Cultures derived from peripheral blood CD34(+) progenitor cells of head and neck cancer patients and from cord blood are functionally different

Patients with head and neck squamous cell carcinoma (HNSCC) have profound i mmune defects mediated, in part,by an increased number of immune surpressiv e CD34(+) progenitor cells in their peripheral blood and tumor. One means o f overcoming this immune suppression is to stimulate the CD34(+) cells to d ifferentiate into more mature, nonsuppressive progeny such as dendritic cel ls or monocytes. This study determined that CD34(+) cells from the peripher al blood of HNSCC patients have the same potential to differentiate into de ndritic cells as do human umbilical cord blood CD34(+) cells following 12-1 6 days of culture with a cytokine cocktail. When compared function ally, th e cultures that developed from CD34(+) cells of cord blood were able to ind uce an allostimulatory response in naive T-cells, while the cultures that d eveloped from patient CD34(+) cells lacked allostimulatory ability. Both cu ltures expressed class II MHC (HLA-DR), bur the proportion of cells express ing the costimulatory molecules CD80 and CD86 was significantly less in cul tures that developed From HNSCC-patient CD34(+) cells. Therefore, although the CD34(+) cells from the peripheral blood of HNSCC patients can different iate into dendritic cells, their allostimulatory capabilities are impaired, raising the question of their potential effectiveness in stimulating antit umor immune responses. Human Immunology. Published by Elsevier Science Inc.