing activities against multiple strains of HIV-1. This finding indicates that multiple, antigenically diverse epitopes reside around the CD4 attachment site of gp120. Significantly, depletion of the Id+Ab from affinity-purified total anti-gp120 antibodies abrogated most of the neutralizing activities of these antibodies, suggesting that neutralizing anti-gp120 antibodies consist of two major specificities, either to the V3 region or to the CD4 attachment site. The understanding of specificities and neutralizing activities of different anti-gp120 antibodies in seropositive healthy individuals will be helpful for designing effective vaccines and immunotherapeutic strategies for AIDS.     

Human immune response to group A streptococcal carbohydrate (A-CHO). II. Antigen-independent stimulation of IgM anti-A-CHO production in purified B cells by a monoclonal anti-idiotopic antibody

The paper describes the induction by a monoclonal anti-idiotopic antibody (anti-Id mAb) of specific antibody production to group A streptococcal carbohydrate (A-CHO) in purified human B cells of several unrelated individuals. The anti-Id mAb, designated 16F498 (anti-Id498), recognizes a recurrent idiotope (Id 498) associated with the combining site of human antibodies to N-acetyl-D-glucosamine (GlcNAc), the immunodominant group of A-CHO. Id498 is expressed on IgM anti-GlcNAc antibodies but does not occur on IgG antibodies with the same specificity. It occurs also on a minor population of IgM antibodies without specificity for A-CHO. Id498 was found in 19 of 27 sera from unselected healthy donors and thus seems to be frequently expressed within the adult B cell repertoire. The in vitro induction of anti-A-CHO antibodies was analyzed in human B cells extensively depleted for T cells. Specific antibody secretion required cross-linked anti-Id which was achieved by coupling the mAb to agarose beads. No antibody secretion could be induced by soluble anti-Id (1 and 10 micrograms/ml). An optimal response required soluble T cell-derived factors which were added as a mixture of recombinant interleukin 2 with a T cell hybridoma supernatant that augments B cell growth and differentiation. Under these conditions an antigen-independent specific increase of IgM anti-A-CHO production (2.6- to 10-fold, or up to 2000 ng/ml respectively) could be induced in blood B cell populations of four of six normal individuals expressing the Id498 at serum level.     

Detection of in ovo derived idiotypic antibodies. I. A model for maternal-neonatal idiotype network studies.

Idiotypic vaccines appear to have many advantages over conventional vaccines. Maternal Id or anti-Id that are passively transferred to the fetus or neonate could provide another avenue for vaccination. Based on this premise we have investigated the transmission of idiotypic antibodies from dam to embryo by inoculating laying hens and analyzing their egg yolks for the presence of Id, anti-Id, and anti-anti-Id. The Ag chosen for these studies was BSA. After isolation and concentration BSA Id titers were approximately 256,000. The presence of anti-Id antibody in yolk samples is characterized by the ability of anti-Id to inhibit BSA binding to Id. The anti-Id extracted from yolks inhibited BSA binding to Id by 7 to 53%. Not all of the anti-Id present in samples was binding to a paratope-associated Id because 11 to 16% of the fluoresceinated anti-Id bound to Id-coated beads in the presence of excess BSA. Because a portion of the anti-Id antibodies were internal images of the BSA Id, they should be able to mimic Ag. This idea was confirmed when anti-Id inoculated in hens caused the synthesis of antibodies that would bind BSA and could be detected in an ELISA. Binding of anti-anti-Id to BSA-coated wells could be inhibited by preincubation of anti-anti-Id with BSA in solution. The chicken model provides a novel system to investigate maternal-fetal and maternal-neonatal interactions in the idiotypic network and the cellular mechanisms involved in the ontogeny of the Id network in neonates.     

Monoclonal anti-idiotypic antibodies induce humoral immune responses specific for simian virus 40 large tumor antigen in mice.

