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R M Blaese

Publications and source records attributed to R M Blaese.

At least 181 records · Page 10Linked to original sources
PubMed1979

Synergistic cytotoxicity. II. In vitro arming of monocytes and T cells by a heat labile fraction of human plasma.

In a previous paper we demonstrated that freshly obtained human plasma contain a heat labile nonantibody factor that induced human mononuclear cells to become nonspecifically cytotoxic toward xenogeneic but not allogeneic RBC targets. We now present evidence that this factor has a loose affinity for human monocytes and human T cells and can arm then to kill xenogeneic RBC targets. Furthermore, proteolytic enzymes markedly enhance this arming effect. This ability to be armed by a heat labile component found in fresh human plasma and the fact that proteolytic enzymes markedly enhance cytotoxicity clearly dissociate this model of nonspecific cytotoxicity for previously reported NK models.

Absorption↗
PubMed1979

Fc receptors for IgA on human B, and human non-B, non-T lymphocytes.

Recently, receptors for IgA were demonstrated on subpopulations of human T lymphocytes. In this report, TNP-modified ox erythrocytes coated with the IgA myeloma MOPC-315 were used to detect IgA receptor-bearing lymphocytes within the human non T cell lymphocyte population. A mean of 5.3% (range 2.9 to 12.4%) of E-rosette negative human lymphocytes bound IgA-coated indicator cells. Blocking studies with soluble IgA, IgG, and IgM demonstrated that the IgA receptors on the non-T cell populations were separate and distinct from the Fc-receptors for IgG and IgM. Fractionation of the non-T lymphocytes on anti-human (Fab)2 columns into sIg+ and sIg- populations or by rosetting with EAC to provide CRL+ and CRL- populations demonstrated that Fc-IgA receptors were present on a subpopulation of sIg+, CRL+ lymphocytes, and also on sIg- (non-T, non-B) lymphocytes.

Animals↗
PubMed1979

Tissue distribution of immunoglobulin-secreting cells in normal and IgA-deficient chickens.

A reverse hemolytic plaque assay was employed to enumerate lymphoid cells actively secreting either immunoglobulin (Ig)G, IgA, or IgM in the small intestine, lungs, and lymphoid organs of normal and IgA-deficient chickens. In normal birds, intestinal lamina propria lymphocytes were proportionately richest in cells secreting IgG and IgA whereas the bone marrow was richest in IgM-secreting cells. The highest ratio of IgA to IgG secreting cells was also found in the lamina propria lymphocytes of the intestine (0.9), followed by the IgA to IgG ratios in the intestinal epithelium (0.31), and the lungs (0.19). The IgA to IgG ratios in the bone marrow (0.08) and the spleen (0.02) were considerably lower. Thus, both the intestine and the lungs were relatively enriched in cells actively secreting IgA. These IgA-secreting cells are the likely source of the IgA found in such quantities in intestinal and respiratory secretions. The tissue distribution of Ig-secreting cells was also studied in two generations of birds with experimentally induced IgA deficiency. There was a striking diminution of IgA-secreting cells in all tissues, including the intestine and lungs, whereas cells secreting IgG and IgM were normal or increased. The lack of IgA-secreting cells in these birds represents the effects of donor suppressor T cells having specificity for IgA.

Agammaglobulinemia↗
PubMed1979

The mononuclear phagocyte system: role in expression of immunocompetence in neonatal and adult life.

The cells of the mononuclear phagocyte system are critical elements in host defense. They are essential to many specific immune processes in addition to their well-recognized role in nonspecific resistance. In this report we describe studies of the influence of the maturation of this system of cells on the capacity of the neonatal rat to generate specific immune responses. In addition, studies of human cord blood monocyte function are presented along with data demonstrating a previously unrecognized synergistic action between monocytes and a heat labile, nonantibody, serum factor which may play an important role in host defense. Finally, data are presented demonstrating that one of the recognition processes used by monocytes for cellular interaction is dependent upon a system of natural lectin-like receptors on the monocyte cell surface which recognize membrane-bound oligosaccharides on other cells.

Animals↗
PubMed1979

Spontaneous cytotoxicity. III. Inhibition of human monocyte mediated cytotoxicity by pokeweed mitogen.

We have shown that human mononuclear cells become spontaneously cytotoxic to a variety of erythrocyte targets after 7 days of in vitro culture. This phenomenon of spontaneous cytotoxicity occurs in low concentration of either autologous serum of FCS and is independent of any known stimulant. It does not require exogenous antibody, mitogen, or antigen. Once expressed, the cytotoxic cell has little, if any, specificity. Monocytes appear to be responsible for this observed in vitro cytotoxicity. We now present evidence that the development of spontaneous monocyte-mediated cytotoxicity in vitro is completely reversed by the addition of optimally mitogenic doses of PWM. PWM appears to reverse monocyte-mediated killing by stimulating a potent cell-mediated suppressor. This suppressor cell is radiosensitive and its action is blocked by inhibitors of protein synthesis. In contrast to other mitogen-driven suppressor models, PWM will inhibit spontaneous monocyte-mediated cytotoxicity even when added as late as 6 hr before the end of a 7-day culture.

