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Immunoregulatory molecules produced by macrophages in response to defined substances of microbial origin
THIRD
INTERNATIONAL
LYMPHOKINE
WORKSHOP
393
Aniigen-Specific and Nonspecific Regulation of Lymphokine Production. T. YOSHIDA, M. SUKO, AND S. COHEN, University of Connecticut Health Center, Farmington, Connecticut. Previously we have suggested a two-stage mechanism for antigen nonspecific cutaneous unresponsiveness in desensitized animals for delayed hypersensitivity (DTH). Initially, circulating excess lymphokines inhibit the cutaneous DTH reaction due to the loss of mediator gradient and also to diminished physiological functions of effector macrophages. Later, factors are secreted from macrophages to inhibit the production of lymphokines, thus antigen nonspecifically suppressing the expression of cutaneous DTH response. It was found that at least one of the suppressive agents was prostaglandin El. Recent analysis indicated another arachidonic acid metabolite (i.e., thromboxane B2) as playing a role in this phenomenon. We have also found that cutaneous unresponsiveness to specific antigen continues to be present much longer than antigen nonspecific unresponsiveness, which persists for 96 hr at most. Antigenspecific suppression of DTH was also found to be mediated by mononuclear cells in the desensitized animals. This represents an additional, third stage of desensitization. Thus, anergy induced by large doses of antigen is a consequence of multiple mechanisms, occurring both sequentially and concomitantly. These mechanisms serve to regulate both the production of lymphokines and the expression of lymphokine activity. Immunoregulatory Molecules Produced by Macrophages in Response to Defined Substances of Microbial Origin. ROBERT I. MISHELL, PATRICIA BORMAN, ELAINE KWAN, BARBARA B. MISHELL, MICHAEL R. GOLD, KENNETH H. GRABSTEIN, KARON SHANNON, AND WILLIAM R. USINGER. Department of Microbiology and Immunology, University of California, Berkeley, California 94720. We have been studying the production of immunoregulatory molecules by normal and oil-induced murine macrophages and by macrophage cell lines in response to several defined substances of microbial origin. The bacterial substances include insoluble and soluble peptidoglycans, lipopolysaccharides, lipoproteins, lipoteichoic acids, and polysaccharide exopolymers produced by two bacterial species. They induce interleukin 1 (IL-l), colony stimulating factors (CSF), interferons (IF), and tumor cytocidal substances that are biochemically similar to mediators designated in the literature as tumor necrotizing factors (TNF). The patterns of induction of various macrophage populations and cell lines in response to the various inducers differ, indicating that the bacterial substances activate different subpopulations of macrophages and, in some instances, cause cloned macrophage cell lines to execute different programs. Evidence will be presented showing that some macrophages possess specific surface receptors for peptidoglycans and that the expression of such receptors is regulated in part by T-cell lymphokines. The immunoregulatory effects of IL-l include protection of T helper (but not T suppressor cells) and of the formation of granulocyte-macrophage colonies from the suppressive effects of glucocorticosteroids. Moreover a new lymphokine produced by a hybrid T-cell line has similar activities. Studies to characterize this lymphokine biochemically and to determine its role (if any) in the protection mediated by purified IL-I are currently being pursued and data on this subject will also be presented. Although TNF has been reported to be specific for malignantly transformed cells, our data indicate that, in appropriate concentrations, it completely suppresses mitogenic responses of both T and B lymphocytes and that it is a frequent immunosuppressive macromolecule found in the supernates of adjuvant-activated macrophages. (Supported by NIH Grants AI 15482, CA 25056, and CA 09179.) Dissection of the Proliferative and Differentiative Signals Controlling Murine Cytotoxic T Lymphocyte Responses. K. PFIZENMAIER, C. HARDT, B. T. ROUSE, M. ROLLINGHOFF, P. SCHEURICH, AND H. WAGNER, Institut fur Med. Mikrobiologie der Universitat Mainz, Mainz, West Germany. The induction of antigen-specific primary cytotoxic T lymphocyte (CTL) responses in vitro requires interactions between several cell types and soluble mediators. One essential interaction occurs between the Lyt 2+ CTL precursor (CTL-P) with an antigen-activated Lyt l+ helper T cell. This interaction is considered to occur by way of soluble mediators such as interleukin 2 (IL-2), a lymphokine produced by antigen-triggered helper cells. II-2 binds to receptors on CTL-P which are expressed as a consequence of their preactivation by antigen or mitogen and initiates the clonal expansion of preactivated CTL-P. However, it is not clear whether or not 11-2 is also the stimulus that causes the CTL-P to differentiate into effector CTL. This uncertainty pertains since the widely used source of II-2 for the induction of CTL responses derives from concanavalin A (Con A)-stimulated spleen cell supernatants, a source also rich in other biologically active molecules. We were alerted to the prospect that 11-2 alone may not be
