Stimulation of the adherence of neutrophils to umbilical vein endothelium by human recombinant tumor necrosis factor

Recombinant human tumor necrosis factor (TNF) was found to enhance the adherence of human peripheral blood neutrophils to human umbilical vein endothelial (HUVE) cell monolayers in vitro. The enhancement was due to the effects both on neutrophils and HUVE cells. The effect on neutrophils was maximally induced within 5 min and did not require protein or RNA synthesis. By contrast, maximal effects on HUVE cells took 4 hr to develop and required de novo protein and RNA synthesis; however, exposure of HUVE cells to TNF for as little as 5 min was sufficient to initiate changes leading to maximal adherence of neutrophils at 4 hr. Both the effect on neutrophils and that on HUVE cells were blocked by a monoclonal antibody against TNF. TNF also rapidly induced an increased surface expression of neutrophil antigens recognized by monoclonal antibodies directed against epitopes of a glycoprotein required for optimum adherence and for complement component C3bi receptor (CR3) function. Thus, the mechanism of action of TNF may involve the regulation of expression of cell surface molecules. Our observations show that TNF induces a process central to the development of all inflammatory reactions and that both blood neutrophils and endothelial cells are targets of TNF action. The regulation of inflammatory reactions by TNF or antagonists of TNF has wide-ranging clinical implications.

Correlation between the stimulation of human neutrophil function by monoclonal antibody and by colony-stimulating factor

Purified human neutrophils from 48 individuals were tested for their capacity to kill antibody-coated target cells in vitro in the absence or presence of stimulating agents. The agents used to stimulate cytotoxic capacity were the monoclonal antibody (MAb) WEM-G1, colony-stimulating factor (CSF-alpha), or mononuclear cell supernatant (MNC-SN). There existed an heterogeneity among the neutrophils of different individuals in the capacity to kill target cells both in the unstimulated ("resting") or the stimulated state. A positive correlation was found between the ability of neutrophils to kill in the "resting" state and their capacity to be stimulated by MAb WEM-G1, CSF-alpha, or MNC-SN. Furthermore, a strong positive correlation in the ability of neutrophils to be stimulated by the MAb WEM-G1 and either CSF-alpha (r = .76) or MNC-SN (r = .68), as well as between CSF-alpha and MNC-SN (r = .79) was demonstrated. No correlation was seen, however, between stimulation of neutrophil function in vitro and total blood leukocyte counts, neutrophil counts, monocyte counts, or intensity of binding of MAb WEM-G1. The observation that neutrophils respond to a similar extent to different types of stimulators, -such as cytokines (CSF-alpha and MNC-SN) and MAb, suggests that these two factors may be operating through a common mechanism and the degree of stimulation may reflect an intrinsic responsiveness of neutrophils that differs among individuals. Our results also suggest a potential clinical use of WEM-G1 in measuring neutrophil functional capacity in vitro and predicting the capacity to respond to CSF-like cytokines.

Identification of a human granulocyte functional antigen (GFA-2) involved in antibody-dependent cell-mediated cytotoxicity and phagocytosis

A human neutrophil- and eosinophil-specific surface antigen, GFA-2, has been found to be involved in the antibody-dependent cell-mediated cytotoxicity (ADCC) to extracellular targets, and in phagocytosis. The monoclonal antibody (MAb) WEM-G11 was produced which recognizes the GFA-2 structure. This MAb, when used as F(ab')2, stimulated human neutrophils to kill antibody-coated P815 cells and, in the case of human eosinophils, increased their cytotoxic effect on schistosomula of Schistosoma mansoni in a dose-dependent manner. MAb WEM-G11 F(ab')2 also stimulated the phagocytosis of antibody-coated sheep erythrocytes by neutrophils. The effect of WEM-G11 F(ab')2 was specific, because other MAb, whether tested in the form of F(ab')2 fragments or as whole IgG, failed to stimulate neutrophils despite binding to these cells. In contrast to the F(ab')2 fragments of these cells. In contrast to the F(ab')2 fragments of WEM-G11, the whole IgG of this MAb inhibited ADCC and phagocytosis, presumably through interaction with granulocyte Fc receptors. WEM-G11 F(ab')2, and to a greater extent WEM-G11 IgG, induced degranulation, but only from cytochalasin B-treated neutrophils. GFA-2 was absent from lymphocytes, monocytes, erythrocytes, and myeloid and erythroid colony-forming cells, as shown by flow cytometry and colony-forming experiments. GFA-2 appeared at the promyelocytic stage and increased in density as neutrophils became more mature. In the mature neutrophil, the number of binding sites for WEM-G11 were found to be about 20,000 per cell. By immunoprecipitation, it appeared that GFA-2 consisted of a polypeptide chain of about 95,000 m.w. and a low m.w. peptide of about 43,000. By immunoblotting, it was demonstrated that the epitope recognized by WEM-G11 is in the chain of m.w. 95,000. GFA-2 thus constitutes a novel human granulocyte-specific antigen that is central to the functional activity and differentiation of these cells.

