Leonard G. Presta

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Inhibitory receptors have been proposed to modulate the in vivo cytotoxic response against tumor targets for both spontaneous and antibody-dependent pathways. Using a variety of syngenic and xenograft models, we demonstrate here that the inhibitory FcgammaRIIB molecule is a potent regulator of antibody-dependent cell-mediated cytotoxicity in vivo,(More)
Vascular endothelial growth factor (VEGF) is a major mediator of angiogenesis associated with tumors and other pathological conditions, including proliferative diabetic retinopathy and age-related macular degeneration. The murine anti-human VEGF monoclonal antibody (muMAb VEGF) A.4.6.1 has been shown to potently suppress angiogenesis and growth in a variety(More)
Lec13 cells, a variant Chinese hamster ovary cell line, were used to produce human IgG1 that were deficient in fucose attached to the Asn(297)-linked carbohydrate but were otherwise similar to that found in IgG1 produced in normal Chinese hamster ovary cell lines and from human serum. Lack of fucose on the IgG1 had no effect on binding to human FcgammaRI,(More)
The murine monoclonal antibody mumAb4D5, directed against human epidermal growth factor receptor 2 (p185HER2), specifically inhibits proliferation of human tumor cells overexpressing p185HER2. However, the efficacy of mumAb4D5 in human cancer therapy is likely to be limited by a human anti-mouse antibody response and lack of effector functions. A(More)
Immunoglobulin G (IgG) Fc receptors play a critical role in linking IgG antibody-mediated immune responses with cellular effector functions. A high resolution map of the binding site on human IgG1 for human Fc gamma RI, Fc gamma RIIA, Fc gamma RIIB, Fc gamma RIIIA, and FcRn receptors has been determined. A common set of IgG1 residues is involved in binding(More)
IL-23 is a member of the IL-12 cytokine family that drives a highly pathogenic T cell population involved in the initiation of autoimmune diseases. We have shown that IL-23-dependent, pathogenic T cells produced IL-17 A, IL-17 F, IL-6, and TNF but not IFN-gamma or IL-4. We now show that T-bet and STAT1 transcription factors are not required for the initial(More)
The MHC class I-like Fc receptor FcRn plays an essential role in extending the half-life (t(1/2)) of IgG antibodies and IgG-Fc-based therapeutics in the circulation. The goal of this study was to analyze the effect of human IgG1 (hIgG1) antibodies with enhanced in vitro binding to FcRn on their in vivo t(1/2) in mice expressing human FcRn (hFcRn). Mutants(More)
A global census of the hydrogen bonds in 42 X-ray-elucidated proteins was taken and the following demographic trends identified: (1) Most hydrogen bonds are local, i.e. between partners that are close in sequence, the primary exception being hydrogen-bonded ion pairs. (2) Most hydrogen bonds are between backbone atoms in the protein, an average of 68%. (3)(More)
Vascular endothelial growth factor (VEGF) is an angiogenic inducer that mediates its effects through two high affinity receptor tyrosine kinases, Flt-1 and KDR. Flt-1 is required for endothelial cell morphogenesis whereas KDR is involved primarily in mitogenesis. Flt-1 has an alternative ligand, placenta growth factor (PlGF). Both Flt-1 and KDR have seven(More)
Dimerization is essential for activity of human epidermal growth factor receptors (HER1/EGFR, HER2/ErbB2, HER3/ErbB3, and ErbB4) and mediates intracellular signaling events leading to cancer cell proliferation, survival, and resistance to therapy. HER2 is the preferred dimerization partner. Activation of HER signaling pathways may be blocked by inhibition(More)