Linkage of low and high affinity anti-fluorescein idiotype families

Data presented in this study describes the isolation and characterization of two anti-fluorescein (Fl) hybridoma proteins 3–24 and 12–40, both IgG₁, with a K_a = 2.8 and 3.4 × 10⁶ M⁻¹, respectively, at 37°C. These clones inhibited (6.8 ± 2.8 − 20.8 ± 0.6% at l μg/well) the idiotype-anti-idiotype interactions (IAII) of anti-Fl clones 3–13 and 3–17, which define a previously described low affinity idiotype family. Antibodies 3–24 and 12–40 also inhibited (45.0 ± 3.0 and 61.3 ± 5.6%, respectively, at 1 μg/well) an IAII denfied by a high affinity (K_a = 5.2 ± 1.5 × 10⁹ M⁻¹ at 37°C) anti-Fl clone, 4-4. Hybridoma proteins 3–13 and 3–17 possess similar affinities for Fl (K_a = 3.8 ± 5.1 and 5.9 ± 4.0 × 10⁴ M⁻¹) and are known to be idiotypically unrelated to clone 4-4. While 3–24 and 12–40 appeared very similar, non-identity of their active sites was established by heterologous idiotypic inhibitions, fine specificity of binding and spectral measurements (Q_max and λ_max) of bound Fl. All IAII (3–13, 3–17, 9–40 and 4-4) were inhibited>80% by the presence of 10⁻⁴M F1 or F1-BSA, In addition, four intermediate affinity (6.0 × 10⁶ K_a 5.3 × 10⁸ M⁻¹) anti-FI clones, comprising a second previously described idiotype family (designated the 9–40 family) were further analyzed. Inhibition of the 9–40 IAII by all heterologous proteins in the 9–40 family (except clone 5–27), and clones 3–24, 12–40 and 4-4 ranged from 87.7 ± 1.3 to 95.4 ± 1.0% at 1μg/well. Titration of the 9–40 IAII inhibition by antibodies 9–40, 3–24, 12–40 or 4-4 generated essentially superimposable profiles. In reciprocal inhibition experiments, using the 4-4 IAII, clones 3–24, 12–40, 9–40 and 4-4 gave distinct idiotypic titration patterns. Thus, members of the 9–40 family, 3–24 and 12–40 were more closely related to intermediate affinity clone 9–40 than high affinity clone 4-4. Finally all members of the 9–40 family also significantly inhibited both the 3–13 and 3–17 IAII (11.8 ± 3.1 − 32.9 ± 6.1 at 1 μg/well) and gave distinct idiotypic inhibition profiles. Clones 3–24 and 12–40, characterized in this report, and the 9–40 family provide linkage between idiotypically distinct anti-Fl hybridoma proteins differing in affinity by> 20,000-fold. This linkage provides a greater span in affinity, than in all previously reported idiotypic families, within restricted or unrestricted systems.     

The role of the VL- and VH-segments in the preferential reassociation of immunoglobulin subunits

Competitive reassociation experiments, in which equimolar amounts of two different L-chains were allowed to compete for a limiting amount of H-chain, were performed to assess the role of the V kappa- and J kappa-segments on the ability of an L-chain to compete. Using H- and L-chains from the murine anti-phosphorylcholine (PC) myelomas, TEPC15, MOPC167 and MCPC603, and a series of V kappa 21 L-chains, it was found that the V kappa 21 L-chains competed uniformly better than the anti-PC L-chains, when the anti-PC H-chains were used, despite any differences in the J-segments of the competing L-chains. In addition, when the anti-PC L-chains, which all employ identical J kappa-segments but very diverse V kappa-segments, were in competition against each other, a hierarchy of competitive ability existed which was independent of whether the chains were autologous or heterologous and independent of antigen binding activity. Competitive reassociation experiments between the V kappa 21 and anti-PC L-chains were also performed using the heterologous anti-lysozyme monoclonal HyHEL-10 H-chain or the anti-galactan J539 H-chain, and it was found that the relative competitive ability of the V kappa 21 L-chains with respect to the anti-PC L-chains was dependent on which H-chain was employed. The results suggested that the main factor favouring preferential reassociation by any particular L-chain was the V kappa-segment and that the effects of the J kappa-segment could not be observed where a high degree of diversity in the V-segments existed. Furthermore, while the results implied that specific pairs of VH- and VL-domains had a higher affinity for each other, this was not a necessary criterion in the formation of autologous pairs of H- and L-chains as demonstrated by the preferential heterologous reassociation of the V kappa 21 L-chains over the autologous anti-PC L-chains. These results were consistent with the independent, random rearrangement of immunoglobulin H- and L-chain V-domain gene segments and predict that the hypothetical repertoire of antibodies is not limited by the selection of specific pairs of high-affinity VH-VL domains.     