Identification of a human granulocyte functional antigen (GFA-2) involved in antibody-dependent cell-mediated cytotoxicity and phagocytosis

A human neutrophil- and eosinophil-specific surface antigen, GFA-2, has been found to be involved in the antibody-dependent cell-mediated cytotoxicity (ADCC) to extracellular targets, and in phagocytosis. The monoclonal antibody (MAb) WEM-G11 was produced which recognizes the GFA-2 structure. This MAb, when used as F(ab')2, stimulated human neutrophils to kill antibody-coated P815 cells and, in the case of human eosinophils, increased their cytotoxic effect on schistosomula of Schistosoma mansoni in a dose-dependent manner. MAb WEM-G11 F(ab')2 also stimulated the phagocytosis of antibody-coated sheep erythrocytes by neutrophils. The effect of WEM-G11 F(ab')2 was specific, because other MAb, whether tested in the form of F(ab')2 fragments or as whole IgG, failed to stimulate neutrophils despite binding to these cells. In contrast to the F(ab')2 fragments of these cells. In contrast to the F(ab')2 fragments of WEM-G11, the whole IgG of this MAb inhibited ADCC and phagocytosis, presumably through interaction with granulocyte Fc receptors. WEM-G11 F(ab')2, and to a greater extent WEM-G11 IgG, induced degranulation, but only from cytochalasin B-treated neutrophils. GFA-2 was absent from lymphocytes, monocytes, erythrocytes, and myeloid and erythroid colony-forming cells, as shown by flow cytometry and colony-forming experiments. GFA-2 appeared at the promyelocytic stage and increased in density as neutrophils became more mature. In the mature neutrophil, the number of binding sites for WEM-G11 were found to be about 20,000 per cell. By immunoprecipitation, it appeared that GFA-2 consisted of a polypeptide chain of about 95,000 m.w. and a low m.w. peptide of about 43,000. By immunoblotting, it was demonstrated that the epitope recognized by WEM-G11 is in the chain of m.w. 95,000. GFA-2 thus constitutes a novel human granulocyte-specific antigen that is central to the functional activity and differentiation of these cells.

Fc receptors on mouse neutrophils and eosinophils: antigenic characteristics, isotype specificity and relative cell membrane density measured by flow cytometry

The antigenic characteristics, isotype specificity and density of Fc receptors (FcR) on mouse neutrophils and eosinophils were studied with the aid of the rat monoclonal antibody 2.4 G2 to the mouse macrophage FcR (Unkeless, 1979). This MAb was tested for its reactivity with mouse neutrophil and eosinophil FcR, and for its ability to block the binding of sheep erythrocytes (E) coated with mouse antibodies of different isotypes to granulocytes. The use of E conjugated with fluorescein isothiocyanate (FITC) allowed an objective read-out by flow cytometry. The MAb 2.4.G2 reacted with both neutrophil and eosinophil FcR, blocking the binding of E coated with mouse IgG1, IgG2a and IgG2b in a dose-dependent manner. Blocking was specific, since it did not occur with any of several control MAb of the same rat isotype (IgG2b) as 2.4.G2. Furthermore, the binding to E through the granulocyte receptor for complement (C) was unaffected. IgG3 was unable to promote binding of E to either neutrophils or eosinophils, although it induced high levels of binding to macrophages. These results show that: (i) neutrophil, eosinophil and macrophage FcR have antigenic similarities; (ii) neutrophils and eosinophils, in contrast to macrophages, either have a common FcR for IgG1, IgG2a and IgG2b, or have different FcR for these isotypes which share the antigenic determinant recognized by 2.4.G2; (iii) in contrast to macrophages, neutrophils and eosinophils lack the FcR for IgG3. The MAb 2.4.G2 was used in an indirect immunofluorescence assay monitored by flow cytometry to measure the relative FcR density on neutrophils and eosinophils. This assay showed that neutrophils possess about 65% more FcR than eosinophils on a cell-for-cell basis, providing an explanation for the higher binding of neutrophils to IgG-coated particles at suboptimal antibody concentrations.

