The development of novel therapeutic interventions is a high-priority area of research, with a particular focus on the utilization of cell technologies. The primary impediment to the broader implementation of these technologies is the challenge of ensuring immunological compatibility with the recipient. The utilization of the patient’s own cells introduces a high degree of complexity into the process and results in an escalation in the financial burden of treatment. In certain instances, the preparation of the autologous product is constrained by the paucity of time available for its production. This review examines a number of approaches that currently exist around the world and offer the possibility of significantly reducing the time and cost of preparing cell products, thereby expanding the pool of recipients. These include the establishment of cell line banks with a known haplotype and the utilization of contemporary advancements in genome editing to generate hypoimmune cell lines. The review herein discusses the difficulties and disadvantages of each approach.

Allogeneic chimeric antigen receptor (CAR)-based cell products and induced pluripotent stem cell (iPSC)-derived regenerative grafts increasingly use multilayer immune engineering. Current strategies are strongest against direct human leukocyte antigen (HLA)-dependent recognition but incompletely address natural killer (NK)-cell counter-pressure, priming by recipient antigen-presenting cells, humoral and complement-mediated injury, inflammatory remodeling, blood- and tissue-interface damage, and terminal cell killing. Poxvirus research has characterized diverse immunomodulatory mechanisms relevant to these barriers. We review poxviral control of interferon signaling, antigen processing and presentation, T-cell activation, NK-cell surveillance, cytokine and chemokine networks, complement, inflammatory signaling, and regulated cell death, integrating viral mechanisms with human perturbation, cell-engineering, and transplantation evidence. A qualitative Tier 1–3 framework distinguishes mechanisms close to current cell-therapy practice from those requiring greater product-specific validation or control. The resulting design rules favor graded antigen-presentation control with paired NK validation, local or transient inflammatory buffering, interface-restricted complement protection, and survival enhancement only when independent eliminability is preserved. Selected poxviral proteins can act autonomously outside productive infection, but direct viral-protein expression remains a selective rather than default option. We propose a conditional defense-in-depth framework in which modules are added only when a residual barrier is demonstrated in the final therapeutic product.