Generation of human peripheral blood stable E-rosette-forming T cells by interleukin 1

There is more than one interleukin 1

In 1972, Gery and co-workers(1) detected a factor that promotes murine thymocyte proliferation in culture supernatants of human peripheral blood adherent leukocytes. This factor is active across species lines, does not support the growth of interleukin 2 (IL-2)-dependent lymphocyte lines, is produced by monocytic rather than lymphocytic leukocytes, and has subsequently been termed interleukin 1 (IL- 1)(2). More recently, it has become evident that IL-1 activities can be produced by virtually every nucleated cell type and, in addition, IL-1 has been reported to have stimulatory effects on the growth and differentiation of numerous cell types. In this review, Joost Oppenheim and his colleagues discuss the biochemical characteristics, gene cloning, cell sources, biological properties and actions of IL-1, and give reasons why this pleitotropic, nonspecific hormone-like cytokine is of considerable concern to immunologists.

Functional interactions of human and murine lymphoid cells. I. Analysis of primary and secondary responses

In this study human T-cell responses against murine alloantigens were analyzed. The results show that optimal primary responses are obtained from peripheral blood mononuclear cells only when murine splenic adherent cells (SAC) were used as antigen. Further analysis revealed that human T cells were able to respond directly to murine cells without the need for antigen reprocessing; however, human interleukin 1 (IL-1) was required for optimal stimulation. In contrast, secondary proliferative responses to murine cellular antigens could be induced from primed T cells even in the absence of SAC and/or IL-1. These proliferative responses, and in addition, cytotoxic T-cell responses, were specific for the priming antigen. Long-term human T-cell lines specific for murine alloantigens were found to replace the need for murine T cells in antigen-specific murine B-cell responses to sheep red blood cells. The mechanism of help delivered by the human T cells appeared to be by the release of nonspecific helper-T-cell factors. The evidence presented for this is the inability of these cells to stimulate cells from mice that express the X chromosome B-cell defect xid.

Induction of T-cell proliferation and enhancement of NK activity by supernatants from Con A-stimulated human peripheral blood mononuclear cells: a new lymphokine

Supernatants from human peripheral blood mononuclear cells activated by Con A contain a factor(s) that stimulates blastogenic activity of normal human peripheral blood mononuclear cells. This Con A supernatant (CAS) contains stimulatory activity for E-rosette positive lymphocytes (T cells) and requires adherent cells for stimulation of T-cell proliferation. CAS does not contain detectable amounts of IL-2 as determined by its inability to support CTLL cell growth. Nor does it contain IL-1 or interferon. Examination of functional activity of lymphocytes stimulated for 3 days by CAS revealed that NK activity is augmented. This supernate does not appear to have any direct effect on B-cell function, although it induces suppression of polyclonal PWM stimulation of immunoglobulins. Thus, CAS appears to contain a new cytokine with immunomodulating potential.

Modulation of E-receptor expression on activated T lymphocytes

Our study indicated that the newly synthesized E-receptor, as measured with 125I-labeled monoclonal anti-E receptor antibody, on activated T lymphocytes were responsible for forming stable E-rosettes at 37 degrees C. Maximum induction of new E-receptor expression required at least 50 hr of culture with polyclonal T-cell activators, phytohemagglutinin, or phorbol myristate acetate. Polyclonal B-cell activator, lipopolysaccharide were not able to induce new E-receptor expression on the surface of T lymphocytes. The expression of the new E-receptor paralleled with the induction of Tac antigen expression. Interleukins 1 and 2 or Interferon-gamma were not able to initiate the induction of new E-receptors. However, a neuropeptide, endorphin exhibited biphasic effect on modulating the E-receptor expression, in the absence of polyclonal activators. As is the case with Tac antigen expression, induction of new E-receptor antigen may be a marker for activated T lymphocytes.

Quantification of soluble E-receptor in the serum of patients with various diseases and its accompanying in vitro immunosuppression in neoplasia

Evidence in the literature indicates that soluble E-receptor in the serum may modulate T-dependent immune response. We have developed a solid-phase radioimmunoassay to measure the soluble form of E-receptor from various sources. The assay detects solubilized antigens derived from E-receptor-bearing T lymphocytes and not with non-E-receptor-bearing B lymphocytes. The sensitivity limit of the assay is 0.1 ng/ml of purified E-receptor antigen. Using this assay, one can show that the T-cell mitogen phytohaemagglutinin stimulated both lymphocytes and cells of the resting human T-cell lymphoma cell line Jurkat to shed or secrete E-receptor into the culture medium. Results of the radioimmunoassay performed on human sera indicated that some patients with Hodgkin's disease, melanoma, sarcoma, or acute or chronic lymphocytic leukaemia had elevated levels of this antigen in their serum, whereas normal human sera registered lower levels. Elevated levels of the soluble form of E-receptor in the serum were suggestive of an in vitro assessment of their immunosuppressive activity. These results indicate that activation of T-cell immunity in vivo may result in humoral immunosuppression.

