Immune processing of proteolipid protein by subsets of antigen-presenting spleen cells.
Myelin proteolipid protein (PLP) contains one established antigenic epitope within the 139-151 amino acid sequence, with encephalitogenic activity for SJL mice (PLP139-151). In the current study, the processing and presentation of PLP by subsets of splenic antigen-presenting cells (APC) were examined by comparing their capacity to stimulate PLP-responsive T-cell clones, two of which are specific for PLP139-151, and one which is not specific for this peptide. In order to study whether PLP requires processing before its presentation by APC, PLP-pulsed and fixed APC were shown to stimulate PLP-specific T cells. However, the addition of PLP to unpulsed, fixed APC resulted in the absence of T-cell stimulation, while the ability of these fixed APC to bind antigenic peptide and efficiently present it to T cells, was demonstrated by their ability to use a synthetic peptide for the stimulation of the T cells. In order to study potentially different processing efficiencies among APC subsets, spleen cells were fractionated by adherence to plastic, and their respective APC activities were studied separately. The non-adherent (NAd) APC were unable to stimulate PLP139-151 specific T-cell clones with PLP as antigen. In contrast, a T-cell clone specific for a separate, but unidentified epitope on PLP was stimulated by NAd APC efficiently. In addition, stimulation of PLP139-151-specific T-cell clones by NAd APC did occur when the synthetic peptide instead of intact PLP was used as antigen, indicating a defect in PLP processing by the NAd APC.(ABSTRACT TRUNCATED AT 250 WORDS)
van der Veen
R C
RC
Department of Neurology, Washington University School of Medicine, St. Louis, MO.
Trotter
J L
JL
Kapp
J A
JA
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000502:physiology; D002448:Cell Adhesion; D002999:Clone Cells; D016131:Lymphocyte Subsets / Q000276:immunology*; D009185:Myelin Proteins / Q000276:immunology*; D018991:Myelin Proteolipid Protein; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D009185:Myelin Proteins; D018991:Myelin Proteolipid Protein