Biomedical subjects

M Goebeler

Publications and source records attributed to M Goebeler.

At least 73 records · Page 4Linked to original sources

PubMed1994

Expression of the calcium-binding proteins MRP8 and MRP14 in monocytes is regulated by a calcium-induced suppressor mechanism.

MRP8 and MRP14 are two calcium-binding proteins of the S-100 family the expression of which is restricted to distinct stages of monocytic differentiation. Heteromeric MRP8/MRP14 complexes have been shown to represent their biologically active forms. However, it is not as yet clear whether biochemical modification of complexes, or regulation on the transcriptional level, are responsible for the control of MRP8/MRP14 expression. Employing Western-blot analysis and metabolic labelling we have demonstrated that patterns and metabolism of MRP8/MRP14 complexes do not change during up- or down-regulation of MRP8/MRP14. By Northern-blot analysis it was shown that MRP8/MRP14 are regulated at the transcriptional level rather than by biochemical modification of the complexes. Elevation of intracellular calcium levels by A23187, as well as by thapsigargin, was found to lead to specific down-regulation of MRP8/MRP14 mRNA which is in contrast with data reported for inflammatory factors such as interleukin-1 or tumour necrosis factor alpha. Concomitant application of actinomycin D and calcium ionophore indicated that this suppressive effect is mediated by decreased synthesis rather than increased degradation of MRP8/MRP14 mRNA. Finally, we demonstrated that calcium-mediated down-regulation of MRP8-MRP14 can be antagonized by cycloheximide, suggesting that a calcium-induced repressor protein is responsible for suppression of MRP8-MRP14 at the transcriptional level. Our data indicate that the function of MRP8-MRP14 is restricted to events associated with early stages of myelomonocytic activation.

Antigens, Differentiation↗

PubMed1994

The monoclonal antibody MAC387 detects an epitope on the calcium-binding protein MRP14.

The present study was initiated to identify the antigen recognized by the monoclonal antibody (MAb) MAC387 which is widely used for phenotypical characterization of myelomonocytic cells in situ. MAC387 has been described to show a similar reaction pattern as antisera to a complex formed by the calcium-binding proteins MRP8 and MRP14. However, the exact nature of the molecule recognized by MAC387 has been controversial. Using Western blot analysis, MAC387 was found to detect a single protein band of 14 kDa in lysates of human monocytes and granulocytes. Transfection of embryonic lung fibroblasts L132 with either MRP8 or MRP14 cDNA revealed that MAC387 reacts with MRP14 but not MRP8. This finding was confirmed by dot blot analysis of recombinant MRP8 and MRP14. Our data thus provide unequivocal evidence that MAC387 is a monoclonal antibody directed against the calcium-binding protein MRP14.

Animals↗

PubMed1994

Macrophages and angiogenesis.

Macrophages are supposed to play a key role in inflammatory and tumor angiogenesis. Their importance derives from (1) their ubiquitous presence in normal and especially inflamed tissues, (2) their potential to become activated in response to appropriate stimuli, and (3) their repertoire of secretory products. By release of proteases, growth factors (bFGF, GM-CSF, TGF-alpha, IGF-I, PDGF, VEGF/VPF, TGF-beta), and other monokines (IL-1, IL-6, IL-8, TNF-alpha, substance P, prostaglandins, interferons, thrombospondin 1), activated macrophages have the capability to influence each phase of the angiogenic process, such as alterations of the local extracellular matrix, induction of endothelial cells to migrate or proliferate, and inhibition of vascular growth with formation of differentiated capillaries. This review describes macrophage physiology and the influence of macrophage secretory products on the different phases of angiogenesis in vitro and in vivo.

Animals↗

PubMed1994

Ultrastructural localization of the S-100-like proteins MRP8 and MRP14 in monocytes is calcium-dependent.

