Cell-bound receptors for alloantigens on normal lymphocytes. II. Antialloantibody serum contains specific factors reacting with relevant immunocompetent T lymphocytes

Clonal analysis of the T lymphocytes involved in parent versus F1 graft-versus-host reaction

A systemic graft-versus-host reaction (GVHR) leading to 50% mortality by day 20 was elicited by the injection of CBA (10(5)) or B10 (10(6)) parental T lymphocytes into irradiated (750 rad) and bone marrow protected (CBA X B10)F1 recipients. Between days 12 and 28 the spleens of the sick mice were analyzed by limiting dilution, performed with irradiated F1 cells and a source of interleukin-2 (IL-2), to determine the frequency of cells with an antihost proliferative or cytolytic activity and to derive T lymphocyte clones. The frequency of cells with antihost proliferative or cytolytic activity was approximately 10(-3) in either combination. In the CBA vs F1 GVHR, all eight clones isolated with anti-F1 activity were Lyt-2-, noncytolytic, mixed lymphocyte reaction (MLR) responders and IL-2 producers, three of which mapped to the Ab locus, while in the B10 anti-F1 combination, eight of the nine anti-F1 clones isolated were Lyt-2+, poor MLR responders and non-IL-2 producers, but cytolytic and mapping to Kk. These findings suggest a much higher frequency of T cells recognizing the A-locus antigens in the CBA than in the B10 strain.

Fate of T-lymphocyte injected into immunodeficient allogeneic nude or semi-allogeneic F1 mice: correlation with manifestations of graft-versus-host reaction

This review emphasizes some of the differences between the fate of allogeneic H2-incompatible T-cells, when injected into immunodeficient, T-depleted mice, or as parental cells injected into F1 hybrids. In both conditions, allogeneic cells are eliminated, a rejection which cannot be predicted from the fate of a skin graft. While in both situations a phase of GVHR is observed, it is of short duration in allogeneic T-B reactions, and it is obvious that the production of allo-antibodies by the host, which is enhanced by the GVHR, is the major mechanism of allogeneic T-cell elimination, resulting in a rapid self-cure of the GVHR. In T-vs-B GVHR, the enhancement of the humoral response is strikingly restricted to the allo-antigens of the T-cells, and correspond therefore to a peculiar form of "allogeneic effect", in fact an "allogeneic suicide" which implies a linked T-B collaboration, while in P-F1 combinations, there is a enhancement of the humoral response to unrelated antigens (i.e. unlinked T-B collaboration or the classical allogeneic effect) and a polyclonal B-cell activation, which can result from the much more protracted course of the GVHR. The parental cells surviving in the spleen of an F1 semi-allogeneic host, undergoing a lethal GVHR were characterized at the clonal level: they were exclusively of the Lyt 2- MLR responder and polyvalent helper variety. This indicates that the Lyt-2- and polyvalent helper subset is selected during an allo-reaction in vivo (either because it is more rapidly replicating and/or less negatively selected by the host resistance) and that it is capable of inflicting a lethal GVHR.

Functional helper activity of monoclonal T cell populations: antigen-specific and H-2 restricted cloned T cells provide help for in vitro antibody responses to trinitrophenyl-poly(LTyr,Glu)-poly(DLAla)--poly(LLys)

The ability of long-term cultured and monoclonal T cell populations to provide antigen-specific help was assessed in a system of Ir gene-controlled in vitro antibody responses to soluble antigens. T-cell colonies and monoclonal T-cell lines were generated which proliferated specifically in response to poly(LTyr,Glu)-poly(DLAla)--poly(LLys) [(T,G)-A--L] and were I-A restricted in these proliferative responses. These (T,G)-A--L-specific T-cell populations were evaluated for their ability to help unprimed and T-cell depleted spleen cell populations in the generation of antibody responses to trinitrophenyl (TNP)-(T,G)-A--L in vitro. It was found that long-term T-cell lines, including monoclonal T-cell populations derived by limiting dilution, were highly efficient helper cells for IgM responses to TNP-(T,G)-A--L. These helper T cells were both antigen-specific and I-A restricted in their ability to be activated and to cooperate with T-cell depleted spleen cell populations. Once specifically activated, however, these clones provided help that was antigen nonspecific. These studies have thus demonstrated the ability of antigen-specific and H-2-restricted monoclonal T-cell populations to provide help for responses to soluble antigens in vitro.