Cell Separation↗
PubMed1979

Synergistic cytotoxicity. I. Characterization of a heat labile plasma fraction that induces nonspecific cytotoxicity by human mononuclear cells.

The mechanism by which non-immune mononuclear cells recognize invading foreign material and are activated for cytotoxic attack was studied in a model system employing human mononuclear cells, fresh plasma, and 51Cr-labeled xenogeneic target erythrocytes. In these experiments, fresh antibody-depleted plasma or mononuclear leukocytes alone were poorly cytotoxic to xenogenic erythrocytes. However, these target cells were rapidly lysed when both fresh antibody-depleted plasma and mononuclear cells were present in the assay. The plasma factor could not be removed by extensive absorption with the target cells, was present in plasma from hypogammaglobulinemic patients, was heat labile, and was sensitive to incubation with zymosan and cobra venom factor. The "antigen" specificity of this reaction was directed by the serum factor inasmuch as target cells autologous to the effector cells could be killed in the presence of antibody-depleted xenogeneic plasma, but not autologous plasma. These data suggest that an important mechanism for the recognition of "foreigness" by non-immune mononuclear cells is via interaction with a plasma component, possibly a factor related to serum complement.

Absorption↗
PubMed1978

Immunodeficiency in familial erythrophagocytic lymphohistiocytosis.

4 children with familial erythrophagocytic lymphohistiocytosis and hyperlipidaemia were found to have a previously unrecognised immunological deficiency syndrome which included defects in both humoral and cellular immunity and a plasma inhibitor of in-vitro lymphocyte blastogenesis. The inhibitory activity was proportional to the increase in the triglyceride concentration in the patients' plasma. Immunological deficiency, to which hyperlipidaemia may be a contributing factor, appears to be a significant feature of familial erythrophagocytic lymphohistiocytosis.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1978

Immunoglobulin secreting cells in normal human bronchial lavage fluids.

Immunoglobulin secreting cells were quantitated in the bronchial lavage fluids of 12 normal volunteers and compared with immunoglobulin secreting cells in peripheral blood, by a reverse hemolytic plaque assay. The mean number of cells secreting immunoglobulin (Ig)G in bronchial lavage fluids was 489 per million lymphocytes vs. a mean of 175 IgG secreting cells per million lymphocytes in peripheral blood (P < 0.02). The mean number of IgA secreting cells in bronchial lavage fluids was 633 per million lymphocytes as compared to 100 per million lymphocytes in peripheral blood (P < 0.005). Thus, compared to peripheral blood, cells from the lavage fluids were relatively enriched for both IgG and IgA secreting cells. However, IgA secreting cells were the major class of immunoglobulin secreting cells in bronchial lavage fluids, whereas IgG secreting cells predominated in peripheral blood. The prominence of IgA secreting cells in bronchial lavage fluids was further demonstrated by a mean ratio of IgA/IgG secreting cells in bronchial lavage fluids of 1.26 compared to a ratio in peripheral blood of 0.57 (P < 0.02). Cells secreting IgM were identified in only four of seven bronchial lavage fluid samples studied but in all peripheral blood samples. IgE secreting cells were not present in normal peripheral blood but could be demonstrated in 5 of 11 lavage fluid specimens. Thus, cells actively secreting immunoglobulins can be identified in the lower bronchial-alveolar tree of normal human subjects. Cells secreting IgG, IgA, or IgM may function in local lung defenses against infection; cells secreting IgE may contribute to hypersensitivity reactions in the lung.

Adult↗
PubMed1978

Disorders of suppressor immunoregulatory cells in the pathogenesis of immunodeficiency and autoimmunity.

A series of suppressor cell systems regulate virtually all immunologic processes. Disorders of these systems have been identified in association with a number of diseases. An abnormal number of activated suppressor T-cells have been seen in some patients with common variable hypogammaglobulinemia and in some with selective IgA deficiency. Suppressor T-cells that inhibit immunoglobulin synthesis also develop in an animal model of immunodeficiency, the agammaglobulinemia of the bursectomized bird. Non-T-cell suppressor cells are a pathogenic factor in the humoral immunodeficiency associated with multiple myeloma. At the other end of the spectrum of immunologic response, a reduction in functional activity of suppressor T-cells has been implicated in the pathogenesis of autoimmune diseases. The disorders of suppressor cells that have been shown in immunodeficiency and autoimmunity are important when developing rational strategies for prevention and therapy of these immunologic disorders.

