Enhanced antigen cross-presentation in human colorectal cancer-associated fibroblasts through upregulation of the lysosomal protease cathepsin S

Background Cross-presentation of exogenous antigens in HLA-class I molecules by professional antigen presenting cells (APCs) is crucial for CD8+ T cell function. Recent murine studies show that several non-professional APCs, including cancer-associated fibroblasts (CAFs) also possess this capacity. Whether human CAFs are able to cross-present exogenous antigen, which molecular pathways are involved in this process and how this ultimately affects tumor-specific CD8+ T cell function is unknown. Methods In this study, we investigated the ability of human colorectal cancer (CRC)-derived CAFs to cross-present neoantigen-derived synthetic long peptides (SLPs), corresponding to tumor-derived mutant peptides, and how this affects tumor-specific T-cell function. Processing of the SLP was studied by targeting components of the cross-presentation machinery through CRISPR/Cas9 and siRNA-mediated genetic ablation to identify the key molecules involved in fibroblast-mediated cross-presentation. Multispectral flow cytometry and killing assays were performed to study the effect of fibroblast cross-presentation on T cell function. Results Here, we show that human CRC-derived CAFs display an enhanced capacity to cross-present neoantigen-derived SLPs when compared with normal colonic fibroblasts. Cross-presentation of antigens by fibroblasts involved the lysosomal protease cathepsin S. Cathepsin S expression by CAFs was detected in situ in human CRC tissue, was upregulated in ex vivo cultured CRC-derived CAFs and showed increased expression in normal fibroblasts after exposure to CRC-conditioned medium. Cognate interaction between CD8+ T cells and cross-presenting CAFs suppressed T cell function, reflected by decreased cytotoxicity, reduced activation (CD137) and increased exhaustion (TIM3, LAG3 and CD39) marker expression. Conclusion These data indicate that CAFs may directly suppress tumor-specific T cell function in an antigen-dependent fashion in human CRC.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Breeding brains? Patients' and laymen's perspectives on cerebral organoids

Aim: To explore the perspectives of patients and laymen with regard to the development, use and storage of cerebral organoids, in order to contribute to the ethical debate about this technology. Materials & methods: In depth semi-structured interviews with 28 patients and laymen were conducted. A qualitative thematic analysis was undertaken using a constant comparative method. Results: Three interrelated themes emerged from the empirical material: moral value; willingness to donate; and elements of good governance. Conclusion: Patients and laymen are most concerned about cerebral organoids potentially developing consciousness and potential misuse. They support the use of cerebral organoids under the conditions that donors are adequately informed and that there will be good governance. Perspectives of patients and laymen are helpful to enable responsible development and use of cerebral organoids in practice.Lay abstractIn this study, we asked patients and laymen for their perspectives and opinions on the development, use and storage of so-called 'brain organoids'. Brain organoids are 3D cell structures that resemble parts of the human brain. These can be used as a model to study the development of the human brain and brain diseases. It is a promising technology that also raises ethical questions. For example, what kind of entity is a brain organoid and what should (and should not) be done with it? Our interview-study shows that patients and laymen are concerned that brain organoids might develop consciousness. They are also concerned about potential misuse of brain organoids. Overall, patients and laymen support the development of brain organoids if donors are well-informed and if responsible use is guaranteed by good governance. For them, good governance involves safety measures, well-defined boundaries to research and ethical oversight. The perspectives of these patients and laymen contribute to further development of brain organoids in a morally justifiable and socially acceptable way.Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

Identification of novel essential regulators in the MHC class I network

Chemical Immunolog

Multiple sclerosis-associated CLEC16A controls HLA class II expression via late endosome biogenesis

C-type lectins are key players in immune regulation by driving distinct functions of antigen-presenting cells. The C-type lectin CLEC16A gene is located at 16p13, a susceptibility locus for several autoimmune diseases, including multiple sclerosis. However, the function of this gene and its potential contribution to these diseases in humans are poorly understood. In this study, we found a strong upregulation of CLEC16A expression in the white matter of multiple sclerosis patients (n = 14) compared to non-demented controls (n = 11), mainly in perivascular leukocyte infiltrates. Moreover, CLEC16A levels were significantly enhanced in peripheral blood mononuclear cells of multiple sclerosis patients (n = 69) versus healthy controls (n = 46). In peripheral blood mononuclear cells, CLEC16A was most abundant in mono