Genetically Modified Donor Cells Evading Immune Rejection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for reducing allograft recognition and rejection, such as immunosuppressive therapies and tissue matching, are inadequate as they often result in undesirable side effects and incomplete protection, necessitating a more effective approach to prevent immune cell recognition of transplanted tissues.
Innovation Solution
Genetic modification of donor cells or tissues to reduce expression of major histocompatibility complex (MHC) I proteins and introduce inhibitory factors like HLA-E, HLA-G, or CMV-UL18 to evade CD8+ T cell and NK cell recognition, using techniques like antisense RNA, siRNA, or genomic editing to match the recipient's HLA type.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If immunosuppressive therapies are used to reduce allograft rejection, then graft acceptance is improved, but undesirable side effects and compromised immune system increase
Solution Approach 1:
The patent segments the MHC complex into separate components (MHC heavy chain and β-2 microglobulin) and selectively modifies only the β-2m component through gene editing. This targeted approach allows reduction of allogeneic MHC presentation without completely eliminating MHC function, thereby reducing rejection while minimizing immunosuppression side effects
Solution Approach 2:
The patent changes the genetic parameters of donor cells by introducing recipient-matched HLA alleles or HLA-G/HLA-E variants. This parameter modification creates immunological compatibility between donor and recipient, improving graft acceptance without requiring systemic immunosuppressive therapy
2Reliability
If tissue matching is used to prevent allograft rejection, then immune recognition is reduced, but complete protection is not achieved
Solution Approach 1:
Instead of selecting donor tissue that matches the recipient's MHC type (traditional approach), the patent inverts the strategy by genetically modifying the donor tissue to express recipient-matched HLA molecules. This reverse engineering approach ensures immunological compatibility regardless of initial tissue matching limitations
Solution Approach 2:
The patent creates composite MHC structures by combining recipient-matched HLA heavy chains with modified β-2 microglobulin variants. These composite molecules present a dual function: maintaining normal antigen presentation while avoiding alloreactive T-cell recognition, thereby achieving complete protection against rejection
3Reliability
If MHC I expression is reduced to evade CD8+ T cell recognition, then allograft recognition is reduced, but NK cell activation may increase
Solution Approach 1:
The patent introduces HLA-G or HLA-E molecules as intermediary protective factors that specifically interact with NK cell receptors to deliver inhibitory signals. These intermediary molecules block NK cell activation while the reduced MHC I expression continues to evade CD8+ T cell recognition, resolving the contradiction between the two immune threats
Data Source
AI summary
Allograft recognition and rejection of donor cells in a host is reduced by limiting or even abrogating expression of the donor cell's MHC-I peptides to avoid CD8+ T-cell recognition and by expression of inhibitory factors to avoid an NK cell mediated cytotoxic response.