Macrophage Migration Inhibitory Factor (MIF) Promotes Increased Proportions of the Highly Permissive Th17-like Cell Profile during HIV Infection.

In this study, we evaluate the role of the MIF/CD74 axis in the functionality of CD4+ T lymphocytes (CD4TL) during HIV infection. MDMs from healthy donors were infected with a R5-tropic or Transmitted/Founder (T/F) HIV strain. At day 11 post-MDM infection, allogeneic co-cultures with uninfected CD4TLs plus MIF stimulus were performed. Cytokine production was evaluated by ELISA. MIF plasma levels of people with HIV (PWH) were evaluated by ELISA. The phenotype and infection rate of CD4TLs from PWH were analyzed after MIF stimulus. Intracellular cytokines and transcription factors were evaluated by flow cytometry. Data were analyzed by parametric or non-parametric methods. The MIF stimulation of HIV-infected MDMs induced an increased expression of IL-6, IL-1ß and IL-8. In CD4TL/MDM co-cultures, the MIF treatment increased IL-17A/RORγt-expressing CD4TLs. Higher concentrations of IL-17A in supernatants were also observed. These results were recapitulated using transmitted/founder (T/F) HIV-1 strains. The MIF treatment appeared to affect memory CD4TLs more than naïve CD4TLs. MIF blocking showed a negative impact on IL17A+CD4TL proportions. Higher MIF concentrations in PWH-derived plasma were correlated with higher IL-17A+CD4TL percentages. Finally, MIF stimulation in PWH-derived PBMCs led to an increase in Th17-like population. MIF may contribute to viral pathogenesis by generating a microenvironment enriched in activating mediators and Th17-like CD4TLs, which are known to be highly susceptible to HIV-1 infection and relevant to viral persistence. These observations establish a basis for considering MIF as a possible therapeutic target.

Chloroquine Induces ROS-mediated Macrophage Migration Inhibitory Factor Secretion and Epithelial to Mesenchymal Transition in ER-positive Breast Cancer Cell Lines.

Breast cancer (BC) is the leading cause of cancer-related death in women in the world. Since tumor cells employ autophagy as a survival pathway, it has been proposed that autophagy inhibition could be beneficial for cancer treatment. There are several onging clinical trials where autophagy is being inhibited (using chloroquine, CQ or hydroxychloroquine, HCQ) along with chemotherapy with promising results. However, there is also in vitro evidence in which autophagy inhibition can induce epithelial to mesenchymal transition (EMT) in cancer cells, indicating that, at least in some cases, this strategy could be detrimental for cancer patients. In this study, we found that the genetic inhibition of autophagy primed cells for EMT by inducing a decrease in E-cadherin protein levels, while CQ treatment decreased E-cadherin levels, induced morphological changes related to EMT, increased EMT-related transcription factor (EMT-TF) expression and migration in estrogen receptor positive (ER +) BC cell lines. Importantly, CQ treatment increased intracellular reactive oxygen species (ROS) which induced the secretion of macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine related to malignancy. Both ROS production and MIF secretion were responsible for the mesenchymal morphology and increased migratory capacity induced by CQ. Our results indicate that CQ treatment increased malignancy by inducing ROS production, MIF secretion and EMT and suggest that autophagy inhibition in ER + BC patients might have detrimental effects. Our data indicates that a careful selection of patients should be performed in order to determine who will benefit the most from autophagy inhibition with available pharmacological agents for the treatment of breast cancer.

BEWO trophoblast cells and Toxoplasma gondii infection modulate cell death mechanisms in THP-1 monocyte cells by interference in the expression of death receptor and intracellular proteins.

Crosstalk between trophoblast and monocytes is essential for gestational success, and it can be compromised in congenital toxoplasmosis. Cell death is one of the mechanisms involved in the maintenance of pregnancy, and this study aimed to evaluate the role of trophoblast in the modulation of monocyte cell death in the presence or absence of Toxoplasma gondii infection. THP-1 cells were stimulated with supernatants of BeWo cells and then infected or not with T. gondii. The supernatants were collected and analyzed for the secretion of human Fas ligand, and cells were used to determine cell death and apoptosis, cell death receptor, and intracellular proteins expression. Cell death and apoptosis index were higher in uninfected THP-1 cells stimulated with supernatants of BeWo cells; however, apoptosis index was reduced by T. gondii infection. Macrophage migration inhibitory factor (MIF) and transforming growth factor (TGF)-ß1, secreted by BeWo cells, altered the cell death and apoptosis rates in THP-1 cells. In infected THP-1 cells, the expression of Fas/CD95 and secretion of FasL was significantly higher; however, caspase 3 and phosphorylated extracellular-signal-regulated kinase (ERK1/2) were downregulated. Results suggest that soluble factors secreted by BeWo cells induce cell death and apoptosis in THP-1 cells, and Fas/CD95 can be involved in this process. On the other hand, T. gondii interferes in the mechanism of cell death and inhibits THP-1 cell apoptosis, which can be associated with active caspase 3 and phosphorylated ERK1/2. In conclusion, our results showed that human BeWo trophoblast cells and T. gondii infection modulate cell death in human THP-1 monocyte cells.

