biostudies-literatureDehner CAArthritis FoundationNCATS NIH HHSLupus Research AllianceNational Institutes of HealthArthritis National Research Foundation100084https://www.ebi.ac.uk/biostudies/studies/S-EPMC8844718biostudies-literatureUnknown2(2)Cutaneous T-cell lymphoma (CTCL) is a life-debilitating malignancy of lymphocytes homing to the skin. Although CTCL is thought to arise from a combination of genetic, epigenetic, and environmental factors, specific triggers are unclear. The skin is colonized by a unique microbiota and is heavily influenced by its interactions. We hypothesized that adaptive immune responses to skin commensals lead to clonal T-cell proliferation and transformation in the appropriate genetic background. We therefore collected lesional and nonlesional skin microbiota from patients with CTCL to study T cell interactions using skin T cell explants and peripheral, skin-homing CD4⁺ T cells. By various methods, we identified <i>Bacillus safensis</i> in CTCL lesions, a rare human commensal in healthy skinJID innovations : skin science from molecules to population healthMalignant T Cell Activation by a <i>Bacillus</i> Species Isolated from Cutaneous T-Cell Lymphoma Lesions.PMC8844718R01AI118855UL1 TR001863T32AI07019Pereira MSRuff WEGreiling TRedanz SGirardi MKriegel MADehner CAMcNiff JfalseMalignant T Cell Activation by a <i>Bacillus</i> Species Isolated from Cutaneous T-Cell Lymphoma Lesions.Cutaneous T-cell lymphoma (CTCL) is a life-debilitating malignancy of lymphocytes homing to the skin. Although CTCL is thought to arise from a combination of genetic, epigenetic, and environmental factors, specific triggers are unclear. The skin is colonized by a unique microbiota and is heavily influenced by its interactions. We hypothesized that adaptive immune responses to skin commensals lead to clonal T-cell proliferation and transformation in the appropriate genetic background. We therefore collected lesional and nonlesional skin microbiota from patients with CTCL to study T cell interactions using skin T cell explants and peripheral, skin-homing CD4⁺ T cells. By various methods, we identified <i>Bacillus safensis</i> in CTCL lesions, a rare human commensal in healthy skin2022-01-01T00:00:00Z2022 Mar2025-04-04T22:14:47.74Z2024-11-07T08:21:50.83ZS-EPMC88447183519908910.1016/j.xjidi.2021.100084