Optimization of antigen presentation to T cell hybridomas by purified Ia molecules in planar membranes. Ia molecule polymorphism determines the antigenic fine specificity of the response to cytochrome c peptides.
Ia molecule (Ek,b beta:Ek alpha or Ak beta:Ak alpha)-containing planar membranes were constructed with cholesterol and a 9:1 molar ratio of the phospholipids dipalmitoyl phosphatidylcholine and dilinoleoyl phosphatidylcholine. This lipid composition was found to be optimal for the stimulation of T cell hybridomas of different specificities. Use of this system allowed the detection of weak responses not measurable when other artificial membranes were used. Activation of the cytochrome c, Ek,b beta:Ek alpha-reactive hybridoma 2B4.11 using such membranes resulted in responses comparable to those found using antigen-presenting cells (APC); that is, similar amounts of IL-2 were produced at the same concentrations of antigenic peptides. Presentation of moth and pigeon cytochrome c peptides by Ek beta:Ek alpha- or Eb beta:Ek alpha-reconstituted membranes resulted in 2B4.11 response patterns similar to those previously described using B10.A or B10.A(5R) APC. These data conclusively demonstrate that differential stimulation by moth and pigeon cytochrome c peptides depends solely on structural differences in the E beta:E alpha molecules used for antigen presentation.
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000276:immunology; D000818:Animals; D000938:Antigen-Presenting Cells / Q000145:classification / Q000276:immunology*; D002460:Cell Line; D002784:Cholesterol / Q000276:immunology; D003574:Cytochrome c Group / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000276:immunology*; D006825:Hybridomas; D007376:Interleukin-2 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000187:drug effects; D008563:Membrane Lipids / Q000138:chemical synthesis / Q000276:immunology; D008567:Membranes, Artificial; D051379:Mice; D008815:Mice, Inbred Strains; D010455:Peptides / Q000276:immunology; D010713:Phosphatidylcholines / Q000276:immunology; D011110:Polymorphism, Genetic; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology*
D003574:Cytochrome c Group; D000939:Epitopes; D000949:Histocompatibility Antigens Class II; D007376:Interleukin-2; D008563:Membrane Lipids; D008567:Membranes, Artificial; D010455:Peptides; D010713:Phosphatidylcholines; D015060:1,2-Dipalmitoylphosphatidylcholine; C002448:1,2-linoleoylphosphatidylcholine; D002784:Cholesterol