biostudies-literatureArea-Navarro MAgència de Gestió d'Ajuts Universitaris i de RecercaUniversitat Autònoma de Barcelona11357https://www.ebi.ac.uk/biostudies/studies/S-EPMC12692271biostudies-literatureUnknown26(23)HEK-293 is a highly transfectable human cell line widely used as a model for protein expression. Since large amounts of cells are often required for the purification of HLA immunopeptidomes, suspension-growing variants, such as HEK-293F, facilitate the generation of sufficient cell quantities. The HLA class I-typing of these cells is <i>HLA-A*02:01</i>, -<i>A*03:01</i>, -<i>B*07:02</i>, and -<i>C*07:02</i>. HEK-293T cells have been previously used as a source of HLA peptide ligands derived from SARS-CoV-2 proteins. In this study, we purified and analyzed the HLA-I immunopeptidome of HEK-293 and HEK-293F cells using mass spectrometry. Cell surface expression of specific HLA-I allotypes was determined using flow cytometry with allele-specific antibodies. The HLA-I immunopeptidome of HEK-293 International journal of molecular sciencesSpecific Instability of HLA-A*03:01 Expression in HEK-293 Cells.PMC12692271PPC2024-382020PANDE00079Juan MAlvarez IPalacio JRArea-Navarro MCanals FTirado-Herranz ACerqueira APastor-Moreno AScholz EMarcilla MfalseSpecific Instability of HLA-A*03:01 Expression in HEK-293 Cells.HEK-293 is a highly transfectable human cell line widely used as a model for protein expression. Since large amounts of cells are often required for the purification of HLA immunopeptidomes, suspension-growing variants, such as HEK-293F, facilitate the generation of sufficient cell quantities. The HLA class I-typing of these cells is <i>HLA-A*02:01</i>, -<i>A*03:01</i>, -<i>B*07:02</i>, and -<i>C*07:02</i>. HEK-293T cells have been previously used as a source of HLA peptide ligands derived from SARS-CoV-2 proteins. In this study, we purified and analyzed the HLA-I immunopeptidome of HEK-293 and HEK-293F cells using mass spectrometry. Cell surface expression of specific HLA-I allotypes was determined using flow cytometry with allele-specific antibodies. The HLA-I immunopeptidome of HEK-293 2025-01-01T00:00:00Z2025 Nov2026-05-26T11:06:52.608Z2026-05-24T03:11:04.91ZS-EPMC126922714137351610.3390/ijms262311357