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1.  Targeted Disruption of Migration Inhibitory Factor Gene Reveals Its Critical Role in Sepsis  
To study the biologic role of migration inhibitory factor (MIF), a pleiotropic cytokine, we generated a mouse strain lacking MIF by gene targeting in embryonic stem cells. Analysis of the role of MIF during sepsis showed that MIF−/− mice were resistant to the lethal effects of high dose bacterial lipopolysaccharide (LPS), or Staphylococcus aureus enterotoxin B (SEB) with d-galactosamine and had lower plasma levels of tumor necrosis factor α (TNF-α) than did wild-type mice, but normal levels of interleukin (IL)-6 and IL-10. When stimulated with LPS and interferon γ, macrophages from MIF−/− mice showed diminished production of TNF-α, normal IL-6 and IL-12, and increased production of nitric oxide. MIF−/− animals cleared gram-negative bacteria Pseudomonas aeruginosa instilled into the trachea better than did wild-type mice and had diminished neutrophil accumulation in their bronchoalveolar fluid compared to the wild-type mice. Thioglycollate elicited peritoneal exudates in uninfected MIF−/− mice, but showed normal neutrophil accumulation. Finally, the findings of enhanced resistance to P. aeruginosa and resistance to endotoxin-induced lethal shock suggest that the counteraction or neutralization of MIF may serve as an adjunct therapy in sepsis.
PMCID: PMC2192995  PMID: 9892616
migration inhibitory factor; gene-deficient mice; sepsis; lipopolysaccharide; Pseudomonas aeruginosa
2.  Macrophage migration inhibitory factor: a mediator of matrix metalloproteinase-2 production in rheumatoid arthritis 
Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by destruction of bone and cartilage, which is mediated, in part, by synovial fibroblasts. Matrix metalloproteinases (MMPs) are a large family of proteolytic enzymes responsible for matrix degradation. Macrophage migration inhibitory factor (MIF) is a cytokine that induces the production of a large number of proinflammatory molecules and has an important role in the pathogenesis of RA by promoting inflammation and angiogenesis.
In the present study, we determined the role of MIF in RA synovial fibroblast MMP production and the underlying signaling mechanisms. We found that MIF induces RA synovial fibroblast MMP-2 expression in a time-dependent and concentration-dependent manner. To elucidate the role of MIF in MMP-2 production, we produced zymosan-induced arthritis (ZIA) in MIF gene-deficient and wild-type mice. We found that MMP-2 protein levels were significantly decreased in MIF gene-deficient compared with wild-type mice joint homogenates. The expression of MMP-2 in ZIA was evaluated by immunohistochemistry (IHC). IHC revealed that MMP-2 is highly expressed in wild-type compared with MIF gene-deficient mice ZIA joints. Interestingly, synovial lining cells, endothelial cells, and sublining nonlymphoid mononuclear cells expressed MMP-2 in the ZIA synovium. Consistent with these results, in methylated BSA (mBSA) antigen-induced arthritis (AIA), a model of RA, enhanced MMP-2 expression was also observed in wild-type compared with MIF gene-deficient mice joints. To elucidate the signaling mechanisms in MIF-induced MMP-2 upregulation, RA synovial fibroblasts were stimulated with MIF in the presence of signaling inhibitors. We found that MIF-induced RA synovial fibroblast MMP-2 upregulation required the protein kinase C (PKC), c-jun N-terminal kinase (JNK), and Src signaling pathways. We studied the expression of MMP-2 in the presence of PKC isoform-specific inhibitors and found that the PKCδ inhibitor rottlerin inhibits MIF-induced RA synovial fibroblast MMP-2 production. Consistent with these results, MIF induced phosphorylation of JNK, PKCδ, and c-jun. These results indicate a potential novel role for MIF in tissue destruction in RA.
PMCID: PMC1779381  PMID: 16872482
3.  Macrophage Migration Inhibitory Factor Plays a Critical Role in Mediating Protection against the Helminth Parasite Taenia crassiceps  
Infection and Immunity  2003;71(3):1247-1254.
