Idiotype positive T cells visualized by autoradiography and electron microscopy

A tribute to Jean Lindenmann, co-discoverer of interferon (1924-2015)

In 1957, the discovery of interferon was reported by Isaacs and Lindenmann in the prestigious journal Proceedings of the Royal Society (1957) [1,2]. This discovery was definitely one of the scientific landmarks in cell biology of the past century. It was the result of an initially unplanned and amazingly creative collaboration with Alick Isaacs that lasted from July 1956 to June 1957 at Mill Hill in London. Jean Lindenmann died in Zürich on January 15, 2015, at the age of 90, after having survived Alick Isaacs (1921-1967) for almost five decades.

Studies on chemically induced rat tumors. II. Partial protection against syngeneic lethal tumors by cloned syngeneic cytotoxic T lymphocytes

In the present article we describe studies on a chemically induced sarcoma in DA rats. This tumor expresses a unique antigen which can be demonstrated by both syngeneic antibodies and cytotoxic T cells. We have established cytotoxic T-cell lines (CTLs) specific for the tumor and with high efficient killing capacity in vitro. When testing for the ability of such CTLs to inhibit tumor out-growth in vivo, we found that they had to be inoculated together with the tumor and in the presence of T-cell growth factor to provide any significant degree of protection. We thus believe not only that there is a requirement for addition of CTL-stimulating lymphokines in vivo, but also that the CTLs fail to move from one site in vivo to attack relevant tumor cells at another site. No evidence was obtained that the CTLs gradually could acquire such migratory ability in vivo.

Mechanism of immune transfer by RNA extracts. Immune RNA induces the synthesis of idiotype-bearing antigen receptors in noncommitted cells

Immune RNA (I-RNA) was extracted form lymphoid organs of BALB/c mice immunized with AKR lymphoid cells. Incubation of normal BALB/c spleen cells with this I-RNA (but not with normal RNA) resulted in leukocyte migration inhibition reactions (LMIR) against AKR extracts but not against purified protein derivative or BALB/c sarcoma extracts. This transfer was abolished by pretreating I-RNA with RNAse but not with pronase. The active fraction of I-RNA was retained by and could be eluted from Poly-U Sepharose columns. Normal cells pretreated with I-RNA also reacted in the presence of an anti-idiotypic anti-serum of anti-(BALB/c anti-AKR) specificity. Pretreatment of cells with anti-idiotypic serum plus complement did not inhibit the subsequent transfer of LMIR with I-RNA. Idiotypic receptors were expressed on I-RNA treated cells less than one hour after I-RNA treatment. Using an I-RNA of double specificity, the results suggested that I-RNA entered into and acted on the cells through a nonspecific mechanism. Finally, I-RNA could induce BALB/c anti-AKR idiotypic markers in C57Bl/6 cells, genetically committed for different idiotypes, while RNA extracted from C57Bl/6 immune cells could not induce in BALB/c cells their own genetically acquired idiotypes. This series of data would prove that I-RNA acting as a mRNA is able to induce in normal noncommitted cells the de novo synthesis of antigen receptors similar or identical to those present in the surface of in vivo immunized lymphoid cells of the same strain.

Enrichment of hapten-specific helper T cells using anti-immunoglobulin combining site antibodies

Spleen T cells from phosphorylcholine (PC)-primed BALB/c mice were indirectly stained with affinity column-purified heterologous rabbit anti-TEPC 15 (T 15) antibodies. These antibodies were shown to be directed towards antigenic determinants in or near the combining site of T 15 in that their interaction with the myeloma protein was more than 95% inhibitable by PC. The stained cells were sorted into "bright" and "dull" fractions using a fluorescence-activated cell sorter. Sorted populations were then assessed for enrichment and depletion of PC-specific helper activity using an in vivo adoptive transfer assay. The results indicate that the staining procedure employed enabled the specific enrichment of PC helper T cells and therefore suggest that these T cells bear combining site structures similar to that of the myeloma protein T 15.

Recognition of antigens by T lymphocytes

The present review briefly summarizes our knowledge of antigen-specific B and T lymphocyte receptors. Antigen-specific receptors on mammalian B lymphocytes are mainly monomeric IgM and IgD consisting of conventional immunoglobulin heavy and light chains. The nature of the T lymphocyte receptor which can specifically recognize antigens is not yet fully defined. However, it seems that conventional light chains do not participate in the build up of this receptor, and that the receptor is made up of heavy chains of a new immunoglobulin class which has to be further characterized and which we call Tau-chain. The variable region of the T lymphocyte receptors share idiotypic determinants with the corresponding B lymphocyte receptors. The possible linkage between the T cell idiotypes present on the Tau-chains and molecules which are under the control of genes of the Major Histocompatibility Complex of the species are discussed. In the last part of the review two methods for the induction of specific transplantation tolerance in adult animals are described. These methods are based on the concept that T lymphocytes reactive against alloantigens bear idiotypic determinants against which a specific auto-immune response can be initiated.

