Establishment of a Macrophage-activating Factor Assay System Using the Human Monocytic Cell Line THP-1

BACKGROUND

As the mechanism of macrophage activation is not well-understood, standardization of an assay system for measuring phagocytic activities of macrophages will be useful for research on macrophages. Previously, we established a novel standardized macrophage-activating factor (MAF) assay system using U937.

MATERIALS AND METHODS

Using the human monocytic cell line THP-1, another standardized MAF assay system was established. Characteristic gene expression of U937- and THP-1-derived macrophages was compared by gene expression microarray analysis.

RESULTS

Both U937- and THP-1-derived macrophages showed obvious phagocytic activities with unique characteristics and, therefore, could not be assigned to a single sub-type.

CONCLUSION

Activation of macrophages is an intricate cellular process. Comparison of our two novel assay systems provides new insights into macrophage activation mechanisms.

Adjuvant effect of mushroom glucan and bovine lactoferrin upon Aeromonas hydrophila vaccination in catla, Catla catla (Hamilton)

Mushroom glucan and bovine lactoferrin (Lf), known for their immunostimulatory potential, were used as adjuvant in conjunction with a formalin-killed Aeromonas hydrophila vaccine in catla, Catla catla. In vitro antigen-specific responsiveness of catla leucocytes and protective responses against experimental challenge with homologous antigen were monitored following immunization. Antigen-specific proliferation, 'macrophage activating factor' (MAF) production and antibody production were significantly higher in fish injected with glucan adjuvanted vaccine. Lf adjuvanted preparations showed a weak proliferative response and MAF production, although the antibody production was significantly higher than the controls. A good degree of protection was achieved with the glucan adjuvanted vaccine. However, in spite of producing significant anti-A. hydrophila antibody, Lf adjuvanted vaccine did not confer any protection following challenge with A. hydrophila. The potential of adjuvanticity of mushroom glucan and bovine Lf in intraperitoneal vaccination is discussed.

Gc protein-derived macrophage activating factor (GcMAF): isoelectric focusing pattern and tumoricidal activity

BACKGROUND

Gc protein is the precursor for Gc protein-derived macrophage activating factor (GcMAF), with three phenotypes: Gc1f, Gc1s and Gc2, based on its electrophoretic mobility. The difference in electrophoretic mobility is because of the difference in its posttranslational sugar moiety composition.

MATERIALS AND METHODS

We compared the difference between Gc protein and GcMAF electrophoretic mobility using the isoelectric focusing (IEF) method. The tumoricidal activity of GcMAF-treated macrophage was evaluated after coculture with L-929 cell. The tumoricidal mechanism was investigated using TNF bioassay and nitric oxide (NO) release.

RESULTS

The difference in Gc protein and GcMAF electrophoretic mobility was detected. The tumoricidal activity of GcMAF-treated macrophage was detected, but no release of TNF and NO was detected.

CONCLUSION

The difference of isoelectric focusing mobility in Gc protein and GcMAF would be useful to develop a GcMAF detection method. GcMAF increased macrophage tumoricidal activity but TNF and NO release were not involved in the mechanism.

Nitric oxide inducing factor as a measure of antigen and mitogen-specific T cell responses in chickens

We describe here an assay to measure responses of T cells to in vitro stimulation with antigens and a T cell mitogen (ConA). Spleen cells from chickens immunized with live viruses and an inactivated antigen produced macrophage activating factors (MAF) in response to in vitro stimulation with homologous antigens. The production of MAF, quantitated by the induction of NO in a retrovirus transformed macrophage cell line, HD11 (Beug et al., 1979, Cell 18, 375) was antigen-specific and correlated well with T cell proliferation. Further studies showed that production of MAF was abrogated by cyclosporin A, anti-CD4 and anti-CD8 monoclonal antibodies. These data suggested that production of MAF required T cell activation and can be used as measure of antigen and mitogen-specific T cell responses in chickens.