The clonal proliferation in vitro of enriched populations of human promyelocytes and myelocytes

The proliferative capacity of normal human promyelocytes and myelocytes was demonstrated and characterized on the basis of clonal proliferation in agar. An enriched population of normal human promyelocytes and myelocytes was obtained from bone marrow using the monoclonal antibody WEM G11 and the fluorescence-activated cell sorter (FACS). In cultures stimulated by placental-conditioned medium, these cells generated peak total clone numbers between days 3 and 5 of culture. Clones disappeared rapidly thereafter. These clones were mainly of subcolony size at day 7, although some colonies were generated by this population. The clones were primarily neutrophilic in type. These cells had a plating efficiency of up to 50%, and clonal proliferation was dependent on stimulation by colony-stimulating factor (CSF).

Selective enhancement of the expression of granulocyte functional antigens 1 and 2 on human neutrophils

The regulation of expression of two human granulocyte functional antigens (GFA-1 and GFA-2) was examined. N-formylmethionylleucylphenylalanine (fMet-Leu-Phe) caused a rapid, dose-dependent enhancement of the expression of these antigens, 2- to 4-fold within 30 min, but not of another surface structure, beta 2-microglobulin. Pretreatment of the cells with cytochalasin B at 5 micrograms/ml further enhanced the effect of fMet-Leu-Phe on the expression of GFA-2, raising its surface expression 11-fold. Lipopolysaccharide also stimulated the expression of GFA-1 and GFA-2. The effect of lipopolysaccharide was less than that of fMet-Leu-Phe and was more marked on GFA-1 than on GFA-2. Pretreatment of neutrophils with fMet-Leu-Phe not only stimulated their cytotoxic activity against antibody-coated target cells but also increased their capacity to be stimulated by monoclonal antibodies to GFA-1 and GFA-2. These findings show that the expression of functional surface structures on human neutrophils is subject to rapid and selective regulation.

Regulation of human granulocyte function by products derived from murine tumors

Murine EL-4 thymoma was found to produce a factor that activated antibody-dependent cell-mediated cytotoxicity by human eosinophils and neutrophils. The eosinophil-activating factor had some properties similar to human eosinophil colony-stimulating factor in being heat stable, inactivated by 2-mercaptoethanol, and cochromatographing by gel filtration with a factor that promoted the growth of pure eosinophil colonies from human bone marrow. The neutrophil-activating factor from EL-4 was also heat stable but was not inactivated by 2-mercaptoethanol and was found in two peaks on chromatography, neither having human neutrophil-CSF activity but one cochromatographing with mouse granulocyte-macrophage CSF. EL-4 therefore secretes factors that activate two types of human granulocytes. Several other murine thymomas and macrophage cell lines produced a neutrophil-activating factor, the production of which could not be correlated with that of several other known lymphokines. Murine tumors produce factors that activate human granulocytes.

Studies on the mechanism of the enhancement of delayed-type hypersensitivity by pertussigen

