Role of granulocyte/macrophage colony-stimulating factor in the regulation of murine alveolar macrophage proliferation and differentiation

Granulocyte/macrophage (GM)-CSF is one of the hemopoietic growth factors that stimulates neutrophilic granulocyte and macrophage production by bone marrow progenitor cells. In this study, the effect of GM-CSF on the growth and differentiation of murine pulmonary alveolar macrophages (PAM) was investigated. In the presence of GM-CSF, normal murine PAM were induced to proliferate and develop into macrophage colonies with a dose-response curve similar to that of bone marrow GM colony-forming cells. PAM also responded to CSF-1, a lineage-restricted growth factor, but required much higher doses of CSF-1 and a longer incubation time for optimal colony formation. The proliferative response of PAM to CSF-1, however, was greatly enhanced by the concurrent addition of low doses of GM-CSF. In contrast, low doses of CSF-1 failed to potentiate the proliferative response of PAM to GM-CSF. Macrophages derived from GM-CSF cultures were rounder and less stretched and possessed less FcR-mediated phagocytic activity than cells produced in CSF-1 cultures. A study with hydrocortisone-induced monocytopenia showed that nearly one half of lung macrophages may be sustained by local proliferation of PAM without the continuous migration of blood monocytes. This study suggests that GM-CSF may play a major role in the production of PAM by two modes of action, 1) direct stimulation of cell proliferation and 2) enhancement of their responsiveness to CSF-1, thereby producing more mature and functionally competent macrophages.     

Both granulocyte-macrophage CSF and macrophage CSF control the proliferation and survival of the same subset of alveolar macrophages

The effect of granulocyte-macrophage (GM)-CSF on the proliferation of murine pulmonary alveolar macrophages in vitro was investigated. About 20% of freshly isolated alveolar macrophages formed colonies in both liquid and soft agar cultures in the presence of GM-CSF. GM-CSF was also found to be capable of maintaining the survival of these colony-forming cells in vitro. Moreover, GM-CSF could substitute for CSF-1 in maintaining the survival of CSF-1-responding pulmonary alveolar macrophage colony-forming cells in the absence of CSF-1. The concentration of GM-CSF required for maintaining the survival of colony-forming cells without proliferation was much lower than that required for the proliferation of these cells in vitro. It also enhanced the CSF-1-dependent clonal growth of alveolar macrophages. These data suggest that the colony-forming cells that respond to GM-CSF are the same subset of macrophages that form colonies in the presence of CSF-1. GM-CSF did not inhibit the binding of 125I-CSF-1 to alveolar macrophages at 0 degrees C. However, the preincubation of macrophages with GM-CSF at 37 degrees C resulted in a transient down-regulation of CSF-1 binding activity.     

Appearance of a Cell Surface Antigen Associated with the Activation of Peritoneal Macrophages in Mice

A relatively large population of murine peritoneal exudate macrophages induced with viable BCG or heat-killed Corynebacterium parvum was stained by the antiserum prepared against purified gangliotetraosyl ceramide (asialo GM1), while only a small population of peritoneal resident macrophages or peritoneal exudate macrophages induced with proteose peptone was stained. The cytotoxicity assay of those macrophages with anti-asialo GM1 plus complement supported these results. Peritoneal macrophages induced with BCG or C. parvum showed strong cytotoxicity for EL4 cells in vitro, while resident or peptone-induced peritoneal macrophages showed no cytotoxicity. BCG- or C. parvum-induced peritoneal cells contained both NK cells and cytotoxic macrophages, and either in vivo or in vitro pretreatment of the cells with anti-asialo GM1 and complement abolished the activities of both types of cells. Peptone-induced peritoneal macrophages incubated with lymphokines (LK) or lipopolysaccharide (LPS) were cytotoxic for EL4 cells and contained an increased number of cells stained by anti-asialo GM1. The cytotoxicity of these in vitro activated macrophages was reduced by treatment with anti-asialo GM1 plus complement. When peptone-induced peritoneal macrophages were incubated with LK, the number of cells stained by anti-Ia antiserum increased, but the number did not increase when the macrophages were incubated with LPS. Pretreatment of peptone-induced macrophages with anti-asialo GM1 plus complement did not affect the ability of the macrophages to be activated by LK. These results taken together strongly suggest that the antigen (s) reactive with anti-asialo GM1 is expressed on the cell surface of cytotoxic peritoneal macrophages in mice.     