Mouse monoclonal anti-Id antibodies were generated against a mouse mAb (Ab-1) preparation specific for SV40 large tumor Ag (T-Ag). Four monoclonal anti-Id preparations each inhibited the binding of the monoclonal anti-SV40 T-Ag Ab-1 preparation to SV40 T-Ag. These anti-Id preparations appeared to recognize similar idiotopes on the monoclonal anti-SV40 T-Ag Ab-1 based on competitive cross-inhibition studies. One of these anti-Id preparations, designated 57B, was examined further for its in vivo modulatory capacity in mice. This anti-Id induced an Ab-3 response in BALB/c mice that recognized SV40 T-Ag (Ag+) and expressed an Id that was shared by the monoclonal anti-SV40 T-Ag Ab-1 preparation (Id+). The Id expressed on the Ab-3 differed from the Id induced in BALB/c mice immunized with the nominal SV40 T-Ag. Furthermore, characterization of the humoral immune response induced by anti-Id immunization indicated that the Ab-3 also recognized different epitopes on SV40 T-Ag when compared to the anti-SV40 T-Ag Ab-1 preparation used to generate the anti-Id. These studies indicate that monoclonal anti-Id can be used to induce humoral immune responses to a viral encoded tumor-associated Ag in vivo with 1) and Id specificity that differs from that expressed on antibodies produced by immunization with the nominal Ag and 2) an epitope specificity distinct from the Ab-1 preparation used for the production of the anti-Id.     

抗SEA鸡卵黄抗体用于血吸虫循环抗原检测的初步研究

目的:探讨抗可溶性虫卵抗原(SEA)鸡卵黄抗体(Immunoglobulin Y,IgY)用于血吸虫循环抗原检测的可行性。方法:以纯化的鸡抗SEA卵黄抗体为捕捉抗体,以酶标抗SEA单克隆抗体NP28-5B进行双抗体夹心酶联免疫吸附试验法(S-ELISA)检测急、慢性血吸虫病病人和健康人血清,并与常规检测抗体的酶联免疫吸附试验(SEA-ELISA)法做比较。结果:S-ELISA法测得SEA浓度(y)与A450值(x)呈明显的正相关(r=0.9481,y=459.22x-108.14)。S-ELISA法检测急性血吸虫病人循环抗原的阳性率为100%,慢性血吸虫病人循环抗原的阳性率为84.40%,健康人的特异性为96%。两种方法对血吸虫病的检出率差异无统计学意义(P>0.05)。结论:S-ELISA可用于血吸虫病的免疫诊断。     

Idiotypic and antiidiotypic T and B lymphocytes in myasthenia gravis.

The prevalence of Id and anti-Id T and B cells as measured by their reactivities with two human mAb, one antiacetylcholine receptor mAb and one anti-Id mAb, was studied in 38 patients with myasthenia gravis and in 27 healthy individuals. Id and anti-Id T cells were estimated by enumerating the numbers of cells secreting IFN-gamma in response to 10 pg/ml of the human mAb. T cell stimulation, measured as numbers of IFN-gamma-secreting cells that exceeded the mean + 2 SD of controls, was induced by the Id mAb in 78.9% of the patients and in 7.4% of the controls, whereas the anti-Id mAb-stimulated T cells in 55.3% of the patients and in 3.7% of the controls. The mean value of the Id and anti-Id-reactive T cells in the patients was 18.3/10(5) and 10.1/10(5) PBMC, respectively. B cells secreting IgM antibodies binding to the human mAb were increased in patients with myasthenia gravis compared to healthy controls. Seventy-five percent of the patients and 12% of the controls had B cells secreting IgM antibodies binding to the Id mAb, although 89% of the patients and 16% of the controls had B cells secreting IgM antibodies binding to the anti-Id mAb. The mean value of B cells secreting IgM antibodies binding to Id or anti-Id mAb in the patients were 7.4 cells/10(6) and 5.5 cells/10(6) PBMC, respectively. We conclude that Id and anti-Id T and B cells are present in myasthenia gravis. These methods allow a quantitative estimation of T and B cells with defined specificities and thus a way of mapping the repertoire of lymphocytes.     