Immunohistochemical analysis of markers for different macrophage phenotypes and their use for a forensic wound age estimation

A total of 117 vital skin wounds (post infliction intervals between a few seconds and 7 months), 20 postmortem wounds and skin specimens with beginning or advanced signs of putrefaction were investigated. Different markers for macrophage maturation (27 E 10, RM 3/1, 25 F 9, G 16/1) were analyzed by immunohistochemistry. The early stage inflammation marker 27 E 10 stained macrophages, but also monocytes and neutrophilic granulocytes localized in blood vessels or bleeding induced postmortem and therefore provided no further information for a forensic wound age estimation in comparison to the routine histological detection of macrophages. The antigens recognized by the RM 3/1- (intermediate stage inflammation marker) and 25 F 9-antibodies (late stage inflammation marker) were expressed exclusively by histiocytes and inflammatory cells that had migrated from the blood vessels as part of the acute inflammatory response associated with an intravital reaction. The morphometrical analysis revealed positive results (defined as at least a two-fold increase in number in 2 or more microscope fields when compared to the maximum value of histiocytes found in uninjured skin) for the RM 3/1- or 25 F 9-antibody earliest in wounds aged 7 or 11 days, respectively. Similarly to the 25 F 9-antibody, the chronic stage inflammation marker (G 16/1) reacted with a macrophage subpopulation first detectable 12 days after wounding but showed positive results in a comparably reduced percentage of cases. On the other hand, this marker did not stain a relevant number of resident macrophages thus facilitating the evaluation of the specimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Macrophage activation factors and cytokines in peritoneal fluid from patients with endometriosis

Endometriosis is often associated with infertility, which might be a consequence of intraperitoneal macrophage activation and various immunological events related to it. To determine what triggers macrophage activation and what immunologic conditions occur in the peritoneal cavity of a patient with endometriosis, we measured the amounts of phospholipase A2, cholesterol fractions (HDL, LDL, and VLDL), interleukins (IL)-1 and 6, granulocyte-macrophage-colony stimulating factor (GM-CSF), and phosphatidylserine in peritoneal fluid. Peritoneal-fluid samples were collected during laparoscopy or laparotomy from 14 patients with endometriosis and from 11 patients with other diseases (5 with myoma uteri, 5 with benign ovarian cysts and 1 with a double uterus) as controls. With regard to phospholipase A2, there were no significant differences between the endometriosis group and the control group. LDL was significantly lower in the endometriosis group than in the control (p < 0.05). The levels of IL-1 and GM-CSF were similar in both groups; IL-6, however, was higher in 7 endometriosis patients with associated infertility than in the 9 non-endometriosis fertile patients. These findings suggest that inflammatory tissues are not related to the activation of intraperitoneal macrophages in endometriosis patients. Cholesterol fractions (HDL or LDL) might participate in macrophage activation in these patients, but this remains to be clarified. The high IL-6 levels observed in infertile endometriosis suggest that some immunological events that prevent patients from becoming pregnant take place in women with endometriosis-associated infertility.

Intracellular localization of a lipopeptide macrophage activator: immunocytochemical investigations and EELS analysis on ultrathin cryosections of bone marrow-derived macrophages

Synthetic lipopeptides, structurally derived from the N-terminal part of bacterial lipoprotein, constitute macrophage and B-lymphocyte activators. The molecular mechanism of macrophage activation by lipopeptides still remains unclear. The purpose of our study was to determine the route and kinetics of lipopeptide distribution in bone marrow-derived macrophages. The intracellular localization of the C-terminally biotinylated lipodipeptide Pam3Cys-Ser was investigated on ultrathin cryosections using the biotinstreptavidin-gold system. Our findings indicate that the lipopeptide penetrates the plasma membrane and can already be found within the cytoplasm, the nuclear membrane, and within the nucleus after 2 min of stimulation. The pattern of lipopeptide distribution obtained 2 min after stimulation resembles that obtained after longer incubation times (8 and 20 min). Correlating distribution patterns were observed when using the method of electron energy loss spectroscopy (EELS). These findings are a clear indication for the rapid uptake of lipopeptides into eukaryotic cells, and are of importance for further studies of the immunostimulating properties of the bacterial lipopeptides and vaccines derived therefrom.