Identification and Mitigation of Defensins in the Immunopurification of Peptide MHC-I Antigens from Lung Tissue.
J Am Soc Mass Spectrom
; 33(9): 1590-1597, 2022 Sep 07.
Article
en En
| MEDLINE
| ID: mdl-34645265
The class I major histocompatibility (MHC-I) complex is a set of diverse cell surface receptors encoded by the human leukocyte antigen gene complex. These receptors present intracellular antigens to cytotoxic T cells providing information on the state and health of cells. Changes in the immunopeptidome during cancer may provide novel targets for therapeutic intervention. To understand how the tumor immunopeptidome is altered, we developed a mass spectrometry (MS) based platform for isolating and identifying MHC-I peptide antigens in lung tumors. In the course of our work, we encountered several large unknown peptide contaminants which had not been previously reported. To understand the source of these major contaminants, we isolated them using offline fractionation and identified them by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as members of the host defense protein family known as the defensins. To mitigate their detrimental effects, we modified our "Original" data-dependent acquisition (DDA) MS method to narrowly target the MHC-I peptides based on their physical properties including charge state and molecular weight ("z state" DDA), evaluated field asymmetric ion mobility spectrometry to attempt gas-phase separation prior to MS analysis, and developed an immunodepletion approach using defensin specific antibodies. This modified approach improves peptide identification and reduces the impact of defensin contamination in lung tissue samples.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espectrometría de Masas en Tándem
/
Neoplasias
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
J Am Soc Mass Spectrom
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos