Dendritic cells/natural killer cross-talk: a novel target for human immunodeficiency virus type-1 protease inhibitors

PLoS One. 2010 Jun 10;5(6):e11052. doi: 10.1371/journal.pone.0011052.


Background: HIV-1 Protease Inhibitors, namely PIs, originally designed to inhibit HIV-1 aspartic protease, can modulate the immune response by mechanisms largely unknown, and independent from their activity on viral replication. Here, we analyzed the ability of PIs to interfere with differentiation program of monocytes toward dendritic cell (DCs) lineage, a key process in the inflammatory response.

Methodology/principal findings: Monocytes from healthy donors were isolated and induced to differentiate in vitro in the presence or absence of saquinavir, ritonavir, nelfinavir, indinavir or amprenavir (sqv, rtv, nlfv, idv, apv, respectively). These drugs demonstrated a differential ability to sustain the generation of immature DCs (iDCs) with an altered phenotype, including low levels of CD1a, CD86, CD36 and CD209. DCs generated in the presence of rtv also failed to acquire the typical phenotype of mature DCs (mDCs), and secreted lower amounts of IL-12 and IL-15. Accordingly, these aberrant mDCs failed to support activation of autologous Natural Killer (NK) cells, and resulted highly susceptible to NK cell-mediated cytotoxicity.

Conclusions/significance: Our findings uncover novel functional properties of PIs within the DC-NK cell cross-talk, unveiling the heterogeneous ability of members of this class drugs to drive the generation of atypical monocyte-derived DCs (MDDCs) showing an aberrant phenotype, a failure to respond appropriately to bacterial endotoxin, a weak ability to prime autologous NK cells, and a high susceptibility to NK cell killing. These unexpected properties might contribute to limit inflammation and viral spreading in HIV-1 infected patients under PIs treatment, and open novel therapeutical perspectives for this class drugs as immunomodulators in autoimmunity and cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Proliferation
  • Dendritic Cells / drug effects*
  • Dendritic Cells / immunology
  • Enzyme-Linked Immunosorbent Assay
  • Flow Cytometry
  • HIV Protease / drug effects*
  • HIV Protease Inhibitors / pharmacology*
  • Humans
  • Immunophenotyping
  • Killer Cells, Natural / drug effects*
  • Killer Cells, Natural / immunology


  • HIV Protease Inhibitors
  • HIV Protease
  • p16 protease, Human immunodeficiency virus 1