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Journal of Biomedicine and Biotechnology
Volume 2010 (2010), Article ID 894971, 6 pages
Research Article

Triggering DTH and CTL Activity by fd Filamentous Bacteriophages: Role of CD4+ T Cells in Memory Responses

1Institute of Genetics and Biophysics “Adriano Buzzati Traverso”, CNR, Via P. Castellino 111, 80131 Naples, Italy
2Institute of Protein Biochemistry, CNR, Via P. Castellino 111, 80131 Naples, Italy

Received 20 November 2009; Revised 4 February 2010; Accepted 13 February 2010

Academic Editor: Kim Klonowski

Copyright © 2010 Giovanna Del Pozzo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The ability of fd bacteriophage particles to trigger different arms of the immune system has been previously shown by us with particular emphasis on the ability of phages to raise CTL responses in vitro and in vivo. Here we show that fd virions in the absence of adjuvants are able to evoke a DTH reaction mediated by antigen specific CD8+ T cells. In addition, we analyzed the induction of CTL responses in mice depleted of CD4+ T cells, and we observed that short-term secondary CTL responses were induced in the absence of CD4+ T cells while induction of long-term memory CTLs required the presence of CD4+ T lymphocytes. These results examine the cellular mechanism at the basis of fd efficiency and provide new elements to further validate the use of fd particles for eliciting and monitoring antigen-specific CTLs.