Selective HSPC Mobilization for In Vivo Gene Therapy
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Solution Overview
Problem
Current methods for in vivo transduction of hematopoietic stem and progenitor cells are inefficient due to physical barriers in the bone marrow and are not suitable for patients with certain hemoglobinopathies, such as sickle cell disease, where G-CSF mobilization is contraindicated, leading to unselective cell mobilization and reduced effective vector dose.
Innovation Solution
The use of a C-X-C chemokine receptor type 2 (CXCR2) agonist like Gro-β or its variants, in combination with a CXCR4 antagonist, to mobilize hematopoietic stem and progenitor cells from the bone marrow into peripheral blood, followed by transduction with a nucleic acid containing a selection marker and administration of a selection agent to ensure only transduced cells survive.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If G-CSF is used as a mobilization agent, then hematopoietic stem and progenitor cells are mobilized into peripheral blood, but unselective cell mobilization occurs leading to leukocytosis and higher cytokine levels
Solution Approach 1:
The patent applies local quality by using a dual-agent mobilization regimen (CXCR4 antagonist plus CXCR2 agonist) that selectively mobilizes primitive HSPCs while leaving committed cells in the bone marrow. This creates a differentiated quality of mobilization where only the desired cell population is released, avoiding the unselective mobilization and associated harmful effects of G-CSF alone.
Solution Approach 2:
The patent changes the mobilization parameters by switching from G-CSF monotherapy to a combination of CXCR4 antagonist and CXCR2 agonist. This parameter change results in altered cell mobilization characteristics: selective release of primitive HSPCs with reduced leukocytosis and lower cytokine production, thereby resolving the contradiction between cell yield and harmful effects.
2Quantity of substance
If G-CSF/AMD3100 mobilization is used, then HSPCs are mobilized into peripheral blood, but the effective vector dose for primitive HSPCs is reduced due to sequestration by committed cells
Solution Approach 1:
The patent achieves selective mobilization of primitive HSPCs using the CXCR4 antagonist plus CXCR2 agonist regimen, ensuring that only the target cell population is released into peripheral blood. This eliminates sequestration by committed cells, maximizing the effective vector dose delivered to primitive HSPCs.
Solution Approach 2:
The patent converts the potential harm of vector sequestration into a benefit by using selective mobilization. Instead of all cells competing for the vector, only primitive HSPCs are mobilized, ensuring that the vector dose is efficiently utilized by the target cells and improving transduction efficiency.
3Reliability
If ex vivo gene therapy is used, then gene correction can be achieved, but the procedure is costly and requires complex manufacturing with cell culture and toxic conditioning
Solution Approach 1:
The patent extracts the complex manufacturing steps (cell culture, ex vivo transduction, toxic conditioning) from the gene therapy process by implementing in vivo transduction. The simplified approach involves only mobilization and direct vector administration, eliminating the need for complex laboratory procedures while maintaining gene correction efficacy.
Solution Approach 2:
The patent inverts the traditional ex vivo approach by performing transduction in vivo rather than ex vivo. Instead of harvesting cells, culturing them, transducing them in the lab, and reinfusing them, the method mobilizes cells and administers the vector directly in the patient, reversing the sequence and eliminating manufacturing complexity.
4Ease of operation
If in vivo transduction is attempted without selective mobilization, then the procedure is simpler, but transduction efficiency is low due to physical barriers of bone marrow stroma
Solution Approach 1:
The patent applies preliminary action by selectively mobilizing primitive HSPCs into peripheral blood before vector administration. This pre-mobilization step removes the physical barriers of bone marrow stroma that would otherwise prevent efficient transduction, ensuring that the vector can access the target cells effectively when administered in vivo.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively mobilizes and transduces hematopoietic stem and progenitor cells, allowing for gene therapy to correct genetic defects in blood cells, reducing leukocytosis and cytokine levels, and providing a more selective and efficient method compared to traditional G-CSF/AMD3100 mobilization regimens.
Implementation Method 1
mobilizing hematopoietic stem and progenitor cells from bone marrow using a C-X-C chemokine receptor type 2 (CXCR2) agonist, such as Gro-β
Implementation Method 2
optionally in combination with a C-X-C chemokine receptor type 4 (CXCR4) antagonist
Data Source
AI summary
The invention relates to the in vivo transduction of hematopoietic stem and progenitor cells (HSPCs) in a subject, such as a human subject, and to the treatment of subjects suffering from various pathologies, such as blood diseases, metabolic disorders, cancers, and autoimmune diseases, among others.