To determine the role of endogenous migration inhibitory factor (MIF) in regulation of immune response during murine cysticercosis caused by the helminth parasite Taenia crassiceps, we analyzed the course of T. crassiceps infection in MIF−/− BALB/c mice. MIF−/− mice were highly susceptible to T. crassiceps and developed significantly higher parasite loads compared to similarly infected MIF+/+ mice. Throughout the course of infection, Taenia crassiceps soluble antigen-stimulated spleen cells from both MIF+/+ and MIF−/− mice produced significant and comparable levels of interleukin-4 (IL-4), but those from MIF−/− mice produced significantly more IL-13, as well as gamma interferon (IFN-γ), suggesting that the susceptibility of MIF−/− mice to T. crassiceps was not due to the lack of IFN-γ production. Interestingly, low levels of both total and specific immunoglobulin G2a were observed in MIF−/− cysticercotic mice despite the high IFN-γ levels; in addition, peritoneal macrophages obtained from T. crassiceps-infected MIF−/− mice at different time points failed to respond efficiently to stimulation in vitro with lipopolysaccharide plus IFN-γ and produced significantly lower levels of IL-12, tumor necrosis factor alpha, and NO compared to those from MIF+/+ mice. These findings demonstrate that MIF plays a critical role in mediating protection against T. crassiceps in vivo. Moreover, these findings also suggest that impaired macrophage function rather than the lack of Th1 development may be responsible for mediating susceptibility to T. crassiceps.
PMCID: PMC148860  PMID: 12595439
4.  Migration-Inhibitory Factor Gene-Deficient Mice Are Susceptible to Cutaneous Leishmania major Infection 
Infection and Immunity  2001;69(2):906-911.
To determine the role of endogenous migration-inhibitory factor (MIF) in the development of protective immunity against cutaneous leishmaniasis, we analyzed the course of cutaneous Leishmania major infection in MIF gene-deficient mice (MIF−/−) and wild-type (MIF+/+) mice. Following cutaneous L. major infection, MIF−/− mice were susceptible to disease and developed significantly larger lesions and greater parasite burdens than MIF+/+ mice. Interestingly, antigen-stimulated lymph node cells from MIF−/− mice produced more interleukin-4 (IL-4) and gamma interferon (IFN-γ) than those from MIF+/+ mice, although the differences were statistically not significant. IFN-γ-activated resting peritoneal macrophages from MIF−/− mice showed impaired macrophage leishmanicidal activity and produced significantly lower levels of nitric oxide and superoxide in vitro. The macrophages from MIF−/− mice, however, produced much more IL-6 than macrophages from wild-type mice. These findings demonstrate that endogenous MIF plays an important role in the development of protective immunity against L. major in vivo. Furthermore, they indicate that the susceptibility of MIF−/− mice to L. major infection is due to impaired macrophage leishmanicidal activity rather than dysregulation of Th1 and Th2 responses.
PMCID: PMC97968  PMID: 11159984
5.  Maturation In Vivo of Schistosoma mansoni Schistosomula After Culture In Vitro with Granulocytes and Antibody 
Infection and Immunity  1983;39(1):225-232.
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.
PMCID: PMC347930  PMID: 6822415
6.  Passive Transfer by Cells of Type II Collagen-Induced Arthritis in Rats 
Journal of Clinical Investigation  1978;62(2):359-366.
