Fine antigenic specificity and genetic restriction of lysozyme-specific suppressor T cell factor produced by radiation leukemia virus-transformed suppressor T cells

Antigen specific down regulation of murine collagen induced arthritis: T suppressor cell circuits in arthritis immunotherapy

The present article summarizes a series of experiments which have been performed to describe an antigen-specific suppressor cell pathway for the suppression of the erythema and edema associated with an animal model of rheumatoid arthritis, collagen induced arthritis (CIA). Initial studies utilized the adoptive transfer of splenic cell subpopulations to establish the presence of suppressor cells in lymphoid tissues of mice which were suppressed for collagen induced arthritis. Subsequent studies generated T cell hybridomas from animals which had been suppressed for collagen induced arthritis by a single injection of a large quantity of Type II collagen. The T cell hybridomas varied in their self surface expression of glycoproteins which are associated with genetically determined functions. The suppressor T cells generated, described a regulatory suppressor cell pathway comprised of at least afferent suppressor T cells and effector suppressor T cells. The cells act in an antigen-specific fashion with regard to the suppression of collagen induced arthritis but appear to be polymorphic in their recognition of the interstitial collagens. The studies, taken together, indicate that the use of antigen specific T suppressor cells in the form of T cell hybridomas can be utilized as a form of immunotherapy in experimental arthritis.

Computerized data analysis in cellular immunology. Enhancement and suppression of immune responses

Data obtained from assays for the evaluation of helper or suppressor activity are analyzed by statistical techniques that increase the accuracy and amount of information. The analysis is performed by a set of simple and ready to use computer programs which do not require statistical expertise and are available on request.

T cell receptor-homologous mRNA from a suppressor T cell clone directs the synthesis of antigen-specific suppressive products

The LH8-105 T cell clone, obtained by radiation leukemia virus-induced transformation of hen egg-white lysozyme (HEL)-specific mouse suppressor T lymphocytes, constitutively releases in the culture supernatant products able to induce specific suppression of the immune response to HEL. LH8-105 cells rearrange and express the genes encoding the alpha and beta chains of the antigen-specific T cell receptor and display membrane T cell receptor structures. LH8-105 mRNA specific for the alpha and beta chains of the T cell receptor were positively selected on filter-bound cDNA encoding constant regions of alpha and beta chains, eluted and translated into Xenopus laevis oocytes. Translation products were then tested in vivo for specific suppression of the anti-HEL antibody response. LH8-105 culture supernatant and translation products of LH8-105 poly(A)+ RNA or a mixture of alpha and beta chain-homologous mRNA induce HEL-specific suppression whereas translation products of LH8-105 mRNA eluted from irrelevant DNA or unrecombined mRNA eluted from alpha and beta cDNA do not exert suppressive activity. These results indicate that alpha and beta chain-homologous mRNA expressed in LH8-105 cells direct the synthesis of molecules able to induce HEL-specific suppression.

Immunoregulation of lysozyme-specific suppression. III. Epitope-specific amplification of immunosuppression induced by monoclonal suppressor-T-cell products

The hen egg-white lysozyme (HEL)-specific suppression induced by soluble molecules produced by a monoclonal T-cell lymphoma line (LH8-105) obtained from HEL-specific suppressor T lymphocytes has been examined. Injection of I-J+ molecules from LH8-105 cell culture supernatant (TsFa) in HEL-primed mice during the afferent phase of the response induced Lyt-2+ second order suppressor T (Ts) cells which, upon transfer into HEL-CFA-primed syngeneic recipients, inhibit the delayed-type hypersensitivity (DTH) response to HEL. Transfer of spleen cells from TsFa-injected mice primed with HEL or human lysozyme suppresses the DTH response to HEL in recipient mice whereas this response is not affected by cell transfer from ring-necked pheasant egg-white lysozyme (REL)-primed and TsFa-injected mice, indicating that induction of second order Ts by TsFa is specific for a lysozyme epitope including phenylalanine at position 3. Fine antigenic specificity of second order Ts-cell induction is confirmed by similar results obtained upon injection of TsFa in mice primed with HEL N-terminal synthetic peptide or with an analog in which, as in REL, phenylalanine has been substituted by tyrosine at position 3. The same fine antigenic specificity observed in the induction of second order Ts cells is also present in the expression of TsFe suppressive activity. The similar antigenic specificity of Tsa and Tse suggests that Tse cells could result from amplification of the Tsa cell population or these two cell subsets could reflect different maturation stages of the same cell type rather than distinct T-cell populations activated in cascade.