The potentiation of delayed-type hypersensitivity (DTH) reactions by pertussigen, a protein toxin from Bordetella pertussis, has been studied in adoptive transfer assays. Lymph node or spleen cells from mice treated with or without pertussigen at the time of immunization with protein antigens were transferred to naive, syngeneic recipients that were challenged with antigen. Cells from donors treated with pertussigen had the capacity to transfer vigorous, antigen-specific DTH reactions. Cells from immunized donors not given pertussigen transferred little or no DTH. These results indicate that pertussigen is able to augment DTH reactions by potentiating the antigen reactivity of cell populations in lymphoid organs. The phenotype of the effector cells induced by pertussigen was Thy-1 positive, L3T4 positive, and Ly-2 negative. Cells from mice given pertussigen and an irrelevant antigen had no influence on specific DTH responses, suggesting that pertussigen enhances the activity of the antigen-specific cell type mediating DTH. The effect of pertussigen and of immunization on the lymphocyte subpopulations present in the lymph nodes was studied by analysis of suspensions of lymph node cells by flow cytometry. In immunized and in nonimmune mice, pertussigen increased the ratio of Ly-2-negative:Ly-2-positive T cells, and reduced the overall proportion of B cells. In immunized mice, pertussigen induced a much higher proportion of large dividing cells from 5 days after sensitization onwards. The relevance of these changes in lymphocyte behavior to the development of enhanced and prolonged DTH in mice given pertussigen is discussed.

Studies on the mechanism of the enhancement of delayed-type hypersensitivity by pertussigen

The potentiation of delayed-type hypersensitivity (DTH) reactions by pertussigen, a protein toxin from Bordetella pertussis, has been studied in adoptive transfer assays. Lymph node or spleen cells from mice treated with or without pertussigen at the time of immunization with protein antigens were transferred to naive, syngeneic recipients that were challenged with antigen. Cells from donors treated with pertussigen had the capacity to transfer vigorous, antigen-specific DTH reactions. Cells from immunized donors not given pertussigen transferred little or no DTH. These results indicate that pertussigen is able to augment DTH reactions by potentiating the antigen reactivity of cell populations in lymphoid organs. The phenotype of the effector cells induced by pertussigen was Thy-1 positive, L3T4 positive, and Ly-2 negative. Cells from mice given pertussigen and an irrelevant antigen had no influence on specific DTH responses, suggesting that pertussigen enhances the activity of the antigen-specific cell type mediating DTH. The effect of pertussigen and of immunization on the lymphocyte subpopulations present in the lymph nodes was studied by analysis of suspensions of lymph node cells by flow cytometry. In immunized and in nonimmune mice, pertussigen increased the ratio of Ly-2-negative:Ly-2-positive T cells, and reduced the overall proportion of B cells. In immunized mice, pertussigen induced a much higher proportion of large dividing cells from 5 days after sensitization onwards. The relevance of these changes in lymphocyte behavior to the development of enhanced and prolonged DTH in mice given pertussigen is discussed.

Eosinophil-mediated killing of schistosomula of Schistosoma mansoni: oxidative requirement for enhancement by eosinophil colony stimulating factor (CSF-alpha) and supernatants with eosinophil cytotoxicity enhancing activity (E-CEA)

Factors which enhance eosinophil-mediated killing of antibody-coated schistosomula of Schistosoma mansoni include semipurified eosinophil colony stimulating factor (CSF-alpha) and eosinophil cytotoxicity enhancing activity (E-CEA) present in supernatants from cultured mononuclear cells. We have examined the mechanism of enhancement. Both actions require oxygen in order to enhance killing and do not enhance killing under anaerobic conditions (P less than or equal to 0.005). E-CEA had no detectable effect upon oxidative metabolism. In contrast to CSF-alpha which, in our previous studies, increased superoxide anion productions and quantitative leukocyte iodination, E-CEA had no detectable effect upon oxidative metabolism. In order to test whether active oxygen products might mediate enhancement of killing, the effects of the addition of superoxide dismutase and catalase were tested. Neither enzyme showed inhibition of CSF-alpha or E-CEA enhancement of eosinophil-mediated killing. The effects of CSF-alpha and E-CEA were not additive. These studies suggest that both CSF-alpha and E-CEA exert enhancement of killing by means of an as yet unidentified oxygen requiring process.

