Browsing by Subject "Cytokines"
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Item Open Access Enhanced angiogenic effects of RGD, GHK peptides and copper (II) compositions in synthetic cryogel ECM model(Elsevier, 2020) Zoughaib, M.; Luong, D.; Garifullin, Ruslan; Gatina, D. Z.; Fedosimova, S. V.; Abdullin, T. I.Synthetic oligopeptides are a promising alternative to natural full-length growth factors and extracellular matrix (ECM) proteins in tissue regeneration and therapeutic angiogenesis applications. In this work, angiogenic properties of dual and triple compositions containing RGD, GHK peptides and copper (II) ions (Cu2+) were for the first time studied. To reveal specific in vitro effects of these compositions in three-dimensional scaffold, adamantyl group bearing peptides, namely Ada-Ahx-GGRGD (1) and Ada-Ahx-GGGHK (2), were effectively immobilized in bioinert pHEMA macroporous cryogel via host-guest β-cyclodextrin-adamantane interaction. The cryogels were additionally functionalized with Cu2+ via the formation of GHK-Cu complex. Angiogenic responses of HUVECs grown within the cryogel ECM model were analyzed. The results demonstrate that the combination of RGD with GHK and further with Cu2+ dramatically increases cell proliferation, differentiation, and production of a series of angiogenesis related cytokines and growth factors. Furthermore, the level of glutathione, a key cellular antioxidant and redox regulator, was altered in relation to the angiogenic effects. These results are of particular interest for establishing the role of multiple peptide signals on regeneration related processes and for developing improved tissue engineering materials.Item Open Access Enhanced immunostimulatory activity of cyclic dinucleotides on mouse cells when complexed with a cell-penetrating peptide or combined with CpG(Wiley - V C H Verlag GmbH & Co. KGaA, 2015) Yildiz, S.; Alpdundar, E.; Gungor, B.; Kahraman, T.; Bayyurt, B.; Gursel, I.; Gursel, M.Recognition of pathogen-derived nucleic acids by immune cells is critical for the activation of protective innate immune responses. Bacterial cyclic dinucleotides (CDNs) are small nucleic acids that are directly recognized by the cytosolic DNA sensor STING (stimulator of IFN genes), initiating a response characterized by proinflammatory cytokine and type I IFN production. Strategies to improve the immune stimulatory activities of CDNs can further their potential for clinical development. Here, we demonstrate that a simple complex of cylic-di-GMP with a cell-penetrating peptide enhances both cellular delivery and biological activity of the cyclic-di-GMP in murine splenocytes. Furthermore, our findings establish that activation of the TLR-dependent and TLR-independent DNA recognition pathways through combined use of CpG oligonucleotide (ODN) and CDN results in synergistic activity, augmenting cytokine production (IFN-α/β, IL-6, TNF-α, IP-10), costimulatory molecule upregulation (MHC class II, CD86), and antigen-specific humoral and cellular immunity. Results presented herein indicate that 3′3′-cGAMP, a recently identified bacterial CDN, is a superior stimulator of IFN genes ligand than cyclic-di-GMP in human PBMCs. Collectively, these findings suggest that the immune-stimulatory properties of CDNs can be augmented through peptide complexation or synergistic use with CpG oligonucleotide and may be of interest for the development of CDN-based immunotherapeutic agents.Item Open Access Impaired toll like receptor-7 and 9 induced immune activation in chronic spinal cord injured patients contributes to immune dysfunction(Public Library of Science, 2017) Gucluler, G.; Adiguzel, E.; Gungor, B.; Kahraman, T.; Gursel, M.; Yilmaz, B.; Gursel, I.Reduced immune activation or immunosuppression is seen in patients withneurological diseases. Urinary and respiratory infections mainly manifested as septicemia and pneumonia are the most frequent complications following spinal cord injuries and they account for the majority of deaths. The underlying reason of these losses is believed to arise due to impaired immune responses to pathogens. Here, we hypothesized that