Expression of defined idiotypes throughout the BALB/c anti-fluorescyl antibody response: Affinity and idiotype analyses of heterogeneous antibodies

Heterogeneous BALB/c anti-fluorescyl antibodies were shown to display increases (> 50-fold) in binding affinity from the primary through the tertiary responses. The structural basis of such affinity maturation and the diversity exhibited by anti-fluorescyl antibodies was examined by idiotypic analysis using a panel of anti-idiotype reagents specific for seven different monoclonal antifluorescyl antibodies. Because these clones exhibited binding affinities characteristic of a secondary or hyperimmune response, it was possible to examine the mechanism of affinity maturation by determining the prevalence of the seven idiotypes (Id-4-4-20, Id-20-19-1, Id-20-20-3, Id-6-10-6, Id-20-4-4, Id-4-6-10 and Id-6-19-1) in specifically purified heterogeneous preparations with low (i.e. primary response) or high (i.e. secondary and tertiary responses) binding affinities. Four of the idiotypes were not detected in heterogeneous preparations and thus each represented less than 0.1 % of the total anti-fluorescein repertoire. Although results indicated that each of three other clones expressed unique or private idiotypic determinants not present in the heterogeneous population, these idiotypes (Id-4-4-20, Id-6-10-6, Id-6-19-1) were detected and ranged from 0.2 to 2.0% of the repertoire. However, results indicated that each clone expressed unique or private idiotypic determinants not present in the heterogeneous population. Determinants expressed by such high-affinity monoclonal antibodies were expressed equally in all heterogeneous preparations examined. Because those determinants which were expressed were found in either low- or high-affinity heterogeneous antibodies, it is likely that the higher affinities exhibited by monoclonal antibodies derived from a secondary response are associated with unique idiotypic determinants which were not detected in polyclonal preparations. Hence, the process of affinity maturation may find as its structural correlate a mechanism such as somatic mutation which generates individual or unique idiotypes.     

Idiotypic and fine specificity analysis of a (4-hydroxy-3-nitrophenyl)acetyl (NP)-specific suppressor T cell hybridoma at the level of cell surface structures, isolated receptor material and functional suppressor factor

The (4-hydroxy-3-nitrophenyl)acetyl (NP)-specific T suppressor cell hybridoma 7C3-13 was established by fusing splenic B10.BR T cells enriched on NP-coated petri dishes with the AKR thymoma BW5147. 7C3-13 was selected by anti-NPb idiotypic and anti-I-Jk antibodies in microcytotoxicity tests. The hybridoma expressed H-2k, I-Jk, Qa-1, Thy-1.1 as well as idiotypic (binding site-related) and framework Ig VH determinants, while it was negative for I-A, I-E/C, Thy-1.2, Lyt-1, Lyt-2 and Ig constant region determinants. Hapten-binding receptor material could be isolated from 7C3-13 cells on NP-coupled nylon nets and functionally active T suppressor factor (TsF) could be extracted from the hybridoma. Both types of soluble molecules express NPb idiotype, but the TsF carries I-J determinants in addition while the isolated receptors do not. The molecular weight of the isolated receptor material is 80 000, that of the TsF activity is 27 000 and 57 000-64 000, respectively. We thus were able to show that NP-binding molecules can be obtained in the form of cellular surface receptors, isolated receptor material and extracted TsF from one and the same, monoclonal, cell source.     

