Purposeful movement of human migratory cells away from an agent source

Patent Number: 7,141,363

Chemotactic gradients are critically important in stem cell function. This is demonstrated not only in the fact that the bone marrow constitutively secretes SDF-1 in order to allow systemically infused stem cells to home back to the bone marrow, but also in regenerative medicine where injured tissue releases chemokines to attract endogenous stem cells.

The current patent deals with the opposite of chemotaxis. Specifically, the patent describes something the inventors call fugetaxis, which means “running away” from the cell secreting the specific agent.

Essentially claims of the patent cover ways of screening for agents that repel cells away from the source that the agent is produced from (fugetactic agents). Specifically, the patent covers ways of screening supernatants, cells, antibodies, and small molecules for ability to induce cell repulsion.

Why is this relevant? Firstly, the cancer cells call in endothelial stem cells by chemotaxis. If one could figure out fugetactic agents for endothelial cells, and someone deliver these to the tumor, than theoretically angiogenesis could be inhibited.

Alternatively, the specification mentions that certain tumor cells naturally secrete fugetactic agents that repel T cells. By identifying said agents and inhibiting them, it may theoretically be possible to overcome tumor immune escape.

It appears that some of the concepts in this patent have been published (Poznansky et al. Thymocyte emigration is mediated by active movement away from stroma-derived factors. J Clin Invest. 2002 Apr;109(8):1101-10). The paper describes how developing lymphocytes are actively “pushed out” of the thymus by fugetactic factors.

View this patent on the USPTO website.