Induction of specific immune unresponsiveness with purified mixed leukocyte culture-activated T lymphoblasts as autoimmunogen. II. An analysis of the effects measured at the cellular and serological levels

T lymphoblasts specific for foreign histocompatibility antigens and purified via mixed leukocyte culture (MLC) and 1 g velocity sedimentation procedures can be used as autoimmunogen to produce specific immunological unresponsiveness in adult animals. This unresponsiveness is positively correlated to the production of autoanti-idiotypic antibodies in the blast immunized animals and no evidence of coexisting alloimmunity was found. We consider this autoanti-idiotypic immunity to be the specific inducing agent of the immune tolerance. The blast immunization procedure will lead to selective reduction in T-cell reactivity against the relevant alloantigens as measured by MLC, cell-mediated lympholysis, or graft-versus-host assays. However, in individual animals, dichtomy in suppression between two T-cell assays could sometimes be observed indicating elimination of only a select group of idiotypic functionally distinct population of T cells in these blast-immunized animals. Attempts to abrogate already immune animals by the autoblast procedure were successful, in part suggesting the use of the present procedure when trying to induce in accelerated reversion of such immunity.

Lymphocyte surface immunoglobulins: detection, characterization, and occurrence in disease of the lymphoid system

Surface immunoglobulins (Igs) of lymphocytes are of considerable interest because these molecules probably function as receptors for antigen, and knowledge of their molecular properties should provide information on the mechanisms of immune differentiation. The density and types of surface Ig on a cell provide markers useful in indicating the class of a lymphocyte and its stage of maturity. Moreover, knowledge of the specificities of the surface Ig of neoplastic lymphocytes might suggest the nature of agents involved in the generation of the disease. Two broad classes of lymphocytes, bone marrow-derived lymphocytes (B cells) active in antibody secretion, and thymus-derived lymphocytes (T cells) which mediate cellular immune reactions, and their subpopulations must be considered with reference to the nature, origin, and function of their surface immunoglobulin. This article analyzes direct and indirect methods for the demonstration of surface Igs and describes certain physicochemical properties of isolated surface Ig molecules. Roles of these surface molecules in recognition of antigen, initiation of all differentiation, and cooperation among lymphocytes and accessory cells are discussed.

Specific elimination of cytotoxic effector cells. I. Adsorptive behavior of effectors and their precursors and spleen cell monolayers

Monolayers formed of normal mouse spleen cells attached to polystyrene coated with poly-L-lysine were tested for their ability to bind specifically antigen-reactive cells in normal or primed mouse spleen. 88 to greater than 98% of the activity of cytotoxic populations was removed by a single adsorption. However, normal spleen cells or spleen cells previously primed in vitro could not be depleted of their capacity to be sensitized, even when adsorption effectively removed all residual cytotoxic activity from the same previously primed population. In fact, exposure to an immunoadsorbent augmented the ultimate cytotoxicity generated in a nonspecific fashion. This augmentation was especially dramatic in the case of a previously primed population and may have reflected the removal of a nonspecific suppressor. If antigen-reactive precursors cannot be removed efficiently by adsorption, other approaches to the generation of tolerant lymphoid populations, such as specific suppression of precursor differentiation must be sought.

The immune response to oxidized ferredoxin. I. Specificity of the response to the amino terminal determinant

Several synthetic peptide analogues of the amino terminal antigenic determinant (ala-tyr-lysile-ala-asp-ser) of oxidized ferredoxin (O-Fd) were tested for their ability to inhibit the complement fixation reaction between O-Fd and homologous rabbit antiserum, and to inhibit the migration of spleen cells from guinea-pigs immunized to O-Fd or to a conjugate of the amino terminal heptapeptide (N7) and bovine serum albumin (N7-BSA). The results of the migration inhibition assay suggest that the tetrapeptide and longer peptides of the native sequence were all recognized and stimulated the production of migration inhibition factor. Peptides modified at the aspartic residue were partially active while the serine modified peptide was not. Modification at the amino end of the heptapeptide had no effect on migration inhibition. As specificity controls, it was shown that the N7-BSA conjugate inhibited migration in O-Fd immunized animals, while O-Fd inhibited migration in N7-BSA immunized animals. The hexa-, hepta-, aspartic-deleted and serine-modified peptides were able to inhibit the complement fixation reaction with O-Fd and specific rabbit antiserum. Inhibition found with the serine-modified peptide and the lack of inhibition with the amino-modified peptide or the di-, tri-, tetra- and pentapeptides indicates the determinant recognized by the rabbit antibodies is either larger or is located nearer the middle of the heptapeptide than the determinant which induced the production of MIF.

Evolutionary and developmental aspects of T-cell recognition

Studies relating to the nature of the antigen-specific T-cell receptor are reviewed in the light of present knowledge of phylogenetic and ontogenetic development. It is suggested that this evidence supports the concept that immunoglobulin (Ig) is the T-cell receptor, and that the following conclusions may be tentatively drawn.

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