Functional and biochemical characterization of a secreted I-J(+) suppressor factor that binds to immunoglobulin

A secreted product of a T cell leukemic cell line, LH-8, was examined for its biochemical and biological properties. The factor that we have termed Immunoglobulin-Binding T cell Suppressor Factor (IgB-TsF) was shown to be suppressive for the in vitro and in vivo humoral response to a variety (but not all) antigens tested. The cell surface phenotype of the LH-8.1 subclone was M.Ig(-), Thy-1(+), L3T4(-), Lyt-2(+), FcR(-), MAC-1(-), and H-2b(+). In addition, both the cell surface and secreted factor, IgB-TsF, of LH-8.1 expressed determinants that were recognized by anti-I-Jb mAbs but not by an anti-I-Jd monoclonal. The same factor also retained an affinity for the Fc portion of approximately 30% of randomly selected, purified mAbs. This binding could be abolished if the Fab or F(ab')2 fragments of these mAb were used, but was found to be unrelated to isotype of the respective mAbs. Using subclones that expressed quantitative differences in their ability to exert suppression as sources of biosynthetically labeled IgB-TsF, we have shown the suppressor activity correlated with a single, 28 kD protein. Furthermore, comparisons of these same subclones that differ in their suppressor activity, do not show any direct correlation of this biological activity with the expression of the previously described T cell receptor genes. It also suggests that at least some suppressor cell subsets may use the same or related family of T cell receptor genes for their recognitive stage of activation as helper and cytotoxic T cell subsets, but not for their effector stage of immunologic suppression.

Rearrangement and expression of the alpha- and beta-chain genes of the T-cell antigen receptor in functional murine suppressor T-cell clones

Two different antigen-specific radiation leukemia virus (RadLV)-transformed suppressor T-cell clones, LH8.105 and LA41, exhibiting anti-lysozyme and anti-acetylcholine-receptor suppressor activity, respectively, have been examined for rearrangement and expression of genes encoding the alpha and beta chains of the T-cell receptor for antigen. LH8.105 cells express the T-cell-receptor polypeptides, as shown by specific immunoprecipitation. In both cell lines, potentially functional transcripts of alpha- and beta-chain genes are detected by RNA blot analysis. These suppressor T-cell clones exhibit alpha-chain gene rearrangements, deletion of both alleles of the constant-region (C) gene segment C beta 1, and rearrangement of the two alleles of C beta 2 when analyzed by Southern blot hybridization. Restriction analysis suggests that the DNA rearrangement is beyond the second joining-region (J) minigene of the J beta 2 cluster. These results establish that at least some mouse suppressor T-cell clones, like helper and cytotoxic T lymphocytes, rearrange and transcribe the genes coding for the alpha and beta chains of the antigen-specific T-cell receptor.

Disulfide-linked surface molecules of monoclonal antigen-specific suppressor T cells: evidence for T cell receptor structures