Mononuclear cell-mediated enhancement of granulocyte function in man

Human monocyte-enriched mononuclear cells (MNC) (greater than 95% monocytes) powerfully stimulated the antibody-dependent killing of tumor cells by purified human neutrophils (NE) or eosinophils (EO). The enhancement was observed when the mononuclear cell to granulocyte ratio was as low as 1:100. Media conditioned by MNC also stimulated antibody-dependent killing by NE and EO as well as the uptake and killing of Candida albicans by NE. There was a heterogeneity amongst individuals in the capacity of their MNC to elaborate this factor, and approximately 15% of individuals did not produce detectable factor. Different factors in the MNC supernatant were involved in NE and EO activation. The EO-activating factor (AF) had a m.w. of approximately 27,000 and migrated as a single band on phenyl-Sepharose chromatography. The NE-AF had a m.w. of 22,000 and migrated as two distinct bands on phenyl-Sepharose chromatography. EO-colony-stimulating factor (CSF) co-purified with EO-AF, and granulocyte-macrophage-CSF co-purified with both bands of NE-AF. It is concluded that MNC elaborate CSF-like molecules that powerfully stimulate human granulocyte function.

Mononuclear cell-mediated enhancement of granulocyte function in man

Human monocyte-enriched mononuclear cells (MNC) (greater than 95% monocytes) powerfully stimulated the antibody-dependent killing of tumor cells by purified human neutrophils (NE) or eosinophils (EO). The enhancement was observed when the mononuclear cell to granulocyte ratio was as low as 1:100. Media conditioned by MNC also stimulated antibody-dependent killing by NE and EO as well as the uptake and killing of Candida albicans by NE. There was a heterogeneity amongst individuals in the capacity of their MNC to elaborate this factor, and approximately 15% of individuals did not produce detectable factor. Different factors in the MNC supernatant were involved in NE and EO activation. The EO-activating factor (AF) had a m.w. of approximately 27,000 and migrated as a single band on phenyl-Sepharose chromatography. The NE-AF had a m.w. of 22,000 and migrated as two distinct bands on phenyl-Sepharose chromatography. EO-colony-stimulating factor (CSF) co-purified with EO-AF, and granulocyte-macrophage-CSF co-purified with both bands of NE-AF. It is concluded that MNC elaborate CSF-like molecules that powerfully stimulate human granulocyte function.

Stimulation of human granulocyte function by monoclonal antibody WEM-G1

From a panel of monoclonal antibodies (MAb) produced against purified human neutrophils, MAb WEM-G1 was selected for its ability to stimulate granulocyte function as assessed by the capacity to kill antibody-coated tumor target cells. MAb WEM-G1 bound to neutrophils and eosinophils and not to monocytes, lymphocytes, or erythrocytes, and thus identified a granulocyte differentiation antigen. It enhanced killing by both neutrophils and eosinophils in a dose-dependent fashion, with a range of effector-to-target ratios and dilutions of anti-target cell antibody. The effect of MAb WEM-G1 was additive with that of colony-stimulating factor (CSF-alpha). Similarly, the ability of neutrophils to exhibit enhanced cytotoxicity in the presence of WEM-G1 was increased by preincubation of neutrophils with CSF-alpha. Immunoprecipitation analysis showed that WEM-G1 identified a cell-surface protein on human neutrophils of approximate molecular weight 110,000. It is suggested that this structure is involved in regulation of the function of human granulocytes.

Newer aspects of regulation of human granulocyte function

The regulation of granulocyte function by cell-derived factors is emphasised in this review. The most important of these cell-derived factors belongs to a class of substances known as colony stimulating factors (CSF) so named because they stimulate the maturation of progenitor cells into clumps or "colonies" of mature cells. CSF mediated regulation of granulocytes is likely to be important for the two reasons (i) the site of CSF production can determine the site of granulocyte activation and (ii) the type of CSF produced can determine the type of granulocyte activated. Blood mononuclear cells were found to be a good source of granulocyte activating material suggesting that interaction between these two cell types is important in vivo. The potential clinical use of CSF-like substances is discussed.

Attempts to modify lung granulomatous responses to Schistosoma japonicum eggs in low and high responder mouse strains

