Acta pathologica, microbiologica, et immunologica Scandinavica. Section C, Immunology最新文献

The in vitro chemotactic response of peritoneal macrophages fourteen days after immunization with BCG was greater than that of macrophages from control mice. Peritoneal macrophages from mice treated with other agents which enhance bactericidal activity, and macrophages induced with proteose-peptone were less responsive to chemotactic stimuli than resident macrophages. The addition of PPD or PHA lymphokines to the peritoneal cells from BCG injected mice depressed the chemotactic response, but increased unstimulated migration. PPD had no effect on the migration of resident macrophages, but PHA lymphokines depressed the chemotactic activity of these cells.

The luminol-dependent chemiluminescence (CL)-response of phagocytosing declined steadily during in vitro differentiation and was approximately 10% of the initial value by the fourth day of culture. A parallel decline in myeloperoxidase (MPO)-activity of monocyte cell lysates was observed during the same period, and a close correlation was found between peak luminol-dependent CL-response and MPO-activity. The lucigenin-dependent CL-response of phagocytosing monocytes in parallel cultures declined to about 85% of the initial value during four days of in vitro culture. Chemiluminescence was determined in solutions of luminol or lucigenin subjected to fixed amounts of H2O2 or enzymatically generated fluxes of H2O2. Horseradish peroxidase (HRPO) markedly enhanced the luminol-dependent CL but not the lucigenin-dependent CL of this cell-free system. Similar results were obtained when a crude MPO extract was substituted for the HRPO. Despite this evidence that luminol-dependent CL is enhanced by peroxidases, addition of HRPO to the assay medium did not increase the luminol-dependent CL-response of four days old, phagocytosing monocytes.

The host anti-tumor reactivity against a syngeneic transplantable T lymphoma (WEHI-7) was studied. The experimental subjects were normal mice, mice with WEHI-7-injected growing tumors, and partially resistant mice, immunized with mitomycin-treated WEHI-7 lymphoma cells. The cellular reactivity against tumor cells in vitro, i.e. natural killer (NK) activity, activity against WEHI-7 cells, and antibody-dependent cellular cytotoxicity (ADCC) were all increased in tumor-bearing animals but were not detected in immunized mice. Reactivity against agar-clonable (colony-forming) tumor cells (approximately 40% of the total tumor population) decreased in the tumor-bearing animals in which tumor had not yet disseminated, and host spleen and peritoneal cells from late tumor-bearing animals with disseminated tumor cells actually enhanced clonable tumor cells in vitro. Specific antibody production against WEHI-7 tumor cells was detected neither in tumor-bearing, nor in partially resistant mice. However, tumor-bearing animals did respond with production of plaque-forming cells after immunization with sheep red blood cells (SRBC), although the response decreased with the increasing tumor burden. The response of spleen cells from tumor-bearing mice to mitogen stimulation showed that the B-cell compartment was unaffected by tumor growth, while the T-cell compartment showed a slight stimulation. The results confirm the heterogeneous nature of the WEHI-7 cell population by demonstrating different sensitivity of tumor cell sub-sets to host reactivity in vitro.

A factor which is responsible for the growth inhibitory properties of certain mouse sera and related to NK-activity, has been studied. The factor was isolated from hybrid B6D2F1 (C57Bl/6 x DBA/2) serum, which is histo-compatible with the mouse tumour (B16 melanoma) used and has high NK-activity. Growth inhibitory activity was measured in an in vitro assay. It was independent of complement activation. The responsive factor was isolated and characterized by ion exchange chromatography. Concanavalin A affinity chromatography, gel filtration and iso-electric focusing. It appears to be a protein and had been labelled growth-inhibitory factor (GIF). It has a molecular weight of 230 000-260 000 daltons and an iso-electric point in the pH range 4.6-5.0. It was not retained on Concanavalin A columns.

A correlation between natural killer (NK) cell activity and growth inhibition (GI), as measured in an in vitro assay with B16 melanoma cells, mediated by a serum growth-inhibitory factor (GIF), among various strains of mice has been demonstrated. Beige mice (bg/bg), known to express low NK-activity, were also low in GIF activity and showed increased susceptibility to both B16 melanoma cells and another solid tumor (Lewis lung carcinoma) in vivo. In vivo treatment with various protease inhibitors that reduced NK-activity, also reduced growth inhibition mediated by GIF. Protease inhibitors that did not affect NK-activity did not affect GIF either. All of 4 B16 melanoma clones selected against GIF in vitro and resistant to GIF showed both resistance to NK-cells in vitro and increased growth potential in vivo. However, P-815, an NK-resistant cell line, was sensitive to GIF.