Synergistic defense system by cooperative natural effectors against metastasis of B16 melanoma cells in H-2-associated control: different behavior of H-2+ and H-2- cells in metastatic processes

H-2+ and H-2- cells of B16 melanoma were established by repeated fluorescence-activated cell sorting. The H-2- line formed no metastasis in untreated C57BL/6 mice, whereas the H-2+ cells showed evidence of metastatic development. This difference was ascribed mainly to the increased susceptibility of H-2- cells to attack by natural effector mechanisms, particularly asialo GM1+ NK cells. After treatment with both anti-asialo GM1 serum and whole body irradiation (400 rad), numerous colonies of H-2- cells formed in the lung, whereas the metastasis was only marginally enhanced by irradiation and moderately by treatment with anti-asialo GM1 serum. With the H-2+ cells, treatment with each modality significantly increased the number of metastatic colonies. Therefore collaboration of asialo GM1+ NK cells and radiosensitive natural effectors seems to be the main mechanism involved in the synergistic effects on defense against H-2- cell metastasis, and to a lesser extent against H-2+ cell metastasis. Irradiation (1000 rad) to the right lung to abrogate the organ-associated defense increased the colonies, particularly in the H-2+ cells. On the other hand, treatment with anti-asialo GM1 serum increased colonization in the early phase of metastasis with H-2- cells and may have abolished asialo GM1+ NK cells capable of recognizing the reduced expression of H-2 antigens and eliminating H-2- cells in the blood-born phase. Natural defense mechanisms probably exert suppressive effects on the metastasis of H-2+ cells, mainly in the organ-associated phase after extravasation.     

L929 cell conditioned medium protects RAW264.7 cells from oxidative injury through inducing antioxidant enzymes

We have previously found that L929 cell conditioned medium (L929-CM) could protect mouse peritoneal macrophages from oxidative injury. To uncover the mechanism further, we investigated the effect of L929-CM on the oxidative injury caused by tbOOH to RAW264.7 cell lines. The results showed that L929-CM could protect RAW264.7 cells from oxidative injury (presented by cell morphology and cell survival rate), and L929-CM could also improve total superoxide dismutase (SOD), selenium-dependent and non-selenium-dependent glutathione peroxidase (SeGPx and non-SeGPx) activities in RAW264.7 cells. RT-PCR analysis showed that, L929-CM could induce plasma glutathione peroxidase (PLGPx) mRNA expression, while there was no inducing effect of L929-CM on phospholipid hydroperoxide glutathione peroxidase (PHGPx) mRNA expression in RAW264.7 cells. 5 microg/ml actinomycin D, 30 microg/ml cycloheximide (de novo protein synthesis inhibitor) and 50 microg/ml acetovanilone (intracellular superoxide anion production inhibitor) had no effects in attenuating the induction of PLGPx expression by L929-CM.     

Release of the cytokines colony-stimulating factor-1, granulocyte-macrophage colony-stimulating factor, and IL-6 by cloned murine vascular smooth muscle cells

Vascular smooth muscle cells were cultured from the mesenteric arteries of MRL lpr/lpr, MRL +/+, CBA/J, or C3H/HeJ mice and evaluated for their ability to synthesize a range of cytokines. Vascular smooth muscle cells of MRL +/+, MRL lpr/lpr, and CBA/J origin released biologically significant amounts of CSF-1 and IL-6 and relatively low but detectable amounts of granulocyte macrophage-CSF (GM-CSF) but not IL-2, IL-3, or IL-4. Vascular smooth muscle cells of C3H/HeJ origin produced lower amounts of CSF-1 and IL-6, and GM-CSF was barely detectable. Production of these cytokines did not require the exogenous growth factors present in FCS and occurred, although at lower levels, in serum-free medium supplemented with insulin, transferrin, and albumin. Cloned lines of MRL +/+ vascular smooth muscle cells, with electron microscopic and immunochemical properties of vascular smooth muscle cells, produced CSF-1, IL-6, and GM-CSF, establishing that vascular smooth muscle cells were a direct source of CSF-1, IL-6, and GM-CSF. These observations highlight the need for experiments to directly address the question of whether vascular smooth muscle cells constitutively produce these cytokines under physiologic conditions in vivo and suggest that vascular smooth muscle cells may participate actively in inflammation by releasing cytokines that are active on lympho-hemopoietic and other cells.     