Antigen-nonspecific macrophage factors modulating the antibody response in vitro

Antibody response to an antigen involves the co-operation between three types of cells: macrophages, T cells and B cells. The cognate interactions between these cells play a fundamental role in the expression of a specific antibody response, but the last is modulated by antigen-nonspecific soluble factors produced either by macrophages or by T cells. Macrophages elaborate a spectrum of molecules modulating the function of lymphoid cells; among them are IL1 and prostaglandins of the E series, which are respectively enhancer and inhibitor of the antibody response in vitro. These molecules alter T cell and B cell activities through different mechanisms involving activation or inhibition of IL2 production, or alteration of cells surface antigens. However, the cellular events following the fixation of soluble factor on its receptors are not known.

Thermostable erythrocyte rosette-forming lymphocytes in hereditary hemochromatosis. I. Identification in peripheral blood

Although the immunoregulatory role of iron has been demonstrated in vitro, evidence for a similar role in vivo is controversial. We have, therefore, studied certain functional and structural properties of lymphocytes in hereditary (idiopathic) hemochromatosis (HH), a disease characterized by iron overload. T- and B-lymphocyte percentages in peripheral blood, serum immunoglobulin levels, and proliferative responses of peripheral blood mononuclear cells (PBM) to lectins were comparable with those of controls. Furthermore, HH serum with elevated iron concentrations did not significantly alter proliferative responses of normal lymphocytes to mitogens. In contrast to those normal findings was the identification of a subset of T lymphocytes in HH that formed rosettes with sheep red blood cells (SRC) at 37 degrees C in abnormally high numbers. Those lymphocytes that formed thermostable erythrocyte rosettes (TE-R) were not immature thymocytes, activated T lymphocytes, or an artifact of passive attachment of anti-SRC antibodies to the HH lymphocyte surface. Their presence did not correlate with a concentration of iron in the serum, the length of treatment, or the presence of the HLA antigen, A3. We conclude that the cellular expression of HH may be detected not as an immunological abnormality, but rather as an abnormality in receptor expression.

The role of E receptors in the attachment of thymocytes and T lymphocytes to human target cells

Human thymocytes, activated T lymphocytes, and neuraminidase-treated T cells possess the distinct capacity of forming conjugates with various human cell lines. The present study investigated whether E receptors, which endow human T cells with their capacity to bind sheep red blood cells (SRBC), are involved in this phenomenon. Monoclonal antibodies to human T cells and various simple sugars were studied for their effect on the attachment of human T cells to target cells. A-22, a monoclonal antibody to the E receptor, inhibited the formation of E rosettes by T cells and SRBC, and reacted in immunofluorescent-staining assays with the majority of human thymocytes and peripheral T cells, and with T-cell lines capable of forming E rosettes. When human thymus cells were treated with A-22 antibody they showed a reduction of up to 70% in their capacity to attach to the GM-4762 lymphoblast cell line and the K-562 myeloid line. Antibody treatment of the target cells, rather than of the thymus cells, had no effect on the formation of conjugates between thymus cells and target cells. Treatment of thymus cells with various monoclonal antibodies to T cells which do not react with the E receptor had no inhibitory effect. The exposure of human thymus cells to various simple sugars (D-mannose, D-fucose, galactose, and lactose) markedly reduced their capacity of forming conjugates with target cells. Exposure of neuraminidase-treated peripheral blood lymphocytes and of activated T cells to A-22 antibody inhibited their attachment to human target cells. The present study suggests that E receptors play a role in the attachment of human thymus cells and activated T cells to other human cells, and raises the possibility that these T-cell receptors may be involved in the process of recognition of "self" structures by human T lymphocytes.