By two-dimensional polyacrylamide gel electrophoresis analysis under nonreducing/reducing conditions, five proteins with interchain disulfide bridges are revealed on the surface of the suppressor T cell lymphoma line LH8-105 obtained by radiation leukemia virus-induced transformation of hen egg-white lysozyme-specific suppressor T lymphocytes. Two disulfide-linked surface proteins expressed by LH8-105 cells have been positively identified by immunoprecipitation with specific antisera. The major labeled membrane protein of LH8-105 cells is the murine leukemia virus env glycoprotein gp70. The second disulfide-linked molecule identified on LH8-105 cells has a molecular mass of 84 kDa under nonreducing conditions and 42 kDa after reduction, and is immunoprecipitated by an antiserum which recognizes the T cell receptor for antigen. A disulfide-linked molecule of a similar molecular mass is also immunoprecipitated from surface-labeled LH8-105 cells by a rabbit antiserum directed against a synthetic peptide predicted from the nucleotide sequence of a cDNA clone encoding the beta chain constant region of a helper T cell hybridoma. Therefore, a dimeric structure comparable to the T cell receptor expressed by cytotoxic and helper T cells is present on the cell surface of these monoclonal antigen-specific suppressor T cells.

Immunosuppression by cell-free translation products from monoclonal antigen-specific suppressor T cell mRNA

Polypeptides synthesized in a rabbit reticulocyte lysate system directed by mRNA from the T cell line LH8-105, obtained by radiation leukemia virus-induced transformation of hen egg-white lysozyme (HEL)-specific suppressor T lymphocytes, are able, when injected into mice, to specifically suppress the antibody response and delayed-type hypersensitivity to HEL. The suppressive activity exerted by in vitro translated proteins appears to be independent from post-translational modifications. These in vitro translated polypeptides display fine antigenic specificity in immunosuppression and bind to HEL but not to the closely related ring-necked pheasant egg-white lysozyme immunosorbents. Suppressive molecules obtained by cell-free translation of LH8-105 mRNA or by culture supernatant of LH8-105 cells display, by gel filtration, a similar molecular mass of about 82-90 kDa.

Acetylcholine receptor-specific suppressive T-cell factor from a retrovirally transformed T-cell line

In both experimental and human myasthenia gravis an impairment in the immune regulation leads to an increased synthesis of antibodies against the nicotinic acetylcholine receptor (AcChoR). The present work reports the establishment of an AcChoR-specific suppressive T-cell line obtained by viral transformation of AcChoR-enriched murine T lymphocytes. Enriched T cells from Torpedo AcChoR-primed mice, prestimulated in vitro with antigen, were infected with radiation leukemia viruses and injected intravenously in congeneic recipient mice. Six months later lymphomas were observed in 20% of the injected mice and two of them, of donor origin, were established as permanent continuous cell lines in vitro. One of these lines, named LA41, expresses Thy-1.2, Lyt-2, and I-Jb surface markers. Culture supernatants of LA41 cells suppress the antigen-specific in vitro proliferation of Torpedo AcChoR-primed lymphocytes. This suppression is antigen-specific since the response induced by fetal calf AcChoR and by other antigens is not affected by addition of LA41 culture supernatant in the proliferative assay. LA41 culture supernatant injected in vivo at the time of antigen-priming suppresses also significantly the production of anti-AcChoR antibodies but not the synthesis of antibodies against other antigens--i.e., fetal calf AcChoR or alpha-bungarotoxin. These data show that LA41 cells constitutively produce Torpedo AcChoR-specific suppressor factor.

Immunoregulation of lysozyme-specific suppression. I. Induction and suppression of delayed-type hypersensitivity to hen egg-white lysozyme

Subcutaneous immunization with hen egg-white lysozyme (HEL) in complete Freund's adjuvant induces, both in antibody responder and nonresponder mice, a classical delayed-type hypersensitivity (DTH) reaction evaluated as footpad swelling. This response can be specifically transferred to naive recipients by Lyt-1+2- T cells and passive transfer is restricted by genes mapping in or to the left of the I-A region of the H-2 complex. Fine antigenic specificity analysis shows that HEL-primed T cells mediating DTH recognize ring-necked pheasant egg-white lysozyme, a lysozyme closely related to HEL, but fail to respond to human lysozyme, differing from HEL at 40% amino acid residues. Complete cross-reactivity between native and denaturated (reduced and carboxymethylated) HEL is exhibited by T cells involved in the DTH response. Subcutaneous injection of HEL coupled to spleen cells is also able to induce antigen-specific and genetically restricted DTH responses whereas the same cells administered by i.v. or i.p. route induce predominantly suppressor T cell activation. These suppressor T cells specifically inhibit the induction phase of DTH reactivity to HEL.

