The coming of age of Langerhans cell histiocytosis

SARS-CoV-2 genome-wide T cell epitope mapping reveals immunodominance and substantial CD8 + T cell activation in COVID-19 patients

“…Pre-existing T cell immunity, in the context of SARS-CoV-2-reactive T cells in unexposed healthy individuals, has been reported by several studies ( 13 15 , 17 , 19 ), and it has been hypothesized that this is due to the shared sequence homology between the SARS-CoV-2 genome and other common cold coronaviruses (HCoV-OC43, HCoV-HKU1, HCoV-NL63, and HCoV-229E). Having evaluated the full spectrum of minimal epitopes for T cell recognition, we sought to evaluate the sequence homology at the peptide level, and its association with the SARS-CoV-2 T cell reactivity we observed in healthy donors.…”

“…Several studies using overlapping peptide pools spanning different region of SARS-CoV-2 viral proteins have shown a broad range of T cell activation in convalescent COVID-19 patients ( 8 , 9 , 11 , 14 , 15 , 31 35 ). Our work now provides a detailed characterization of minimal epitopes derived from the complete SARS-CoV-2 genome for their CD8 + T cell immunogenicity, immunodominance, and functional and phenotypical characteristics in COVID-19 patients and healthy donors.…”

“…Initial analysis of SARS-CoV-2 unexposed individuals revealed substantial presence of CD4 + and CD8 + T cells cross-reactive to SARS-COV-2 peptides ( 11 , 15 , 17 , 36 39 ). Longitudinal analysis of cross-reactive and induced CD8 + T cells before and after SARS-CoV-2 infection has been followed in individual cases ( 39 ), but the role of pre-existing T cells in overall immune response and disease outcome is not yet established.…”

“…Several recent studies have reported robust T cell immunity in SARS-CoV-2-infected patients ( 8 10 ), and unexposed healthy individuals also showed functional T cell reactivity restricted to SARS-CoV-2 ( 9 , 11 15 ). The observed T cell cross-reactivity is hypothesized to derive from routine exposure to common cold coronaviruses (HCoV) (HCoV-OC43, HCoV-HKU1, HCoV-NL63 and HCoV-229E) that widely circulate, with 90% of the human population being seropositive for these viruses ( 16 , 17 ) and substantial sequence homology to the SARS-CoV-2 genome ( 18 , 19 ).…”

Long‐term outcome, clinical course and treatment approaches of paediatric langerhans cell histiocytosis: A greek reference centre report

“…It has also led to the application of targeted therapy with BRAF and mitogen-activated protein kinase (MEK) inhibitors in LCH. 4,[12][13][14] The aim of our study was to present, and analyse, the clinical characteristics and treatment responses of a cohort of consecutive paediatric patients diagnosed with LCH over a 45-year period at a Reference Centre, the Department of Pediatric Hematology-Oncology of the 'Aghia Sophia' Children's Hospital, Athens, Greece.…”