Antigen binding and idiotypic properties of reconstituted immunoglobulins G derived from homogeneous rabbit anti-pneumococcal antibodies.

Recombinations and hybridizations of H and L-chains derived from several homogeneous rabbit antibodies to type 3 pneumococcal polysaccharide (SIII) were carried out. All reconstitution experiments performed gave rise to genuine IgG molecules. Antigen-binding studies and affinity measurements for a hexasaccharide ligand derived from SIII were made. In addition, heterologous antiidiotypic serum raised against one rabbit anti-SIII antibody was used to measure the reconstitution of idiotypic determinants in hybrid immunoglobulin molecules. The results show that full recovery of the antigen-binding properties was obtained only when chains derived from the same antibody molecules were reassociated. Similarly, the complete regain of idiotypic determinants (studied in one antibody system) could only be demonstrated in the homologous recombinants. The pairing of an H-chain with several heterologous L-chains, which differed in 6-11 positions in the 3 hypervariable sections, led to the formation of hybrid IgG molecules which had an affinity at least 100-fold lower than that of the parent anti-body molecule and a number of hapten-binding sites which did not exceed 0.30.     

Monoclonal Anti-Azobenzenearsonate Antibodies Expressing the Cross-reactive Idiotype: Immunochemical Studies Show that All Idiotypic Determinants Reside on a Single Molecule

Cell lines that secreted antibodies to the hapten azobenzenearsonate (ABA) were established by hybridization of immune A/J spleen cells to the non-secreting myeloma, NS-I. Solid-phase radioimmunoassays (RIA) were developed for rapid screening of hybridoma supernatants to detect antibodies to ABA and lo detect antibodies bearing the ABA cross-reactive idiotype (CRI). Hybrid clones secreting both CRI⁺ and CRI⁻ anti-ABA antibodies were obtained. The supernatant from one clone (7-1-3) strongly inhibited binding of iodinated anti-idiotype serum in a competitive RIA. This clone expressing the CRI produced immunoglobulin of the IgG2a subclass. Solid-phase absorption of anti-idiotype serum followed by competitive radioimmunoassay analyses revealed that all the idiotypic determinants recognized by anti-idiotype scrum reside on this monoclonal antibody.     

Idiotypic analysis of five xenogeneic antisera to anti-human thyroglobulin monoclonal antibodies

Five xenogeneic anti-idiotypic antisera (anti-id) were produced against individual BALB/c-derived monoclonal antibodies (mAb) which bound to different peptidic determinants on the human thyroglobulin molecule (Tg). Idiotypic analysis performed using sensitive radioimmunoassays revealed that: (1) the anti-id highly precipitated their homologous ligands; (2) two anti-id displayed minor cross-reactivities with one or two heterologous mAb; (3) each unlabelled homologous mAb was able to inhibit the idiotype binding of the corresponding anti-id; (4) no significant inhibition of homologous idiotype binding was observed with large excess of heterologous mAb; (5) efficient inhibition of mAb binding to Tg was observed only when homologous anti-id served as inhibitor. The data support the conclusion that xenogeneic anti-id may detect on their corresponding ligands individual idiotypic specificities that can be located at the mAb-combining site. Such reagents may constitute appropriate probes for further studies on anti-Tg autoimmunity.     