Inheritance of antibody specificity V. Anti-2-phenyloxazolone in the mouse

Antibodies to hapten 2-phenyloxazolone (phOx) of all BALB/c and DBA/2 mice have the same idiotype and the same major (public) isoelectric focusing pattern whose main spectrotype is called Ox-1. Neither of these characteristics could be readily demonstrated in anti-phOx antibodies of C57BL, C3H or LP mice; these antibodies were heterogeneous, and lacked public spectrotypes. Also, a fine specificty difference could be demonstrated between anti-phOx antibodies of BALB/c and C5MBL mice; the latter have a higher relative affinity than the former for a structural analogue of phOx (2-o-iodophenyloxazolone). The three BALB/c characteristics were inherited in congenic and recombinant inbred strains as an allotype-linked block, defining a new VH marker, VHphOx. Murine anti-phOx antibodies were found to exhibit three types of conservatism: (a) Every individual mouse of strains BALB/c, DBA/2 or BAB-14 had an almost indistinguishable IEF pattern. (b) These patterns (and the cross-reactive idiotype) remained virtually unchanged during an immunization course of 70 days. (c) An identical idiotype (and in some cases IEF pattern) was present in mouse strains of five different allogroups.

Specific transplantation tolerance induced by autoimmunization against the individual's own, naturally occurring idiotypic, antigen-binding receptors

Serum or urine from normal adult Lewis rats can be shown to contain detectable amounts of idiotypic, antigen-binding receptors with specificity for the major histocompatibility complex locus antigens of the rat, the Ag-B locus antigens. Such purified naturally occurring receptor molecules, be they of T- or B-lymphocyte origin, can be used in a polymerized form to provoke the production of auto-anti-idiotypic antibodies when injected back into normal Lewis rats. As a consequence of this autoimmunity, lymphocytes of these Lewis rats can be shown to be depleted of cells carrying the relevant idiotypic receptors signifying reactivity against a given Ag-B locus-determined antigen(s). This specific lack of idiotypic lymphocytes is manifested as a selective loss of reactivity against the relevant Ag-B-incompatible antigens as measured by graft versus host or MLC reactions. Furthermore, autoimmune Lewis rats display specific transplantation tolerance against the skin grafts from the relevant strain, as demonstrated by specific prolongation of graft survival. A further indication of the specific tolerence state of these rats comes from the highly reduced ability to produce circulating antibodies against the relevant Ag-B antigens. No side effects of these autoimmunization procedures have been noted so far. It would thus seem clear that a prolonged state of specific transplantation tolerance can be achieved via autoimmunization against the individual's naturally occurring idiotypic, antigen-binding receptors.

Fractionation of immunocompetent cells with different physical properties

This paper deals with recent developments in the fractionation of immunocompetent cells with different physical properties, using preparative free flow cell electrophoresis, fractionation of cells according to their size and density.

Idiotypic analysis of lymphocytes in vitro. I. Specificity and heterogeneity of B and T lymphocytes reactive with anti-idiotypic antibody

Guinea pig anti-idiotypic antibodies (anti-Id) of the IgG1 class, directed to an A/J antibody to Group A streptococcal carbohydrate (A-CHO), or directed to a BALB/c myeloma protein that binds the same antigen, stimulate B-precursor cells as well as T-helper cells when injected into mice of the appropriate strain. The strain-specific induction of both precursor and helper activity was detected by in vitro secondary responses of primed spleen cells to A-CHO or to 2,4,6-trinitrophenyl (TNP) upon challenge with Group A streptococcal vaccine (Strep.A) or with TNP-Strep.A, respectively. B- and T-cell populations primed with anti-Id were uniform with respect to the binding of antigen and of anti-Id. This was in contrast to cells primed with Strep.A, which were heterogenous. Taken together, B and T cells that possess the same antigen-binding specificity share idiotypic determinants, reveal the same idiotypic polymorphism, and may display similar degrees of heterogeneity with respect to the binding of antigen and anti-Id. Since the anti-Id used in this study detect Id determinants associated with the heavy chain of the variable region of mouse antibodies, the data suggest that this region of the immunoglobulin molecule is shared between T- and B-cell antigen receptors.