Immunoregulation of lysozyme-specific suppression. II. Hen egg-white lysozyme-specific monoclonal suppressor T cell factor suppresses the afferent phase of delayed-type hypersensitivity and induces second-order suppressor T cells

Culture supernatant from a monoclonal T cell lymphoma line (LH8-105) obtained by radiation leukemia virus-induced transformation of hen egg-white lysozyme (HEL)-specific suppressor T lymphocytes is able, when injected into mice, to specifically suppress the delayed-type hypersensitivity (DTH) reaction induced by HEL. The suppressor T cell factor (TsF) exhibits fine antigenic specificity since it suppresses the DTH response induced by HEL without affecting the DTH response induced by ring-necked pheasant egg-white lysozyme (REL), a lysozyme closely related to HEL. Conversely, LH8-105 TsF is able to suppress the DTH response induced by human lysozyme, distantly related to HEL but sharing a common epitope critical for induction of suppressive activity. The fine antigenic specificity of LH8-105 TsF for a restricted epitope on the HEL molecule is confirmed by binding to HEL but not to REL immunosorbents. This TsF also bears I-J determinants, as demonstrated by binding to monoclonal anti-I-J immunosorbents, and it suppresses the afferent but not the efferent phase of the DTH response to HEL. The afferent suppression is controlled by genes apparently mapping in the I-J subregion of the H-2 complex since I-J-incompatible mice are not suppressed by LH8-105 TsF injection. This inducer-type TsF induces second-order effector suppressor T cells only in HEL-primed mice indicating the primary role of antigen, in association with H-2 (I-J) products, in the afferent portion of this suppressive circuit.

Monoclonal suppressor T-cell factor displaying V H restriction and fine antigenic specificity

The production of stable T-cell clones is essential for the study of T-cell-derived, specific immunoregulatory products and of specific T-cell receptors. T-cell clones have been established by radiation leukaemia virus (RadLV)-induced transformation of suppressor T lymphocytes specific for hen egg white lysozyme (HEL). We report here that culture supernatant obtained from these T-cell clones can, when injected into mice, specifically suppress the anti-HEL antibody response. This monoclonal T-cell product suppresses the antibody response induced by HEL and human lysozyme, but not that induced by ring-necked pheasant egg white lysozyme (REL), thus displaying fine antigenic specificity probably restricted to an epitope involving phenylalanine at amino acid residue 3, present in the N-terminal region of HEL and shared by human lysozyme but absent in REL. The suppression induced by this monoclonal T-cell product is restricted by both H-2 and Igh-1 genes whereas anti-HEL antibodies bearing a predominant idiotype are induced in all mice strains tested, irrespective of their H-2 haplotype or Igh-1 allotype.

Monoclonal suppressor factor specific for lactate dehydrogenase B. I. Mechanism of interaction between the factor and its target cells

Hybridomas secreting a monoclonal T suppressor-effector factor (TseF) were produced by fusion of a lactate dehydrogenase B (LDHB)-specific long-term T suppressor-effector (Tse) cell line with the BW5147 thymoma. A short exposure (4 h) to TseF completely suppresses the antigen-specific and A-restricted proliferation of LDHB-primed Lyt-1+2- [possibly helper (Th)] cells. The action of TseF on Th cells, as that of the Tse cells themselves, is antigen-specific and A-restricted. The interaction of TseF with Th cells involves two binding events, of which one occurs via antigen bridge, and the other represents the recognition of a factor-derived Ak-like moiety by the anti-Ak receptor of Th cells. The Ak-like moiety of the TseF carries the determinants that serve as restriction elements for antigen recognition by Th cells, and additional determinants demonstrable by T cell-specific monoclonal "anti-Ak" antibodies, however, it lacks serologically detectable determinants of the B cell-derived A alpha A beta class II Mhc molecules.