Donor T cell STAT3 deficiency enables tissue PD-L1-dependent prevention of graft-versus-host disease while preserving graft-versus-leukemia activity.

STAT3 deficiency (STAT3-/-) in donor T cells prevents graft-versus-host disease (GVHD), but the impact on graft-versus-leukemia (GVL) activity and mechanisms of GVHD prevention remains unclear. Here, using murine models of GVHD, we show that STAT3-/- donor T cells induced only mild reversible acute GVHD while preserving GVL effects against nonsusceptible acute lymphoblastic leukemia (ALL) cells in a donor T cell dose-dependent manner. GVHD prevention depended on programmed death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) signaling. In GVHD target tissues, STAT3 deficiency amplified PD-L1/PD-1 inhibition of glutathione (GSH)/Myc pathways that regulate metabolic reprogramming in activated T cells, with decreased glycolytic and mitochondrial ATP production and increased mitochondrial ROS production and dysfunction, leading to tissue-specific deletion of host-reactive T cells and prevention of GVHD. Mitochondrial STAT3 deficiency alone did not reduce GSH expression or prevent GVHD. In lymphoid tissues, the lack of host-tissue PD-L1 interaction with PD-1 reduced the inhibition of the GSH/Myc pathway despite reduced GSH production caused by STAT3 deficiency and allowed donor T cell functions that mediate GVL activity. Therefore, STAT3 deficiency in donor T cells augments PD-1 signaling-mediated inhibition of GSH/Myc pathways and augments dysfunction of T cells in GVHD target tissues while sparing T cells in lymphoid tissues, leading to prevention of GVHD while preserving GVL effects.

Human-in-the-Loop Adaptive Control of a Soft Exo-Suit With Actuator Dynamics and Ankle Impedance Adaptation.

Soft exo-suit could facilitate walking assistance activities (such as level walking, upslope, and downslope) for unimpaired individuals. In this article, a novel human-in-the-loop adaptive control scheme is presented for a soft exo-suit, which provides ankle plantarflexion assistance with unknown human-exosuit dynamic model parameters. First, the human-exosuit coupled dynamic model is formulated to express the mathematical relationship between the exo-suit actuation system and the human ankle joint. Then, a gait detection approach, including plantarflexion assistance timing and planning, is proposed. Inspired by the control strategy that is used by the human central nervous system (CNS) to handle interaction tasks, a human-in-the-loop adaptive controller is proposed to adapt the unknown exo-suit actuator dynamics and human ankle impedance. The proposed controller can emulate human CNS behaviors which adapt feedforward force and environment impedance in interaction tasks. The resulting adaptation of actuator dynamics and ankle impedance is demonstrated with five unimpaired subjects and implemented on a developed soft exo-suit. The human-like adaptivity is performed by the exo-suit in several human walking speeds and illustrates the promising potential of the novel controller.

Association of the macrophage migration inhibitory factor promoter polymorphisms with benign lymphoepithelial lesion of lacrimal gland.

AIM: To identify the association of the macrophage migration inhibitory factor (MIF) gene polymorphism with the susceptibility of benign lymphoepithelial lesions (BLEL) of the lacrimal gland. METHODS: A total of 40 BLEL of lacrimal gland cases were matched with 40 healthy subjects (HS). Extraction the plasma and whole blood DNA of patients of lacrimal gland BLEL and HS. Elisa and polymerase chain reaction was used to determine in plasma contents of MIF and MIF gene SNP-173G>C and STR -794 CATT(5-8) polymorphism, respectively. RESULTS: The MIF levels in plasma were significantly higher in patients with lacrimal gland BLEL versus HS (P<0.001). The -173 G>C MIF polymorphism was significantly associated with lacrimal gland BLEL, with a significantly higher frequency of the C allele in lacrimal gland BLEL patients compared with HS (OR=2.38, 95% CI=1.07-5.31, P=0.032), and the -173 C/x is more frequent in patients than in HS, P=0.037. Besides, we found that the carriage rate of the MIF -173C/x is associated with higher plasma levels of MIF in the BLEL of lacrimal gland. CONCLUSION: MIF -173G/C variants play an insidious role in susceptibility of BLEL of lacrimal gland. Otherwise, there is no statistically significant correlation exists between MIF-794 CATT (5-8) and BLEL of lacrimal gland.