锂对小鼠高增殖潜能集落形成细胞和粒巨噬系祖细胞体外增殖…

本文观察了锂对ＢＡＬＢ／Ｃ小鼠骨髓高增殖潜能集落形成细胞和粒巨噬系祖细胞ＣＦＵ－ＧＭ体外增殖的影响。ＨＰＰ－ＣＦＣ集落由ＩＬ－１,ＩＬ－６,ＷＥＨＩ３条件培养液及Ｌ９２９条件培养液所支持,而ＣＦＵ－ＧＭ由ＷＥＨＩ３－ＣＭ所支持。结果显示,ＬｉＣｌ浓度在０．４－２ｍｍｏｌ／Ｌ时呈现剂量依赖性抑制ＨＰＰ－ＣＦＣ增殖;而在０．４－１ｍｍｏｌ／Ｌ的浓度范围内,则对ＣＦＵ－ＧＭ的增殖起剂量依赖性促进作用。     

Interactions of phosphatidylinositol kinase, GTPase-activating protein (GAP), and GAP-associated proteins with the colony-stimulating factor 1 receptor.

The interactions of the macrophage colony-stimulating factor 1 (CSF-1) receptor with potential targets were investigated after ligand stimulation either of mouse macrophages or of fibroblasts that ectopically express mouse CSF-1 receptors. In Rat-2 cells expressing the mouse CSF-1 receptor, full activation of the receptor and cellular transformation require exogenous CSF-1, whereas NIH 3T3 cells expressing mouse c-fms are transformed by autocrine stimulation. Activated CSF-1 receptors physically associate with a phosphatidylinositol (PI) 3'-kinase. A mutant CSF-1 receptor with a deletion of the kinase insert region was deficient in its ability to bind functional PI 3'-kinase and to induce PI 3'-kinase activity precipitable with antiphosphotyrosine antibodies. In fibroblasts, CSF-1 stimulation also induced the phosphorylation of the GTPase-activating protein (GAP)-associated protein p62 on tyrosine, although GAP itself was a relatively poor substrate. In contrast to PI 3'-kinase association, phosphorylation of p62 and GAP was not markedly affected by deletion of the kinase insert region. These results indicate that the kinase insert region selectively enhances the CSF-1-dependent association of the CSF-1 receptor with active PI 3'-kinase. The insert deletion mutant retains considerable transforming activity in NIH 3T3 cells (G. Taylor, M. Reedijk, V. Rothwell, L. Rohrschneider, and T. Pawson, EMBO J. 8:2029-2037, 1989). This mutant was more seriously impaired in Rat-2 cell transformation, although mutant-expressing Rat-2 cells still formed small colonies in soft agar in the presence of CSF-1. Therefore, phosphorylation of GAP and p62 through activation of the CSF-1 receptor does not result in full fibroblast transformation. The interaction between the CSF-1 receptor and PI 3'-kinase may contribute to c-fms fibroblast transformation and play a role in CSF-1-stimulated macrophages.     