A radioisotopic assay for acute granulomatous hypersensitivity (AGH) to lyophilized eggs of Schistosoma japonicum has been used to further examine responses to egg antigens in various inbred strains of mice. The ranking of responsiveness in mice from high (C57BL/6), intermediate (BALB/c) to low (CBA/H) was not influenced by high or low egg-sensitization regimens. However, the low responsiveness of responder mice sensitized with eggs by the intraperitoneal compared with the subcutaneous route of injection appears to be an egg dose-related phenomenon. The high AGH responsiveness of C57BL/6 mice can be increased further by sensitization with eggs in the presence of purified pertussigen from Bordetella pertussis but CBA/H mice treated identically remain low responders. The monoclonal anti-egg antibody, P.41, which produces a prominent bleb-type circumoval precipitate with eggs, has been shown to be directed against major 'immunopathologic antigen(s)' of S. japonicum eggs. Thus, C57BL/6 mice were sensitized for AGH by injection of soluble extracted egg antigen (SEA) bound to an immunoabsorbent of P.41 antibody on Sepharose. No success has been achieved in modulating AGH in C57BL/6 mice by injection of hyperimmune antisera raised against lyophilized eggs in either high or low responder mouse strains. This failure is in line with previous results using antisera as well as monoclonal anti-egg antibodies. The consistent failure to demonstrate a modulating effect of antibodies in this compared with other laboratories may be related to the use of lyophilized rather than viable eggs. The data suggest that activities of antisera in granuloma modulation in murine schistosomiasis japonica result from egg destruction or inhibition of production of immunopathologic antigens by eggs rather than through effects on immunopathologic immune responses.

Enhancement of the intensity, persistence, and passive transfer of delayed-type hypersensitivity lesions by pertussigen in mice

Pertussigen, a purified protein from Bordetella pertussis, was shown to increase delayed-type hypersensitivity (DTH) to protein antigens in mice. First, it caused an approximately twofold enhancement of the magnitude of 24-h DTH reactions. Second, the peak magnitude of DTH was delayed to 4-7 d after challenge, at which time it was five times more intense than in mice not receiving pertussigen. This reaction was antigen specific, and histologically was characterized by a dense mononuclear infiltrate. Third, pertussigen prolonged DTH so that it was still detectable 3-6 wk after challenge. The effect of pertussigen was seen only in antigen-driven reactions and was time and dose dependent, with 400 ng given 3 d after immunization resulting in the most prolonged reaction. The administration of pertussigen to the recipients of sensitized lymph node cells resulted in DTH that was more intense and prolonged than the reactions in control mice. Administration of pertussigen provides a model of prolonged and enhanced T cell-dependent inflammatory responses.

Eosinophil activation by colony-stimulating factor in man: metabolic effects and analysis by flow cytometry

Substantial increases in the killing capacity of human eosinophils after in vitro incubation with human placental conditioned medium (HPCM), a standard source of colony-stimulating factor (CSF), have recently been described. In this article, the interaction between HPCM and purified human eosinophils is analyzed by flow cytometry and by effects on iodination, superoxide production, and protein synthesis. HPCM increased the intensity of natural eosinophil autofluorescence (aFlu) (460 nm) after the absorption of ultraviolet light (360 nm) in a manner that was both time and dose dependent. Measured in arbitrary units, eosinophil aFlu was 72 +/- 7.3 (arithmetic mean +/- SEM) and 121 +/- 3.2 after 18-hr incubations in the absence or presence of HPCM, respectively. The activity in HPCM responsible for these changes cochromatographed on Ultrogel AcA44 columns with CSF and with the less hydrophobic variant of CSF (CSF-alpha) on phenyl Sepharose. Mouse spleen, but not mouse lung, conditioned medium was also active on human eosinophils in this assay. Both CSF-alpha and mouse spleen conditioned medium also contain eosinophil colony-stimulating activity (CSA), whereas inactive CSFs with no effect on mature eosinophils, CSF-beta, and mouse lung conditioned medium also lack eosinophil CSA. CSF-alpha stimulated superoxide production of resting eosinophils (from 0.03 +/- 0.03 to 0.47 +/- 0.08 nmole cytochrome-c reduced/10(5) eosinophils) and of eosinophils incubated with preopsonized zymosan (from 0.15 +/- 0.06 to 0.73 +/- 0.07). It also stimulated iodination by resting eosinophils (from 0.76 +/- 0.16 to 2.60 +/- 0.72 nmoles l/10(7) eosinophils/hr) and of eosinophils incubated with preopsonized zymosan (from 7.52 +/- 2.08 to 29.8 +/- 1.32). In contrast, CSF-beta was inactive in these assays. CSF-alpha also stimulated, between 2- and 15-fold, the new protein synthesis of eosinophils. Thus, substances that stimulate the differentiation of progenitor cells into eosinophils also interact with peripheral mature eosinophils, and the activation of postmitotic cells may be a physiologic role of CSF-like molecules.

