Induction of immunity to a human osteosarcoma-associated antigen in mice using anti-idiotypic antibodies

Polyclonal rabbit anti-idiotypic antibodies (Ab2) were produced and analyzed for their ability to stimulate humoral immunity against a human tumor-associated antigen (TAA) in BALB/c mice. Murine monoclonal antibody (Mab) OSA-1 recognizes an 85,000-Da TAA present on both human osteosarcoma tissue and osteosarcoma cell lines. Rabbits were immunized with OSA-1 (Ab1) to produce Ab2. The polyclonal Ab2 were shown to react against an idiotope located at or near the antigen combining site of Ab1. Ab2 were demonstrated to be potent inhibitors of TAA binding to Ab1. BALB/c mice were immunized with this Ab2 preparation and then tested for the presence of osteosarcoma TAA reactive antibodies. Sera from Ab2-immunized mice were shown by Western blot to contain antibodies whose specificity resembled Ab1. Thus, immunization with polyclonal rabbit Ab2 was shown to stimulate production of Ab3 in mice which reacted against a human osteosarcoma TAA.     

Detection of human auto-anti-idiotypic antibodies (Ab2). I. Isolation and characterization of Ab2 in the serum of a ragweed immunotherapy-treated patient

This study documents, by means of both solid and liquid phase assays, the presence of anti-idiotypic antibodies (Ab2) in the serum of one allergic individual undergoing ragweed immunotherapy. Serum from this individual was collected and F(ab')2 fragments specific for ragweed antigen E (AgE) were prepared (Ab1). These AgE-specific F(ab')2 Ab1, following absorption with normal immunoglobulin, were studied for their capacity to specifically bind autologous Ab2. The binding of Ab1 to Ab2 was demonstrated to be inhibitable by ragweed AgE but not by another allergen (oak) to which the patient reacted. These findings demonstrate the presence and binding specificities of Ab2 in the serum of a ragweed immunotherapy patient and may serve as a model to study the role of Ab2 in the regulation of Ab1 in allergic patients.     

Epibodies in autoimmunity: antisera against autoantibodies to the renal glomerular basement membrane react with idiotypes as well as with autoantigens

The results reported here show that we have experimentally produced xenogeneic anti-idiotypic antibodies to rat autoantibodies specific for the renal GBM and one of its components, laminin. Cross-reactive idiotypes have been detected by anti-idiotypic antibodies (anti-Id) on autoantibodies to the GBM (anti-GBM) from rats of different strains, confirming the results obtained in other autoantibody systems. During the course of studies aimed at determining whether anti-Id were directed to the paratope of anti-GBM antibodies, we have observed the presence of anti-GBM (and anti-laminin) antibodies in rabbit sera with anti-Id. Affinity chromatography experiments suggest that anti-GBM reactions detected with our anti-Id sera may be caused by a heterogeneous combination of anti-Id. Thus, Ab2 alpha (and/or Ab2 gamma, all reacting with Ab1), Ab2 epsilon (epibodies, that bind to both Ab1 and GBM) and Ab3 (similar to Ab1 and therefore, reacting with GBM) may be present in our anti-Id sera. It has been suggested that antibodies displaying epibody properties may be involved in the mutual regulation of autoreactive clones and represent an important component of the autoimmune process.     

Albumin binding proteins of endothelial cells identified by anti-idiotypic antibodies.

