Myeloid precursor cell useful for gene therapy and for modulation of immune responses

Patent Number: 7,198,909

Myeloid progenitor cells are known to be responsible for producing polymorphonuclear leukocytes as well as monocytes in the blood. Besides their well-known function in the classical hematopoietic system, myeloid progenitor cells ahve been reported by various groups to have immune modulatory function, specifically, the ability to inhibit immune responses through factors such as TGF, PGE, and other soluble mediators.

In the current patent, 2 claims were issued. The first claim covers expression of nucleic acids in myeloid-specific cells through transfection by retroviral vector of the nucleic acid into myeloid cells derived from the spleen. The second claim is dependent on the first claim and covers the use of myeloid specific promoters to drive expression of the gene of interest.

The patent presents a problem. How feasible is it to extract cells from human spleen? The concepts in the patent are very interesting...if you could specifically transfect myeloid lineage cells you can, for example, generate monocytes with a specific phenotype...lets say to stimulate angiogenesis. However it appears at face value that this limitation of needing to use the spleen as a source of myeloid cells will impede commercialization of this patent.

View this patent on the USPTO website.