MRP8 and MRP14 are members of the S-100 family of Ca(2+)-binding proteins and are expressed by granulocytes and monocytes. Members of this family have been described to be involved in membrane and cytoskeleton interactions; we therefore studied the subcellular distribution of MRP8/MRP14 in cultured human monocytes at the ultrastructural level. Monospecific rabbit antisera against MRP8 and MRP14 and a monoclonal antibody (moAb 27E10), which exclusively recognizes the MRP8/MRP14 heterodimer but not the monomers, were used in both immunoperoxidase/preembedding- and immunogold/cryotechniques. Comparing non-stimulated monocytes with Ca2+ ionophore A23187-treated cells, we could demonstrate that MRP8 and MRP14 associate with membrane and cytoskeletal structures in a Ca(2+)-dependent manner. Employing moAb 27E10, MRP8/MRP14 complexes were shown to be translocated to these cellular components. In addition, immunogold double-labelling experiments revealed a clear co-localization of MRP8/MRP14 complexes with the type III intermediate filament vimentin. Analysis of immunogold-labelled cryosections of renal allografts after acute vascular rejection demonstrated that a subpopulation of infiltrating macrophages showed a similar association of MRP8/MRP14 to the cytoskeleton in situ; this finding emphasizes the in vivo relevance of our observations. We conclude that Ca(2+)-dependent translocation of MRP8/MRP14 occurs to distinct subcellular components suggesting a role of these proteins for the modulation of cytoskeletal and membrane interactions.

Antigens, Differentiation↗

PubMed1994

Substance P and calcitonin gene-related peptide modulate leukocyte infiltration to mouse skin during allergic contact dermatitis.

The effects of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) on leukocyte infiltration during allergic contact dermatitis (ACD) in mice were studied. Concomitant topical application of SP or CGRP with the allergen oxazolone resulted in enhanced leukocyte recruitment at the sites of challenge. Immunohistochemical studies revealed that the numbers of T-helper (L3T4+) and cytotoxic (Lyt-2) lymphocytes and infiltrating macrophages (BM8+) were increased. In addition, ICAM-1 and MHC class II molecule expression by these cells was enhanced after neuropeptide application. Analysis by confocal laser scanning microscopy revealed an increase in the immunoreactivity for SP and CGRP in nerve fibres during the course of ACD. Flow cytometry studies showed that SP and CGRP did not upregulate expression of the adhesion molecules ICAM-1 and VCAM-1 by murine endothelial cell lines in vitro. This suggests that increased infiltration of leukocytes during ACD is not a consequence of direct neuropeptide-promoted upregulation of endothelial adhesion molecules in vivo. In conclusion, our observations provide evidence for a modulatory role of neuropeptides in the pathogenesis of ACD.

Animals↗

PubMed1994

Differential regulation of the macrophage-specific surface antigen RM3/1 by cyclosporine, azathioprine, and dexamethasone.

CsA, AZA, and dexamethasone (DEX) were examined for their ability to modulate expression of surface antigens on human monocytes. Peripheral blood monocytes were cultured for 1 day, treated with various concentrations of immunosuppressants, and subsequently analyzed for expression of macrophage differentiation antigen RM3/1, intercellular adhesion molecule-1 (CD54), beta 2-integrin (CD18), and HLA-DR using flow cytometry and indirect immunofluorescence microscopy. The RM3/1 antigen was found to be significantly down-regulated by CsA and AZA in a dose-dependent manner, whereas DEX led to a marked up-regulation of the RM3/1 molecule. In contrast, expression of CD54, CD18, and HLA-DR by macrophages was not affected by treatment with these immunosuppressants. Effects of AZA, CsA, and DEX on RM3/1 surface expression were shown to be mediated via modulation of RM3/1 de novo synthesis. Immunohistochemical analysis of rejected renal allografts revealed that the RM3/1 antigen is expressed by the majority of infiltrating macrophages. Our data demonstrate that CsA, AZA, and DEX differentially affect gene expression, resulting in distinct macrophage phenotypes. Characterization of the RM3/1+ macrophage population in vitro and during the course of allograft rejection in vivo may thus provide further insights regarding the mode of immunosuppressant action on nonspecific effector mechanisms.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1994

Expression of murine VCAM-1 in vitro and in different models of inflammation in vivo: correlation with immigration of monocytes.

