title: Activation-related differences in HLA class I-bound peptides: presentation of an IL-1 receptor antagonist-derived peptide by activated, but not resting, CD4+ T lymphocytes.
abstract: We have compared by reverse phase HPLC the set of peptides eluted from HLA class I molecules in resting and activated CD4+ Jurkat cells. Two peptides were identified that are presented de novo upon activation. After sequencing, one of these peptides turned out to derive from IL-1R antagonist (IL-1Ra). In keeping with this observation, we found that activated, but not resting, Jurkat cells express IL-1Ra. These data indicate that activation of a CD4+ T cell line may result in presentation of peptides derived from proteins expressed de novo after activation. Since IL-1Ra was not known to be expressed by cells of the T lineage, we also investigated its pattern of expression in normal T lymphocytes. Reverse transcriptase-PCR analyses allowed us to demonstrate that IL-1Ra is expressed upon activation by normal CD4+ lymphocytes from peripheral blood and by thymocytes, but not by CD8+ T cells. Interestingly, of the two forms of IL-1Ra that have been detected in different cell lineages, the intracellular one and the secreted one, only the former is expressed by activated CD4+ T cells.
authors.affiliation: Servizio di Immunogenetica, Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy. frumento@sirio.cba.unige.it
authors.forename: G
authors.initials: G
authors.lastname: Frumento
authors.forename: A
authors.initials: A
authors.lastname: Corradi
authors.forename: G B
authors.initials: GB
authors.lastname: Ferrara
authors.forename: A
authors.initials: A
authors.lastname: Rubartelli
mesh_terms: D017951:Antigen Presentation / Q000187:drug effects; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D006680:HLA Antigens / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007399:Interphase / Q000187:drug effects / Q000276:immunology*; D007424:Intracellular Fluid / Q000276:immunology / Q000378:metabolism; D007536:Isomerism; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000187:drug effects; D010446:Peptide Fragments / Q000276:immunology* / Q000378:metabolism; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012795:Sialoglycoproteins / Q000378:metabolism*
chemical_list: D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D010446:Peptide Fragments; D017472:Receptors, Interleukin-1; D012795:Sialoglycoproteins