Comparative properties of monoclonal antibodies comprising a high-affinity anti-fluorescyl idiotype family

The T-dependent BALB/c murine immune response to fluorescein (F1) is characterized by structural heterogeneity at the protein level exemplified in part by a significantly wide range of affinities (Ka), and apparent lack of dominant idiotypes. In order to generate an idiotype family, xenogenic anti-idiotype (anti-ID) antibodies raised against anti-F1 monoclonal antibody (MCA) 4-4 (Ka = 1.7 X 10(10) M-1) were used in a solid-phase radioimmunoassay (SPRIA) to screen 68 anti-F1 hybridomas generated from multiple cell fusions for idiotypically related immunoglobulins. Four affinity-purified MCAs (designated 9-40, 10-25, 5-14 and 5-27) bearing 4-4 idiotypic determinants (ID 4-4) exhibited discrete isoelectric focusing spectrotypes (pI range = 6.8-7.7), significantly different fluorescence quenching values (38-95%) of bound ligand, binding affinities ranging from 3.3 X 10(7) to 5.3 X 10(8) M-1, similar active site inaccessibility to iodide, and closely related fine-specificity patterns for fluorescyl analogues. Idiotypic relatedness of each MCA to prototype 4-4 was quantitated by SPRIA, the results demonstrating that: each 125I-labeled MCA bound significantly to solid-phase anti-ID 4-4, and the concns of heterologous MCAs 9-40, 10-25 and 5-14 required for 50% inhibition of 125I-4-4/anti-ID 4-4 binding were comparable to homologous Ig protein. The finding that ID 4-4 bearing anti-F1 MCAs exhibit various binding properties and affinities is consistent with variable-region somatic diversification in anti-F1 affinity maturation.     

Specificity of T and B lymphocytes for myeloma protein 315.

The antibody response of BALB/c mice directed against the idiotype of the BALB/c myeloma protein MOPC 315 (M315) is T cell-dependent. The specificity of helper T cells for M31 5 was investigated. Helper cells were primed with M31 5, M315 affinity-labeled with N^α-bromoacetyl-N^ε-2,4-dinitrophenyl-L-lysine, M315 L-chain and H-chain the M315 Fv fragment, myeloma protein MOPC 460 and monoclonal human kappa and lambda chains. The primed cells were transferred together with (4-hydroxy-5-iodo-3-nitrophenyl(acetyl)) (NIP)-primed B cells to 500 R-irradiated recipient syngeneic BALB/c mice which were challenged with NIP_sM315. The anti-NIP antibody responses were augmented by helpers primed with all derivatives and subunits of M315. This effect disappeared almost completely when the helper cells were treated with anti-Thy-1,2 and C prior to transfer. Priming with M460 induced weak and inconsistent helper effects, which opens the possibility that some of the helper cells may recognize nonidiotypic determinants on M315. The strong and consistent helper effect induced by free M315 L-chain (L-31 5)-primed cells was not due to dissociation of NIP-L-315 from intact NIP₅ M315 used for challenge, because L-315-primed T cells also augmented the antibody response against the idiotype of M315 which is only expressed on associated (H+L) chain pairs. In contrast, BALB/c antibodies elicited by free L-315 were specific for a determinant which was present on free L-chains but which was not or only minimally accessible on the complete M315. The data indicate that the helper cells recognize determinants which are separate from the ligand binding site of M315 and which are accessible on both the complete M315 7 S subunit and its isolated chains. In contrast, B cells stimulated by free L-315 recognize determinants which are hidden on associated (H+L) chains. Moreover, the associated (V_L+V_H) domains of M31 5 Fv fragment, which lacks C domains are immunogenic for T helper cells.     

Analysis of the Repertoire of Anti-Idiotypic B-Cell Responses to Self-I-Ak- or -I-Ek-Reactive Monoclonal Antibodies in A.TL Mice