VCAM-1 (vascular cell adhesion molecule-1) is a cytokine-inducible adhesion molecule which is known to mediate adhesion of mononuclear cells to endothelial cells in vitro via binding to the integrin VLA-4 (very late antigen-4). To further elucidate the role and regulation of VCAM-1 in vivo, we compared in vitro and in vivo expression of VCAM-1 in response to cytokines and investigated immunohistochemically the expression of VCAM-1 in three murine models of experimental inflammation. These models differed with regard to the pathogenetic mechanism and the subsequent infiltrate: allergic contact dermatitis (ACD) to DNFB as a T cell-controlled, DTH type of inflammation, cutaneous infection with Leishmania major as a chronic granulomatous inflammation and the cauterized cornea as a model for acute inflammation. VCAM-1 was found to be markedly enhanced on vascular endothelia in all types of inflammation and after subcutaneous administration of LPS and TNF-alpha. Administration of IL-4, however, failed to induce VCAM-1 both in vivo and in vitro. The increased VCAM-1 expression in the inflammatory models correlated with the appearance of infiltrating monocytes/macrophages. A concomitant influx of CD4-positive/CD8-positive lymphocytes was only observed in ACD and Leishmaniasis.

Animals↗

PubMed1993

Resistance of mice to experimental leishmaniasis is associated with more rapid appearance of mature macrophages in vitro and in vivo.

Resistance to murine leishmaniasis has been related to the propagation of specific Th cell subsets (Th1 and Th2). This study shows that there are differences between resistant and susceptible mice in the initial myelomonocytic infiltrate, which precede the specific T cell response. After subcutaneous injection of 2 x 10(7) Leishmania major into footpads of resistant C57Bl/6 and susceptible BALB/c mice we performed immunohistochemical studies on the infiltrate. Two days after infection the percentage of more mature, F4/80-positive macrophages in the lesion increased faster in C57Bl/6 mice (63%) than in BALB/c mice (29%). The same strain-specific differences were observed after infection of corresponding strains of athymic mice (57.2% in C57Bl/6 nu/nu; 33.6% in BALB/c nu/nu), thus excluding a T cell-controlled phenomenon. After 1 wk the infiltrate in susceptible mice began to reveal significantly more cells containing MRP14, which is expressed by granulocytes and less mature monocytes but not by mature macrophages. No corresponding differences were found between athymic strains, suggesting that at this point organization of the infiltrate falls under control of protective T cells. In bone marrow cultures of BALB/c and C57Bl/6 mice, the percentage of F4/80-positive macrophages was also increasing faster in C57Bl/6 mice than in BALB/c mice. Increased expression of the F4/80 Ag was associated with higher leishmanicidal activity of C57Bl/6 macrophages. MRP14-positive bone marrow cells on the other hand were rarely infected by parasites. We suggest 1) that the earlier appearance of leishmanicidal macrophages in lesions of C57Bl/6 mice could influence propagation of either Th1 or Th2 cells by reduction of parasite load or by differential secretion of decisive cytokines and 2) that the diffuse accumulation of granulocytes and inflammatory monocytes in susceptible mice facilitates spread of disease.

Animals↗

PubMed1993

MRP8 and MRP14, S-100-like proteins associated with myeloid differentiation, are translocated to plasma membrane and intermediate filaments in a calcium-dependent manner.

MRP8 and MRP14 are two Ca(2+)-binding proteins of the S-100 family expressed by myelomonocytic cells. Both proteins assemble to noncovalently associated complexes in a Ca(2+)-dependent manner. Members of the S-100 family are known to play a role in cytoskeletal-membrane interactions; therefore, we investigated the subcellular distribution of MRP8/MRP14 and their complexes in human monocytes. Using differential centrifugation and subsequent Western blot or enzyme-linked immunosorbent assay analysis, we found that MRP8/MRP14 were almost completely translocated from the cytoplasma to membrane and cytoskeletal structures in a Ca(2+)-dependent manner. Using a cross-linking technique, complexed forms of MRP8/MRP14 were found to be associated with the plasma membrane. Analysis of MRP-transfected L132 cells showed that the MRP8 as well as the MRP14 component of the MRP8/MRP14 complex may independently bind to membrane and cytoskeletal structures. Furthermore, immunogold electron microscopy showed a colocalization of MRP8/MRP14 and the intermediate filament type III protein vimentin in A23187-treated monocytes. Our data indicate that, in analogy to other S-100-like proteins, MRP8 and MRP14 play a role in Ca(2+)-dependent cytoskeletal-membrane interactions. Restriction of MRP8/MRP14 expression to distinct stages of myelomonocytic differentiation suggests that these proteins are involved in highly specific pathways of intracellular signaling in phagocytes.

Antibodies, Monoclonal↗

PubMed1993

Expression of calcium-binding proteins MRP8 and MRP14 is associated with distinct monocytic differentiation pathways in HL-60 cells.

