In:
Immunotherapy, Future Medicine Ltd, Vol. 1, No. 3 ( 2009-05), p. 347-354
Abstract:
Monocyte-derived dendritic cells (DCs) loaded with heat-inactivated HIV are used in therapeutic immunizations. It is not known whether they migrate in vivo to lymph nodes. We used an 111 In-oxine-labeled DC (ILDC) method to visualize the migration of DCs. The activity, time and incubation medium were investigated to obtain the highest cellular viability and radiolabeling yield. A trypan-blue exclusion test was used to determine the cellular viability. In five patients, 2 × 10 6 ILDCs were injected subcutaneously in the arm. An initial dynamic study was performed during the first 5 min after injection. This was followed by static acquisitions at several time points, using a high-resolution (general electric) γ-camera and quantifying the activity at regions of interest drawn on the injection point. The sensitivity of the γ-camera was evaluated. The highest number of viable DCs ( 〉 83%) and the best radiolabeling yield ( 〉 70%) were obtained with 1.11 MBq 111 In-oxine, after 10 min of incubation at 37°C in sodium chloride solution 0.9%. We did not observe migration of ILDCs to local lymph nodes in any patient. However, focal uptake at the place of injection continued during the study period. We observed a higher than expected loss of activity from the injection point (median A t /A 0 = 0.60 at day 2), which correlated with an increase in total cytotoxic T lymphocytes (CD8 + and granzyme B + cells) in the lypmphoid tissue observed after immunization (R 2 = 0.92, p = 0.03). If more than 20,000 ILDCs had migrated, they could have been detected. In future trials, a higher number of DCs or alternative methods should be used to assess the migration of DCs to lymph nodes.
Type of Medium:
Online Resource
ISSN:
1750-743X
,
1750-7448
Language:
English
Publisher:
Future Medicine Ltd
Publication Date:
2009
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