The Novel Role of MIF in the Secretion of IL-25, IL-31, and IL-33 from PBMC of Patients with Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune inflammatory joint disease with complex pathogenesis associated with cytokine dysregulation. Macrophage migration inhibitory factor (MIF) plays a role in systemic inflammation and joint destruction in RA and could be associated with the secretion of other immune-modulatory cytokines such as IL-25, IL-31, and IL-33. For the above, our main aim was to evaluate the IL-25, IL-31, and IL-33 secretion from recombinant human MIF (rhMIF)-stimulated peripheral blood mononuclear cells (PBMC) of RA patients. The rhMIF and lipopolysaccharide (LPS) plus rhMIF stimuli promote the secretion of IL-25, IL-31, and IL-33 (p < 0.05) from PBMC of RA patients. The study groups, the different stimuli, and the interaction between both showed a statistically significant effect on the secretion of IL-25 (p < 0.05) and IL-31 (p < 0.01). The study of the effect of the RA patient treatments and their interaction with the effect of stimuli did not show an interaction between them. In conclusion, our study generates new evidence for the role of MIF in the secretion of IL-25, IL-31, and IL-33 and its immunomodulatory effect on RA.

MIF promotes a differential Th1/Th2/Th17 inflammatory response in human primary cell cultures: Predominance of Th17 cytokine profile in PBMC from healthy subjects and increase of IL-6 and TNF-α in PBMC from active SLE patients.

Macrophage migration Inhibitory Factor (MIF) is a cytokine associated with the pathogenesis of autoimmune inflammatory diseases. There is evidence that MIF functions in a positive-feedback-loop with proinflammatory cytokines and could perpetuate the inflammatory process in Systemic Lupus Erythematosus (SLE).The aim of this study was to assess the effect of recombinant-human-MIF (rhMIF) on the expression of Th1, Th2 and Th17 cytokines in Peripheral Blood Mononuclear Cells (PBMC) from Healthy Subjects (HS) and SLE patients. The PBMC were isolated from SLE patients classified according to the 1997 SLE ACR criteria and HS donors; all subjects included were women from an unrelated Mexican-Mestizo population. The PBMC isolated were stimulated with rhMIF, LPS and ISO-1 in different combinations; Th1, Th2 and Th17cytokine profiles levels were determined by MAGPIX Bio-plex assay in supernatants from cell cultures. We observed in supernatants of PBMCs from HS treated with rhMIF a predominance of Th17 cytokine profile with an increase of IL-17A, IL-17F and IL-21 versus PBMCs from SLE patients, which showed an inflammatory profile represented by increase of IL-6 cytokine. According to SLE remission/activity presented at enrollment in the study (Mex-SLEDAI index), the PBMC from active SLE patients showed higher levels of TNF-α and IL-6 versus PBMC from remission SLE patients. In conclusion, our results suggest that MIF can induce a differential inflammatory response in physiological and pathological conditions with a predominance of a Th17 cytokine profile in PBMC from HS and an increase in TNF-α and IL-6 expression in PBMC from active SLE patients.

Th1/Th17 Cytokine Profile is Induced by Macrophage Migration Inhibitory Factor in Peripheral Blood Mononuclear Cells from Rheumatoid Arthritis Patients.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is an immunoregulatory cytokine that plays a crucial role as a regulator of the innate and adaptive immune responses and takes part in the destructive process of the joint in rheumatoid arthritis (RA) by promoting angiogenesis and inducing proinflammatory cytokines and matrix metalloproteinases (MMP). We evaluated if recombinant human MIF (rhMIF) induces the production of TNF-α, IFN-γ, IL-1ß, IL-6, IL-10, IL-17A, and IL- 17F in peripheral blood mononuclear cells (PBMC) from RA patients and control subjects (CS). METHODS: The PBMC from RA patients and CS were stimulated for 24 hours with combinations of LPS, rhMIF or the MIF antagonist ISO-1. Cytokine profiles were measured using a multiplex immunoassay and, macrophage migration inhibitory factor (MIF) was determined by ELISA kit. RESULTS: The PBMC of CS and RA produced Th1 and Th17 cytokines under stimulation with rhMIF, however, this effect was higher in the cells of RA patients. The rhMIFstimulated PBMC from RA patients produced higher levels of Th1 and Th17 cytokines in comparison with unstimulated cells: TNF-α (538.81 vs. 5.02 pg/mL, p<0.001), IFN-γ (721.90 vs. 8.40 pg/mL, p<0.001), IL-1ß (150.14 vs. 5.17 pg/mL, p<0.05), IL-6 (19769.70 vs. 119.85 pg/mL, p<0.001), IL-17A (34.97 vs. 0.90 pg/mL, p<0.01) and IL-17F (158.43 vs. 0.92 pg/mL, p<0.001). CONCLUSION: These results highlight the potential role of MIF in the establishment of the chronic inflammatory process in RA via Th1 and Th17 cytokine profile induction and provide new evidence of the role of MIF to stimulate the IL-17A and IL-17F expression in PBMC from RA and CS.

