[Show abstract][Hide abstract] ABSTRACT: Introduction and Aims: Experimental glomerulonephritis (GN) induced by immunoglobulins against antigens from the glomerular basal membrane (GBM)
is a well-recognized model to induce rapidly progressive GN. It results in an inflammatory response, characterized by early
infiltration of innate immune system into the kidney and involvement of several cytokines and chemokines. Among these, IL-1β
plays an important role in the clinical development of renal injury. Gevokizumab is a recombinant humanized monoclonal antibody
to human IL-1β. It modulates IL-1β receptor-mediated signaling and targets diseases with an inflammatory process. In line
with previous published data on the role of IL-1β in development of GN, the main objective of the study was to assess whether
administration of gevokizumab prevents the progression of anti-GBM disease by blocking glomerular and tubular inflammation
in an experimental glomerulonephritis model in mice.
Methods: For induction of anti-GBM, C57BL/6J mice (8/group) were pre-immunized with normal goat IgG in complete Freund’s adjuvant
before an intravenous administration of anti-GBM serum. Mice received gevokizumab i.p. (0.1, 1 and 10 mg/Kg, every 3 days)
or control IgG2 for 14 days. The effect of gevokizumab was assessed by measuring albuminuria, proteinuria, urinary NGAL and
BUN. Inflammatory cytokines IL-1β, TNF-α and IL-6, as well as CCL2 and CRP were measured on mouse serum and kidney cortex
(ELISA). Glomerular and tubular injuries were evaluated on kidney sections after H&E, Masson Trichrome and Sirius Red stainings.
Myeloid cell infiltration was verified by immunohistochemical staining with CD11b antibodies. Renal fibrosis was assessed
by collagen type I and type IV Western blot. All data were analyzed by independent sample two-tailed t test.
Results: A significant dose-related decrease in albuminuria was observed in mice treated with gevokizumab at 1 mg/Kg (6.3±2.3 mg/mmol)
and 10 mg/Kg (1.4±1.2 mg/mmol), when compared to mice treated with a control IgG2 (43.8±14.7 mg/mmol). Gevokizumab was also
able to significantly reduce urinary NGAL (control IgG2: 643±199 ng/ml, 10 mg/Kg: 207±73 ng/ml) and BUN (control IgG2: 15.9±1.5
mg/dl, 1 mg/Kg: 9.4±0.8 mg/dl, 10 mg/Kg: 8.8±0.6 mg/dl). Mice subjected to anti-GBM injury and treated with control IgG2 demonstrated
a significant increase in several cytokines and growth factors, suggesting that a systemic inflammatory response took place
in this model. Gevokizumab at 10 mg/Kg significantly decreased serum levels of IL-1β (247±33 vs 584±52 pg/ml in control IgG2
group), NGAL (345±122 vs 923±142 ng/ml in control IgG2 group), CRP (10340±1128 vs 13140±657 ng/ml in control IgG2 group),
CCL2 (1344±879 vs 36160±7410 pg/ml in control IgG2 group), IL-6 (13.9±12.1 vs 131.8±30.1 pg/ml in control IgG2 group) and
TNFα (322±57 vs 576±88 pg/ml in control IgG2 group). In the kidney cortex, gevokizumab significantly reduced levels of IL-1β
at 10 mg/Kg (1.0±0.1 vs 3.2±0.7 pg/µg protein in control IgG2 group), CCL2 (0.38±0.06 vs 0.68±0.05 pg/µg protein in control
IgG2 group) and TNF-α (3.7±0.6 vs 8.2±1.9 pg/µg protein in control IgG2 group) suggesting that modulation of IL-1β by gevokizumab
in the kidney was achieved. Histological analysis provided evidence that gevokizumab at 1 and 10 mg/Kg significantly decreased
glomerular and tubulointerstitial injury scores and attenuated the infiltration of CD11b+ cells and collagen type I deposition,
when compared to control IgG2.
