Peptide loading of empty major histocompatibility complex molecules on RMA-S cells allows the induction of primary cytotoxic T lymphocyte responses
✍ Scribed by Marloes L. H. De Bruijn; Ton N. M. Schumacher; John D. Nieland; Hidde L. Ploegh; W. Martin Kast; Cornelis J. M. Melief
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 851 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0014-2980
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✦ Synopsis
Peptide loading of empty major histocompatibility cornpiex molecules on RMA-S cells allows the induction of primary cytotoxic T lymphocyte responses"
The antigcn processing-defectivc mutant cell linc RMA-S expresses at the cell surface major histocompatibility complex (MHC) class I molecules devoid o f pcptide that can be cfficiently loaded with cxogcnous immunogenic peptides.We now report that viral pcptide-loadcd RMA-S cells, unlike parental RMA cclls, can induce primary cytotoxic Tlymphocyte (CTL) responses in v i m , in a T helper cell-independcnt fashion. This was shown for an H-2K1'-hinding peptide of Sendai virus nucleoprotein and an H-2D1'-binding pcptide of adcnovirus type 5 E I A protein with responding splecn cclls of CS7BL/6 mice, thc strain of origin of RMA and RMA-S cclls. Primary Sendai peptide-induced CTL lyse both peptide-loaded and virus-infected cells. Pre-culture of RMA-S cells at low temperature (22"-26"C), which incrcases the amount of cmpty MHC class I molecules at the cell surfacc, decreases the pcptide concentrations rcquired for thc induction of primary CTL rcsponscs. Primary pcptide-specific CTL responses induced by peptide-loaded RMA-S cclls are CD4+ cell-and MHC TI+ ccll-independent. CTL response induction is blocked by the prcsence of CDX monoclonal antibody during culturc. Dircct peptide binding studies confirm thc efficient loading o f empty MHC moleculcs on RMA-S cclls with peptide and show 2.5-fold more peptidc bound per KMA-S cell compared to RMA cells. An additional factor cxplaining the diffcrence in primary response induction betwccn R M A and RMA-S cells is related to the CD8 dependence of these rcsponscs. MHC class I molecules occupied with irrelevant peptides (a majority present o n RMA, largely absent on RMA-S) may interfere in the intcraction of the CD8 molecule with rclcvant MHC/pcptide complexes. The results delineate a novel strategy of pcptide based in vitro immunization t o elicit CD8+ cytotoxic Tcell responses.