susceptibility to infections of chronic spinal cord injured (SCI) patients might be due to impairment in recognition of pathogen associated molecular patterns and subsequently declining innate and adaptive immune responses that lead to immune dysfunction. We tested our hypothesis on healthy and chronic SCI patients with a level of injury above T-6. Donor PBMCs were isolated and stimulated with different toll like receptor ligands and T-cell inducers aiming to investigate whether chronic SCI patients display differential immune activation to multiple innate and adaptive immune cell stimulants. We demonstrate that SCI patients' B-cell and plasmacytoid dendritic cells retain their functionality in response to TLR7 and TLR9 ligand stimulation as they secreted similar levels of IL6 and IFNα. The immune dysfunction is not probably due to impaired T-cell function, since neither CD4+ T-cell dependent IFNγ producing cell number nor IL10 producing regulatory T-cells resulted different outcomes in response to PMA-Ionomycin and PHA-LPS stimulation, respectively. We showed that TLR7 dependent IFNγ and IP10 levels and TLR9 mediated APC function reduced substantially in SCI patients compared to healthy subjects. More importantly, IP10 producing monocytes were significantly fewer compared to healthy subjects in response to TLR7 and TLR9 stimulation of SCI PBMCs. When taken together this work implicated that these defects could contribute to persistent complications due to increased susceptibility to infections of chronic SCI patients. © 2017 Gucluler et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Item Open Access Nanosized delivery systems for tissue regeneration(John Wiley & Sons, 2016-03-11) Çınar, Göksu; Mumcuoğlu, Didem; Tekinay, Ayşe B.; Güler, Mustafa O.; Güler, Mustafa O.; Tekinay, Ayşe B.This chapter focuses on advanced delivery of biologics including growth factors (GFs), cytokines, genes, or siRNAs using a variety of nanosized systems for different regeneration applications focusing on bone, cartilage, nervous system, and muscle regeneration strategies. Gene therapy provides permanent genetic alteration, but only transient actions of protein therapeutics can be needed for tissue regeneration applications. The limitations of biologics delivery and alternative strategies for overcoming recent problems are underlined presenting recent examples from the literature. In addition, specific targeting and cellular internalization strategies of biologies delivery for tissue regeneration are discussed for providing future perspectives to the readers in this field. Overall, it is believed that advanced nanosized delivery systems integrated with multicomponent designs will open new opportunities in delivery technologies and strategies for tissue regeneration.Item Open Access Regulation of human monocyte differentiation into m1- and m2-like macrophages(Bilkent University, 2016-05) Bayık, DefneMyeloid-derived suppressor cells (MDSC) play a key role in down-regulating activated T and NK cells. MDSC are emerging as targets for cancer immunotherapy since they protect tumor cells from immune elimination. We previously showed that the TLR7/8 agonist R848 and the TLR2/1 dual agonist PAM3 had opposite effect on the maturation of human monocytic MDSC (mMDSC). While the former triggered them to differentiation in M1-like macrophages with pro-inflammatory/anti-tumoricidal capacity, the latter generated immunosuppressive M2-like macrophages. This work seeks to identify the soluble factors that regulate the differentiation of mMDSC into macrophages. Our studies reveal that TNFα and M-CSF are essential for mMDSC to mature into functional M1- and M2-like macrophages, respectively. IL-6 and IL-10 play secondary roles but when used in combination with TNFα or M-CSF exceed the effects of TLR agonists. Understanding the response of mMDSC to cytokines should help efforts to direct the mMDSC maturation to therapeutic benefit. The finding that PAM3 could induce human mMDSC to mature into M2-like macrophage triggered us to study the effect of this TLR agonist on other monocyte populations. Our findings reveal that PAM3 was