Macrophage migration inhibitory factor induces phosphorylation of Mdm2 mediated by phosphatidylinositol 3-kinase/Akt kinase: Role of this pathway in decidual cell survival.

The phosphatidylinositol 3-kinase (PI3K)/Akt pathway has an anti-apoptotic effect through several downstream targets, which includes activation of the transformed mouse 3T3 cell double-minute 2 (Mdm2) protein, its translocation to the nucleus and degradation of the tumor suppressor p53. We show that Mif, the Macrophage Migration Inhibitory Factor, an important cytokine at the maternal fetal interface in several species, triggers phosphorylation of Mdm2 protein in a PI3K/Akt-dependent manner, thereby preventing apoptosis in cultured mouse decidual cells. Inhibition of Akt and PI3K suppresses the pathway. Mif treatment also changes the nuclear translocation of p53 and interferes with the apoptotic fate of these cells when challenged with reactive oxygen species. In conclusion, an important mechanism has been found underlying decidual cell survival through Akt signaling pathway activated by Mif, suggesting a role for this cytokine in decidual homeostasis and in the integrity of the maternal-fetal barrier that is essential for successful gestation.

Effect of macrophage migration inhibitory factor (MIF) in human placental explants infected with Toxoplasma gondii depends on gestational age.

Because macrophage migration inhibitory factor (MIF) is a key cytokine in pregnancy and has a role in inflammatory response and pathogen defense, the objective of the present study was to investigate the effects of MIF in first- and third-trimester human placental explants infected with Toxoplasma gondii. Explants were treated with recombinant MIF, IL-12, interferon-γ, transforming growth factor-ß1, or IL-10, followed by infection with T. gondii RH strain tachyzoites. Supernatants of cultured explants were assessed for MIF production. Explants were processed for morphologic analysis, immunohistochemistry, and real-time PCR analysis. Comparison of infected and stimulated explants versus noninfected control explants demonstrated a significant increase in MIF release in first-trimester but not third-trimester explants. Tissue parasitism was higher in third- than in first-trimester explants. Moreover, T. gondii DNA content was lower in first-trimester explants treated with MIF compared with untreated explants. However, in third-trimester explants, MIF stimulus decreased T. gondii DNA content only at the highest concentration of the cytokine. In addition, high expression of MIF receptor was observed in first-trimester placental explants, whereas MIF receptor expression was low in third-trimester explants. In conclusion, MIF was up-regulated and demonstrated to be important for control of T. gondii infection in first-trimester explants, whereas lack of MIF up-regulation in third-trimester placentas may be involved in higher susceptibility to infection at this gestational age.

Do interleukin-6 and macrophage-migration inhibitory factor play a role during sex-associated susceptibility in murine cysticercosis?

In murine Taenia crassiceps cysticercosis, females sustain larger intensities of infection than males. However, during chronic infection, this difference disappears and males show a feminization process. To further study the role of two cytokines, interleukin-6 (IL-6) and macrophage-migration inhibitory factor (MIF), known to be involved in immunoendocrinological processes during sex-associated susceptibility in cysticercosis, IL-6 and MIF gene knockout (KO) mice were infected, and the number of parasites and serum sex-steroid levels were measured. Results show that IL-6 and MIF KO mice of both genders infected with T. crassiceps cysticerci harbor similar numbers of parasites, with no change in sex-hormone levels. However, in wild-type strains, females have twice as many parasites as males. At the same time, there is a decrease of 80% in testosterone and dihydrotestosterone serum levels, and a 100-fold increase in the levels of estradiol in infected male mice. These results suggest a role for both IL-6 and MIF genes in sex-associated susceptibility in murine T. crassiceps cysticercosis.

Mechanism of immunosuppression in leprosy: presence of suppressor factor(s) from macrophages of lepromatous patients

Human peripheral blood mononuclear cell proliferation induced by Mycobacterium leprae could...