Cutaneous immune-related adverse events in patients with melanoma treated with checkpoint inhibitors.

Checkpoint inhibitor (CPI) therapy has vastly improved long-term outcomes in metastatic malignant melanoma (MMM). Therapy takes the form of monoclonal antibody infusions that target immune cell checkpoint proteins, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and programmed death 1/programmed death ligand 1 (PD1/PDL1). Cutaneous immune-related adverse effects (IrAEs) are frequent in patients with MMM treated with CPIs. Our aim was to review the clinical presentations of cutaneous IrAEs associated with CPI therapy in adult patients with MMM. We carried out a literature review of clinical trials, case series and case reports of patients with melanoma and those with other cancers treated with anti-CTLA4, anti-PD1/PDL1, or a combination of these therapies. Diverse clinical presentations of cutaneous IrAEs are recognized. Anti-CTLA4 therapy has a higher associated rate of cutaneous IrAEs than anti-PD1/PDL1 therapies. Low-grade cutaneous IrAEs are common and are usually managed supportively while continuing CPI therapy. Delayed presentations arising after established use of CPIs can make therapy-associated cutaneous IrAEs difficult to distinguish from coincidental dermatological disease. Vitiligo-like depigmentation is a good prognostic indicator of outcome in patients with melanoma. Life-threatening adverse events including toxic epidermal necrolysis are rare. The identification of predictive biomarkers that highlight patients at risk of life-threatening IrAEs remains an unmet need. The involvement of dermatologists in the multidisciplinary assessment of cutaneous IrAEs is increasingly pertinent in the management and care of CPI-treated patients with melanoma.

Tolerogenic dendritic cells generated with dexamethasone and vitamin D3 regulate rheumatoid arthritis CD4+ T cells partly via transforming growth factor-ß1.

Tolerogenic dendritic cells (tolDC) are a new immunotherapeutic tool for the treatment of rheumatoid arthritis (RA) and other autoimmune disorders. We have established a method to generate stable tolDC by pharmacological modulation of human monocyte-derived DC. These tolDC exert potent pro-tolerogenic actions on CD4+ T cells. Lack of interleukin (IL)-12p70 production is a key immunoregulatory attribute of tolDC but does not explain their action fully. Here we show that tolDC express transforming growth factor (TGF)-ß1 at both mRNA and protein levels, and that expression of this immunoregulatory cytokine is significantly higher in tolDC than in mature monocyte-derived DC. By inhibiting TGF-ß1 signalling we demonstrate that tolDC regulate CD4+ T cell responses in a manner that is at least partly dependent upon this cytokine. Crucially, we also show that while there is no significant difference in expression of TGF-ßRII on CD4+ T cells from RA patients and healthy controls, RA patient CD4+ T cells are measurably less responsive to TGF-ß1 than healthy control CD4+ T cells [reduced TGF-ß-induced mothers against decapentaplegic homologue (Smad)2/3 phosphorylation, forkhead box protein 3 (FoxP3) expression and suppression of (IFN)-γ secretion]. However, CD4+ T cells from RA patients can, nonetheless, be regulated efficiently by tolDC in a TGF-ß1-dependent manner. This work is important for the design and development of future studies investigating the potential use of tolDC as a novel immunotherapy for the treatment of RA.

Synovial CD4+ T-cell-derived GM-CSF supports the differentiation of an inflammatory dendritic cell population in rheumatoid arthritis.

OBJECTIVE: A population of synovial inflammatory dendritic cells (infDCs) has recently been identified in rheumatoid arthritis (RA) and is thought to be monocyte-derived. Here, we investigated the role and source of granulocyte macrophage-colony-stimulating factor (GM-CSF) in the differentiation of synovial infDC in RA. METHODS: Production of GM-CSF by peripheral blood (PB) and synovial fluid (SF) CD4+ T cells was assessed by ELISA and flow cytometry. In vitro CD4+ T-cell polarisation experiments were performed with T-cell activating CD2/CD3/CD28-coated beads in the absence or presence of pro-Th1 or pro-Th17 cytokines. CD1c+ DC and CD16+ macrophage subsets were flow-sorted and analysed morphologically and functionally (T-cell stimulatory/polarising capacity). RESULTS: RA-SF CD4+ T cells produced abundant GM-CSF upon stimulation and significantly more than RA-SF mononuclear cells depleted of CD4+ T cells. GM-CSF-producing T cells were significantly increased in RA-SF compared with non-RA inflammatory arthritis SF, active RA PB and healthy donor PB. GM-CSF-producing CD4+ T cells were expanded by Th1-promoting but not Th17-promoting conditions. Following coculture with RA-SF CD4+ T cells, but not healthy donor PB CD4+ T cells, a subpopulation of monocytes differentiated into CD1c+ infDC; a process dependent on GM-CSF. These infDC displayed potent alloproliferative capacity and enhanced GM-CSF, interleukin-17 and interferon-γ production by CD4+ T cells. InfDC with an identical phenotype to in vitro generated cells were significantly enriched in RA-SF compared with non-RA-SF/tissue/PB. CONCLUSIONS: We demonstrate a therapeutically tractable feedback loop of GM-CSF secreted by RA synovial CD4+ T cells promoting the differentiation of infDC with potent capacity to induce GM-CSF-producing CD4+ T cells.

Polarized projection of stereo cerebral angiograms for audience viewing.

A simple and inexpensive method for producing stereo angiographic images for projection to large audiences is presented. Two 35 mm images are produced using a conventional reflex camera and direct positive film. When properly taken, these film chips can be mounted in stereo mounts and projected using a polarized light stereo projector.