Studies were conducted to identify and localize albumin binding proteins (ABPs) in endothelial cells using rabbits polyclonal anti-idiotypic antibodies (Ab2) raised against the affinity-purified anti-bovine serum albumin IgG. Ab2 were purified by fast performance liquid chromatography. The anti-idiotypic nature of the IgG was assessed by (i) the capacity to inhibit albumin binding to its specific antibody in a dose-dependent manner, (ii) the lack of interaction with albumin, and (iii) the interaction with anti-albumin antibodies of diverse origins. The latter characteristic indicates that although polyclonal, the purified anti-idiotypic antibodies contain some of the Ab2 beta type. The binding of Ab2 to cultured bovine aortic endothelial cell surfaces was saturable and specific as demonstrated by radioimmunoassay (RIA) and immunofluorescence studies respectively. A competitive RIA was used to test whether Ab2 competed for albumin binding to bovine aortic endothelial cells (BAECs) (presumably to ABPs). It was found that Ab2 inhibited binding of [125I]albumin to BAECs in a dose-dependent fashion. Immunoblot analysis of extracts of BAECs, microvascular endothelial cells, and lung showed that both Ab2 and albumin bind specifically to two polypeptides with an apparent molecular mass of 18 and 31 kDa. In addition, upon radioiodination of BAECs apical membrane proteins, Ab2 bound specifically and immunoprecipitated restrictively two radiolabeled cell surface proteins of 18 and 31 kDa. The results provide direct evidence for the presence of the 18 and 31 kDa peptides (ABPs) on the endothelial cell membrane and/or associated structures, i.e. open plasmalemmal vesicles and uncoated pits.     

A common idiotype expressed on a murine anti-Sm monoclonal antibody and antibodies in SLE sera.

A rabbit anti-idiotypic antiserum made against a murine monoclonal anti-Sm autoantibody (Y2) was used in a solid-phase radioimmunoassay to investigate idiotypic cross-reactivity among anti-Sm antibodies present in sera from patients with systemic lupus erythematosus. Sera from 25 of 51 SLE patients (49%) containing anti-Sm antibodies were positive for this Y2 idiotype compared to only one of 22 normal human sera. Nine of 28 SLE patients (32%) whose sera were anti-Sm negative were also positive for the Y2 idiotype in low titre. Binding was not due to rheumatoid factor-like activity but was specific for the Y2 determinant and could be eliminated by absorption with Y2 monoclonal antibodies. The anti-idiotypic antibody blocked the ability of 12 of 25 anti-Sm positive lupus sera to bind Sm. Conversely, Sm antigen inhibited the binding of anti-idiotypic antibody in nine of 12 lupus sera.     

The immune response against anti-idiotope antibodies II. The induction of antibodies bearing the target idiotope (Ab3 beta) depends on the frequency of the corresponding B cells

In the present study we use two monoclonal anti-idiotope antibodies (Ac38 and Ac146; Ab1) against the germ line-encoded, lambda 1 chain-bearing and (4-hydroxy-3-nitrophenyl)acetyl (NP)-binding antibody B1-8 (Ab1) for the induction of complementary antibodies (Ab3) and ask the question to what extent antibodies bearing B1-8-like idiotopes (Ab3 beta) are represented in the Ab3 population. In this experimental system, Ab3 beta is distinguished from the remaining Ab3 population (Ab3 alpha) by three properties which Ab3 beta may share with B1-8: (a) the binding of NP, (b) the binding to Ac146 (if induced by Ac38) or the binding to Ac38 (if induced by 146) and (c) that they carry lambda 1 chains. Antibodies with all three properties are induced in low amounts by both anti-idiotopes. Also, Ac146 induces only Ab3 alpha (bearing kappa chains and not binding NP and Ac38). In contrast, Ac38 triggers almost exclusively a lambda 1 chain-bearing response, i.e. Ab3 beta. The response has an unusually large size, reaches its maximum after a week and is long-lasting. An analysis at the level of lipopolysaccharide-reactive precursor B cells demonstrates that, in this case, cells expressing Ab3 beta occur at exceedingly high frequency (approximately equal to 10(-3] and are at least 10 times more frequent than cells expressing Ab3 alpha. The high frequency of Ab3 beta-expressing cells correlates with the contribution of several VH, D and J genes to the expression of this particular idiotope. In the case of the Ac146 anti-idiotope antibody, the response is dominated by Ab3 alpha. Ab3 beta represents less than 10% of the total response, reaches maximal levels 2 weeks after immunization and declines rapidly. This correlates with a low frequency of precursor B cells expressing Ab3 beta (approximately equal to 10(-5] and a restriction of the corresponding idiotope to rare VH-D combinations, caused presumably by a stringent contribution of the H chain to this idiotope which covers the NP-binding site. Our data suggest that anti-idiotypic antibodies (Ab2) against Ab1 will preferentially induce antibodies idiotypically related to Ab1 if the corresponding idiotopes are expressed in high frequency in the B cell compartment. This is expected in cases where Ab2 recognizes an idiotope that can be formed by many germ line-encoded VH-D-VL-combinations.     

