TARGATT™ RUO Hypo Plus Human iPSC

One common strategy for engineering hypoimmune cells is to disrupt genes involved in HLA expression using B2M/CIITA double knock-out, which eliminates the expression of HLA Class I and II molecules.

But HLA knockout alone might not be enough. Natural killer (NK) cells provide another layer of immune surveillance. Unlike conventional T cells, NK cells can become activated when they encounter cells with abnormally low levels of HLA Class I. And this creates an important engineering challenge: reducing HLA Class I expression may decrease T-cell recognition, but the same modification can potentially increase susceptibility to NK-cell-mediated killing.

Rather than relying exclusively on HLA reduction, AST-9750 TARGATT™ Hypo Plus Human iPSC combines two targeted knockouts—B2M and CIITA—with five complementary immune-modulatory knock-ins that address complementary immune pathways.

This product also harnesses the power of the TARGATT™ platform, which means you can insert all these genes in a single reaction—up to 20 kb—with additional DNA over 20 kb added in nested reactions. And its placement at the H11 safe harbor locus avoids the potential for silencing and harmful random integration that you get with lentivirus and transposon-mediated integration and consistently delivers gene expression*.

*Constructs must have already been shown to be expressable in iPSCs or the differentiated cell type.

A characterized iPSC starting point for allogeneic and multilineage immune-evasion research:

• Favorable development profile – reprogrammed from CD34+ cord blood cells for reduced immunogenicity and fewer somatic mutations compared to reprogrammed adult cells
• Hypoimmunogenic – B2M/CIITA double knock-out eliminates expression of HLA Class I and II molecules to avoid recognition by CD8+ and CD4+ T cells
• Five complementary immune – modulatory knock-ins – HLA-F-B2M, CD200, CCL21, HLA-G-B2M and SERPINB9 knock-ins available
• Large knock-in ready – reliable H11 safe harbor locus using TARGATT large knock-in technology

How it works:

AST-9750 TARGATT™ Hypo Plus Human iPSC is a starting platform designed to address multiple mechanisms involved in allogeneic immune recognition and clearance by combining two targeted knockouts with five complementary immune-modulatory knock-ins.

B2M and CIITA double knockout

The cell surface expression of HLA I and HLA II molecules is eliminated by knocking out two genes:

B2M, which encodes the ß2-microglobulin protein, a key part of the HLA class I complex
CIITA, the HLA II transactivator which is essential for transcription of HLA class II genes

Knocking out cell surface expression of HLA I and HLA II eliminates the T cell response, although other gene edits are needed to avoid innate immune responses.