Interferon-γ and interferon inducers such as polyinosinic-polycytidylic acid (poly I:C) promote natural-killer (NK)-cell-mediated killing of a wide range of tumor cells both in vitro and in vivo. The aim of the present work was to administer poly I:C to irradiated, leukemic mice, both before and after syngeneic bone marrow transplant with the intent of boosting the host’s natural immunity in the critical peritransplant period. Briefly, DBA/2 mice were injected with Friend-virus-induced erythroleukemia cells. After 5 days of tumor growth, some mice received daily injections of poly I:C for the next 4 days while control, leukemic mice received the saline vehicle only. All mice were then irradiated (450 R × 2 at 4-hour intervals) and transplanted 1 day following irradiation with bone marrow from age- and sex-matched, normal DBA/2 donor mice. After transplant, daily injections of poly I:C (or vehicle) continued for 8 more days. On day 9 after transplant, treated and control mice were killed, and the total cellularity, total numbers of lymphoid cells, the total numbers of NK cells (identified by the presence of an immuno-labelled, specific cell surface marker) were obtained from both the spleen and the bone marrow. Other identically treated mice subjected, however, to several additional rounds of poly I:C treatment were sampled 3 and 6 months after irradiation and bone marrow transplant. The results indicated that (a) poly I:C administered in the peritransplant period (before and after transplant) significantly increases the absolute numbers of NK cells in both the bone marrow and spleen of the transplanted host at all time intervals studied, (b) no erythroleukemic tumor cells were found, even as late as 6 months after transplant in the poly-I:C-treated hosts in spite of the fact that poly I:C treatment in this group had been terminated more than 2 months prior to tissue sampling, and (c) survival was significantly improved by pre- and posttransplant treatment with poly I:C.

Keywords:
Bone marrow, Transplantation, Leukemia, Natural killer cells
This content is only available via PDF.
1998
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.