锂对小鼠高增殖潜能集落形成细胞和粒巨噬系祖细胞体外增殖的影响

本文观察了锂对ＢＡＬＢ／Ｃ小鼠骨髓高增殖潜能集落形成细胞（ＨＰＰ－ＣＦＣ）和粒巨噬系祖细胞ＣＦＵ－ＧＭ体外增殖的影响。ＨＰＰ－ＣＦＣ集落由ＩＬ－１、ＩＬ－６、ＷＥＨＩ３条件培养液（ＷＥＨＩ３－ＣＭ,含有ＩＬ－３）及Ｌ９２９条件培养液（Ｌ９２９－ＣＭ,含有Ｍ－ＣＳＦ）所支持,而ＣＦＵ－ＧＭ由ＷＥＨＩ３－ＣＭ所支持。结果显示,ＬｉＣｌ浓度在０．４－２ｍｍｏｌ／Ｌ时呈现剂量依赖性抑制ＨＰＰ－ＣＦＣ增殖;而在０．４－１ｍｍｏｌ／Ｌ的浓度范围内,则对ＣＦＵ－ＧＭ的增殖起剂量依赖性促进作用。这些结果提示ＬｉＣｌ对ＨＰＰ－ＣＦＣ和ＣＦＵ－ＧＭ的作用不同,可能锂有诱导ＨＰＰ－ＣＦＣ向成熟细胞分化的作用     

A mechanism for anti-asialo GM 1 antibody-induced anaphylactoid response in mice infected with Trichinella pseudospiralis

Intravenous injection of anti-asialo GM 1 antibody into mice infected with Trichinella pseudospiralis resulted in rapid acute illness or death accompanied by a dramatic rise in hematocrit values in these animals. The described antibody-induced changes were reversible by intravenous infusion of Hanks' balanced salt solution (HBSS). These effects were not seen in uninfected mice or in Trichinella spiralis-infected mice injected with anti-asialo GM 1 antibody. Viability of T. spiralis or T. pseudospiralis infective L1 larvae, both isolated worms and those housed in muscle, was unaffected by exposure to anti-asialo GM 1 antibody and complement. Infectivity of larvae of T. pseudospiralis decreased significantly following exposure to anti-asialo GM 1 antibody. Release of protein by T. pseudospiralis infective L1 larvae during incubation in the presence of anti-asialo GM 1 antibody was significantly greater than that released by worms incubated in normal rabbit serum or HBSS. Protein released by infective L1 larvae of T. pseudospiralis was identified as Trichinella excretory/secretory antigens by immunoblot. Intravenous injection of T. pseudospiralis excretory/secretory products resulted in anaphylaxis in T. pseudospiralis-infected mice but not in uninfected or T. spiralis-infected mice. Excretory/secretory product-induced anaphylactoid response also was reversible by the intravenous injection of HBSS or by injection of an antihistamine. Significantly higher levels of total IgE were observed in sera from mice infected with T. pseudospiralis compared to uninfected or T. spiralis-infected mice. Binding of anti-asialo GM 1 antibody to the surface of T. pseudospiralis muscle larvae induced release of excretory/secretory antigen by the parasite.(ABSTRACT TRUNCATED AT 250 WORDS)     

Impaired functional activity of alveolar macrophages from GM-CSF-deficient mice

We hypothesized that pulmonary granulocyte-macrophage colony-stimulating factor (GM-CSF) is critically involved in determining the functional capabilities of alveolar macrophages (AM) for host defense. To test this hypothesis, cells were collected by lung lavage from GM-CSF mutant mice [GM(-/-)] and C57BL/6 wild-type mice. GM(-/-) mice yielded almost 4-fold more AM than wild-type mice. The percentage of cells positive for the beta(2)-integrins CD11a and CD11c was reduced significantly in GM(-/-) AM compared with wild-type cells, whereas expression of CD11b was similar in the two groups. The phagocytic activity of GM(-/-) AM for FITC-labeled microspheres was impaired significantly compared with that of wild-type AM both in vitro and in vivo (after intratracheal inoculation with FITC-labeled beads). Stimulated secretion of tumor necrosis factor-alpha (TNF-alpha) and leukotrienes by AM from the GM(-/-) mice was greatly reduced compared with wild-type AM, whereas secretion of monocyte chemoattractant protein-1 was increased. Transgenic expression of GM-CSF exclusively in the lungs of GM(-/-) mice resulted in AM with normal or supranormal expression of CD11a and CD11c, phagocytic activity, and TNF-alpha secretion. Thus, in the absence of GM-CSF, AM functional capabilities for host defense were significantly impaired but were restored by lung-specific expression of GM-CSF.     

Transduction of human colony-stimulating factor-1 (CSF-1) receptor into interleukin-3-dependent mouse myeloid cells induces both CSF-1-dependent and factor-independent growth.

