title: Dendritic cells/natural killer cross-talk: a novel target for human immunodeficiency virus type-1 protease inhibitors.
abstract: 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.
  
  
  RESULTS
  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
  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.
authors.affiliation: Department of Cellular and Molecular Biology and Pathology, University of Naples Federico II, Naples, Italy.
authors.forename: Maria Letizia
authors.initials: ML
authors.lastname: Giardino Torchia
authors.forename: Elena
authors.initials: E
authors.lastname: Ciaglia
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Masci
authors.forename: Laura
authors.initials: L
authors.lastname: Vitiello
authors.forename: Manuela
authors.initials: M
authors.lastname: Fogli
authors.forename: Andrea
authors.initials: A
authors.lastname: la Sala
authors.forename: Domenico
authors.initials: D
authors.lastname: Mavilio
authors.forename: Luigi
authors.initials: L
authors.lastname: Racioppi
mesh_terms: D049109:Cell Proliferation; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D016333:HIV Protease / Q000187:drug effects*; D017320:HIV Protease Inhibitors / Q000494:pharmacology*; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology
chemical_list: D017320:HIV Protease Inhibitors; D016333:HIV Protease; C514803:p16 protease, Human immunodeficiency virus 1