Peptide loading of empty major histocompatibility complex molecules on RMA-S cells allows the induction of primary cytotoxic T lymphocyte responses

Eur J Immunol. 1991 Dec;21(12):2963-70. doi: 10.1002/eji.1830211210.


The antigen processing-defective mutant cell line RMA-S expresses at the cell surface major histocompatibility complex (MHC) class I molecules devoid of peptide that can be efficiently loaded with exogenous immunogenic peptides. We now report that viral peptide-loaded RMA-S cells, unlike parental RMA cells, can induce primary cytotoxic T lymphocyte (CTL) responses in vitro, in a T helper cell-independent fashion. This was shown for an H-2Kb-binding peptide of Sendai virus nucleoprotein and an H-2Db-binding peptide of adenovirus type 5 E1A protein with responding spleen cells of C57BL/6 mice, the strain of origin of RMA and RMA-S cells. Primary Sendai peptide-induced CTL lyse both peptide-loaded and virus-infected cells. Pre-culture of RMA-S cells at low temperature (22 degrees - 26 degrees C), which increases the amount of empty MHC class I molecules at the cell surface, decreases the peptide concentrations required for the induction of primary CTL responses. Primary peptide-specific CTL responses induced by peptide-loaded RMA-S cells are CD4+ cell- and MHC class II+ cell-independent. CTL response induction is blocked by the presence of anti-CD8 monoclonal antibody during culture. Direct peptide binding studies confirm the efficient loading of empty MHC molecules on RMA-S cells with peptide and show 2.5-fold more peptide bound per RMA-S cell compared to RMA cells. An additional factor explaining the difference in primary response induction between RMA and RMA-S cells is related to the CD8 dependence of these responses. MHC class I molecules occupied with irrelevant peptides (a majority present on RMA, largely absent on RMA-S) may interfere in the interaction of the CD8 molecule with relevant MHC/peptide complexes. The results delineate a novel strategy of peptide based in vitro immunization to elicit CD8+ cytotoxic T cell responses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / immunology
  • Amino Acid Sequence
  • Animals
  • Antigens, Viral / chemistry*
  • Cell Line
  • Cytotoxicity, Immunologic
  • H-2 Antigens / metabolism*
  • Immunity, Cellular
  • Immunologic Memory
  • In Vitro Techniques
  • Major Histocompatibility Complex
  • Mice
  • Molecular Sequence Data
  • Parainfluenza Virus 1, Human / immunology
  • Peptides / chemistry
  • Peptides / immunology*
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocytes, Cytotoxic / immunology*
  • Temperature


  • Antigens, Viral
  • H-2 Antigens
  • Peptides