Immune response to human immunodeficiency virus. In vivo administration of anti-idiotype induces an anti-gp160 response specific for a synthetic peptide

Anti-idiotypic antibodies (anti-Id) to chimpanzee antibodies directed against a synthetic peptide corresponding to a native epitope associated with gp41 of human immunodeficiency virus (HIV) envelope glycoprotein were produced in rabbits. The peptide was analogous to amino acid sequences 735 to 752 from the human T cell leukemia virus-IIIB isolate of HIV. Characteristics of the anti-Id preparation included: 1) detection of a shared determinant present on a second chimpanzee and one of three rabbit antibody preparations directed against the synthetic peptide, 2) failure to recognize an idiotype (Id) in BALB/c mouse antisera to the peptide, and 3) partial inhibition of the homologous chimpanzee Id preparation from binding either peptide or a recombinant HIV gp160 preparation. Immunization of BALB/c mice with the anti-Id induced an antipeptide response which bound a recombinant gp160 preparation without subsequent peptide or gp160 exposure. The anti-gp160 containing sera from mice immunized with anti-Id were able to inhibit the Id-anti-Id reaction indicating that an Id-positive antibody response was induced. This Id is not normally expressed in the murine anti-gp 160 immune response to the synthetic peptide and suggests that this anti-Id may activate normally silent clones. This study indicates that Id networks may be operational during the immune response to HIV epitopes. Alternatively, anti-Id may be useful in altering the serologic characteristics of an antibody response to HIV and may offer potential for modulating the immune response in this viral infection.     

Antiidiotypic antibody related to the 84 kD human sperm membrane protein

Wistar rats were inoculated with purified YWK-I antibody.The anti-idiotypic antibodies were isolated from rat sera by successive passage over affinity chromatography columns of YWK-I mAb and normal mouse Igs.Specificity of anti-Id antibody was established by ELISA.The 84kD protein inhibited the binding of anti-Id to YWK-I mAb,but failed to repress antibody against normal mouse Ig binding to YWK-I mAb.In competitive inhibition assay,84kD protein had shown the ability to compete with anti-Id binding to YWK-I mAb in a dose-dependent manner.Crude sperm extract showed a lower competitive ability.No effect was found with the irrelevant 36kD sperm protein.The antisera from the Balb/C micr immunized with AId contained Ab3 that reacted with 84kD sperm protein.The binding of anti-Id to YWK-I mAb was inhibited by Ab3 in a dose-dependent fashion and Ab3 was shown to be able to induce human sperm agglutination.These results indicate that anti-Id which may mimic an epitope of the 84kD protein could be exploited as an antigen to raise antibodies against sperm protein.     

Expression of idiotype on the surface of human B cells producing anti-DNA antibody

We analyzed the idiotype (Id) expression on the surface of human anti-DNA antibody-producing cells. Murine monoclonal anti-Id antibodies with a specificity for determinants associated with the antigen-binding sites of human monoclonal anti-DNA autoantibodies were prepared. One anti-Id antibody reacted only with surface Id on anti-ssDNA-producing cells, but not with those on anti-dsDNA-producing B cell clones. Another anti-Id antibody did bind the surface Id on anti-dsDNA clones, but not those on anti-ssDNA clones. The interaction between anti-Id and surface Id was inhibited by pretreatment of the clones with DNA or appropriate polynucleotide antigens, or by preabsorption of anti-Id antibodies with free anti-DNA antibodies. Surface IgM and IgD expressed the same Id as the antibody secreted from the clones. The treatment of Id-positive clones by anti-Id antibody induced the redistribution of surface Id on the cells, indicating that these cells serve as targets for the regulatory action of anti-Id antibody.     

Antiidiotypic vaccination against murine coronavirus infection.

Rabbit polyclonal antiidiotypic antibodies were generated against a neutralizing mAb specific for a conformational epitope on the S glycoprotein of murine hepatitis virus, strain A59 (MHV-A59). These anti-Id were directed predominantly against an Id that was undetectable in rabbit and rat anti-MHV-A59 sera and weakly represented in syngeneic and allogeneic antiviral sera. However, some partial idiotypic sharing was observed between the Id-bearing antibody and a mAb with a similar antigenic site specificity. The anti-Id inhibited the virus-binding and neutralizing activities of the immunizing antibody, demonstrating that they recognize paratope-associated idiotopes. Mice immunized with affinity-purified anti-Id developed MHV-A59-specific antibodies that neutralized viral infectivity to high titers. Moreover, these animals survived an otherwise lethal challenge with viral murine hepatitis virus, unlike control mice immunized with normal rabbit Ig. These results indicate that at least a subpopulation of the polyclonal anti-Id could induce a protective immune response directed toward a biologically important MHV-A59 epitope, and demonstrate the feasibility of antiidiotypic vaccination against a coronavirus infection.     