To investigate the role of immunologic hypersensitivity to collagen in the causation of type II collagen-induced arthritis in rats, passive transfer experiments were performed. Wistar/Lewis rats used in these experiments were demonstrated to be histocompatible by prolonged skin graft survival and mixed lymphocyte cultures. Popliteal lymph node weight assays excluded a potential for graft-vs.-host reactivity in this strain. 9 of 32 naive rats developed arthritis after intravenous receipt of pooled spleen and lymph node cells from donors that had been injected intradermally with type II collagen emulsified in incomplete Freund's adjuvant. This passively transferred synovitis was evident clinically as well as histologically. In control cell transfer experiments involving a total of 97 recipients, transfer of arthritis was shown to require viable cells sensitized to type II collagen. These controls included 17 rats receiving cells from unimmunized donors, 20 recipients of cells from donors injected with incomplete Freund's adjuvant alone, and 24 recipients of cells from rats injected with type I collagen in adjuvant. Deliberate addition of solubilized type II collagen to unsensitized cells at the time of transfer or injection of heat-killed sensitized cells also did not cause arthritis in a total of 36 recipients. These latter two control groups indicate that disease transfer was not the result of antigen carry-over. Intravenous injection of sera from arthritic donors was incapable of passively transferring clinical or histologic synovitis in 30 recipients. Thus, these studies directly implicate immunologic sensitivity to the cartilage type of collagen in the etiology of this autoimmune disease.
PMCID: PMC371773  PMID: 27533
7.  Humoral and Cellular Sensitivity to Collagen in Type II Collagen-Induced Arthritis in Rats 
We have recently described a new animal model of arthritis induced by intradermal injection of a distinct type of collagen found in cartilage (type II collagen). Since immunologic sensitivity to collagen could play a role in the pathogenesis of this type II collagen-induced arthritis in rats, the ability of purified types of native collagens to induce cellular and humoral responses was quantified by antigeninduced tritiated thymidine incorporation into lymphocytes by collagen and passive hemagglutination, respectively. Rats injected intradermally with native heterologous or homologous type II collagens in adjuvant developed type-specific cellular as well as humoral reactivity. Types I and III collagens were less immunogenic than was type II. The latter collagen induced brisk cellular and humoral responses that were equivalent whether complete Freund's adjuvant or incomplete Freund's adjuvant were employed. Both responses could be induced by native type II collagens modified by limited pepsin digestion, indicating that they are not attributable to determinants in the telopeptide regions of the molecule. Thus, these studies demonstrate the unique immunogenic as well as arthritogenic properties of the type II collagen molecule and indicate that both result from a helical conformation of its structurally distinct α-chains. Further, they suggest that type II collagen may, by humoral or cellular mechanisms, provoke or perpetuate inflammation in other arthritic diseases.
PMCID: PMC372517  PMID: 618915
The Journal of Experimental Medicine  1974;140(5):1303-1316.
Highly purified populations of T and B lymphocytes obtained by affinity column separation were stimulated by antigen and their ability to produce two mediators, migration inhibitory factor (MIF) and lymphocyte mitogenic factor (LMF) was assessed. Both T- and B-cell populations made MIF; the production of MIF was antigen-specific using purified protein derivative of tuberculin, streptokinase-streptodornase, and Candida antigens. The MIF activity from both populations could not be attributed to antigen-antibody complexes as the inhibitory activity eluted from Sephadex G-100 columns in the same region corresponding to mol wt 23,000 daltons. Further studies indicate that the T cells producing MIF are proliferating cells whereas the B cells producing this mediator are not. In contrast, LMF was made only by T cells and not B cells when these populations were stimulated by antigen. The LMF induced the [3H]thymidine incorporation into both T and B cells obtained from donors lacking sensitivity to the antigens used to elicit the factor. Chromatographic studies indicate that LMF eluted from Sephadex G-100 in a fraction of mol wt 23,000 daltons where MIF is also found; however, since B cells produce MIF but not LMF, these two factors appear to be distinct from one another. Some of the implications of these findings are discussed. The explanation for the production or lack of production of MIF by lymphocytes obtained from patients with immunodeficiency disorders requires reinterpretation.