用抗-(抗HBc)抗体在同系小鼠中诱导抗-抗Id抗体

用单克隆抗-(抗HBc)抗体(抗-Id)免疫BALB/c鼠,诱生出具有与抗-HBc相同反应性的抗-抗Id抗体(Ab_3)。这种抗体在ELISA试验中可与HBc-Ag特异性反应,并能抑制单克隆抗-HBc与HBcAg的结合。表明我们建立的抗-H-Bc的抗Id能模拟HBcAg刺激小鼠产生免疫反应。     

Anti-idiotypic antibodies to feline leukemia virus: an approach for retroviral immunization strategies.

The present study describes an approach to the development and use of anti-idiotypic antibodies as a possible immunization strategy to prevent retroviral infection. The rationale for using anti-idiotypes (anti-Ids) to try to elicit an antigenic-specific immune response is examined, and the production and characterization of polyclonal and monoclonal anti-Ids are described. Several techniques were used to determine antigenic mimicry and anti-Id subtypes. The potential use of anti-Ids in feline leukemia virus (FeLV) receptor studies and vaccine trials in vivo were investigated. Results from these studies suggest that the anti-Id strategy is feasible for the FeLV model. Polyclonal Ab2 reagents were developed that blocked virus-receptor binding and thus inhibited viral infection in vitro and induced humoral immune responses in 6- to 8-week old kittens characterized by production of Ab3 with the ability to bind the original FeLV envelope protein gp70 as assessed by Western blot analysis.     

Idiotype-anti-idiotype interactions and the control of the anti-β(2→6) polyfructosan response in the mouse: specificity and idiotypy of anti-ABPC48 anti-idiotypic monoclonal antibodies

Seventeen hybridomas, secreting monoclonal anti-idiotypic antibodies (IDA) directed against the BALB/c ABPC48 idiotype, were isolated from one immunized BALB/c mouse. Several IDA also bind another BALB/c idiotype: UPC10. ABPC48 and UPC10 are both myeloma proteins with a β(2→6)-polyfructosan (levan) specificity. The binding of every IDA to the ABPC48 idiotype can be completely inhibited by levan molecules, but at different concentrations. Mutual inhibition assays between the IDA made it possible to define six groups of IDA which bind at least three different idiotopes of ABPC48. Sixteen IDA have been studied by means of mouse anti-anti-idiotypic antibodies (Ab3) directed against two of them, IDA3 and IDA10. Anti-IDA3 Ab3 recognize idiotopes particular to IDA3 which are not found on other monoclonal anti-idiotypic antibodies (Ab2). Anti-IDA10 Ab3 cross-reacts with several monoclonal Ab2, including Ab2 with different spectrotypes belonging or not to the same isotype and Ab2 with different specificities for the ABPC48 idiotype. Some IDA10 idiotopes are present in the polyclonal anti-ABPC48 antibody response of BALB/c, A/J and CBA mice showing that they are recurrent and that their expression is not linked to a particular Igh-C haplotype. In contrast, IDA3 idiotopes are not detected in the same anti-ABPC48 antisera.     