Delayed hypersensitivity induced by anti-T-cell-line antisera is enhanced by pertussigen and not restricted by histocompatibility genes

Anti-T-cell-line antisera were raised by repeatedly injecting mice with syngeneic, antigen-specific, delayed hypersensitivity (DH) inducing cells grown as continuous T-cell lines in vitro. Many of these antisera could induce antigen-specific DH responses which, in some cases, were rather slight. For example, the DH reaction to azobenzenearsonate induced in A/J mice by an A/J antiserum produced against the syngeneic azobenzenearsonate-specific cell line AA3 was only a weak response. Administration of pertussigen, a protein purified from Bordetella pertussis, markedly enhanced this response and prolonged its duration. Histologically the reaction showed the classical mononuclear infiltration of DH. It could be transferred to naive mice by lymph node cells that were anti-Thy-1.2 sensitive, and the transfer was restricted by genes of the major histocompatibility complex (MHC). The induction of DH by antiserum, however, was not influenced by MHC or non-MHC gene products.

Activation of antibody-dependent cell-mediated cytotoxicity of human neutrophils and eosinophils by separate colony-stimulating factors

Semi-purified human colony-stimulating factors (CSF) powerfully enhanced the antibody-dependent cell-mediated cytotoxicity (ADCC) by metrizamide gradient-purified human neutrophils and eosinophils. The stimulation was observed on three different tumor targets, was rapid (less than 1 hr) in onset, and CSF-stimulated cells needed direct contact with targets for killing. A subspecies of human CSF, CSF-alpha, with eosinophil and granulocyte-macrophage (GM) colony-stimulating activity enhanced both eosinophil and neutrophil killing. In contrast, another subspecies of human CSF, CSF-beta, having only GM colony-stimulating activity, only enhanced neutrophil-mediated ADCC. These results support the notion that human CSF have two sites of action: i) the progenitor cell, where they stimulate a relatively slow process of differentiation, and ii) the mature cell, where they have a rapid action of increasing functional capacity. Furthermore, it seems the pattern of CSF receptors on progenitor cells is maintained throughout the lineage of such cells and serves to regulate the function of mature cells.

Eosinophilia and acquisition of resistance to Nematospiroides dubius in mice sensitized with adult worms

BALB/c mice develop resistance to challenge with N. dubius third stage infective larvae (L3) 2-3 weeks after the administration of N. dubius worms. In contrast, CBA/H mice fail to develop resistance. Experiments were performed to test the hypothesis that the reason for the different behaviour of these mice was a difference in their eosinophil response. BALB/c mice and BALB/c leads to (BALB/c x CBA/H)F1 bone marrow chimaeras but not CBA/H mice or CBA/H leads to (BALB/c x CBA/H)F1 chimaeras mounted strong eosinophilia after N. dubius sensitization and the eosinophil response was associated with resistance to L3 infection in these mice. Induction of a mild eosinophilia in CBA/H mice by non-parasite antigen keyhole limpet haemocyanin (KLH) in complete Freund's adjuvant (CFA) following cyclophosphamide (CY) treatment was associated with the acquisition of a degree of resistance to L3 infection. In BALB/c mice, increase in eosinophilia induced by CY and KLH-CFA was not associated with a further reduction in worm numbers. These experiments support the hypothesis that eosinophilia is an important component of host protective immunity in vivo, and suggest a new basis for the heterogeneity of the outcome of some parasite infestations.

Activation of antibody-dependent cell-mediated cytotoxicity of human neutrophils and eosinophils by separate colony-stimulating factors

Semi-purified human colony-stimulating factors (CSF) powerfully enhanced the antibody-dependent cell-mediated cytotoxicity (ADCC) by metrizamide gradient-purified human neutrophils and eosinophils. The stimulation was observed on three different tumor targets, was rapid (less than 1 hr) in onset, and CSF-stimulated cells needed direct contact with targets for killing. A subspecies of human CSF, CSF-alpha, with eosinophil and granulocyte-macrophage (GM) colony-stimulating activity enhanced both eosinophil and neutrophil killing. In contrast, another subspecies of human CSF, CSF-beta, having only GM colony-stimulating activity, only enhanced neutrophil-mediated ADCC. These results support the notion that human CSF have two sites of action: i) the progenitor cell, where they stimulate a relatively slow process of differentiation, and ii) the mature cell, where they have a rapid action of increasing functional capacity. Furthermore, it seems the pattern of CSF receptors on progenitor cells is maintained throughout the lineage of such cells and serves to regulate the function of mature cells.

