CD8.alpha..sup.+lymphoid dendritic cell differentiated from human hematopoietic stem cell and a method for differentiation

Patent Number: 7,390,658

Dendritic cells are the most potent antigen presenting cell, capable of activating naive T cells, as well as inducing generation of suppressor T cells.  Given the potent ability of dendritic cells to stimulate the immune system, they have been used as "natural adjuvants" in cancer therapy.  A discussion of the tolerogenic and tolerance inhibiting activities of dendritic cells reveals that dendritic cells are critical controllers of autoimmunity, transplant rejection, and tumor growth/suppression.  Many patents are issued for ways of generating dendritic cells and specific types of dendritic cells. For example, US patent # 7,338,676 teaches how to use pine cone extracts to activate dendritic cells.

The current patent teaches ways of generating CD8 positive lymphoid dendritic cells from peripheral blood progenitor cells.  Specifically, the first independent claim covers a method for generating CD8 positive dendritic cells from peripheral blood derived CD34 cells by culturing 100,000 CD34 cells per ml first in media made of 5% human serum albumin, 100 U/ml of penicillin, 100 ug/ml of streptomycin, 100 U/ml of L-glutamine and 50 ng/ml of GM-CSF for one week and then in a second medium consisting of 5% human serum albumin, 100 U/ml of penicillin, 100 ug/ml of streptomycin, 100 U/ml of L-glutamine and 200 U/ml of IFN-.gamma. for one week. 

This is a simple protocol involving what appears to be the first differentiation step, and a second maturation step. 

The generation of lymphoid DC could be useful since these have distinct immunological characteristics as compared to myeloid DC.  In some situations, lymphoid DC may actually be tolerogenic and useful for inhibition of immune responses in an antigen-specific manner.
 

View this patent on the USPTO website.