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1.  Anti-phospholipid induced murine fetal loss: novel protective effect of a peptide targeting the β2glycoprotein I phospholipid-binding site. Implications for human fetal loss 
Journal of Autoimmunity  2011;38(2-3):J209-J215.
β2 glycoprotein I (β2GPI)-dependent anti-phospholipid antibodies (aPL) induce thrombosis and affect pregnancy. The CMV-derived synthetic peptide TIFI mimics the PL-binding site of β2GPI and inhibits β2GPI cell-binding in vitro and aPL-mediated thrombosis in vivo. Here we investigated the effect of TIFI on aPL-induced fetal loss in mice. TIFI inhibitory effect on in vitro aPL binding to human trophoblasts was evaluated by indirect immunofluorescence and ELISA. TIFI effect on aPL-induced fetal loss was investigated in pregnant C57BL/6 mice treated with aPL or normal IgG (NHS). Placenta/fetus weight and histology and RNA expression were analyzed. TIFI, but not the control peptide VITT, displayed a dose-dependent inhibition of aPL binding to trophoblasts in vitro. Injection of low doses of aPL at day 0 of pregnancy caused growth retardation and increased fetal loss rate, both significantly reduced by TIFI but not VITT. Consistent with observations in humans, histological analysis showed no evidence of inflammation in this model, as confirmed by the absence of an inflammatory signature in gene expression analysis, which in turn revealed a TIFI-dependent modulation of molecules involved in differentiation and development processes. These findings support the non-inflammatory pathogenic role of aPL and suggest innovative therapeutic approaches to aPL-dependent fetal loss.
PMCID: PMC3313005  PMID: 22196923
Anti-phospholipid syndrome; pregnancy complications; β2 glycoprotein I; murine models; TIFI
2.  Non-redundant role of CCRL2 in lung dendritic cell trafficking 
Blood  2010;116(16):2942-2949.
CCRL2 is a heptahelic transmembrane receptor that shows the highest degree of homology with CCR1, an inflammatory chemokine receptor. CCRL2 mRNA was rapidly (30 min) and transiently (2-4 hrs) regulated during dendritic cell (DC) maturation. Protein expression paralleled RNA regulation. In vivo, CCRL2 was expressed by activated DC and macrophages, but not by eosinophils and T cells. CCRL2−/− mice showed normal recruitment of circulating DC into the lung but a defective trafficking of antigen-loaded lung DC to mediastinal lymph nodes. This defect was associated to a reduction in lymph node cellularity and reduced priming of Th2 response. CCRL2−/− mice were protected in a model of OVA-induced airway inflammation with reduced leukocyte recruitment in the BAL (eosinophils and mononuclear cells) and reduced production of the Th2 cytokines IL-4 and IL-5 and chemokines CCL11 and CCL17. The central role of CCRL2 deficiency in DC was supported by the fact that adoptive transfer of CCRL2−/− antigen-loaded DC in wild type animals recapitulated the phenotype observed in knock out mice. These data show a nonredundant role of CCRL2 in lung DC trafficking and propose a role for this receptor in the control of excessive airway inflammatory responses.
PMCID: PMC3389732  PMID: 20606167
3.  Role of the chemokine decoy receptor D6 in balancing inflammation, immune activation, and antimicrobial resistance in Mycobacterium tuberculosis infection 
The Journal of Experimental Medicine  2008;205(9):2075-2084.
D6 is a decoy and scavenger receptor for inflammatory CC chemokines. D6-deficient mice were rapidly killed by intranasal administration of low doses of Mycobacterium tuberculosis. The death of D6−/− mice was associated with a dramatic local and systemic inflammatory response with levels of M. tuberculosis colony-forming units similar to control D6-proficient mice. D6-deficient mice showed an increased numbers of mononuclear cells (macrophages, dendritic cells, and CD4 and CD8 T lymphocytes) infiltrating inflamed tissues and lymph nodes, as well as abnormal increased concentrations of CC chemokines (CCL2, CCL3, CCL4, and CCL5) and proinflammatory cytokines (tumor necrosis factor α, interleukin 1β, and interferon γ) in bronchoalveolar lavage and serum. High levels of inflammatory cytokines in D6−/− infected mice were associated with liver and kidney damage, resulting in both liver and renal failure. Blocking inflammatory CC chemokines with a cocktail of antibodies reversed the inflammatory phenotype of D6−/− mice but led to less controlled growth of M. tuberculosis. Thus, the D6 decoy receptor plays a key role in setting the balance between antimicrobial resistance, immune activation, and inflammation in M. tuberculosis infection.
