Uptake of Apoptotic K562 Leukaemia Cells by Immature Dendritic Cells is Greatly Facilitated by Serum

Abstract

Dendritic cells (DCs) are potent antigen-presenting cells and play an important role in T-cell-mediated immunity. DCs have been shown to induce strong antitumour immune responses both in vitro and in vivo. One way of providing the DCs with all relevant tumour antigens would be to incubate the DCs with material from dead tumour cells. We have examined the uptake of apoptotic and necrotic K562 leukaemia cells by DCs under different culture conditions. Results from coincubation experiments strongly suggested that uptake of apoptotic K562 cells was dependent upon the addition of autologous serum (AS). Under these conditions, 47-79% of all DCs were shown to ingest apoptotic material. AS also seemed to be important for the expression of functionally important markers, most notably HLA class I, CD86, CCR7 and CD83. The vast majority of DCs were shown to ingest necrotic material from K562 cells, with no additional effect of AS. The results suggest that incubation of DCs with apoptotic material for cell therapeutic purposes may best be performed in the presence of AS.

Differential capability for phagocytosis of apoptotic and necrotic leukemia cells by human peripheral blood dendritic cell subsets

“…concentration of 15 M for 10 min. Apoptosis was induced as described previously [25]. Briefly, a combination of the specific BCR-ABL tyrosine kinase inhibitor CGP 57148 (STI 571; kindly provided by Dr. Elisabeth Buchdunger, Novartis Pharma AG, Basel, Switzerland) and ␥ irradiation was used.…”

“…One strategy is to load DC with material from apoptotic or necrotic tumor cells [2]. We have previously examined uptake of apoptotic and necrotic K562 leukemia cells by iMoDC [25]. Here, we have investigated the uptake of apoptotic and necrotic K562 leukemia cells by PBDC using the uptake by iMoDC as a reference.…”

Differentiation of CD1a− and CD1a+ monocyte-derived dendritic cells is biased by lipid environment and PPARγ

“…20 Other studies reported that the serum concentration of culture media can also influence CD1a ϩ and CD1a Ϫ dichotomy and modify the functional properties of these DC subsets. [21][22][23] The nature of exogenous factors or regulatory pathways that may modulate the ratio of CD1a ϩ and CD1a Ϫ moDCs has not been identified.…”