Interplay between Humoral and CLA+ T Cell Response against Candida albicans in Psoriasis.

Candida albicans (CA) infections have been associated with psoriasis onset or disease flares. However, the integrated immune response against this fungus is still poorly characterized in psoriasis. We studied specific immunoglobulins in plasma and the CA response in cocultures of circulating memory CD45RA- cutaneous lymphocyte antigen (CLA)+/- T cell with autologous epidermal cells from plaque and guttate psoriasis patients (cohort 1, n = 52), and also healthy individuals (n = 17). A complete proteomic profile was also evaluated in plaque psoriasis patients (cohort 2, n = 114) regarding their anti-CA IgA levels. Increased anti-CA IgA and IgG levels are present in the plasma from plaque but not guttate psoriasis compared to healthy controls. CA cellular response is confined to CLA+ T cells and is primarily Th17. The levels of anti-CA IgA are directly associated with CLA+ Th17 response in plaque psoriasis. Proteomic analysis revealed distinct profiles in psoriasis patients with high anti-CA IgA. C-C motif chemokine ligand 18, chitinase-3-like protein 1 and azurocidin were significantly elevated in the plasma from plaque psoriasis patients with high anti-CA levels and severe disease. Our results indicate a mechanism by which Candida albicans exposure can trigger a clinically relevant IL-17 response in psoriasis. Assessing anti-CA IgA levels may be useful in order to evaluate chronic psoriasis patients.

Novel phosphorylated TAK1 species with functional impact on NF-κB and ß-catenin signaling in human Cutaneous T-cell lymphoma.

Cutaneous T-cell lymphomas (CTCLs) represent different subtypes of lymphoproliferative disorders with no curative therapies for the advanced forms of the disease (namely mycosis fungoides and the leukemic variant, Sézary syndrome). Molecular events leading to CTCL progression are heterogeneous, however recent DNA and RNA sequencing studies highlighted the importance of NF-κB and ß-catenin pathways. We here show that the kinase TAK1, known as essential in B-cell lymphoma, is constitutively activated in CTCL cells, but tempered by the MYPT1/PP1 phosphatase complex. Blocking PP1 activity, both pharmacologically and genetically, resulted in TAK1 hyperphosphorylation at residues T344, S389, T444, and T511, which have functional impact on canonical NF-κB signaling. Inhibition of TAK1 precluded NF-κB and ß-catenin signaling and induced apoptosis of CTCL cell lines and primary Sézary syndrome cells both in vitro and in vivo. Detection of phosphorylated TAK1 at T444 and T344 is associated with the presence of lymphoma in a set of 60 primary human samples correlating with NF-κB and ß-catenin activation. These results identified TAK1 as a potential biomarker and therapeutic target for CTCL therapy.