Abstract
BACKGROUND: Smooth muscle cells (SMCs) derived from allogeneic induced pluripotent stem cells (iPSC) hold significant potential in cellular therapy for many cardiovascular diseases. However, their immunological profile is poorly characterized, limiting their clinical progression. AIMS: This study aimed to investigate the immunogenicity of iPSC-SMC in comparison with naturally derived vascular SMCs (v-SMCs). RESULT: We found iPSC-SMCs, in contrast to naturally derived vascular SMCs (v-SMC), triggered T effector memory (T(EM)) cell proliferation. However, expression of T(EM) activation-related proteins was comparable between both cell types. Since arterial v-SMCs can also establish immunoprivilege through indoleamine 2,3 dioxygenase (IDO-1) activity, we therefore investigated IDO-1 expression in two independently engineered iPSC-SMCs (NIBSC 8 (N8) and Yale 6 (Y6)). IDO-1 expression and functionality was markedly reduced in both iPSC-SMC lines compared to v-SMC and unlike v-SMC, neither iPSC-SMC line could modulate the immune response in a co-culture with CD3/CD28 activated peripheral blood mononuclear cells (PBMC). CONCLUSIONS: These results indicate that iPSC-SMC's impaired ability to modulate the immune response through IDO-1 expression contributes to their differing immunogenicity to v-SMC and highlights the importance of immune phenotyping for therapeutic applications of iPSC-derivatives.