Immunological Properties of Murine Parthenogenetic Stem Cells and Their Differentiation Products

Abstract

The perspective to transplant grafts derived from pluripotent stem cells has gained much attention in recent years. Parthenogenetic stem cells (PSCs) are an alternative pluripotent stem cell type that is attractive as source of grafts for allogeneic transplantations because most PSCs are haploidentical for the major histocompatibility complex (MHC). This reduced immunogenetic complexity of PSCs could tremendously simplify the search for MHC-matched allogeneic stem cells. In this study, we have characterized immunological properties of the MHC haploidentical PSC line A3 (H2d/d) and the heterologous PSC line A6 (H2b/d). Both PSC lines largely lack MHC class I molecules, which present peptides to cytotoxic T lymphocytes (CTLs) and serve as ligands for inhibitory natural killer (NK) receptors. They express ligands for activating NK receptors, including the NKG2D ligand RAE-1, and the DNAM-1 ligands CD112 and CD155. Consequently, both PSC lines are highly susceptible to killing by IL-2-activated NK cells. In vitro-differentiated cells acquire resistance and downregulate ligands for activating NK receptors but fail to upregulate MHC class I molecules. The PSC line A6 and differentiated A6 cells are largely resistant to CTLs derived from T cell receptor transgenic OT-I mice after pulsing of the targets with the appropriate peptide. The high susceptibility to killing by activated NK cells may constitute a general feature of pluripotent stem cells as it has been also found with other pluripotent stem cell types. This activity potentially increases the safety of transplantations, if grafts contain traces of undifferentiated cells that could be tumorigenic in the recipient.

Integrating genome-wide CRISPR immune screen with multi-omic clinical data reveals distinct classes of tumor intrinsic immune regulators

“… 17 19 35 Additionally, multiple factors/pathways including RNF31 , RELA, and the TNFα pathway identified in other screens were also identified in our screens using the murine MC38 colon cancer cell line. We also identified other factors such as ALDOA and SERBINB9 , 36 which have been reported to regulate T cell-mediated killing. 7 These results suggest that in vitro genome-wide CRISPR immune screens can sensitively and reliably elucidate the immunoregulatory potential of tumor intrinsic factors and demonstrate the value of genome-wide immune screens as complementary approaches to discover novel prognostic biomarkers and therapeutic targets for immunotherapy.…”

T helper cells with specificity for an antigen in cardiomyocytes promote pressure overload-induced progression from hypertrophy to heart failure

“…RNA was obtained from hearts of C57BL/6, OT-II, cMy-mOVA, and cMy-mOVA-OT-II mice and transcribed into cDNA, which was used to analyze the expression of Ova mRNA by qPCR as described previously 56 using primers for Ova (forward: 5′-AGT GGC ATC AAT GGC TTC T-3′, reverse: 5′-GTT GAT TAT ACT CTC AAG CTG CTC A-3′) 21 and the housekeeping gene Gapdh (forward: 3′-TGT GTC CGT CGT GGA TCT GA-3′, reverse: 5′-TTG CTG TTG AAG TCG CAG GAG-3′). The Δct values (ct Ova minus ct Gapdh ) were used to calculate the relative expression of Ova in single heart samples in reference to the mean of the Δct values for the hearts of cMy-mOVA mice (Δct reference) (2 Δct Ova /2 Δct reference ) 57 .…”