Pertussis toxin B-oligomer dissociates T cell activation and HIV replication in CD4 T cells released from infected lymphoid tissue

Massimo Alfano, Jean Charles Grivel, Silvia Ghezzi, Davide Corti, Matteo Trimarchi, Guido Poli, Leonid Margolis

Research output: Contribution to journalArticlepeer-review


Objective: To investigate, in human lymphoid tissue infected with HIV-1 ex vivo, the immunostimulatory and HIV inhibitory properties of pertussis toxin B oligomer (PTX-B) and of the genetically modified non-toxic PT-9K/129G. Methods: Human tonsils from uninfected donors were infected ex vivo with R5 or X4 HIV-1 in the presence or absence of PTX-B. Virus replication was evaluated in culture supernatants; cells emigrated from tissue blocks were immunostained for lymphocytic and activation markers. HIV DNA and cell proliferation were evaluated with real-time PCR and [3H]thymidine incorporation, respectively. Results: Both PTX-B and PT-9K/129G inhibited HIV-1 replication. These compounds activated and stimulated the proliferation of emigrated cells, most of which were CD4 T lymphocytes. Cells emigrated from infected tissues did not produce detectable virus in unstimulated or in PTX-B- or PT-9K/129G-stimulated cultures whereas robust virus production was triggered by phytohemagglutinin (PHA) or interleukin-2 (IL-2). Analysis of HIV DNA content indicated that infected cells were present among emigrated cells and that their number greatly increased following IL-2 stimulation, whereas it remained constant in the presence of PTX-B or PT-9K/129G. Conclusions: PTX-B and PT-9K/129G inhibit both R5 and X4 HIV-1 replication in human lymphoid tissue ex vivo. In contrast to PHA and IL-2, they promote the proliferation of CD4 T lymphocytes emigrated from tissue, including HIV-infected cells, without triggering virus replication. Therefore, these emigrated CD4 T cells represent a novel model of a latent inducible HIV reservoir. Thus, PTX-B and the clinically approved PT-9K/129G are potential antiretroviral agents endowed with immunostimulatory capacity.

Original languageEnglish
Pages (from-to)1007-1014
Number of pages8
JournalAIDS (London, England)
Issue number10
Publication statusPublished - Jul 1 2005


  • HIV
  • Latency
  • Lymphoid tissue
  • PTX
  • T-cell proliferation

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology


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