The specificity of T lymphocyte responses to chemically defined antigens

A system is described that allows the definition of T cell receptor specificity with some precision. It involves immunization of guinea pigs with hapten coupled to mycobacteria. The T cells of such animals respond to many but not all carriers modified by that hapten. Such T cells recognize neither hapten nor carrier alone, but rather determinants involving both the hapten and the carrier. No evidence for hapten-specific T cells was found. A model of the antigen binding site of the T cell receptor emerged from these experiments. According to this model, the T cell receptor consists of a single site of relatively large extent involving multiple subsites which are of low and roughly equal affinity. Thus, the haptenic group is not immunodominant for T cells as it is for B cells and for anti-hapten antibody. This suggests that the antigen binding receptor on T cells differs in some fundamental way from that on B cells. It is proposed that antigen recognition by T cells is mediated by an immunoglobulin heavy chain variable region that is not paired with an immunoglobulin light chain variable region.

T-lymphocyte receptors for alloantigens

Recent developments in research on T-cell receptors for alloantigens have been reviewed. Recognition of these antigens is T-cell dependent and, when measured in the PAR test, can be shown to take place with receptors present on T cells, with those shed spontaneously from T cells and also with "recognition structures" of as yet unknown origin and structure present in post-transplantation alloantiserum but absent from B-cell induce alloantiserum. All recognizing structures of parent T-cell origin mentioned above also induce formation of anti-T cell receptor antisera when injected into appropriate F1 hybrid animals. The highly specific inhibitory activity of the sera can be demonstrated both in vitro and in vivo, and the most fascinating aspect constitutes cytotoxic elimination of T cells bearing receptors for a given alloantigenic specificity without harming T cells with other alloreceptors. The biochemical nature of T-cell receptors is not known and, depending on the physical form in which it is investigated, high molecular weight as well as considerably lower molecular weight structures have been found. It has, on the other hand, become quite clear that the antigen-binding region of B- and T-cell receptors shows idiotypic similarity and it is, therefore, likely that this part of the receptor molecule of both lymphocyte classes is similar if not identical

Shared idiotypic determinants on B and T lymphocytes reactive against the same antigenic determinants. II. Determination of frequency and characteristics of idiotypic T and B lymphocytes in normal rats using direct visualization

Anti-idiotypic antibodies made against the antigen-binding receptors of T lymphocytes for a given antigen (Ag-B locus antigens in rats) can be shown to react with IgG antibodies of the same antigen-binding reactivity. Using such anti-idiotypic antibodies, normal Lewis T lymphocytes of B and T type can be visualized by the use of anti-(Lewis-anti-DA) antibodies. Visualization was made possible by the use of direct fluorescent antibody tests or by autoradiography. Using the first technique and naked eye observations 6.2% of normal Lewis T lymphocytes expressed idiotypic markers signifying anti-DA reactivity, whereas anti-DA-reactive B lymphocytes as measured by this approach was in the order of 1.1%. Autoradiography was purified normal Lewis T lymphocytes gave similar figures. When comparing the intensity of fluorescence at the single cell level using quantitative cytofluorometry anti-idiotypic antibodies reactive with T lymphocytes gave a similar degree of intensity as was obtained using anti-Ig antibodies against B lymphocytes.

Shared idiotypic determinants on B and T lymphocytes reactive against the same antigenic determinants. III. Physical fractionation of specific immunocompetent T lymphocytes by affinity chromatography using anti-idiotypic antibodies