Twenty anti-idiotypic antisera (anti-Ids) were produced in A.TL mice to self-I-Ak or -I-Ek-reactive monoclonal antibodies (mAbs), constructed in the A.TH anti-A.TL combination. The reactivity of these anti-Ids was examined in a panel of 31 anti-Iak A.TH mAbs, using direct idiotype binding, cross-competitive inhibition of idiotype binding, and isoelectrofocusing (IEF) assays. Among 13 anti-Ids produced against anti-I-Ak mAbs, one only recognized individual idiotypic specificities (IdIs) on its corresponding mAb, while the 12 others identified homologous IdIs and recurrent idiotypic specificities also expressed on heterologous anti-I-Ak and/or I-Ek mAbs. Two sets of major cross-reactive idiotypes (IdXs) were characterized on two groups of mAbs recognizing public Ia.1, I-Ak,f,u and r) or private (Ia.2, I-Ak) determinants clustered in two spatially distinct epitope regions of the I-Ak molecule, respectively. By contrast, most (5/7) of the anti-Ids raised against mAbs recognizing polymorphic or monomorphic (Ia.7-like) I-Ek determinants displayed specificity apparently restricted to their corresponding mAb IdIs. This finding contrasted with the previous characterization, using xenogeneic anti-idiotypic reagents, of an interstrain IdX expressed on all mAbs defining Ia.7-like determinants in the IEk epitope group I. These data indicate that A.TL mice can readily develop anti-idiotypic responses towards self Ia-reactive mAb minor idiotypes (IdIs) and that recognition of anti-Iak mAb IdXs in such mice is preferentially observed when anti-I-Ak mAbs are used as immunogens.     

Induction of chronic idiotype suppression by ligands binding to the variable (not the constant) region of the idiotypic target

It was previously shown that in C57BL/6 mice chronic suppression of an idiotypically defined subset of λ1 chain-bearing anti-(4-hydroxy-3-nitrophenyl)acetyl (NP) antibodies is achieved by neonatal administration of allogeneic monoclonal anti-idiotope antibodies reactive with this subset, or by NP coupled to mouse immunoglobulin. The present data show that isologous monoclonal anti-idiotope antibodies have the same effect. In contrast, antibodies against constant region determinants of λ1, μ or δ immunoglobulin chains failed to induce chronic suppression of the same antibody subset. Furthermore, the effect of the anti-idiotope antibodies was neutralized by idiotypic antibodies of the IgG₁ class, injected before or together with the anti-idiotype. These results suggest that the mere complexing of idiotypic molecules on the B cell surface or in the circulation is insufficient for the induction of chronic idiotype suppression. In the present system, induction appears to require the binding of a ligand to idiotype-bearing receptor V regions, expressed on the surface of B (or T ?) cells.     

Development of an anti-idiotype monoclonal antibody mimicking the structure of lipopolysaccharide (LPS) inner-core determinants

An anti-idiotype antibody has been developed which is specific for idiotypic determinants of a BALB/c mouse IgG₃ monoclonal antibody (MAbY1-4A6) directed against the inner-core Kdo region of lipopolysaccharide (LPS). Armenian hamsters were immunized with MAbY1-4A6 and splenocytes from immunized animals fused with Sp2/0 myeloma cells. Eight clones secreting antibodies that bound to MAbY1-4A6, but not control IgG₃, were identified and subcloned. Culture supernatants from one hybridoma, termed MAb4G2, contain monoclonal antibody that binds to the variable region of MAbY1-4A6 and dose-dependently inhibits binding of MAbY1-4A6 to Re chemotype rough mutant LPS (Re-LPS). This antibody also inhibits binding of three additional mouse monoclonal antibodies specific for the inner-core of Re-LPS. MAb4G2 also recognizes a significant proportion of antibodies present in polyclonal R-chemotype antisera generated in mice (Re-LPS) and rabbits (J5 Rc-LPS). Mice and hamsters immunized with MAb4G2 or Re-LPS generate antibodies which cross-react with both immunogens. Cumulatively, these data suggest that MAb4G2 can function as an internal image of the Kdo-specific monoclonal antibody, MAbY1-4A6, mimicking the antigenic structure and immunogenicity of a portion of the LPS inner-core Kdo region.     