TLR7 and TLR8 agonist resiquimod (R848) differently regulates MIF expression in cells and organs.

Since its first description in 1966, macrophage migration inhibitory factor (MIF) was found to play a critical role in inflammatory and immune responses as well as in disease pathogenesis especially in tumor pathogenesis and cancer progression. MIF is expressed in different cell types and is associated with many disease severity and tumor pathogenesis. Here, we investigated the influence of TLR7 and TLR8 agonist resiquimod (R848), an immune response inducer used as a prophylactic agent for several infectious diseases as well as anticancer agents and vaccine adjuvant on MIF expression in cells and organs. Humans, mice and rats cell lines from different tissues (blood, retinal, nasopharynx, brain and liver) and C57BL/6J mice organs (brain, liver and spleen) were used for this investigation. In vitro, R848 induced MIF gene overexpression except in brain and liver cells. Furthermore, it enhanced cells ability to release soluble MIF and differently regulated mRNA expression of MIF-related receptors (CD74, CXCR4, CXCR2 and CD44). Its influence on MIF gene expression and MIF proteins release was more consistent in cancer cells. In vivo, a strong positive expression of MIF was observed in different regions in brain and spleen in response to R848 treatment; however in liver, increased MIF expression was observed in hepatocytes only. On the other hand, R848 treatment had induced a slight enhancement of MIF concentration in the plasma of C57BL/6J mice. Taken together, these data suggest that R848 differently regulates MIF mRNA expression depending on organ types and could influence MIF concentration in cellular microenvironment.

Insulin-like factor binding protein-3 promotes the G1 cell cycle arrest in several cancer cell lines.

Insulin-like growth factor binding protein-3 (IGFBP-3) is a multi-functional protein known to induce apoptosis of various cancer cells in an insulin-like growth factor (IGF)-dependent and IGF-independent manner. In our previous study, we found that IGFBP-3 induced apoptosis through the activation of caspases in 786-O cells. In this study, we further examined that whether IGFBP-3 induced apoptosis through the induction of cell cycle arrest in 786-O, A549 and MCF-7 cells. Our results showed that overexpressed IGFBP-3 resulted in typical apoptotic ultrastructures in A549 cells under transmission electron microscope. The result of flow cytometry analysis indicated that IGFBP-3 arrested the cell cycle at G1-S phase in 786-O, A549 and MCF-7 cells. In A549 cells, quantitative real-time PCR and Western blot analysis showed a significant change in the expression of cell cycle-regulated proteins-a decrease in cyclin E1 expression, an increase in p21 expression. These results indicate a possible mechanism for G1 cell cycle arrest by IGFBP-3. Taken together, cyclin E1 and p21 may play important roles in the IGFBP-3-inducing G1 cell cycle arrest and apoptosis in several human cancer cells.

Colocalization and identification of interaction sites between IGFBP-3 and GalNAc-T14.

GalNAc-T14 was identified as a novel IGFBP-3 binding partner in previous studies. Here, we furtherly confirmed the interaction between them by confocal microscopy, and identified the binding domain and probable interaction sites of GalNAc-T14 with IGFBP-3. The result of subcellular localization indicated that GalNAc-T14 was distributed in the cytosol, whereas IGFBP-3 existed in the cytosol and nucleolus. Confocal analyses demonstrated that IGFBP-3 and GalNAc-T14 colocalized in the cytosol. The result from yeast two hybrid assay showed that the C terminus of GalNAc-T14 (408-552aa) was essential for the interaction between GalNAc-T14 and IGFBP-3, especially Tyr(408), Pro(409), and Glu(410) of GalNAc-T14 may play key roles in the interaction with IGFBP-3. In conclusion, these studies demonstrated that IGFBP-3 and GalNAc-T14 are colocalized in MCF-7 cells and confirmed the interaction between IGFBP-3 and GalNAc-T14. This interaction may play an important role in the functional regulation of IGFBP-3.