E-GEOD-41482 - Distinguishing innate memory CD8+ T from homeostatically expanded CD8+ T cells
Released on 19 February 2013, last updated on 2 June 2014
Innate memory phenotype (IMP) CD8+ T cells are non-conventional αβ T cells exhibiting features of innate immune cells, and are significantly increased in the absence of non-receptor tyrosine kinase ITK. Their developmental path and function are not clear, particularly whether they can contribute to antigen specific responses. We found that WT bone marrow gives rise to IMP CD8+ T cells in irradiated MHCI-/- recipients, resembling those in Itk-/- mice determined by expression of surface markers. However, CD8+ T cells share similar expression of memory markers. We used microarrays to compare the global programme of gene expression to determine whether the CD8+ T cells selected by hematopoietic MHCI are IMP CD8+ T cells as observed in the absence of ITK, or the result of homeostatic expansion of T cell contamination in the donor bone marrow. Through analysis of global gene expression correlation and differential expression, we determined that hematopoietic MHCI dependent IMP CD8+ T cells generated in irradiated MHCI-/- recipients, resemble those in Itk-/- mice, but distinct from CD8+ T cells derived via homeostatic proliferation. Cell sorting was performed using a FACSAria Cell Sorter (BD Biosciences, San Diego, CA). IMP CD8+ T cells (TCRβ+CD8α+CD44hi) were sorted from splenocytes of WT→MHCI-/- chimeras 8 weeks post transplantation and 8-week old Itk-/- mice. To generate HP cells, naïve CD8+ T cells (TCRβ+CD8α+CD44lo) were sorted and injected into Rag1-/- recipients (0.5 million /mouse, retro-orbital injection), followed by sorting of TCRβ+CD8α+ splenocytes 8 weeks post adoptive transfer. We sought to compare cells with the same gender and age, thus all donors were female, and ages (absolute age for Itk null and age post transfer for chimeras and HP model) were 8 weeks.
transcription profiling by array
Weishan Huang <email@example.com>, Avery August