0000000000025396
AUTHOR
Pamela Aranda Lopez
Antifungal drugs influence neutrophil effector functions
There is a growing body of evidence for immunomodulatory side effects of antifungal agents on different immune cells, e.g., T cells. Therefore, the aim of our study was to clarify these interactions with regard to the effector functions of polymorphonuclear neutrophils (PMN). Human PMN were preincubated with fluconazole (FLC), voriconazole (VRC), posaconazole (POS), isavuconazole (ISA), caspofungin (CAS), micafungin (MFG), conventional amphotericin B (AMB), and liposomal amphotericin B (LAMB). PMN then were analyzed by flow cytometry for activation, degranulation, and phagocytosis and by dichlorofluorescein assay to detect reactive oxygen species (ROS). Additionally, interleukin-8 (IL-8) re…
Phenotypic and functional characterization of neutrophils and monocytes from patients with myelodysplastic syndrome by flow cytometry.
Myelodysplastic syndrome (MDS) is a clonal stem cell disorder frequently associated with inefficient granulopoiesis showing dysplastic polymorphonuclear neutrophils (PMNs). To assess PMN functionality in MDS in a clinical routine setting, 30 MDS patients and ten healthy volunteers were analyzed for PMN and monocyte phenotype and function (degranulation, CD62L shedding, oxidative burst and phagocytosis) upon stimulation with lipopolysaccharide by multi-color flow cytometry (MCFC). Our data show a heterogeneous pattern for CD66, CD16 and CD64 expression on PMNs of MDS patients. CD62L shedding rate and CD66 degranulation were reduced. Interestingly, we detected correlations between the WHO ada…
Idelalisib Impairs TREM-1 and TLR Mediated Neutrophil Activation
Abstract Introduction: Polymorphonuclear neutrophils (PMN) play an essential role in innate inflammatory processes. Their functions are strictly regulated and many activating / inhibiting mechanisms along with their pathways are only incompletely understood. Besides toll-like receptors (TLR) and NOD-like receptors (NLR), triggering receptor expressed on myeloid cells (TREM)-1 is implicated in innate immune activation of these cells and plays a role in infectious as well as non-infectious conditions. Activation of TREM-1 results in release of pro-inflammatory chemokines and cytokines, increased surface expression of cell activation markers and degranulation. In TREM-1 downstream pathways and…
Neutrophil extracellular traps impair fungal clearance in a mouse model of invasive pulmonary aspergillosis
Abstract Neutrophil extracellular traps (NETs) are formed by polymorphonuclear neutrophils (PMN) and contribute to the innate host defense by binding and killing bacterial and fungal pathogens. Because NET formation depends on histone hypercitrullination by peptidylarginine deiminase 4 (PAD4), we used PAD4 gene deficient (Pad4-/-) mice in a mouse model of invasive pulmonary aspergillosis (IPA) to address the contribution of NETs to the innate host defense in vivo. After the induction (24 h) of IPA by i.t. infection with Aspergillus fumigatus conidia, Pad4-/- mice revealed lower fungal burden in the lungs, accompanied by less acute lung injury, TNFα and citH3 compared to wildtype controls. T…
Combined immunotherapy: CTLA-4 blockade potentiates anti-tumor response induced by transcutaneous immunization.
Abstract Background The epidermal application of the Toll Like Receptor 7 agonist imiquimod and a T-cell peptide epitope (transcutaneous immunization, TCI) mediates systemic peptide-specific cytotoxic T-cell (CTL) responses and leads to tumor protection in a prophylactic tumor setting. However, it does not accomplish memory formation or permanent defiance of tumors in a therapeutic set-up. As a distinct immunologic approach, CTLA-4 blockade augments systemic immune responses and has shown long-lasting effects in preclinical experiments as well as in clinical trials. Objective The study investigates the vaccination capacity of TCI in combination with the checkpoint inhibitor CTLA-4 in matter…
Transcutaneous immunization with a novel imiquimod nanoemulsion induces superior T cell responses and virus protection
Abstract Background Transcutaneous immunization (TCI) is a novel vaccination strategy utilizing the skin associated lymphatic tissue to induce immune responses. TCI using a cytotoxic T lymphocyte (CTL) epitope and the Toll-like receptor 7 (TLR7) agonist imiquimod mounts strong CTL responses by activation and maturation of skin-derived dendritic cells (DCs) and their migration to lymph nodes. However, TCI based on the commercial formulation Aldara only induces transient CTL responses that needs further improvement for the induction of durable therapeutic immune responses. Objective Therefore we aimed to develop a novel imiquimod solid nanoemulsion (IMI-Sol) for TCI with superior vaccination …
Ibrutinib Abrogates TREM-1 Mediated Neutrophil Activation
Abstract Triggering receptor expressed on myeloid cells 1 (TREM-1) is an activating receptor on neutrophils (PMN) and important in the innate host defence against microbial pathogens. Here we examined the influence of the Bruton tyrosine kinase (BTK) inhibitor ibrutinib on TREM-1 dependent activation of human PMNs. Firstly, ibrutinib specifically inhibited TREM-1 mediated PMN activation of the oxidative burst and CD62L shedding, whereas TLR mediated activation remained unaffected. Correspondingly, ibrutinib suppressed ERK phosphorylation after TREM-1, but not after TLR ligation. To clarify whether this TREM-1 specific effect of ibrutinib was also relevant in vivo, we treated mice with ibrut…
Transcutaneous immunization with CD40 ligation boosts cytotoxic T lymphocyte mediated antitumor immunity independent of CD4 helper cells in mice.
Transcutaneous immunization (TCI) is a novel vaccination strategy that utilizes skin-associated lymphatic tissue to induce immune responses. Employing T-cell epitopes and the TLR7 agonist imiquimod onto intact skin mounts strong primary, but limited memory CTL responses. To overcome this limitation, we developed a novel imiquimod-containing vaccination platform (IMI-Sol) rendering superior primary CD8+ and CD4+ T-cell responses. However, it has been unclear whether IMI-Sol per se is restricted in terms of memory formation and tumor protection. In our present work, we demonstrate that the combined administration of IMI-Sol and CD40 ligation unleashes fullblown specific T-cell responses in th…
9-Phenanthrol enhances the generation of an CD8 + T cell response following transcutaneous immunization with imiquimod in mice
Abstract Background Transcutaneous immunization (TCI) is a non-invasive vaccination strategy targeting the skin-associated lymphoid tissue. Topical application of the TLR7 agonist imiquimod as adjuvant in combination with peptide antigens activates the innate immune system and mounts cytotoxic T lymphocyte (CTL) responses. Objective Based on the commercial 5% imiquimod-containing drug Aldara we aimed to develop an improved formulation with superior vaccination efficiencies. The primary target was the enhancement of mast cell activation as important key for the function of the innate immune system. Methods We investigated the effects of 9-phenanthrol (9-phe) on the activation of mast cells i…