Structural analysis of monoclonal anti-arsonate antibodies: idiotypic specificities are determined by the heavy chain

Hybrid immunoglobulin molecules were constructed from the isolated heavy and light chains of monoclonal anti-arsonate antibodies which differed in their expression of a cross-reactive idiotype. The reconstructed molecules were tested for public and private idiotypic determinants associated with the A-strain response to the hapten p-azophenylarsonate and it was found that both an appropriate heavy chain and an appropriate light chain were required for expression of idiotypic determinants. While appropriate heavy chains could be derived only from idiotype-positive antibodies, appropriate light chains could be derived not only from idiotype positive antibodies, but also from certain idiotype-negative molecules. Similarly, recombinant (hybrid) molecules constructed from two idiotype-positive immunoglobulins differing quantitatively in the degree of idiotypic character, expressed the character at a level which correlated with that of the heavy chain donor. Thus, while the serological expression of idiotypic determinants occurs only in the context of the appropriate VHVL combination, these data demonstrate that the determinants comprising the major cross-reactive idiotype of the anti-arsonate response of A/J mice have their bases in heavy chain structures.     

Correlated expression of VH framework and VH idiotypic determinants on T helper cells and on functionally undefined T cells binding group A streptococcal carbohydrate

Antibodies to framework determinants of the VH and V lambda fragments of MOPC 315 and antisera to the VH idiotype determinants of the A 5 A antibody were used to analyze the antigen receptors of mouse T (and B) cells. This was done by using the antibodies as inhibitors in (a) an assay in which the binding of radiolabeled streptococcal carbohydrate (A-CHO) antigen by primed and unprimed T and B cells is determined and (b) an assay in which the helper activity of group A streptococcal vaccine-primed T cells is determined. The results suggest that the major proportion of primed and unprimed T cells binding A-CHO (70-90%) exhibit VH framework and VH idiotypic determinants. This population appears to include the helper T cells. A minor proportion of T cells (10-30%) express V lambda-related framework determinants and lack VH framework and VH idiotypic determinants. This population does not include T helper cells. Taken together, the data suggest that a subpopulation of T cells, including the helper cells, uses entire Ig VH regions as part of their antigen receptor system.     

Control of idiotope expression by monoclonal anti-idiotope and idiotope-bearing antibody

Preinjection of C57BL/6 mice with nano-to microgram amounts of a monoclonal IgG1 antibody directed against a binding site-related idiotope of the anti-NP [(4-hydroxy-3-nitro-phenyl)acetyl] antibody B1-8 results in enhancement or suppression of the corresponding and of another B1-8 idiotope in a subsequent anti-NP response, depending on the dose of the injected anti-idiotope antibody. The enhancing and suppressive effects appear two weeks after anti-idiotope administration and are maximal after 6-8 weeks. They are predominantly expressed at the level of IgG, not IgM, antibodies. Enhancement of idiotype expression, i.e. idiotypic memory, can also be induced by the injection of idiotypic antibody of the IgM class, namely antibody B1-8. This effect might represent one of the general mechanisms by which immunological memory is established.     

Kappa Chain (VχIII) Subgroup-Related Activity in an Idiotypic Anti-Cold Agglutinin Serum

In a search for H- or L-chain-related cross-idiotypic specificity among human anti-I and anti-i cold agglutinins, two idiotypic antisera raised against the IgMχ cold agglutinin Da were tested for their binding activity to isolated cold agglutinin H and L chains. Negligible H-chain binding activity was found, but there was high-titre L-chain binding activity in one of the antisera. This was an unsuspected V_χIII subgroup activity which enabled the classification of V_χIII proteins into three subgroups. The χ chains of five out of six anti-I and anti-i cold agglutinins belonged to the antigenically most active V_χIII subgroup. Absorption of the idiotypic antiserum with a Bence Jones protein of this latter subgroup did Dot appreciably alter the precipitating cross-idiotypic activity of the antiserum when tested with intact cold agglutinins. However, these studies do not rule out the possible existence of a V_χIII subgroup-associated conformational antigen in an intact Fab region, which is seen as a 'cross idiotypic' antigen by heterologous (rabbit anti-human) antisera.     

Conserved V(D)J junctional sequence of cross-reactive cytotoxic T cell receptor idiotype and the effect of a single amino acid substitution.