Anti-idiotypic antibody response to monoclonal anti-CD4 preparations in nonhuman primate species.

A series of mouse monoclonal anti-CD4 preparations was characterized for the ability to recognize overlapping epitopes on CD4 and to inhibit HIV/simian immunodeficiency virus (SIV) syncytium formation. Based on this characterization, mAb able to recognize CD4 epitopes overlapping the HIV binding site were selected and used to immunize nonhuman primates to elicit the production of specific anti-Id antibodies. Five baboons and five rhesus monkeys were immunized with either individual or a cocktail consisting of several monoclonal anti-CD4 preparations. All the nonhuman primates produced specific anti-Id that recognized either private or cross-reactive Id depending on the monoclonal anti-CD4 used to generate the anti-Id response. Inhibition assays were performed to ascertain the ability of: 1) soluble CD4 to inhibit the Id-anti-Id reaction and 2) the various anti-Id to inhibit the CD4-monoclonal anti-CD4 reaction. These studies demonstrated that some of the anti-Id recognized a cross-reactive Id that was associated with the Ag-combining site. In addition, some of the anti-Id weakly recognized SIV gp120 by Western blot analysis. These studies may be useful in designing experiments that may lead to a better understanding of the CD4-HIV gp120 interaction and to the production of Id and/or anti-Id reagents that might be used to manipulate this virus-receptor interaction.     

Strategies for production of monoclonal anti-idiotype antibodies against human B cell lymphomas

Murine monoclonal antibodies (MAB) against the idiotype (Id) of B lymphocyte malignancies are powerful reagents for the study of these diseases, and are potentially useful for treatment. Different strategies for the production of these anti-Id MAB have been compared. Initially, the Id Ig from nonsecreting B cell tumors was "rescued" by human X mouse or human X human hybridization. These somatic cell hybridizations resulted in the secretion of human Ig in 10 and 100% of the fusions, respectively. In a second step, anti-Id MAB were produced by using the "rescued" Id Ig as immunogen. A more streamlined approach is based on a one-step procedure in which the tumor cell suspension is used as immunogen. This method of immunization, coupled with a four-layer ELISA, results in the detection of anti-Id MAB in a frequency of approximately 1% of the total hybrids. By using a pool of 10 different anti-Id MAB, each reactive with the tumor of one patient, we searched for idiotypic relatedness among a panel of 50 additional tumors. No cross-reactions were found, indicating that our current strategy results in the identification of unique idiotypic determinants among human B cell tumors. Idiotypic Ig can be found in the serum of patients with B cell tumors. Among groups of patients, there is a wide spectrum of serum Id levels, ranging from less than 0.01 microgram/ml to greater than 500 micrograms/ml.     

A study of auto-anti-idiotypes to BSA

In order to study the idiotypic relationships between the antibody populations produced in different species during normal immune responses to ordinary protein Ag, we raised immune sera in mice and chickens by using three protein Ag: BSA, keyhole limpet hemocyanin, and diphtheria toxoid. An avidin-biotin ELISA was used to measure idiotypic binding between antibody populations from these sera. We found that the chicken sera contained auto-anti-idiotypes (AAI) against Ag-specific antibodies that were present in the same serum and that co-purified with those antibodies on Ag-Sepharose columns. These AAI were present in secondary response chicken anti-BSA serum at levels comparable with those of the anti-BSA antibody. The chicken AAI also react specifically with Id in mouse anti-BSA serum. The mouse anti-BSA serum completely inhibits the binding between the chicken Id and AAI. This similarity between the Id of whole populations of antibodies produced in two distantly related species, in the absence of any manipulation with idiotypic or anti-idiotypic reagents, suggests that the AAI detected in this way are internal image antibodies. It indicates there is positive selection for such AAI to be internal images.