0000000000860637
AUTHOR
Alexander Visekruna
Pro- and Antitumorigenic Capacity of Immunoproteasomes in Shaping the Tumor Microenvironment
Abstract Apart from the constitutive proteasome, the immunoproteasome that comprises the three proteolytic subunits LMP2, MECL-1, and LMP7 is expressed in most immune cells. In this study, we describe opposing roles for immunoproteasomes in regulating the tumor microenvironment (TME). During chronic inflammation, immunoproteasomes modulated the expression of protumorigenic cytokines and chemokines and enhanced infiltration of innate immune cells, thus triggering the onset of colitis-associated carcinogenesis (CAC) in wild-type mice. Consequently, immunoproteasome-deficient animals (LMP2/MECL-1/LMP7–null mice) were almost completely resistant to CAC development. In patients with ulcerative c…
IL-17 and TNF-α Are Key Mediators of Moraxella catarrhalis Triggered Exacerbation of Allergic Airway Inflammation
Alterations of the airway microbiome is often associated with pulmonary diseases. For example, detection of the bacterial pathogen Moraxella catarrhalis in the upper airways is linked with an increased risk to develop or exacerbate asthma. However, the mechanisms by which M. cattarhalis augments allergic airway inflammation (AAI) remains unclear. We here characterized the cellular and soluble mediators of M. catarrhalis triggered excacerbation of AAI in wt and IL-17 deficient as well as in animals treated with TNF-alpha and IL-6 neutralizing antibodies. We compared the type of inflammatory response in M. catarrhalis infected, HDM-allergic and animals infected with M. catarrhalis at differen…
Tc9 cells, a new subset of CD8+T cells, support Th2-mediated airway inflammation
Similar to T-helper (Th) cells, CD8(+) T cells also differentiate into distinct subpopulations. However, the existence of IL-9-producing CD8(+) T (Tc9) cells has not been elucidated so far. We show that murine CD8(+) T cells activated in the presence of IL-4 plus TGF-β develop into transient IL-9 producers characterized by specific IFN-γ and IL-10 expression patterns as well as by low cytotoxic function along with diminished expression of the CTL-associated transcription factors T-bet and Eomesodermin. Similarly to the CD4(+) counterpart, Tc9 cells required for their differentiation STAT6 and IRF4. Tc9 cells deficient for these master regulators displayed increased levels of Foxp3 that in t…