PMCID: PMC2139736  PMID: 4608321
It was reported previously that the incubation of normal guinea pig macrophages with partially purified products of activated lymphocytes resulted in altered macrophage function including increased cell adherence to culture vessels, spreading, phagocytosis, and glucose carbon-1 oxidation. Studies reported here demonstrate that such macrophages also exhibit enhanced bacteriostasis. Lymphocytes were stimulated with concanavalin A, the culture supernatant was chromatographed over Sephadex G-100 and the fraction of mol wt 25,000–55,000, rich in lymphocyte mediators, was cultured with normal guinea pig macrophages for 1–3 days. Macrophages incubated with fractions from unstimulated lymphocyte cultures served as controls. The resulting macrophage monolayers were infected with Listeria monocytogenes. Macrophages incubated with mediator-rich fractions exhibited 2- to 10-fold enhanced bacteriostasis compared to controls. Further studies indicate that this enhancement was attributable to intrinsic changes in the macrophages and not simply a consequence of the number of macrophages on the monolayers. The studies support the concept that macrophage bacteriostasis can be enhanced by lymphocyte mediators. However, macrophages, which have been preincubated directly with sensitive lymphocytes and antigen exhibit even greater bacteriostasis and sometimes bactericidal capacity, suggesting that either a labile lymphocyte factor or direct lymphocyte macrophage interaction may also be involved in bactericidal activity.
PMCID: PMC2180559  PMID: 4200649
As reported previously, antigenically stimulated guinea pig lymphocytes elaborate a soluble factor which activates macrophages in the sense of promoting increased adherence, spreading, phagocytosis, and glucose oxidation through the hexose monophosphate pathway. Further studies on the characteristics and kinetics of this substance were carried out. The activating factor could not be distinguished from a previously characterized lymphocyte mediator, migration inhibitory factor (MIF), on the basis of Sephadex G-100 gel filtration, CsCl density gradient centrifugation, or sensitivity to neuraminidase. It was, however, shown to be distinct from two other lymphocyte mediators, chemotactic factor for macrophages and lymphotoxin. The kinetics of activation were further studied. The data suggest that the 3 day period required by macrophages to manifest a response to the activating factor consists of two stages. In the first, requiring 1–2 days, the macrophages are refractory to the influence of activating factor, but undergo changes which render them receptive. In the second, they respond to activating factor with increased cell adherence and glucose oxidation. Once macrophages have been activated, the effect persists in the absence of activating factor for 24 h. Finally, it was shown that activation in unfractionated supernatants followed the same time-course as that in more purified fractions. The data suggests that the activating factor is the same as MIF and that, in vitro, macrophages respond to this substance with migration inhibition before they become sensitive to its activating influence.
PMCID: PMC2139484  PMID: 4119587
A single injection of ε,DNP-Lys7–10 can render previously sensitized guinea pigs specifically unreactive to subsequent intradermal challenge with that antigen. Antigen-reactive lymphocytes, as assayed by macrophage-migration in-inhibition or thymidine incorporation, were depleted from the peritoneal exudates of those animals. In contrast, it was intriguing to find that lymph node lymphocytes from such animals responded normally in the antigen-induced thymidine incorporation assay. These studies demonstrate a compartmentalization of antigen-reactive lymphocytes in desensitized animals which may account for the short-lived nature of this phenomenon.
PMCID: PMC2139091  PMID: 15776572
The Journal of Experimental Medicine  1971;133(6):1356-1376.
Sensitized lymphocytes were incubated in vitro with the specific antigen Supernatants from these cultures were chromatographed on Sephadex G-100 columns. Supernatant fractions containing MIF, chemotactic factor, and lymphotoxin, but free of antigen and antibody, were incubated with normal peritoneal exudate macrophages. Macrophage adherence, phagocytosis, spreading, motility, and direct hexose monophosphate oxidation were enhanced, while protein synthesis was unaffected. Thus, antigen-stimulated lymphocytes secrete a factor or factors which enhance certain macrophage functions. Implications for models of cellular immunity and cellular hypersensitivity are discussed.
PMCID: PMC2138934  PMID: 5576335
Suppression of delayed hypersensitivity in vivo is correlated in vitro with the absence of macrophage migration inhibition in the presence of the antigen used to induce partial tolerance. The suppression of delayed hypersensitivity is antigen-specific in vivo as well as in vitro. The lymphocytes, and not the macrophages, are the cells involved in the induction of tolerance in terms of delayed hypersensitivity which is characterized by an absence of migratory factor activity.
PMCID: PMC2138816  PMID: 5413331
The Journal of Experimental Medicine  1968;128(6):1451-1459.