MRP8 and MRP14 are two calcium-binding proteins of the S-100 family which are expressed during distinct stages of monocytic maturation. To further investigate their regulation the human leukemic cell line HL-60 which can be induced to differentiate to monocytes/macrophages by 12-O-tetradecanoylphorbol 13-acetate (TPA), 1,25-(OH)2 Vitamin D3 (VD3), tumor necrosis factor-alpha (TNF-alpha) and interferon-g (IFN-g) were analyzed for expression of MRP8/MRP14. Employing Northern blotting, a sandwich enzyme-linked immunosorbent assay and immunocytochemical analysis we determined MRP8/MRP14 mRNA and protein levels, which were found to be elevated after VD3 and reduced after TPA treatment. TNF-alpha and IFN-g did not affect MRP8/MRP14 levels. Western blot analysis revealed that formation of MRP8/MRP14 to biologically active complexes which has previously been shown to be a calcium-mediated process is not dependent on the differentiation stages of HL-60 cells. Restriction of MRP8/MRP14 expression to only distinct pathways of monocytic differentiation in HL-60 cells may thus reflect different functional phenotypes of monocytes/macrophages in vivo.

Calcium-Binding Proteins↗

PubMed1993

Expression and complex assembly of calcium-binding proteins MRP8 and MRP14 during differentiation of murine myelomonocytic cells.

In the present study we analyzed expression and biochemical properties of the two recently cloned calcium-binding proteins MRP8 and MRP14, both members of the S-100 family, in murine myelomonocytic cells. Expression of MRPs was found to be restricted to granulocytes and distinct stages of macrophage differentiation when compared to the expression of other markers (Mac-1, F4/80) in transformed macrophage cell lines (M1, RMB.TG, WEHI.TG, J774A, P388D) and resident and exudate peritoneal and tissue macrophages. Similarly, mRNA and protein levels of MRP8/MRP14 in murine bone marrow cells decreased during culture in L cell-conditioned medium. Applying a cross-linking technique, the formation of noncovalently associated heteromeric MRP8/MRP14 complexes of 25, 35, and 48 kd was demonstrated. Our data suggest that MRP8/MRP14 expression and complexation are characteristic for granulocytes and distinct stages of macrophage differentiation in mice. Analysis of the MRP8/MRP14+ phenotype of macrophages may provide further insights into the mechanisms underlying macrophage differentiation.

Animals↗

PubMed1993

Expression of intercellular adhesion molecule-1 by murine macrophages is up-regulated during differentiation and inflammatory activation.

Intercellular adhesion molecule-1 (ICAM-1, CD54) is a cell-surface glycoprotein which has been shown to play an important role for cell/cell interaction. Little is known about its occurrence in the murine monocyte/macrophage (M phi) lineage; hence, we analyzed ICAM-1 expression in cells and cell lines representing different stages of M phi maturation and studied its regulation during inflammatory activation. Flow cytometric analysis of bone marrow-derived M phi cultured in the presence of M-CSF, of thioglycollate-elicited peritoneal M phi and of M1 myeloblasts differentiated by lipopolysaccharide (LPS) treatment revealed that ICAM-1 is increasingly expressed during monocytic maturation. Accordingly, the myelomonocytic cell lines RMB.TG, WEHI.TG, J774A and P388D, which can be ordered in a linear differentiation sequence, showed increasing levels of ICAM-1 expression. Furthermore, ICAM-1 expression by bone marrow-derived M phi could be up-regulated by tumor necrosis factor-alpha, interferon-gamma and LPS. In two models of murine experimental inflammation, i.e. induction phase of contact hypersensitivity and cutaneous leishmaniasis, which are both dependent on M phi/T cell interaction, M phi expressing ICAM-1 were found to be highly abundant. In addition, it was demonstrated that co-culture of Leishmania maior parasites with bone marrow M phi led to up-regulation of ICAM-1 on these cells. In conclusion, our data clearly demonstrate that ICAM-1 is increasingly being expressed during maturation of murine M phi. Cytokines and inflammatory stimuli modulate M phi ICAM-1 expression as well thus referring to its considerable role during inflammation, e.g. providing accessory or costimulatory signals for T cell activation.