A retroviral vector encoding the receptor for human colony-stimulating factor-1 (CSF-1) was introduced into murine myeloid FDC-P1 cells which require interleukin-3 (IL-3) for their proliferation and survival in culture. Cells expressing the CSF-1 receptor (CSF-1R), selected by fluorescence-activated cell sorting in the continued presence of murine IL-3, formed colonies in semisolid medium and were able to proliferate continuously in liquid cultures containing human recombinant CSF-1. Thus, although they do not synthesize endogenous murine CSF-1R, FDC-P1 cells express the downstream components of the CSF-1 mitogenic pathway necessary for its signal-response coupling. After receptor transduction, slowly proliferating factor-independent variants that produced neither CSF-1 nor growth factors able to support the proliferation of parental FDC-P1 cells also arose. When the human CSF-1R was expressed in FDC-P1 cells under the control of an inducible metallothionein promoter, the frequencies of both CSF-1-responsive and factor-independent variants increased after heavy-metal treatment. In addition, a monoclonal antibody to human CSF-1R arrested colony formation by both the CSF-1-dependent and factor-independent cells but did not affect their growth in response to IL-3. Therefore, the induction of both the CSF-1-dependent and factor-independent phenotypes depended on expression of the transduced human CSF-1R.     

Interactions among granulocyte-macrophage colony-stimulating factor, macrophage colony-stimulating factor, and IFN-gamma lead to enhanced proliferation of murine macrophage progenitor cells

This report examines the actions of IFN-gamma on monocytopoiesis in murine liquid and semisolid bone marrow cultures. The proliferative response of bone marrow cells to macrophage CSF and granulocyte-macrophage CSF was assayed by measuring [3H]TdR uptake in a range of mouse strains. No interstrain difference in kinetics was observed for CSF-1 action, but GM-CSF acted significantly more rapidly on C57B1/6, Swiss, and to a lesser extent A/J mice than on BALB/c or CBA. IFN-gamma inhibited [3H]TdR incorporation elicited by CSF-1, and to a much lesser extent, GM-CSF. When the two CSF were added together, the effects were not additive; in fact, the response was the same as that seen with GM-CSF alone. When IFN-gamma was also added, the response was restored to the level seen with CSF-1 alone. In essence, the inhibitory actions of GM-CSF and IFN-gamma were mutually exclusive. The mechanism of these actions was investigated using colony assays. As expected, CSF-1 caused the formation of pure macrophage colonies, whereas GM-CSF stimulated production of macrophage, granulocyte, and mixed granulocyte macrophage colonies. When the two CSF were added in combination, the total colony count was greater than with either alone, but less than additive. The number of pure macrophage colonies was reduced to the number seen with GM-CSF alone. IFN-gamma reduced the number of colonies in the presence of CSF-1, but slightly increased the number with GM-CSF. In the presence of both CSF, IFN-gamma increased the colony count by around 25 to 40%, so that the numbers were greater than the combined total of CSF-1 plus GM-CSF added separately. Similar results were obtained in all mouse strains tested. The results suggest that the thymidine uptake data reflect changes in the number of progenitor cells responding rather than changes in cell cycle time. The results are discussed in terms of the possibility that coadministration of GM-CSF and CSF-1 could ameliorate the myelosuppressive actions of IFN-gamma in vivo, leading to more effective use of this agent as a biologic response modifier.     

Macrophage growth factor CSF-1 stimulates human monocyte production of interferon, tumor necrosis factor, and colony stimulating activity