Protective role of anti-idiotypic antibodies in autoimmunity--lessons for type 1 diabetes

Circulating autoantibodies to beta cell antigens are present in the majority of patients with Type 1 diabetes. These autoantibodies can be detected before and at time of clinical diagnosis of disease. Although the role of autoantibodies in the pathogenesis of the disease is debated, their presence indicates a dysregulation of the humoral immune response. Mechanisms regulating autoantibodies in Type 1 diabetes are not well understood. In contrast, in other autoimmune diseases there is acceptance that autoantibodies are regulated not only by antigen but also by other antibodies that bind to the antigen-binding site of these autoantibodies (anti-idiotypic antibodies). The proposed purpose of this network is to maintain an equilibrium between autoantibodies and their anti-idiotypic antibodies, preventing autoimmunity, while allowing a robust response to exogenous antigen. Anti-idiotypic antibodies regulate both autoantibody binding and their levels by a) neutralizing autoantibodies, and b) inhibiting the secretion of autoantibodies. Because it has been proposed that the B lymphocytes that produce autoantibodies function as autoantigen presenting cells, inhibiting their binding to autoantigen by anti-idiotypic antibodies may prevent development of autoimmune disease. This hypothesis is supported by the presence of anti-idiotypic antibodies in healthy individuals and in patients in remission from autoimmune diseases, and by the lack of anti-idiotypic antibodies during active disease. We recently reported the presence of autoantibodies to glutamate decarboxylase in the majority of healthy individuals, where their binding to autoantigen is prevented by anti-idiotypic antibodies. These anti-idiotypic antibodies are absent at clinical diagnosis of Type 1 diabetes, revealing the presence of autoantibodies. Type 1 diabetes (T1D) is an autoimmune disease characterized by the dysfunction and destruction of insulin-producing beta cells by autoreactive T cells. Although much progress has been made towards understanding the respective roles of effector and regulatory T cells in this beta cell destruction, the development of autoantibodies to beta cell proteins is widely considered simply a by-product of the autoimmune destruction of the beta cells, rather than having an active role in the pathogenesis. This view is starting to change based on increasing recognition that autoantibodies can have defined roles in other autoimmune diseases, and the emergence of new data on their role in T1D. This exploration of the role of autoantibodies in autoimmune disease has been spurred, in part, by increasing recognition that development of autoimmune diseases is influenced by regulatory antibodies (anti-idiotypic antibodies) directed against the unique binding site of autoantibodies. This review provides an overview of the development and function of these anti-idiotypic antibodies, and present evidence supporting their role in the development of autoimmune diseases. Finally, we conclude this review with a model of the events that may cause loss of anti-idiotypic antibodies and the implications for the development of T1D.     

Protective role of anti-idiotypic antibodies in autoimmunity – Lessons for type 1 diabetes

Circulating autoantibodies to beta cell antigens are present in the majority of patients with Type 1 diabetes. These autoantibodies can be detected before and at time of clinical diagnosis of disease. Although the role of autoantibodies in the pathogenesis of the disease is debated, their presence indicates a dysregulation of the humoral immune response. Mechanisms regulating autoantibodies in Type 1 diabetes are not well understood. In contrast, in other autoimmune diseases there is acceptance that autoantibodies are regulated not only by antigen but also by other antibodies that bind to the antigen-binding site of these autoantibodies (anti-idiotypic antibodies). The proposed purpose of this network is to maintain an equilibrium between autoantibodies and their anti-idiotypic antibodies, preventing autoimmunity, while allowing a robust response to exogenous antigen. Anti-idiotypic antibodies regulate both autoantibody binding and their levels by a) neutralizing autoantibodies, and b) inhibiting the secretion of autoantibodies. Because it has been proposed that the B lymphocytes that produce autoantibodies function as autoantigen presenting cells, inhibiting their binding to autoantigen by anti-idiotypic antibodies may prevent development of autoimmune disease. This hypothesis is supported by the presence of anti-idiotypic antibodies in healthy individuals and in patients in remission from autoimmune diseases, and by the lack of anti-idiotypic antibodies during active disease. We recently reported the presence of autoantibodies to glutamate decarboxylase in the majority of healthy individuals, where their binding to autoantigen is prevented by anti-idiotypic antibodies. These anti-idiotypic antibodies are absent at clinical diagnosis of Type 1 diabetes, revealing the presence of autoantibodies. Type 1 diabetes (T1D) is an autoimmune disease characterized by the dysfunction and destruction of insulin-producing beta cells by autoreactive T cells. Although much progress has been made towards understanding the respective roles of effector and regulatory T cells in this beta cell destruction, the development of autoantibodies to beta cell proteins is widely considered simply a by-product of the autoimmune destruction of the beta cells, rather than having an active role in the pathogenesis. This view is starting to change based on increasing recognition that autoantibodies can have defined roles in other autoimmune diseases, and the emergence of new data on their role in T1D. This exploration of the role of autoantibodies in autoimmune disease has been spurred, in part, by increasing recognition that development of autoimmune diseases is influenced by regulatory antibodies (anti-idiotypic antibodies) directed against the unique binding site of autoantibodies. This review provides an overview of the development and function of these anti-idiotypic antibodies, and present evidence supporting their role in the development of autoimmune diseases. Finally, we conclude this review with a model of the events that may cause loss of anti-idiotypic antibodies and the implications for the development of T1D.     