Phagocytosis and killing of Propionibacterium acnes by human peripheral blood leukocytes were promoted by normal human serum and by serum depleted of immunoglobulin G and M. Serum that had been heat-inactivated, depleted of complement component C3, or depleted of C4 and factor B, did not promote phagocytosis or killing. Depletion of complement-component C4 or factor B from normal human serum did not impair its capacity to promote phagocytosis and killing of P. acnes. These results indicate that phagocytosis of P. acnes is mediated by complement component C3, activated either by the classical or by the alternative pathway. P. acnes was phagocytosed as efficiently under anaerobic as under aerobic conditions. The bacteria were, however, killed at a considerably slower rate by anaerobically incubated leukocytes than by leukocytes incubated in air. Thus, oxygen dependent mechanisms were essential for killing of P. acnes.

Using a modified Boyden chamber technique, variables in the cell environment were investigated and found to have a profound influence on the monocyte chemotactic responsiveness. The concentration of monocytes, pH of cell suspension, the presence of protein, the concentration and pH of cytotaxins, time allowed for migration and the temperature were all found to be critical factors for the migration response. Optimal concentrations of casein, zymosan-activated serum and N-f-methionyl-leucyl phenylalanine had equal cytotactic potency. The addition of gentamycin decreased the monocyte chemotactic responsiveness, while penicillin had no effect. Under standardized conditions the technical variability was moderate and the intra-individual variability in healthy donors was continuously less than twenty per cent.

The immunosuppressive drugs cyclosporin A (CyA) and methylprednisolone (MP) abolished the elaboration of the lymphokine leukocyte migration inhibitory factor (LIF) by mononuclear cells challenged by recall antigen. Suppression in both cases was reversible upon removal of the drugs, and participation of T suppressor cells of their mediators could not be demonstrated. The CyA-induced effect was exerted in the early stage of lymphocyte activation (less than 60 min), whereas MP still inhibited LIF release when added 60 min after the antigen. In contrast to earlier findings that the drugs failed to affect the release of T cell-activating factor (TAF) and lymphocyte-activating factor (LAF) from macrophages (M-phi's) stimulated by phorbol myristate acetate. MP (but not CyA) markedly reduced TAF production by M-phi's incubated with tuberculin. M-phireover, partially purified TAF and LAF both restored LIF production in the presence of CyA (but not MP), an effect not mimicked by the T cell product T cell growth factor. However, suppression by both drugs was abrogated by exogenous cGMP. Hence, CyA seems to obstruct the interaction between TAF/LAF and the immune T cell, whereas MP affects antigen-induced T cell activation at the Mo level as well as the level of lymphokine production and/or release. The effects of both drugs seem related to intracellular events involving cGMP.

The influence of serum on the motility of normal monocytes in mononuclear cell preparations was investigated using a modified Boyden assay. Undiluted sera from 9 patients with active SLE and from 6 healthy controls were studied, using pooled normal serum as a reference. When the cells were suspended in SLE serum, both spontaneous motility, and motility in response to zymosan treated reference serum, were reduced. By contrast, the capacity of the SLE sera to generate chemotactic activity on zymosan treatment was hardly affected at all. In zymosan treated control sera, pronounced spreading and decreased motility of monocytes were observed, while zymosan treatment of SLE serum promoted spreading and increased the motility of cells. No consistent relationship was found between complement components and C1q binding immune complexes and the decreased monocyte motility in the SLE sera tested. Cell motility in the assay remained unaffected by the addition of prednisolone to the reference serum.

The antibody response, measured as total immunoglobulin, of 66 splenectomized children to a 14-valent pneumococcal capsular polysaccharide vaccine was determined by an enzyme-linked immunosorbent assay. It did not differ significantly from that of 12 non-splenectomized children for 10 of the 14 polysaccharide antigens studied, but was lower for polysaccharide types 2, 3, 8 and 12F. Significant responses of both IgG and IgM antibody against all four antigens studied were found in 10 splenectomized and against all 14 antigens in five non-splenectomized children. In 2/10 splenectomized and 1/5 non-splenectomized children the arbitrary IgG/IgM ratio was below 1 in contrast to the pattern found in the other 12 patients. The increase in anti-pneumococcal antibody after vaccination in seven non-splenectomized children receiving corticosteroid therapy was only significantly lower than that of 12 untreated non-splenectomized children against two of the 14 antigens, and similar or higher against all antigens in five splenectomized children receiving steroid therapy compared to 66 splenectomized children not receiving such therapy. In 22 splenectomized children 70% of the peak geometric mean total antibody concentration four weeks after vaccination was still present after two years. Adverse reactions to the vaccine included local reactions at the vaccination site in 56% and fever in 9%. Side-effects were correlated to the geometric mean concentration of total antibody present at the time of vaccination. Immunogenicity of each of the 14 vaccine antigens varied considerably, as did the responses of different individuals.