Animals↗

PubMed1993

Nickel chloride and cobalt chloride, two common contact sensitizers, directly induce expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule (ELAM-1) by endothelial cells.

Intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (ELAM-1, E-selectin) are endothelial surface molecules that play a role for leukocyte recruitment to sites of inflammation, e.g., during contact hypersensitivity. We studied the effects of sensitizing agents (2,4-dinitro-benzenesulfonic acid, metal salt haptens) and chemically related substances on endothelial adhesion molecule expression. Using flow cytometry and an enzyme-linked immunosorbent assay, NiCl2 and, to a lesser extent, CoCl2 were found to up-regulate ICAM-1, VCAM-1, and ELAM-1 expression on cultured human umbilical vein endothelium whereas the other substances tested showed no effects. Induction of adhesion molecules by NiCl2 required de novo mRNA and protein synthesis. Up-regulation could be blocked by kinase inhibitor H-7 but not staurosporine, suggesting involvement of phosphorylation events independent of protein kinase C activation. Concomitant application of NiCl2 and neutralizing antibodies to IL-1 did not block up-regulation by the hapten demonstrating that the latter did not act via an IL-1-dependent autocrine mechanism. Regarding ELAM-1 induction, pre-treatment for 24 h with NiCl2 produced hyporesponsiveness to IL-1 and TNF-alpha upon restimulation, suggesting that NiCl2 and these cytokines may partially share a common pathway of activation. In addition, analysis of cultured foreskin specimens revealed that NiCl2 may induce up-regulation of ELAM-1 on microvascular endothelium in vivo. Our data demonstrate that both Ni++ and Co++ to which simultaneous contact sensitivity is frequently observed have the ability to directly up-regulate endothelial adhesion molecules. This shared property may represent an adjuvant mechanism that promotes sensitization and elicitation events in contact hypersensitivity to these haptens.

Capillaries↗

PubMed1993

Changes in phenotypically distinct phagocyte subpopulations during nonspecific modulation of contact sensitization.

Environmental influences are increasingly recognized as nonspecific modulators triggering and aggravating allergic diseases. To obtain better insight into the pathomechanisms of these nonantigen-specific phenomena, we studied the augmenting and inhibitory effects of croton oil and glucocorticosteroid (GC) on the induction of murine allergic contact dermatitis. Application of the irritant croton oil simultaneously with the sensitization dose of the contact allergen oxazolone strongly amplified the inflammatory reaction (measured as ear swelling) during the effector phase. Immunohistologically, this effect correlated with an increased percentage of MRP8- and MRP14-positive phagocytes in the infiltrate of the early inflammatory reaction 8 h after sensitization with oxazolone plus croton oil as compared to oxazolone alone (62 vs. 27%; p < 0.05). Intravenously administered GC was used as an inhibitor of contact sensitization. The suppressive effect of GC on sensitization was dependent on the time of its application: suppression of the inflammatory reaction during the effector phase was clearly more pronounced when GC had been injected 1 day as compared to 1 h before sensitization. Correspondingly, the percentage of BM8-positive macrophages in the infiltrate of the early inflammatory reaction 8 h after sensitization was differentially decreased depending on the time of GC application: suppression of the percentage of BM8-positive macrophages was clearly more pronounced when GC had been injected 1 day as compared to 1 h before sensitization (17 vs. 25%; base value without GC 35%; p < 0.05). Furthermore, the percentage of BM8-positive macrophages in the inflammatory infiltrate of the effector phase was increased when sensitization had been enhanced by concomitant irritant contact dermatitis (47 vs. 59%; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

The contact allergens nickel chloride and cobalt chloride directly induce expression of endothelial adhesion molecules.

Activation of vascular endothelium is a key event in the initial phase of an inflammatory reaction e.g. to contact allergens. In the present study the effect of two common contact sensitizers, NiCl2 and CoCl2, on endothelial expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (ELAM-1, E-selectin) was studied. NiCl2 and CoCl2 were found to upregulate these adhesion molecules on human umbilical vein endothelial cells (HUVEC) in a dose- and time-dependent manner as could be demonstrated by flow cytometry and enzyme-linked immunosorbent assay. During organ culture of foreskin samples treatment with NiCl2 led to upregulation of ELAM-1 and ICAM-1 but not VCAM-1 on microvascular endothelium. Induction of adhesion molecules by NiCl2 was found to depend on de novo mRNA and protein synthesis and could be blocked by the protein kinase inhibitor H-7 in a dose-dependent manner but not by HA-1004 and staurosporine. An autocrine IL-1-dependent mechanism mediating NiCl2 effects could be excluded. Our data demonstrate that allergens as NiCl2 and CoCl2 are capable of directly activating endothelium which is an important step in evolving inflammatory reactions and may thus be of relevance for the pathogenesis of contact hypersensitivity.

