In vitro propagated dendritic cells from patients with human-papilloma virus-associated preneoplastic lesions of the uterine cervix: use of Flt3 ligand.

Dendritic cells (DC) are the most efficient antigen presenting cells. The clinical use of DC as vectors for antitumor and anti-infectious disease immunotherapy has been limited by their low level and accessibility in normal tissue. Substantial numbers of DC can be generated from peripheral blood cultured in the presence of interleukin-4 (IL-4) and granulocyte/macrophage-colony-stimulating factor (GM-CSF). We showed in this study that substantial numbers of DC can be obtained from the peripheral blood of patients with (pre)neoplastic lesions of the uterine cervix. The procedure required relatively small blood samples (10 ml) and the presence of 100 U/ml IL-4 and 800 U/ml GM-CSF in the culture medium. There was no significant difference in the morphology, yield, phenotype and function of generated DC between patients with cervical (pre)neoplastic lesions and healthy individuals. When the hematopoietic factor Flt3 ligand (Flt3L, 40 ng;ml) was added, there was an average increase in the DC population of 26% compared to cultures with GM-CSF and IL-4 alone. Approximately 1.2 x 10(6) cells with the characteristics of dendritic cells could be obtained when Flt3L was included in the medium. The addition of Flt3L did not modify the phenotypic profile of DC (HLA-DR+, CD1a+, CD4+, CD54+, CD80+, CD86+. CD40+, CD3- and CD14-). In addition, Flt3L generated functional DC capable of stimulating the proliferation of alloreactive T cells. These results suggest that Flt3L, in association with GM-CSF and IL-4, provides an advantageous tool for the large-scale generation of DC and that an immunotherapy based on the use of DC generated in vitro is possible in patients with (pre)neoplastic lesions of the uterine cervix.