Spontaneous production of interleukin-1 by human alveolar macrophages

A culture system was developed in which human peripheral blood mononuclear cells depleted of monocytes did not proliferate in response to the lectin mitogen phytohemagglutinin (PHA). The response of these cells to PHA was reconstituted with both autologous and heterologous alveolar macrophages. In addition, a partial restoration of PHA responsiveness was seen when the monocyte-depleted cells (MDC) were cultured with supernatants from purified alveolar macrophages, indicating the presence of Interleukin-1 (IL-1) activity in these supernatants. This is the first evidence suggesting the production of IL-1 by tissue macrophages from normal human subjects. In contrast to previous studies of IL-1 production by blood macrophages, it was found to be unnecessary to stimulate the alveolar macrophages in vitro to generate soluble factor activity. It was also found that alveolar macrophages produced active supernatants after only 2 hr in culture, whereas previous studies have indicated that blood monocytes must be cultured for at least 24 hr before active supernatants are produced. These differences may provide evidence that macrophages within the alveolar spaces are in an activated state.

Isolation of an interleukin-1-like factor from human joint effusions

Interleukin-1 (IL-1) is a macrophage derived mediator whose properties suggest that it could play a role in the pathology of arthritis. To test this hypothesis, joint fluids from patients with serveral different arthritides were tested. Small amounts of IL-1-like activity were recovered from many of these joint fluids after affinity chromatography over a column of rabbit anti-human IL-1. Positive fluids were obtained from patients with rheumatoid arthritis, psoriatic arthritis, Reiter's syndrome, osteoarthritis, gout, and traumatic arthritis. Upon gel filtration, the joint derived factor displayed a molecular weight distribution similar to that of IL-1 derived from human monocytes stimulated in vitro. These results suggest that IL-1 is present in joint effusions and, therefore, might contribute to joint destruction.

T-lymphocyte and B-lymphocyte dichotomy in anuran amphibians: I. T-lymphocyte proportions, distribution and ontogeny, as measured by E-rosetting, nylon wool adherence, postmetamorphic thymectomy, and non-specific esterase staining

We used sheep erythrocyte (SRBC) E-rosetting, nylon wool fractionation thymectomy and nonspecific esterase staining to assess T-lymphocyte characteristics in Rana pipiens during various developmental stages. T-lymphocytes appear in the spleens of premetamorphic tadpoles. We found significant levels of lymphocytes classifiable as T-cells in the peripheral blood of adults, but fewer numbers of T-cells in the thymus, jugular bodies, spleen, pronephros, mesonephros, liver and bone marrow. In addition, thymectomized Xenopus laevis showed a sharp decrease in T-cells as evidenced by E-rosetting, ANAE stain and nylon wool fractionation. The presence of T-lymphocytes in anuran amphibians and the existence of a receptor for SRBC on a population of these cells, suggest conservation of T-cells during evolution.

Accessory function of human tumor cell lines. I. Production of interleukin 1 by the human histiocytic lymphoma cell line U-937

The established human histiocytic lymphoma cell line U-937 spontaneously produced a factor with biological activity similar to that ascribed to interleukin 1 (IL 1). Actually, supernatants from U-937 cells promoted proliferation of thymocytes initiated by concanavalin A (Con A) and replaced the requirement of accessory cells for activation of highly purified circulating T lymphocytes induced by Con A. Phorbol myristate acetate (PMA) significantly increased the titers of the helper factor produced by U-937 cells as compared to that secreted by non-PMA-treated U-937 cells or PMA-stimulated P388D1 murine macrophage tumor cells. Generally U-937 cells did not secrete detectable IL 1 activity during the first 24-48 h of culture. However, after this initial period the level of IL 1 activity increased and reached a maximum at 5-6 days of culture. Finally, the helper factor released by U-937 cells had an apparent mol. wt. of 12000-15000 as determined by Sephadex G-100 chromatography and lacked interleukin 2 activity as shown by its inability to support growth of IL 2-addicted T cell lines. To our knowledge this is the first report of an established human cell line capable of producing IL 1.

Interleukin 1 is more than an interleukin

Gery and co-workers(1) first described lymphocyte activating factor (LAF) in 1972, as an activity produced by cultured human peripheral blood adherent leukocytes which was directly mitogenic for murine thymocytes but not for immunocompetent peripheral lymphocytes. Human LAF also synergistically augmented the mitogenic effects of the lectins ConA and PHA on murine thymocytes and splenic T lymphocytes(1). Since then LAF has been shown to promote lymphocyte differentiation and functions and even to affect a variety of nonlymphocytic larget cells. In view of the many biological activities attributed to this macrophage-derived factor, LAF was renamed 'interleukin 1' (IL 1) at the Second International Lymphokine Workshop at Ermatingen, Switzerland, in 1979(2). Partly as a consequence of the resultant controversy, this term has become widely known and will be used in this review, even though, as J. J. Oppenheim and Igal Gery show, IL 1 is more than a signal between leukocytes.