Direct time-resolved fluorescence immunoassay for serum oestradiol based on the idiotypic anti-idiotypic approach

We report a novel competitive type immunoassay for oestradiol based on the idiotypic anti-idiotypic approach. This has been achieved by the production of an anti-idiotypic antibody (anti-Id) which is directed against the oestradiol binding site of the primary idiotypic antibody (Ab1). In this format the primary Ab1 was captured onto the surface of microtitre wells and oestradiol standards or serum samples were then allowed to compete with europium labelled anti-Id for the binding sites of Ab1. Fluorescence was proportional to the concentration of oestradiol over the range 0-8 ng/ml. The sensitivity of the assay was 80 +/- 20 pg/ml, whilst the intra-assay variation ranged from 3 to 10%, and the inter-assay variation from 7.3 to 15%. The results obtained by the fluorescence immunoassay correlated well with those obtained by an extraction radioimmunoassay using tritiated antigen and dextran-coated charcoal for separation of bound and free ligand (n = 60, r = 0.98). The idiotypic anti-idiotypic approach in hapten immunoassays enables antibodies to be labelled instead of haptens, and thus permits the development of robust and sensitive immunoassays.     

Specific detection of antibodies in cancer patients following immunotherapy with anti-idiotype

Assays were compared for specificity and sensitivity in detecting in cancer patients' sera antibodies (Ab) raised during the course of immunotherapy with goat anti-idiotypic antibodies (Ab2) bearing the internal image of a colon carcinoma-associated antigen defined by monoclonal antibody (MAb) CO17-1A (Ab1). The human Ab were tested for binding to tumor cells, isolated tumor antigen (Ag), and Ab2, and for the capacity to inhibit binding of Ab2 to Ab1. Chimeric (human/mouse) MAb CO17-1A was used as a positive control in all assays. Of the four different cell binding assays used, the mixed hemadsorption assay (MHA) showed the highest specificity and sensitivity. For detection of Ag-binding human Ab, the enzyme-linked immunosorbent assay (ELISA) with Ag as target and peroxidase (PO)-labeled anti-human IgG antibodies as tracer for detection of human Ab binding to the target, showed higher specificity and sensitivity as compared to radioimmunoassay (RIA). For detection of human Ab binding specifically to Ab2, three different ELISAs and three RIAs were used. Best results were obtained in the ELISA with anti-human IgG antibodies as target and biotinylated Ab2 as tracer for detection of human Ab binding to the target. Of four different inhibition assays used, the ELISA which measures inhibition of binding of biotinylated Ab2 to Ab1 by human Ab or chimeric antibody at 37 degrees C was the most sensitive and specific. These assays have general applicability for the characterization of human Ab responses in Ab2 vaccination approaches to various tumors and pathogens and therefore provide the basis for the establishment of a correlation between Ab responses and clinical outcome of the disease.     