Evidence for the control of eosinophilia by the major histocompatibility complex in mice

The genetic control of eosinophilia has been studied in congenic strains of mice. Eosinophilia was induced with cyclophosphamide followed by keyhole limpet hemocyanin in complete Freund's adjuvant. After this treatment, BALB/c mice developed a high eosinophil response, whereas CBA, C57BL and A/J mice developed a low one. The major histocompatibility complex (MHC) was found to exert a control on eosinophilia, as B10.D2 mice developed a higher eosinophil response than B10, B10.A, or B10.BR. BALB/c-H-2k mice had a lower response than BALB/c, and A.TL mice had a higher response than A/J or A.TH. If a single gene within the MHC is responsible for these effects, the most likely position for it is in the vicinity of the Tla locus. Splenectomy reduced eosinophilia in BALB/c and A.TL mice, but not in A/J mice, indicating that the spleen is a significant site of eosinophil production in high responder strains.

Maturation in vivo of Schistosoma mansoni schistosomula after culture in vitro with granulocytes and antibody

Seven experiments were carried out to test the relationship between the morphological assay for damage to schistosomula in vitro with toluidine blue and the loss of the ability of damaged organisms to mature in vivo. Schistosomula were prepared by penetration of rat skin and cultured for 12 to 38 h in the presence of various combinations of purified human eosinophils or neutrophils and heat-inactivated human antischistosomular serum. Samples were scored for microscopically detectable damage, and the remaining organisms were injected intravenously into normal mice. These mice were perfused after 5.5 to 7 weeks, and the recovery of adult worms was determined. After culture of schistosomula in medium alone, between 8.4 and 32.7% of injected organisms matured into adult worms. There was no significant difference in the capacity of freshly prepared and cultured schistosomula to mature in vivo. Schistosomula cultured with antibody alone showed no significant damage in vitro, and in only one of seven experiments was there a significant (35%) reduction compared with the medium controls in their capacity to mature in vivo. Schistosomula cultured with neutrophils alone or eosinophils alone showed no significant damage in vitro and no loss of viability in vivo. Schistosomula cultured with neutrophils and antibody showed a 28% reduction in recovery in one experiment but an increase in recovery (12 and 46%) in two other experiments. In contrast, schistosomula cultured with eosinophils and antibody showed evidence of both marked damage in vitro (22 to 93% dead organisms) and loss of viability in vivo (26 to 98% reduction in recovery) in all seven experiments. These findings justify the use of the toluidine blue morphological assay as an estimate of irreversible damage to schistosomula and confirm that human eosinophils and neutrophils differ markedly in their capacity to mediate antibody-dependent damage in vitro.

Bullous pemphigoid blister fluid stimulates eosinophil colony formation and activates eosinophils

An eosinophil stimulating material (ESM) is described in the blister fluids (BF) of six patients with bullous pemphigoid (BP). This ESM is similar in function to a subspecies of human colony stimulating factor (CSF), CSF-alpha, since (i) it stimulated the production from bone marrow cells of day 14 colonies (31 +/- 15, arithmetic mean +/- 1 s.e.m. colonies, n = 5) in semi-solid agar, (ii) a large proportion (47 +/- 12%, n = 5) of these colonies were eosinophilic and (iii) it activated purified peripheral eosinophils as judged by increased autofluorescence (a mean increase of 23.6 +/- 6.6 units measured by flow cytometry, n = 10). BF from patients with four other blistering diseases, burn blisters, suction blisters from normal, eosinophilic or BP patients, various sera, histamine and eosinophil chemotactic factor (ECF-A) lacked activities in these assays. This description of a tissue accumulation of a CSF like substance suggests that there exists a physiological role for CSF in the periphery. In addition it supports the concept that local activation of eosinophils contributes to the pathogenesis of BP.