CSF-1, a macrophage colony stimulating factor that causes proliferation and differentiation of progenitor cells, may also have effects on mature cells. Human peripheral blood monocytes were used to examine this possibility. Monocytes, separated from normal blood by density centrifugation and adherence, were incubated for 3 days with or without CSF-1 (1,000 U/ml, purified from the MIA PaCa pancreatic carcinoma line). The two groups of cells were then washed and tested for the ability, when induced, to produce several factors. When induced for 2 days with LPS and PMA, the monocytes produced a factor that was cytotoxic to L929 cells, and this factor was completely neutralized by polyclonal antibody to tumor necrosis factor. The cells preincubated with CSF-1 consistently produced an average of 12 times more of this factor than cells not exposed to CSF-1. Monocytes induced with LPS and PMA also produced a colony stimulating activity, as measured by colony formation when using mouse bone marrow. Cells preincubated with CSF-1, washed, and induced with LPS and PMA produced more than three times as much activity compared with control monocytes. When monocytes were induced with poly-I.C, 22-fold higher levels of interferon were produced by the cells exposed to CSF-1. These results show that CSF-1 has direct stimulating effects on mature human monocytes, and suggest that the macrophage growth factor may have clinical application in the treatment of infectious diseases and cancer.     

Flow cytometric analysis reveals the presence of asialo GM1 on the surface membrane of alloimmune cytotoxic T lymphocytes

Previous studies have demonstrated that natural killer (NK) cells express the glycolipid asialo GM1, as evidenced by the sensitivity of NK cells to treatment with anti-asialo GM1 serum and complement. Because alloimmune cytotoxic T lymphocytes (CTL) were found to be insensitive to treatment with anti-asialo GM1 serum and complement, it was concluded that asialo GM1 is expressed by NK but not by CTL. However, fluorescence studies indicated that a significant proportion of peripheral T cells did express asialo GM1. Flow cytometric studies were undertaken to determine the extent to which alloimmune CTL express asialo GM1. Affinity-purified, monospecific IgG anti-asialo GM1 antibodies were used to label cells from mixed lymphocyte cultures. Separation of asialo GM1-positive and -negative fractions by cell sorting revealed that the majority of CTL activity resides in the asialo GM1-positive population. When these studies are compared with similar studies of splenic NK activity, it is apparent that, despite the relative insensitivity of CTL to treatment with anti-asialo GM1 and complement, both CTL and NK activity are enriched in the asialo GM1-positive cell population obtained by cell sorting.     

Comparison of murine lymphokine-activated killer cells, natural killer cells, and cytotoxic T lymphocytes

Precursors and effectors of murine lymphokine-activated killer cells, natural killer cells, and cytotoxic T lymphocytes are compared. Natural killer cells are resistant to gamma-irradiation (1000 R) whereas precursors of lymphokine-activated killer cells and cytotoxic T lymphocytes are sensitive. Lower doses of gamma-irradiation (500 R) remove precursors for cytotoxic T lymphocytes but not lymphokine-activated killer cells. In addition, lymphokine-activated killer cells are regenerated before classical CTL after sublethal doses of gamma-irradiation. Natural killer cells are resistant to anti-Thy 1 and C' and anti-thymocyte serum, but sensitive to anti-asialo GM1 and complement. Precursors of cytotoxic T lymphocytes are sensitive to anti-Thy 1 and complement and anti-thymocyte serum, but are resistant to anti-asialo GM1 and complement. Precursors of lymphokine-activated killer cells are partially sensitive to anti-Thy 1 and complement and anti-thymocyte serum, but are resistant to anti-asialo GM1 and complement. Effector cells of cytotoxic T lymphocytes are sensitive to anti-Thy 1 and complement and resistant to anti-asialo GM1 and complement. Lymphokine-activated killer cell effectors are sensitive to anti-asialo GM1 and complement at 24 hr after activation. These effectors are more closely aligned with classical natural killer effectors. Lymphokine-activated killer effectors, 7 days after activation, are resistant to anti-asialo GM1 and complement and sensitive to anti-Thy 1 and complement. Relationships and differences among these cytotoxic subsets are discussed.     