Allergens↗

PubMed1992

The calcium-binding proteins MRP8 and MRP14 form a membrane-associated heterodimer in a subset of monocytes/macrophages present in acute but absent in chronic inflammatory lesions.

Monocytes/macrophages expressing an epitope recognized by a monoclonal antibody 27E10 are present in acute but are absent in chronic inflammatory disorders. This report shows that the 27E10 antigen is formed by noncovalent association of the two Ca(2+)-binding proteins MRP8 and MRP14 which belong to the S100 protein family. Identification has been confirmed immunochemically, by matrix-assisted UV-laser desorption/ionization spectrometry and by partial amino acid sequencing. Surface expression of the MRP8/MRP14 complex on a subset of monocytes is reported for the first time and shown to be up-regulated in a Ca(2+)-dependent manner. The 27E10 surface-positive monocytes isolated by cell separation techniques release high amounts of tumor necrosis factor-alpha and interleukin-1 beta in contrast to their 27E10 surface-negative counterparts thus emphasizing their role in inflammation.

Acute Disease↗

PubMed1992

Expression of the calcium-binding proteins MRP8 and MRP14 by early infiltrating cells in experimental contact dermatitis.

The immune response to an allergen is not only dependent on the inflammatory stimulus, but also on the genetic disposition of the individual. Important effector cells in the immune response are myelomonocytic cells in their various differentiation stages. We recently described the expression of MRP8 and MRP14, two calcium-binding proteins of the S-100 family, by these cells during inflammatory activation. Here, we investigated whether their expression in murine contact dermatitis is dependent on the stimulus by which dermatitis is elicited, and if it is related to the genetic constitution of different inbred strains of mice. Therefore we performed immunohistochemical studies on the distribution of MRP8- and MRP14-positive cells during experimentally induced allergic (ACD) and irritant contact dermatitis (ICD). Both forms of dermatitis were elicited in BALB/c and C57B1/6 mice. BALB/c mice were found to react with a more intense inflammatory response in both ACD and ICD (high responders) than C57Bl/6 mice (low responders). The expression of MRP8 and MRP14 in both forms of dermatitis correlated with the early influx of macrophages and with the cell density of the infiltrate. Also the percentage of MRP8- and MRP14-positive cells in the infiltrate during ACD or ICD was higher in the more intense inflammatory reaction of BALB/c mice compared to C57Bl/6 mice. We conclude that MRP8 and MRP14 define a differentiation stage of inflammatory macrophages and that their expression correlates with the activity of inflammatory processes.

Animals↗

PubMed1991

The severity of irritant contact dermatitis in various strains of mice correlates with endothelial expression of migration inhibitory factor (MIF).

Irritant contact dermatitis to croton oil in BALB/cByJ, C57Bl/6J and six recombinant inbred CxB strains of mice was investigated in relation to variations in endothelial migration inhibitory factor (MIF) reactivity. MIF has been shown to be a mediator of cellular immunity and operates as a differentiation signal inducing an inflammatory type of macrophage. The intensity of the ear swelling response reached a maximum 8 h after induction of contact dermatitis, with highest values in BALB/cByJ and CxB4/ByAH mice and weak reactions in CxB2/ByAE, CxB7/ByAK, C57Bl/6J and CxB1/ByAD mice. After the same time period (8 h) cryostat sections were immunostained for capillary endothelium expressing MIF. The most pronounced MIF expression was observed in BALB/cByJ mice, and CxB4/ByAH mice showed intermediate reactions and the other strains weak reactions. Endothelial MIF expression correlated well with the intensity of ear swelling (Pearson's correlation coefficient 0.82). Patterns of endothelial MIF expression in recombinant inbred strains suggest that endothelial MIF expression is not under the control of a single gene. Our data support the hypothesis that endothelial MIF expression plays a prominent role in inflammatory events and correlates with the severity of inflammation.

Animals↗