INTERNATIONAL
LYMPHOKINE
WORKSHOP
393
Aniigen-Specific and Nonspecific Regulation of Lymphokine Production. T. YOSHIDA, M. SUKO, AND S. COHEN, University of Connecticut Health Center, Farmington, Connecticut. Previously we have suggested a two-stage mechanism for antigen nonspecific cutaneous unresponsiveness in desensitized animals for delayed hypersensitivity (DTH). Initially, circulating excess lymphokines inhibit the cutaneous DTH reaction due to the loss of mediator gradient and also to diminished physiological functions of effector macrophages. Later, factors are secreted from macrophages to inhibit the production of lymphokines, thus antigen nonspecifically suppressing the expression of cutaneous DTH response. It was found that at least one of the suppressive agents was prostaglandin El. Recent analysis indicated another arachidonic acid metabolite (i.e., thromboxane B2) as playing a role in this phenomenon. We have also found that cutaneous unresponsiveness to specific antigen continues to be present much longer than antigen nonspecific unresponsiveness, which persists for 96 hr at most. Antigenspecific suppression of DTH was also found to be mediated by mononuclear cells in the desensitized animals. This represents an additional, third stage of desensitization. Thus, anergy induced by large doses of antigen is a consequence of multiple mechanisms, occurring both sequentially and concomitantly. These mechanisms serve to regulate both the production of lymphokines and the expression of lymphokine activity. Immunoregulatory Molecules Produced by Macrophages in Response to Defined Substances of Microbial Origin. ROBERT I. MISHELL, PATRICIA BORMAN, ELAINE KWAN, BARBARA B. MISHELL, MICHAEL R. GOLD, KENNETH H. GRABSTEIN, KARON SHANNON, AND WILLIAM R. USINGER. Department of Microbiology and Immunology, University of California, Berkeley, California 94720. We have been studying the production of immunoregulatory molecules by normal and oil-induced murine macrophages and by macrophage cell lines in response to several defined substances of microbial origin. The bacterial substances include insoluble and soluble peptidoglycans, lipopolysaccharides, lipoproteins, lipoteichoic acids, and polysaccharide exopolymers produced by two bacterial species. They induce interleukin 1 (IL-l), colony stimulating factors (CSF), interferons (IF), and tumor cytocidal substances that are biochemically similar to mediators designated in the literature as tumor necrotizing factors (TNF). The patterns of induction of various macrophage populations and cell lines in response to the various inducers differ, indicating that the bacterial substances activate different subpopulations of macrophages and, in some instances, cause cloned macrophage cell lines to execute different programs. Evidence will be presented showing that some macrophages possess specific surface receptors for peptidoglycans and that the expression of such receptors is regulated in part by T-cell lymphokines. The immunoregulatory effects of IL-l include protection of T helper (but not T suppressor cells) and of the formation of granulocyte-macrophage colonies from the suppressive effects of glucocorticosteroids. Moreover a new lymphokine produced by a hybrid T-cell line has similar activities. Studies to characterize this lymphokine biochemically and to determine its role (if any) in the protection mediated by purified IL-I are currently being pursued and data on this subject will also be presented. Although TNF has been reported to be specific for malignantly transformed cells, our data indicate that, in appropriate concentrations, it completely suppresses mitogenic responses of both T and B lymphocytes and that it is a frequent immunosuppressive macromolecule found in the supernates of adjuvant-activated macrophages. (Supported by NIH Grants AI 15482, CA 25056, and CA 09179.) Dissection of the Proliferative and Differentiative Signals Controlling Murine Cytotoxic T Lymphocyte Responses. K. PFIZENMAIER, C. HARDT, B. T. ROUSE, M. ROLLINGHOFF, P. SCHEURICH, AND H. WAGNER, Institut fur Med. Mikrobiologie der Universitat Mainz, Mainz, West Germany. The induction of antigen-specific primary cytotoxic T lymphocyte (CTL) responses in vitro requires interactions between several cell types and soluble mediators. One essential interaction occurs between the Lyt 2+ CTL precursor (CTL-P) with an antigen-activated Lyt l+ helper T cell. This interaction is considered to occur by way of soluble mediators such as interleukin 2 (IL-2), a lymphokine produced by antigen-triggered helper cells. II-2 binds to receptors on CTL-P which are expressed as a consequence of their preactivation by antigen or mitogen and initiates the clonal expansion of preactivated CTL-P. However, it is not clear whether or not 11-2 is also the stimulus that causes the CTL-P to differentiate into effector CTL. This uncertainty pertains since the widely used source of II-2 for the induction of CTL responses derives from concanavalin A (Con A)-stimulated spleen cell supernatants, a source also rich in other biologically active molecules. We were alerted to the prospect that 11-2 alone may not be