Agammaglobulinemia↗
PubMed1977

Effect of Corynebacterium parvum, methanol-extraction residue of BCG, and levamisole on macrophage random migration, chemotaxis, and pinocytosis.

Three parameters of macrophage function: random migration, chemotaxis, and pinocytosis, were studied in the guinea pig after administration of Corynebacterium parvum, methanol-extraction residue of BCG, and levamisole (LMS), a synthetic anthelmintic. Macrophage migration studies were performed with a modified Boyden chamber. Pinocytosis was assessed by the uptake of colloidal 198Au. After ip administration, each of the three immunostimulators induced an increase in macrophage chemotactic responsiveness and, to a lesser extent and duration, in random motility. Kinetic, dose-response, and time course data for the effect of each agent on macrophage movement were explored. LMS was the most effective stimulator of macrophage activation, which occurred earlier and persisted longer than it did with the other agents. Macrophages from animals receiving each of the agents showed enhanced pinocytosis. Measurement of macrophage random migration, chemotaxis, and pinocytosis appeared to provide a rapid and quantitative assessment of several parameters of macrophage function and, when studied with other immunologic parameters, may provide useful tools for the evaluation of potential immunoadjuvants.

Animals↗
PubMed1977

Immunoregulatory properties of fractions from human pregnancy urine: evidence that human chorionic gonadotropin is not responsible.

The immunologically privileged position of the histoin-compatible fetus and placenta is a striking example of a physiologic immunoregulatory mechanism. This study was designed to examine the effects of human chorionic gonadotropin (HCG) on the recognitive proliferative phase and the cytotoxic effector phase of in vitro cell-mediated immune responsiveness, since HCG has previously been reported to be immunosuppressive in vitro and in vivo. Commercial preparations of HCG were found to be potent inhibitors of lymphocyte proliferative responses to nonspecific mitogens like phytohemagglutinin (PHA), specific antigens such as streptolysin-O (SLO), and allogeneic cells as measured in the one-way mixed leukocyte response. Cytotoxic effector function of lymphocytes as measured by antibody-dependent cellular cytotoxicity (ADCC) and mitogen-induced cellular cytotoxicity were also markedly inhibited by these preparations. However, the 50% inhibitory concentration varied widely from lot to lot of these commercial materials. After dialysis, a portion of the inhibitory activity was lost from some but not all HCG lots. The dialysate from those lots with diminished activity was found to be immunosuppressive in vitro but contained no HCG detectable by radioimmunoassay. Following dialysis, the immunosuppressive activity of the various HCG lots remained variable and correlated poorly with values for HCG obtained by a double antibody radioimmunoassay. HCG preparations purified to a homogeneity sufficient for amino acid sequence were found to be only minimally immunosuppressive to the in vitro PHA response and had almost no effect on proliferative responses to antigens and allogeneic cells. These data do not support the concept of a primary immunoregulatory role for HCG, but they suggest that other uncharacterized compounds partially co-purified from pregnant urine along with HCG may have such immunoregulatory activity. Further characterization and identification of this immunoregulatory material(s) is essential, since it appears to have many of the properties of an ideal immunosuppressive compound: a) nontoxicity, b) ready reversibility, c) activity at very low concentration, and d) activity on a broad range of cellular immune functions.

Chorionic Gonadotropin↗
PubMed1977

Spontaneous cytotoxicity of human peripheral blood mononuclear cells toward red blood cell targets. II. Time-dependent loss of suppressor cell activity.

In a previous paper we demonstrated that human peripheral blood mononuclear cells become strikingly cytotoxic toward a wide variety of red blood cell targets after 7 days of in vitro culture. The cell responsible for cytotoxicity does not rosette with SRBC and demonstrates both surface adherence and phagocytic properties. In this paper we wish to show that development of spontaneous cytotoxicity is due to a time-dependent loss of suppressor cell function. Fresh autologous lymphocytes, when added to cultured cells, abrogate the subsequent expression of spontaneous cytotoxicity toward RBC targets. The suppressor cell is radioresistant; requires 24 hr to suppress optimally; is inactivated by heating at 56 degrees C for 15 min, and is enriched in the non-T interface after SRBC rosette depletion over a discontinuous Ficoll-Hypaque gradient. Furthermore, the addition of a cell-free sonicate of fresh lymphocytes is capable of inhibiting spontaneous cytotoxicity toward RBC targets. However, if mononuclear cells are allowed to incubate in tissue culture medium for 7 days they are no longer suppressive after sonication. These data suggest that fresh mononuclear cells exert a potent negative regulatory influence on monocyte killing. Our culture conditions by removing this negative influence have produced a new model of spontaneous nonspecific killing by monocytes.

Antigens↗