unique among TLR agonists in generating M2-like macrophages. We compared the polarizing activity of PAM3 to that of M-CSF. PAM3 was slightly less efficient than M-CSF in driving maturation of HLA-DR+ monocytes based on phenotypic characterization and phagocytic ability. Yet macrophages generated by PAM3 or M-CSF were equally capable of suppressing T cell proliferation. Analysis of gene regulatory networks by microarray and subsequent validation of the pathways identified by using specific inhibitors defined the NF-κB – COX-2 axis as playing a primary role. However, PAM3 also induced monocyte differentiation via an IL-6-dependent pathway that was largely absent from M-CSF driven cultures. Our findings clarified the pathways by which immunosuppressive M2-like macrophage arise from human monocytes and identify PAM3 as a potential therapeutic modulator of monocyte differentiation in patients with autoimmune disease. Extracellular vesicles (EV) are a heterogeneous population of biological nanoscaled particles that serve as vectors to enhance intercellular communication. In addition to this physiological role evidence indicates that EV can be harnessed as therapeutic agents for cancer. The major limitation to EV-based therapeutics is their rapid clearance by the reticuloendothelial system (RES). To overcome this problem, we sought to reduce macrophage uptake of EV by blocking scavenger receptors. In vitro results using human and murine cells suggests that inhibiting class A scavenger receptors selectively impairs EV uptake by monocytes and macrophages. In vivo studies document reduced liver accumulation and enhanced plasma circulation of i.v. injected EV after such blockade. These findings provide a strategy for reducing EV uptake by the RES thereby increasing their targeting and activity.Item Open Access Secreted mutant calreticulins as rogue cytokines in myeloproliferative neoplasms(Elsevier, 2023-02-23) Pecquet, C.; Papadopoulos, N.; Balligand, T.; Chachoua, Ilyas; Tisserand, A.; Vertenoeil, G.; Nédélec, A.; Vertommen, D.; Roy, A.; Marty, C.; Nivarthi, H.; Defour, J.-P.; El-Khoury, M.; Hug, E.; Majoros, A.; Xu, E.; Zagrijtschuk, O.; Fertig, T. J.; Marta, D. S.; Gisslinger, H.; Gisslinger, B.; Schalling, M.; Casetti, I.; Rumi, E.; Pietra, D.; Cavalloni, C.; Arcaini, L.; Cazzola, M.; Komatsu, N.; Kihara, Y.; Sunami, Y.; Edahiro, Y.; Araki, M.; Lesyk, R.; Buxhofer-Ausch, V.; Heibl, S.; Pasquier, F.; Havelange, V.; Plo, I.; Vainchenker, W.; Kralovics, R.; Constantinescu, S. N.Mutant calreticulin (CALR) proteins resulting from a −1/+2 frameshifting mutation of the CALR exon 9 carry a novel C-terminal amino acid sequence and drive the development of myeloproliferative neoplasms (MPNs). Mutant CALRs were shown to interact with and activate the thrombopoietin receptor (TpoR/MPL) in the same cell. We report that mutant CALR proteins are secreted and can be found in patient plasma at levels up to 160 ng/mL, with a mean of 25.64 ng/mL. Plasma mutant CALR is found in complex with soluble transferrin receptor 1 (sTFR1) that acts as a carrier protein and increases mutant CALR half-life. Recombinant mutant CALR proteins bound and activated the TpoR in cell lines and primary megakaryocytic progenitors from patients with mutated CALR in which they drive thrombopoietin-independent colony formation. Importantly, the CALR-sTFR1 complex remains functional for TpoR activation. By bioluminescence resonance energy transfer assay, we show that mutant CALR proteins produced in 1 cell can specifically interact in trans with the TpoR on a target cell. In comparison with cells that only carry TpoR, cells that carry both TpoR and mutant CALR are hypersensitive to exogenous mutant CALR proteins and respond to levels of mutant CALR proteins similar to those in patient plasma. This is consistent with CALR-mutated cells that expose TpoR carrying immature N-linked sugars at the cell surface. Thus, secreted mutant CALR proteins will act more specifically on the MPN clone. In conclusion, a chaperone, CALR, can turn into a rogue cytokine through somatic mutation of its encoding gene. © 2023 The American Society of Hematology.