Anti-idiotypic antibodies made against antigen-binding receptors on T lymphocytes with specificity for certain Ag-B locus antigens selectively react with T lymphocytes with potential immune reactivity against the very same Ag-B antigens. This was shown by affinity chromatography of normal Lewis T lymphocytes on anti-Ig columns after contact with the relevant anti-idiotypic antiserum. Here, it could be shown that incubation of the cells with an anti-(Lewis-anti-BN) antiserum caused subsequent selective retention of potential graft-vs.-host (GvH)-reactive cells against BN on the anti-Ig column, whereas Lewis T cells with reactivity against DA or August (Au) (carrying distinct Ag-B antigens in comparison to BN) passed through. The retained cells could be eluted and shown to display highly increased reactivity against BN with virtually no reactivity left against DA or Au antigens. Analogous results were obtained using an anti-(Lewis-anti-DA) antiserum. The anti-idiotypic antibodies can be used in fluorescent antibody tests to directly visualize the idiotype-positive cells. Using the separation design described above we analyzed selectively enriched or deleted T lymphocytes for presence of idiotypic cells as well as specific GvH reactivity. A highly significant positive correlation was found between percentage of a given idiotype in a population of T cells and the relevant GvH potential of the same T cells that can be visualized are indeed the very same T cells that express immune reactivity against the expected antigens. The present data would thus directly demonstrate the existence of a largely nonoverlapping population of immunocompetent T cells capable of reacting against the various Ag-B locus antigens in the rat. Highly purified, functionally intact immunocompetent T lymphocytes with restricted immune reactivity can thus be produced from normal lymphocyte populations for further analysis.

Induction of T and B cell immunity by anti-idiotypic antibody

A small dose of the IgG1 fraction of anti-idiotypic antibody (aId1) raised in guinea pigs against a strain A/J antibody specific for streptococcal Group A carbohydrate sensitizes A/J mice against Group A streptococci. This is opposed to the previously established suppressive function of anti-idiotypic antibody of the IgG2 class (aId2). Correspondingly, aId1 but not aId2 is eliminated from the circulation in the way typical of an immunogenic molecule. However, the stimulatory component in the IgG1 fraction is not necessarily itself IgG1 antibody. Sensitization occurs in both B and helper T lymphocytes and is specific for Group A streptococci. In the B cell compartment sensitization is restricted to precursor cells expressing the idiotype. The concomitant activation of T helper cells therefore suggests that these cells make use of receptors with a similar or identical idiotype. Efficient sensitization by aId1 of both T and B cells is also demonstrated in strain C57L/J mice which upon immunization with Group A streptococci express a partially cross-reacting idiotype as a minor component. When such animals were primed with aId1, essentially all of the anti-carbohydrate antibody carried the partially cross-reacting idiotype.

Spontaneous release of T cell receptors for alloantigens. III. The effects of anti-T cell receptor antiserum, of alloantiserum and of trypsin on T cell receptor release

Spleen and lymph node T lymphocytes cultivated in vitro spontaneously released receptors for alloantigens. Among the various specificities, those receptors fitting certain alloantigens could be absorbed by formolized cells or proper genotype without influencing receptors for other alloantigens. Shedding of T cell receptors could be inhibited for 8 h by treating cells with antisera directed against T cell receptors (anti-RS antisera). Inhibition experiments indicated that resynthesis of T cell receptors appears to be complete by 8 h. Experiments on prevention of receptor shedding revealed highly specific and presumably cytotoxic elimination of T cells with receptors for given alloantigens. Treatment of cells with alloantiserum obtained by skin graft rejection failed to inhibit spontaneous release of T cell receptors, whereas treatment of lymphocytes with trypsin resulted in an 8-h delay of receptor shedding similar to that after treatment of cells with anti-RS antisera. This inhibition was, however, nonspecific.

Inhibition of mixed leukocyte culture by anti-idiotypic antibodies

(CBA x C57BL/6)F1 antisera prepared by injecting F1 mice with CBA T lymphocytes or CBA anti-C57BL/6 alloantibodies were tested for their ability to inhibit the mixed leukocyte culture (MLC) response. Presence of antiserum throughout the culture period in the absence of complement did not have any effect on the MLC response. Treatment of CBA responder cells with F1 antiserum and complement prior to the culture specifically inhibited the MLC response. Specificity of the suppression was ascertained; absorption of the F1 sera with F1 or C57BL/6 spleen cells did not remove the suppressive factor, whereas absorption with CBA spleen cells did so. F1 antiserum treatment left intact the response to third party alloantigens (DBA/2). Immunabsorbent columns with alloantibody of corresponding specificity removed the suppressive factor from anti-T cell sera as well as from antisera to alloantibody. The data suggest that the circulating alloantibody population contains molecules which share idiotypic determinants with surface receptors on T cells recognizing the same alloantigens.