A dominant T cell population bearing the cross-reactive idiotype of T cell antigen receptor (TcR) has been obtained using an anti-TcR monoclonal antibody (mAb) developed in syngeneic mice. Forty-four cytotoxic T cell (CTL) clones with reactivity to a mAb (N9-127) were selected out of 396 H-2Db-restricted CTL clones specific for FBL-3 tumor antigen from C57BL/6 mice. These CTL clones were divided into two groups according to the blocking pattern of cytotoxic activities with mAb N9-127. All eight CTL clones chosen from both groups expressed TcR with a specific combination of alpha and beta chains (V alpha 1J alpha 112-2/V beta 10D beta 2.1J beta 2.7), and the difference in the blocking susceptibility resided in a single amino acid substitution (Gly to Asp) in the D-J joint of beta chain. This provides direct evidence for the molecular basis of cross-reactive idiotypes of TcR recognized by mAb.     

Characterization of virus-specific cytotoxic T cell clones from allogeneic bone marrow chimeras

We established several H-2-restricted lymphocytic choriomeningitis virus (LCMV)-specific cytotoxic T cell clones from spleens of virus-primed C57BL/6 or C57BL/10 (H-2b) and B10.BR (H-2k) mice and from allogeneic C57BL/10----B10.BR and B10.BR----C57BL/10 bone marrow chimeras. Two T cell clones of H-2b origin and restricted to H-2b, 3 of H-2k origin and restricted to H-2k were compared with two clones each derived from the two types of chimeras. Their surface phenotype was found to be Lyt-2+, L3/T4- and KJ16-133+ (2 of 9). Clones from chimeras expressed bone marrow donor H-2 and are restricted to the recipient H-2. H-2k-restricted clones were all specific for Kk whereas all H-2b-restricted clones were specific for Db. These restriction specificities could be further defined by the blocking activity of various monoclonal anti-H-2 antibodies. Interestingly the anti-H-2Db antibodies blocked the restricted virus-specific killing activity of the clones derived B10.BR----C57BL/10 chimeras much more effectively than the activity of the clones derived from conventional H-2b mice. The various clones differed with respect to their fine specificity for LCMV strains. The 3 clones of conventional B10.BR origin only recognized LCMV-WE but not LCMV-Armstrong, Aggressive or Docile; H-2b-restricted conventional clones recognized target cells infected with all LCMV strains except LCMV-UBC-Docile; the T cell clones from the bone marrow chimeras recognized with one exception all LCMV strains tested.     

Idiotypic analysis of antibodies against the terpolymer L-glutamic acid60-L-alanine30-L-tyrosine10 (GAT). IV. Induction of CGAT idiotype following immunization with various synthetic polymers containing glutamic acid and tyrosine.

The immune responses of all inbred strains of mice specific to the synthetic terpolymer poly(LGlu60LAla30LTyr10), referred to as GAT10, are characterized by the presence of anti-GAT antibodies which share a common (CGAT) idiotype. In this report, we describe the ability of the synthetic polymers, LGlu33LAla33LTyr33, LGlu51-LAla34LTyr15 and poly-L(Tyr, Glu)-DLAla--LLys [(T,G)-A--L] to induce antibodies with CGAT idiotypic specificities. All of these polymers contain "GT"-related determinants. Following immunization with these polymers, antisera from responder mice bind the corresponding 125I-labeled antigen and 125I-labeled poly(LGlu50LTyr50) or GAT10. These antisera shared the CGAT idiotype which is associated with the antibody fraction with binding specificity for GAT10. Collectively, the present results indicate that GT-related determinants are required for the induction of the CGAT idiotype. Moreover, since the immune responses to these synthetic polymers are under distinct H-2-linked immune response (Ir) gene control, a mouse strain can be nonresponder to one polymer and responder to another; in this case, only the latter polymer induces CGAT idiotype. Thus, although the immune responses of inbred strains of mice to different polymers are under distinct Ir gene control, the antibody responses can be idiotypically related.