Validation of RNA-based molecular clonotype analysis for virus-specific CD8+ T-cells in formaldehyde-fixed specimens isolated from peripheral blood

J Immunol Methods. 2007 Sep 30;326(1-2):127-38. doi: 10.1016/j.jim.2007.07.016. Epub 2007 Aug 9.

Abstract

Recent advances in the field of molecular clonotype analysis have enabled detailed repertoire characterization of viably isolated antigen-specific T cell populations directly ex vivo. However, in the absence of a biologically contained FACS facility, peripheral blood mononuclear cell (PBMC) preparations derived from patients infected with agents such as HIV must be formaldehyde fixed to inactivate the pathogen; this procedure adversely affects nucleic acid template quality. Here, we developed and validated a method to amplify and sequence mRNA species derived from formaldehyde fixed PBMC specimens. Antigen-specific CD8+ cytotoxic T-lymphocyte populations were identified with standard fluorochrome-conjugated peptide-major histocompatibility complex class I tetramers refolded around synthetic peptides representing immunodominant epitopes from HIV p24 Gag (KRWII[M/L]GLNK/HLA B*2705) and CMV pp65 (NLVPMVATV/HLA A*0201 and TPRVTGGGAM/HLA B*0702), and acquired in separate laboratories with or without fixation. In the presence of proteinase K pre-treatment, the observed antigen-specific CD8+ T-cell repertoire determined by molecular clonotype analysis was statistically no different whether derived from fixed or unfixed PBMC. However, oligo-dT recovery methods were not suitable for use with fixed tissue as significant skewing of clonotypic representation was observed. Thus, we have developed a reliable RNA-based method for molecular clonotype analysis that is compatible with formaldehyde fixation and therefore suitable for use with primary human samples isolated by FACS outside the context of a biological safety level 3 containment facility.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / metabolism*
  • CD8-Positive T-Lymphocytes / virology
  • Cell Separation
  • Cells, Cultured
  • Clone Cells
  • Complementarity Determining Regions / genetics
  • Fixatives*
  • Flow Cytometry
  • Formaldehyde*
  • Genes, T-Cell Receptor beta*
  • HIV-1 / immunology
  • HIV-1 / metabolism
  • HeLa Cells
  • Humans
  • Immunophenotyping*
  • Mice
  • RNA / analysis*
  • RNA / blood
  • RNA / metabolism
  • Virus Inactivation

Substances

  • Complementarity Determining Regions
  • Fixatives
  • Formaldehyde
  • RNA