PMCID: PMC2526202  PMID: 18695004
4.  Role of ChemR23 in directing the migration of myeloid and plasmacytoid dendritic cells to lymphoid organs and inflamed skin 
Chemerin is a chemotactic agent that was recently identified as the ligand of ChemR23, a serpentine receptor expressed by activated macrophages and monocyte-derived dendritic cells (DCs). This paper shows that blood plasmacytoid and myeloid DCs express functional ChemR23. Recombinant chemerin induced the transmigration of plasmacytoid and myeloid DCs across an endothelial cell monolayer. In secondary lymphoid organs (lymph nodes and tonsils), ChemR23 is expressed by CD123+ plasmacytoid DCs and by CD1a+ DC-SIGN+ DCs in the interfollicular T cell area. ChemR23+ DCs were also observed in dermis from normal skin, whereas Langerhans cells were negative. Chemerin expression was selectively detected on the luminal side of high endothelial venules in secondary lymphoid organs and in dermal endothelial vessels of lupus erythematosus skin lesions. Chemerin+ endothelial cells were surrounded by ChemR23+ plasmacytoid DCs. Thus, ChemR23 is expressed and functional in plasmacytoid DCs, a property shared only by CXCR4 among chemotactic receptors. This finding, together with the selective expression of the cognate ligand on the luminal side of high endothelial venules and inflamed endothelium, suggests a key role of the ChemR23/chemerin axis in directing plasmacytoid DC trafficking.
PMCID: PMC2213064  PMID: 15728234
5.  Increased DC trafficking to lymph nodes and contact hypersensitivity in junctional adhesion molecule-A–deficient mice 
Journal of Clinical Investigation  2004;114(5):729-738.
Junctional adhesion molecule-A (JAM-A) is a transmembrane adhesive protein expressed at endothelial junctions and in leukocytes. In the present work, we found that DCs also express JAM-A. To evaluate the biological relevance of this observation, Jam-A–/– mice were generated and the functional behavior of DCs in vitro and in vivo was studied. In vitro, Jam-A–/– DCs showed a selective increase in random motility and in the capacity to transmigrate across lymphatic endothelial cells. In vivo, Jam-A–/– mice showed enhanced DC migration to lymph nodes, which was not observed in mice with endothelium-restricted deficiency of the protein. Furthermore, increased DC migration to lymph nodes was associated with enhanced contact hypersensitivity (CHS). Adoptive transfer experiments showed that JAM-A–deficient DCs elicited increased CHS in Jam-A+/+ mice, further supporting the concept of a DC-specific effect. Thus, we identified here a novel, non-redundant role of JAM-A in controlling DC motility, trafficking to lymph nodes, and activation of specific immunity.
PMCID: PMC514585  PMID: 15343392
6.  Fractalkine (CX3CL1) as an amplification circuit of polarized Th1 responses 
Journal of Clinical Investigation  2001;107(9):1173-1181.
Fractalkine (FKN, CX3CL1) is a membrane-bound CX3C chemokine induced by primary proinflammatory signals in vascular endothelial cells (ECs). Here we examined the role of FKN in polarized Th1 or Th2 responses. Proinflammatory signals, including LPS, IL-1, TNF, and CD40 ligand, induced FKN, as did IFN-γ, which had synergistic activity with TNF. IL-4 and IL-13 did not stimulate the expression of FKN and markedly reduced induction by TNF and IFN-γ. TNF alone or combined with IFN-γ also induced release of soluble FKN, which was inhibited by IL-4 and IL-13. In light of this differential regulation of FKN by the master cytokines that control polarized responses, we analyzed the interaction of FKN with natural killer (NK) cells and polarized T-cell populations. NK cells expressed high levels of the FKN receptor CX3CR1 and responded to FKN. CX3CR1 was preferentially expressed in Th1 compared with Th2 cells. Th1 but not Th2 cells responded to FKN. By immunohistochemistry, FKN was expressed on ECs in psoriasis, a Th1-dominated skin disorder, but not in Th2-driven atopic dermatitis. Similarly, ECs in Mycobacterium tuberculosis granulomatous lymphadenitis, but not those in reactive lymph node hyperplasia or in Castelman’s disease, showed immunoreactive FKN. These results indicate that regulated expression of FKN in ECs participates in an amplification circuit of polarized type I responses.
PMCID: PMC209276  PMID: 11342581

Results 1-6 (6)