Biological mimicry of antigenic stimulation: analysis of the in vivo antibody responses induced by monoclonal anti-idiotypic antibodies

In this study, the induction of protective antibodies against a bacterial pathogen in mice was used as a model for idiotype vaccine development. The antibody responses induced in different strains of mice by the hapten phosphorylcholine (PC) coupled to ovalbumin, PC-OVA, were compared with the responses induced by carrier conjugates of two different anti-idiotopic antibodies. One anti-idiotope, 4C11, exhibits the characteristics of an internal image of phosphorylcholine, and therefore is classified as an Ab2 beta; the other, F6, does not mimic antigen, and therefore is classified as an Ab2 alpha. The analysis of the temporal kinetics of the IgM and IgG1 anti-PC responses induced by nominal and idiotope antigens revealed dynamic responses characterized by changes in the quality and quantity of the antibody populations during the course of the immune response. All three antigens could stimulate antibodies that were PC-specific and T15 idiotope-positive in BALB/c and A/St mice. The highest titre of T15+ anti-PC antibodies was achieved with an immunization protocol which involved priming with Ab2 alpha followed by challenge with PC-OVA. Antibodies specific for the extended hapten, diazophenylphosphorylcholine, and hapten-carrier bridge determinants were being stimulated late in the responses to PC-OVA. BALB-c, A/St and CBA/N (Xid) mice all produced, late in the response to Ab2 alpha, high T15+ antibody titres which do not bind PC. The induction of T15+, non-PC binding, antibody suggests that T15 is a regulatory idiotope, expressed on antibodies having differing antigenic specificities. With regard to vaccine development, these results support the contention that effective induction of antibodies does not depend on stimulating a unique idiotope but can be achieved by anti-idiotypes reacting with different idiotopes. In addition, these results suggest that the combined use of idiotope and nominal antigens in an immunization protocol may provide the maximal protective immunity.     

Low frequency of CD4+CD25+ Treg in SLE patients: a heritable trait associated with CTLA4 and TGFβ gene variants

Background

In certain cases, anti-idiotypic antibodies that recognize an antigen-combining site of an antibody can mimic the structure and/or function of certain nominal antigens. This feature makes them particularly useful if conventional experimental approaches fail to fulfil expectations, especially when the molecule of interest is infectious, toxic or difficult to isolate and purify. We suggest the application of an anti-idiotype concept to the field of prion biology, with the aim of evoking a humoral immune response against the pathological isoform of the prion protein (PrP^Sc). Different ways to induce anti-idiotypic responses were studied in mice and chickens using various forms of V5B2, a PrP^Sc-specific monoclonal antibody we have described previously.

Results

The preparation of anti-idiotypic monoclonal antibodies was achieved with well-defined strategies of immunization, selection and subsequent characterization. Our results demonstrate that it is possible to induce a strong anti-idiotypic immune response against the V5B2 monoclonal antibody in both xenogeneic and syngeneic experimental systems. From the competition seen between polyclonal and monoclonal anti-idiotypic antibodies and the original immunogen, the P1 peptide, and even more importantly, the ultimate target antigen, PrP^Sc, we conclude that selected antibodies bind to the antigen-combining site of the V5B2 monoclonal antibody and might even resemble the PrP^Sc-specific epitope. The involvement of both antigen-combining sites in the interaction between V5B2 and the most promising monoclonal anti-idiotypic antibody was further supported by molecular docking.

Conclusion

The results of the present study not only provide an example of the successful production of Ab2 monoclonal antibodies based on a well planned strategy for selection, but should also provide a new experimental approach that is applicable to the field of prion diseases.     

Dissection of an antibody paratope into peptides discloses the idiotope recognized by the cognate anti-idiotypic antibody

Using methods of parallel synthesis, the complete amino acid sequence of an Ab 1 antibody (Tg 10, an anti-human thyroglobulin monoclonal antibody) was made in the form of a set of 100 synthetic overlapping peptides. This set of immobilized peptides was allowed to react with the cognate Ab2 (AI 10, a highly purified rabbit anti-idiotypic polyclonal antibody to Tg 10). A dominant peptide idiotope, INTFSGVPTYA, was thus mapped, which corresponds mainly to the CDR2 region from the V(H) domain of the Tg 10 mAb. A synthetic peptide replica of this idiotope was found to bind to AI 10 with an affinity (K(D) in the 10(-8) M range, as measured using BIACORE technology) which represents a significant part of the affinity of the complete Tg 10 antibody (K(D) in the 10(-9) M range). The synthetic peptide also elicited anti-idiotypic antibodies in rabbits that recognized specifically the Ab1 antibody in an Ab1- and antigen-inhibitable manner. The peptide idiotope was further characterized chemically by the identification of residues important for binding to the Ab2 and by modelization of its structure. Our approach makes it readily possible to map and characterize functional, continuous-type idiotopes that could be further used to manipulate the immune response by peptide technologies.     