Development and characterization of monoclonal antibodies to murine macrophage colony-stimulating factor

The macrophage-specific CSF (CSF-1), purified from murine L cell-conditioned medium, supports the in vitro proliferation and survival of various murine mononuclear phagocyte colony-forming cells. In this report we describe the production and functional characterization of two monoclonal antibodies (mAb) to CSF-1 obtained from rat X rat hybridomas. These two mAb are functionally distinct and recognize different epitopes on CSF-1. The mAb 5A1 binds to and inhibits the biologic function of CSF-1, and the second mAb (D24) binds CSF-1 but does not neutralize its biologic activity. The mAb 5A1 inhibits colony formation of tissue mononuclear phagocyte colony-forming cells as well as the committed bone marrow stem cells for both granulocytes and monocytes. The extent of colony inhibition by mAb 5A1 is dependent on the tissue origin of colony-forming cells. CSF-1 complexed with mAb 5A1 does not bind to its cell surface receptor of peritoneal exudate macrophages, and mAb 5A1 does not complex with cell-bound CSF-1. Although both bone marrow cell-derived macrophages and J774.1 macrophages bind CSF-1, mAb 5A1 inhibits the proliferation of only bone marrow cell-derived macrophages. The non-neutralizing mAb D24 does not block binding of CSF-1 to its cellular receptor, and it recognizes cell-bound CSF-1.     

Expression of colony-stimulating factors and inflammatory cytokines in the uterus of CD1 mice during days 1 to 3 of pregnancy.

Morphological and immunohistochemical analyses have documented the development of an acute inflammatory response, marked by the early appearance of granulocytes and later infiltration of mononuclear cells, in the uterus immediately after mating in mice. The response peaked on Day 1 and subsided by Day 3. In the present study, RNAs for macrophage colony-stimulating factor (CSF-1) and granulocyte-macrophage colony-stimulating factor (GM-CSF) and for interleukin 1 alpha (IL-1 alpha), IL-1 beta, interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-alpha) were detected in uterine tissue on Day 1. With the exception of IL-6, which was higher on Day 3 than on Day 1, and IL-1 alpha, which was not reduced on Day 2, concentrations of cytokine mRNA decreased to Day 3. No bioactivity was detected for GM-CSF, granulocyte colony-stimulating factor or IL-3, but CSF-1, IL-1, IL-6 and TNF-alpha were detected on Day 1 using bioassays. Changes in concentrations approximately paralleled those for mRNA. The concentrations of mRNA for CSF-1, IL-1, IL-6 and TNF-alpha were higher on Day 1 of pregnancy than in the uteri of cycling mice 24 h earlier. The data are consistent with previous morphological observations demonstrating the expression of an acute inflammatory response in the mouse uterus after mating. Further, the data demonstrate the expression of genes for CSF-1, GM-CSF, IL-1 alpha, IL-1 beta, IL-6 and TNF-alpha is induced in the uterus during mating.     

Control of macrophage lineage populations by CSF-1 receptor and GM-CSF in homeostasis and inflammation

There is recent interest in the role of monocyte/macrophage subpopulations in pathology. How the hemopoietic growth factors, macrophage-colony stimulating factor (M-CSF or CSF-1) and granulocyte macrophage (GM)-CSF, regulate their in vivo development and function is unclear. A comparison is made here on the effect of CSF-1 receptor (CSF-1R) and GM-CSF blockade/depletion on such subpopulations, both in the steady state and during inflammation. In the steady state, administration of neutralizing anti-CSF-1R monoclonal antibody (mAb) rapidly (within 3-4 days) lowered, specifically, the number of the more mature Ly6C(lo) peripheral blood murine monocyte population and resident peritoneal macrophages; it also reduced the accumulation of murine exudate (Ly6C(lo)) macrophages in two peritonitis models and alveolar macrophages in lung inflammation, consistent with a non-redundant role for CSF-1 (or interleukin-34) in certain inflammatory reactions. A neutralizing mAb to GM-CSF also reduced inflammatory macrophage numbers during antigen-induced peritonitis and lung inflammation. In GM-CSF gene-deficient mice, a detailed kinetic analysis of monocyte/macrophage and neutrophil dynamics in antigen-induced peritonitis suggested that GM-CSF was acting, in part, systemically to maintain the inflammatory reaction. A model is proposed in which CSF-1R signaling controls the development of the macrophage lineage at a relatively late stage under steady state conditions and during certain inflammatory reactions, whereas in inflammation, GM-CSF can be required to maintain the response by contributing to the prolonged extravasation of immature monocytes and neutrophils. A correlation has been observed between macrophage numbers and the severity of certain inflammatory conditions, and it could be that CSF-1 and GM-CSF contribute to the control of these numbers in the ways proposed.