Immune‐privileged embryonic Swiss mouse STO and STO cell‐derived progenitor cells: major histocompatibility complex and cell differentiation antigen expression patterns resemble those of human embryonic stem cell lines

Abstract

Summary Embryonic mouse STO (S, SIM; T, 6‐thioguanine resistant; O, ouabain resistant) and 3(8)21‐enhanced green fluorescent protein (EGFP) cell lines exhibit long‐term survival and hepatic progenitor cell behaviour after xenogeneic engraftment in non‐immunosuppressed inbred rats, and were previously designated major histocompatibility complex (MHC) class I‐ and class II‐negative lines. To determine the molecular basis for undetectable MHC determinants, the expression and haplotype of H‐2K, H‐2D, H‐2L and I‐A proteins were reassessed by reverse transcriptase–polymerase chain reaction (RT‐PCR), cDNA sequencing, RNA hybridization, immunoblotting, quantitative RT‐PCR (QPCR), immunocytochemistry and flow cytometry. To detect cell differentiation (CD) surface antigens characteristic of stem cells, apoptotic regulation or adaptive immunity that might facilitate progenitor cell status or immune privilege, flow cytometry was also used to screen untreated and cytokine [interferon (IFN)‐γ]‐treated cultures. Despite prior PCR genotyping analyses suggestive of H‐2q haplotypes in STO, 3(8)21‐EGFP and parental 3(8)21 cells, all three lines expressed H‐2K cDNA sequences identical to those of d‐haplotype BALB/c mice, as well as constitutive and cytokine‐inducible H‐2Kd determinants. In contrast, apart from H‐2Ld[LOW] display in 3(8)21 cells, H‐2Dd, H‐2Ld and I‐Ad determinants were undetectable. All three lines expressed constitutive and cytokine‐inducible CD34; however, except for inducible CD117[LOW] expression in 3(8)21 cells, no expression of CD45, CD117, CD62L, CD80, CD86, CD90·1 or CD95L/CD178 was observed. Constitutive and cytokine‐inducible CD95[LOW] expression was detected in STO and 3(8)21 cells, but not in 3(8)21‐EGFP cells. MHC (class I+[LOW]/class II–) and CD (CD34+/CD80–/CD86–/CD95L–) expression patterns in STO and STO cell‐derived progenitor cells resemble patterns reported for human embryonic stem cell lines. Whether these patterns reflect associations with mechanisms that are regulatory of immune privilege or functional tissue‐specific plasticity is unknown.

Human Embryonic Stem Cell-extracts Inhibit the Differentiation and Function of Monocyte-derived Dendritic Cells

“…In addition to their pluripotent capacity to give rise to almost any type of cell present in the adult body, ESCs have been found to be non-immunogenic. Furthermore, they possess the ability to inhibit allogeneic immune responses and as a result can protect allogeneic solid organ transplants from immune attack [13][14][15][16][17][18][19][20][21]. However, to overcome allogeneic immune responses, a minimum of 5.0×10 6 cells are required in murine in-vivo studies (30% teratoma formation), with 20× 10 6 being the optimal number (90% teratoma formation), whereas 1.0 ×10 6 cells were found to be completely ineffective [16].…”

“…Interestingly, hESCs also possess properties of immune privilege similar to fetal tissues during pregnancy [13][14][15][16][17][18][19][20]. Specifically, hESCs seem to be non-immunogenic and do not elicit immune responses in the presence of allogeneic immune cells and can persist across allogeneic and even xenogeneic barriers [14,15,17,18,[21][22][23].…”

“…These specialized immune properties of ESCs are consistent across several species. Both rat and mouse undifferentiated ESCs also lack the expression of immune stimulatory molecules and possess resultant "stealth" capabilities when introduced to allogeneic hosts [15,16,18].…”

Simulated microgravity decreases apoptosis in fetal fibroblasts

“…The STO [Sandos inbred mice (SIM)] thioguanine-and ouabainresistant) cell line is derived from a continuous line of SIM skin fetal fibroblasts (14,15). Two milliliters of cells at a density of 2.5x10 5 cells/ml were seeded in 12.5-cm² flasks and cultured at 37˚C and 5% CO 2 in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 1% penicillin/streptomycin (all were from Invitrogen, Merelbeke, Belgium).…”

Transmission of Porcine Endogenous Retrovirus Produced from Different Recipient Cells In Vivo

“…CsA is generally used as an immune suppressant to reduce immune rejection in organ transplantation, since the major histocompatibility complex (MHC) classes of cells used for transplantation are different from those of host animals [34, 35]. Thus, the immune escape virus may be critical for zoonosis in the host when the immune system is suppressed for transplantation.…”