Exploring the feasibility of an anti-idiotypic cocaine vaccine: analysis of the specificity of anticocaine antibodies (Ab1) capable of inducing Ab2beta anti-idiotypic antibodies

Conventional vaccination with the cocaine molecule conjugated to a protein carrier is a new approach in the treatment of addiction. Experimentally, this strategy has been shown to alter the pharmacokinetics as well as the psychostimulant effect of a cocaine challenge. The purpose of this study was to investigate whether a more stable and less controversial molecule, an anti-idiotypic antibody, which mimics the configuration of the cocaine molecule (Ab2beta), could be successfully used instead of cocaine. Two cocaine conjugates that presented different areas of the cocaine molecule to the immune system were used to produce monoclonal antibodies specific for cocaine (Ab1). Several anti-idiotypic antibodies were then produced. Four were identified as Ab2beta, or internal images of the antigen; when injected into BALB/c mice, they elicited an anticocaine response. The anticocaine response elicited by one of the four Ab2beta (K1-4c) was sufficient to significantly reduce the level of cocaine that targeted the brain following cocaine challenge, compared with the level of cocaine found in the brain of control animals immunized with irrelevant antibody. In conclusion, the possibility of an anti-idiotypic vaccine seems to be worth pursuing.     

Polyclonal anti-idiotypic antibodies exhibit antigenic mimicry of limited type 1 fimbrial proteins of Escherichia coli.

Polyclonal anti-idiotypic antibodies (anti-Ids)(fim) developed against idiotypes on antibodies (Ab-1s) that specifically bind structural, organelle fimbrial proteins of Escherichia coli were able to modulate immune function in anti-Id(fim)-immunized mice. Proliferation or suppression of splenic lymphoid cell responses by polyclonal anti-Ids in tissue culture appeared to be dose dependent. Anti-Ids were able to induce a dose-dependent T-cell-mediated immunity specific for type 1 fimbrial antigen(s) in immunized animals when assessed in vitro, but they failed to elicit in vivo positive ear-swelling skin reactions. Anti-Ids were unable to induce protective immunity against an in vivo infectious challenge with E. coli in anti-Id-immunized adult animals, but they stimulated a specific, secondary antibody response in anti-Id-challenged mice. Anti-Ids stimulated the development of anti-anti-Ids (Ab-3s) specifically binding a fimbrial antigen(s) and revealed the presence of antibody idiotypes binding E. coli adhesin proteins in the 27- to 29-kilodalton range. Results suggest discrete, but subtle, immunomodulatory effects of the anti-Ids and potential vaccinoid properties capable of stimulating a specific humoral and cellular response in vivo.     

一次融合同时获得抗独特型和抗抗独特型单克隆抗体的杂交瘤

本文在研制带有HBsAg表位内影象的单克隆抗独特型抗体的过程中,用抗-HBs单克隆抗体(Ab_1)免疫同系鼠,除筛选分泌Ab_2β的杂交瘤细胞外,还同时设计了筛选分泌Ab_3的杂交瘤。结果在一次免疫,一只免疫鼠的脾脏细胞,一次融合实验中,同时获得了分泌Ab_2β及Ab_3抗体的杂交瘤细胞株。本文报告筛选Ab_3的方法及对Ab_3所作的免疫化学鉴定。结果获得一株分泌Ab_3单克隆抗体的杂交瘤细胞株,命名为M4。证明Ab_3具有Ab_1的特异性。这一结果不仅提示独特型网络的确在同一个体内客观存在,而且也为研制单克隆抗独特型抗体杂交瘤提供了一条简单、经济、事半功倍的经验。