Idiotype positive T cells visualized by autoradiography and electron microscopy

Anti-idiotypic antibodies were prepared in (CBA X C57BL/6)F1 hybrid mice by immunization either with CBA anti-C57BL/6 alloantiserum or with purified CBA thymus-processed lymphoid cells (T cells) Iodinated anti-mouse Ig or triple sandwich ferritin-labeling techniques served to visualize the reaction between idiotype and anti-idiotype. From 5 to 10% of purified CBA T cells appeared to carry receptors for C57BL/6 antigens. Heavily labeled cells had the morphology of small lymphocytes.

Shared idiotypic determinants on B and T lymphocytes reactive against the same antigenic determinants. I. Demonstration of similar or identical idiotypes on IgG molecules and T-cell receptors with specificity for the same alloantigens

Antigen-binding receptors on T lymphocytes and IgG antibodies with the same antigen-binding specificity as the T-cell receptors display shared or identical idiotypes. This was shown using a system where adult F1 hybrid rats between two inbred strains were inoculated with T lymphocytes from one parental strain. Such F1 hybrid rats produce antibodies directed against idiotypic determinants present on IgG alloantibodies, produced in the T donor genotype strain and with specificity for the alloantigens of the other parental strain. The idiotypic nature of the F1 antialloantibody serum against the parental alloantibodies was demonstrated both by indirect hemagglutination tests or by gel diffusion using alloantisera with different specificity as targets. Furthermore, the F1 anti-T-lymphocyte sera could be shown to contain antibodies against idiotypic parental T lymphocytes as well. This was shown by the capacity of the antisera, in the presence of complement, to wipe out the relevant parental T-cell reactivity against the other parental strain (as measured in MLC or GVH) whilst leaving the T-lymphocyte reactivity against a third, unrelated allogeneic strain intact. These findings demonstrate that F1 hybrid rats inoculated with parental T lymphocytes make anti-idiotypic antibodies directed against both the T cell receptors and IgG alloantibodies of that parental strain with specificity for alloantigens of the other parental strain. In order to prove identity between the anti-idiotypic antibodies against the B and T-cell antigen-binding molecules the following experiments were carried out; highly purified IgG from relevant alloantibody-containing serum in immunosorbent from could be shown to selectively remove both anti-idiotypic activities from the F1 antiserum. Further more, parental normal T lymphocytes could be shown capable of removing from the anti-idiotypic antisera all those antibodies that would cause agglutination of the relevant alloantibody-coated erythrocytes in the indirect agglutination assay. We would thus conclude that T and B lymphocytes reactive against a given antigenic determinant use receptors with antigen-binding areas coded for by the same variable gene subset(s).

Evidence for a B-cell -like helper function in mixed lymphocyte culture between immunocompetent thymus cells

The immunocompetent subpopulation by mouse thymus cell (TH-2) was isolated by buoyant density centrifugation and by hydrocortisone pretreatment. TH-2 cells undergo a proliferative one-way or two-way mixed lymphocyte culture (MLC) response only when cultured with allogeneic or congenic peripheral lymphoid cells. However, mixtures of allogeneic TH-2 cells alone do not proliferate in either one-way or two-way MLC reactions. Such MLC mixtures are proliferative only if mitomycin-blocked peripheral lymphoid cells are also present in the mixture. The peripheral helper cell has been found to be of low net density, non-adherent, insensitive to anti-thy-1 serum cytotoxicity, but sensitive to the cytotoxic effets of anti-immunoglobulin serume plus complement. The helper effect does not depend on proliferation nor does it appear to involve demonstrable soluble mediators. The nature of failure of MLC between TH-2 subpopulations appears to be dependent on the exppression of some product of the K, I regions of the H-2 locus. Possible mechanisms by which a B-cell-like helper cell triggers TH-2 proliferation are discussed terms of the present knowledge of specific alloantigen receptor on T and B cells, and the immunoglobulin Fc region receptors on T cells.