Comparing the Ability of Freshly Generated and Cryopreserved Dendritic Cell Vaccines to Inhibit Growth of Breast Cancer in a Mouse Model

Abstract

Repetitive vaccinations with dendritic cell (DC)-based vaccines over long periods of time can break pre-existing tolerance to tumors and achieve clinically relevant immune response. This requires a large number of DCs to be generated under good manufacturing protocol, which is time- and cost intensive. Thus, producing a large numbers of DCs at one time point and cryopreserving these cells in ready-for-use aliquots for clinical application may overcome this constraint. This could also reduce batch-to-batch variations. In this study, we generated DCs from bone marrow obtained from BALB/c mice. Some of the generated DCs were cryopreserved before conducting various tests. There were no significant differences in the morphology and phenotype between cryopreserved and freshly generated DCs. Both types of DCs pulsed with tumor lysate (TL) from 4T1 murine mammary cancer cells (DC+TL) possessed a similar capacity to stimulate the proliferation of T-cells. In addition, cryopreserved and fresh DC pulsed with TL showed similar tumor growth inhibition patterns. Both DCs induced initial retardation of tumor growth (p<0.05) and prolonged the survival (p<0.05) of tumor-bearing mice treated with DC+TL as compared with nontreated control mice. Cryopreserved DCs shared similar therapeutic efficacy to fresh DCs, and this finding lends supports the routine use of cryopreserved DCs in future clinical trials.

Mature dendritic cell derived from cryopreserved immature dendritic cell shows impaired homing ability and reduced anti-viral therapeutic effects

“…To date, several studies have reported the effect of cryopreservation on antigen-loaded or unloaded matured DCs with results showing that the freezing and thawing process does not interfere with their phenotype in vitro as well as the trafficking and functional properties in vivo 1117. However, in contrast to the validate and consistent findings in cryopreserved mature DCs, systematical investigations on the cellular changes and the in vivo functional properties of frozen immature DC as well as its mature counterpart are very limited, and some in vitro findings are controversial.…”

“…Hence, the properties of cells that have experienced freezing-thawing cycle need to be fully addressed. Several studies in the early 2000s and recent years have described the effect of cryopreservation on the biology and function of DCs in vitro or in vivo , however, some conclusions are controversial10111213 and most importantly, up to now, there is still a lack of confirming evidence on whether cryopreservation would have an effect on DCs’ homing capacity.…”

Targeting specificity of dendritic cells on breast cancer stem cells: in vitro and in vivo evaluations

“…This finding is a little different from those of studies that used a more common breast tumor model. 48 – 50 This study used Swiss and mammary tumor 4T1 cell lines to develop a breast tumor model. The 4T1 cell line comes from BALB/c mice, whereas the Swiss mice retained the complete immune system.…”

Cryopreserved vitamin D3-tolerogenic dendritic cells pulsed with autoantigens as a potential therapy for multiple sclerosis patients

“…The use of cryopreserved tolDC has been elucidated as a solution since one leukapheresis provides enough monocytes to produce large number of tolDC, which can be cryopreserved in ready-to-use aliquots. In this sense, Radhakrishnan and co-workers reported that cryopreserved DC vaccines retained in vitro and in vivo therapeutic efficacy to inhibit breast cancer growth in mice [ 10 ]. However, the process to obtain tolDC is most difficult and may be susceptible to the cryopreservation process.…”