The immunochemical specificity of antigen-induced inhibition of peritoneal exudate cell migration was studied in animals sensitized to chemically defined α,DNP(Lys)18 peptides. It was shown that sensitized peritoneal exudate cells could discriminate between various DNP-oligolysines. Only immunogenic members of the homologous series of α,DNP-L-lysines equal to or larger in size than the heptamer inhibited the migration of specifically sensitized peritoneal exudate cells. In contrast, nonimmunogenic α,DNP-L-lysines, a D-lysine containing stereoisomer of α,DNP L(Lys)9 (α,DNP-L4DL4) and (Lys)9ε, DNP were not inhibitory to the migration of peritoneal exudate cells derived from animals immunized to α,DNP(Lys)18. The exquisite specificity of the in vitro reaction of sensitized cells with antigen contrasts with the previously observed in vivo or in vitro specificity of anti-α,-DNP(Lys)n antibody, but parallels the specificity of the in vivo delayed or anamnestic response. These results suggest the presence of a still undefined but highly specific binding site, which functions as the cellular receptor for antigen on the sensitized lymphoid cell or on some "processing" cell.
PMCID: PMC2138577  PMID: 5688081
The Journal of Experimental Medicine  1965;122(6):1125-1134.
Peritoneal cells from guinea pigs exhibiting delayed hypersensitivity are inhibited from migrating in vitro by specific antigen. This inhibition is prevented by the addition of puromycin to the culture medium. The amount of puromycin necessary to prevent the inhibition by antigen also suppressed the incorporation of C14-leucine into peritoneal cell protein. Additional evidence that the action of puromycin is due to its inhibition of protein synthesis has been obtained with analogues of puromycin; those that inhibit protein synthesis also prevent the action of antigen on the cells, while those analogues that do not inhibit protein synthesis have no effect. Actinomycin also prevents the inhibition of sensitive cells by antigen while chloramphenicol has no effect. The data indicate that the inhibition of sensitive cell migration by antigen requires active protein synthesis. The possible mechanisms by which inhibition of protein synthesis may influence the in vitro reactions of delayed hypersensitivity are discussed.
PMCID: PMC2138096  PMID: 5853077
The Journal of Experimental Medicine  1965;122(6):1161-1171.
Peritoneal cells obtained from animals exhibiting delayed hypersensitivity are inhibited from migrating in vitro by specific sensitizing antigen. This test for the detection of delayed hypersensitivity was applied to the problem of cellular sensitivity in allergic encephalomyelitis (AE). The migration of peritoneal cells obtained from guinea pigs with AE was inhibited specifically by nervous tissue antigens. The specificity of this reaction was further studied. Neonatal rat nervous tissue, which was shown to lack the encephalitogenic antigen, i.e. did not produce AE when injected with complete adjuvant into guinea pigs and rats, did not inhibit the migration of cells from animals with AE. Adult rat nervous tissue, which readily produces AE, and thus contains the encephalitogenic antigen did inhibit the migration of such cells. The finding that cells from animals with AE display hypersensitivity which appears to be directed specifically to the encephalitogenic antigen strongly supports the view that such cells could play an important role in the pathogenesis of this disease.
PMCID: PMC2138099  PMID: 5873682
The Journal of Experimental Medicine  1964;120(6):1189-1200.
Peritoneal exudate cells from animals exhibiting delayed hypersensitivity are inhibited from migrating in vitro by specific antigen. This inhibition is completely abolished by pretreatment of the sensitive cells with trypsin. The action of trypsin is prevented by soybean trypsin inhibitor. The results of experiments with mixtures of normal and sensitive cells suggest that trypsin alters an immunologic capacity of the sensitive cells. Trypsinized sensitive cells are capable of passively transferring delayed hypersensitivity and peritoneal cells taken from recipient animals are inhibited from migrating in vitro by specific antigen. These results suggest that the cells rapidly resynthesize the material removed by trypsin. The possible nature of the material removed by trypsin is discussed.
PMCID: PMC2137791  PMID: 14238934

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