Conclusions: This study demonstrated that gevokizumab may have a beneficial role in the prevention of renal injury and fibrosis, by decreasing
the inflammation induced in a mouse model of anti-GBM disease. Gevokizumab might be useful as a potential therapy for glomerulonephritis
and renal pathologies involving inflammation.
[Show abstract][Hide abstract] ABSTRACT: Focal and segmental glomerulosclerosis (FSGS) is one of the most important renal diseases related to end stage renal failure. Bradykinin has been implicated in the pathogenesis of renal inflammation whereas the role of its receptor 2 (B2RBK) in FSGS has not been studied. FSGS was induced in wild type and B2RBK KO mice by a single intravenous injection of Adriamycin (ADM). In order to further modulate the kinin receptors, animals were also treated with B2RBK antagonist HOE-140, and DALBK, B1RBK antagonist. Here, we show that the blockage of B2RBK with HOE-140 protects mice from FSGS development, including podocyte foot process effacement and reestablishment of slit diaphragm-related proteins. However, B2RBK KO mice were not protected from FSGS. These opposite results were due to B1RBK expression. B1RBK was up regulated after ADM injection and it was exacerbated in B2RBK KO animals. Further, HOE-140 treatment down regulated B1RBK receptor. The blockade of B1RBK in B2RBK KO animals promoted FSGS regression, with a less inflammatory phenotype. These results indicate a deleterious role of both kinin receptors in FSGS model and suggest a possible crosstalk of them in disease progression.
[Show abstract][Hide abstract] ABSTRACT: Allergic asthma is a chronic lung disease resulting from an inappropriate T helper (Th)-2 response to environmental antigens. Early tolerance induction is an attractive approach for primary prevention of asthma. Here, we found that breastfeeding by antigen-sensitized mothers exposed to antigen aerosols during lactation induced a robust and long-lasting antigen-specific protection from asthma. Protection was more profound and persistent than the one induced by antigen-exposed non-sensitized mothers. Milk from antigen-exposed sensitized mothers contained antigen-immunoglobulin (Ig) G immune complexes that were transferred to the newborn through the neonatal Fc receptor resulting in the induction of antigen-specific FoxP3(+) CD25(+) regulatory T cells. The induction of oral tolerance by milk immune complexes did not require the presence of transforming growth factor-beta in milk in contrast to tolerance induced by milk-borne free antigen. Furthermore, neither the presence of IgA in milk nor the expression of the inhibitory FcgammaRIIb in the newborn was required for tolerance induction. This study provides new insights on the mechanisms of tolerance induction in neonates and highlights that IgG immune complexes found in breast milk are potent inducers of oral tolerance. These observations may pave the way for the identification of key factors for primary prevention of immune-mediated diseases such as asthma.
[Show abstract][Hide abstract] ABSTRACT: HTLV-I is an endemic retrovirus responsible for the adult T-cell leukemia/lymphoma (ATLL). This aggressive lymphoid proliferation is associated with a bad prognosis due to the resistance of HTLV-I-infected cells to most classical chemotherapeutic agents. Here we review recent advances in ATLL immunotherapy. We particularly focus on promising data from our group, characterizing a new mouse monoclonal antibody (mAb A24) against the human transferrin receptor (TfR-1). Monoclonal antibodies to target cell differentiation markers on ATLL cells have already been proposed as therapeutic agents. However, in clinical trials acute forms of ATLL were resistant to these immunotherapies. A24 binds TfR-1 (K(d) 2.7 nM) and competes with transferrin for receptor binding. It blocks the proliferation of malignant cells (TfR-1(high)), such as HTLV-I-infected T cells but not of resting cells. A24 induces TfR-1 endocytosis in lysosomal compartments where the receptor is degraded leading to intracellular iron deprivation. In HTLV-I-infected cells, A24 targets and induces apoptosis of both chronic and acute ATLL forms, independent of antibody aggregation, antibody-dependent cellular cytotoxicity and/or complement addition. The antibody efficacy was confirmed in animal models. We are currently developing strategies to use A24 in clinical trials.
Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 02/2008; 22(1):42-8. DOI:10.1038/sj.leu.2404958 · 10.43 Impact Factor