31. Internet Audio Products (3/3)

Two contrasting additions to the online audio market are reviewed: iVocalize, a browser-based audio-conferencing software, and Skype, a PC-to-PC Internet telephone tool. These products are selected for review on the basis of their success in gaining rapid popular attention and usage during 2003-04. The iVocalize review emphasizes the product’s role in the development of a series of successful online audio communities – notably several serving visually impaired users. The Skype review stresses the ease with which the product may be used for simultaneous PC-to-PC communication among up to five users

Technical Evaluation Report 31: Internet Audio Products (3/ 3)

Two contrasting additions to the online audio market are reviewed: iVocalize, a browser-based audio-conferencing software, and Skype, a PC-to-PC Internet telephone tool. These products are selected for review on the basis of their success in gaining rapid popular attention and usage during 2003-04. The iVocalize review emphasizes the product’s role in the development of a series of successful online audio communities – notably several serving visually impaired users. The Skype review stresses the ease with which the product may be used for simultaneous PC-to-PC communication among up to five users. Editor’s Note: This paper serves as an introduction to reports about online community building, and reviews of online products for disabled persons, in the next ten reports in this series. JPB, Series Ed

A novel three-dimensional heterotypic spheroid model for the assessment of the activity of cancer immunotherapy agents

The complexity of the tumor microenvironment is difficult to mimic in vitro, particularly regarding tumor–host interactions. To enable better assessment of cancer immunotherapy agents in vitro, we developed a three-dimensional (3D) heterotypic spheroid model composed of tumor cells, fibroblasts, and immune cells. Drug targeting, efficient stimulation of immune cell infiltration, and specific elimination of tumor or fibroblast spheroid areas were demonstrated following treatment with a novel immunocytokine (interleukin-2 variant; IgG-IL2v) and tumor- or fibroblast-targeted T cell bispecific antibody (TCB). Following treatment with IgG-IL2v, activation of T cells, NK cells, and NKT cells was demonstrated by increased expression of the activation marker CD69 and enhanced cytokine secretion. The combination of TCBs with IgG-IL2v molecules was more effective than monotherapy, as shown by enhanced effects on immune cell infiltration; activation; increased cytokine secretion; and faster, more efficient elimination of targeted cells. This study demonstrates that the 3D heterotypic spheroid model provides a novel and versatile tool for in vitro evaluation of cancer immunotherapy agents and allows for assessment of additional aspects of the activity of cancer immunotherapy agents, including analysis of immune cell infiltration and drug targeting.ISSN:0340-7004ISSN:1432-085

in vivo fluorescence imaging of the activity of CEA TCB, a novel t-cell bispecific antibody, reveals highly specific tumor targeting and fast induction of t-cell-mediated tumor killing

PURPOSE CEA TCB (RG7802, RO6958688) is a novel T-cell bispecific antibody, engaging CD3ε upon binding to carcinoembryonic antigen (CEA) on tumor cells. Containing an engineered Fc region, conferring an extended blood half-life while preventing side effects due to activation of innate effector cells, CEA TCB potently induces tumor lysis in mouse tumors. Here we aimed to characterize the pharmacokinetic profile, the biodistribution, and the mode of action of CEA TCB by combining in vitro and in vivo fluorescence imaging readouts. EXPERIMENTAL DESIGN CEA-expressing tumor cells (LS174T) and human peripheral blood mononuclear cells (PBMC) were cocultured in vitro or cografted into immunocompromised mice. Fluorescence reflectance imaging and intravital 2-photon (2P) microscopy were employed to analyze in vivo tumor targeting while in vitro confocal and intravital time-lapse imaging were used to assess the mode of action of CEA TCB. RESULTS Fluorescence reflectance imaging revealed increased ratios of extravascular to vascular fluorescence signals in tumors after treatment with CEA TCB compared with control antibody, suggesting specific targeting, which was confirmed by intravital microscopy. Confocal and intravital 2P microscopy showed CEA TCB to accelerate T-cell-dependent tumor cell lysis by inducing a local increase of effector to tumor cell ratios and stable crosslinking of multiple T cells to individual tumor cells. CONCLUSIONS Using optical imaging, we demonstrate specific tumor targeting and characterize the mode of CEA TCB-mediated target cell lysis in a mouse tumor model, which supports further clinical evaluation of CEA TCB

A novel three-dimensional heterotypic spheroid model for the assessment of the activity of cancer immunotherapy agents

The complexity of the tumor microenvironment is difficult to mimic in vitro, particularly regarding tumor–host interactions. To enable better assessment of cancer immunotherapy agents in vitro, we developed a three-dimensional (3D) heterotypic spheroid model composed of tumor cells, fibroblasts, and immune cells. Drug targeting, efficient stimulation of immune cell infiltration, and specific elimination of tumor or fibroblast spheroid areas were demonstrated following treatment with a novel immunocytokine (interleukin-2 variant; IgG-IL2v) and tumor- or fibroblast-targeted T cell bispecific antibody (TCB). Following treatment with IgG-IL2v, activation of T cells, NK cells, and NKT cells was demonstrated by increased expression of the activation marker CD69 and enhanced cytokine secretion. The combination of TCBs with IgG-IL2v molecules was more effective than monotherapy, as shown by enhanced effects on immune cell infiltration; activation; increased cytokine secretion; and faster, more efficient elimination of targeted cells. This study demonstrates that the 3D heterotypic spheroid model provides a novel and versatile tool for in vitro evaluation of cancer immunotherapy agents and allows for assessment of additional aspects of the activity of cancer immunotherapy agents, including analysis of immune cell infiltration and drug targeting. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00262-016-1927-1) contains supplementary material, which is available to authorized users