Transient lymphocyte decrease due to adhesion and migration following catumaxomab (anti-EpCAM x anti-CD3) treatment in vivo

• Published in: Clinical & translational oncology Vol. 14; no. 5; pp. 376 - 381
• Main Authors: Dettmar, Kirsten, Seitz-Merwald, Isabell, Lindemann, Carsten, Schroeder, Petra, Seimetz, Diane, Atz, Judith
• Format: Journal Article
• Language: English
• Published: Milan Springer Milan 01.05.2012
• Subjects: Animals; Antibodies, Bispecific - pharmacology; Antigens, Neoplasm - immunology; CD3 Complex - immunology; Cell Adhesion - immunology; Cell Adhesion Molecules - immunology; Cell Movement - immunology; Cells, Cultured; Cytokines - secretion; Epithelial Cell Adhesion Molecule; Female; Flow Cytometry; Human Umbilical Vein Endothelial Cells - cytology; Human Umbilical Vein Endothelial Cells - drug effects; Human Umbilical Vein Endothelial Cells - immunology; Humans; Leukocytes, Mononuclear - cytology; Leukocytes, Mononuclear - drug effects; Leukocytes, Mononuclear - immunology; Lymphocyte Activation - drug effects; Medicine; Medicine & Public Health; Mice; Mice, Inbred BALB C; Oncology; T-Lymphocytes - cytology; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; Tumor Necrosis Factor-alpha - pharmacology; Trifunctional antibody; Catumaxomab; Redistributi; T lymphocyte; Adhesion; Endothelium
• ISSN: 1699-048X; 1699-3055
• DOI: 10.1007/s12094-012-0811-5

Introduction In patients, a transient decrease in peripheral blood lymphocyte counts was observed following intraperitoneal administration of the trifunctional monoclonal antibody catumaxomab (anti-human EpCAM x anti-human CD3). The aim of this study was to clarify the observed effect in a preclinical mouse model and to analyse the related mechanism of action in vitro . Materials and methods A related antibody, BiLu (antihuman EpCAM x anti-mouse CD3), was administered to mice and blood leukocytes were analysed. In vitro studies measured activation and cytokine secretion from human peripheral blood mononuclear cells (PBMC). For the analysis of T cell adhesion, PBMC were preincubated with catumaxomab and then co-cultured with human endothelial cells (HUVEC); T cell adhesion was assessed in the presence or absence of endothelial cell preactivation by TNFα. Adherent T cells were determined by flow cytometry. Results Treatment of mice with BiLu resulted in a dosedependent transient decrease in CD3+ T cells (both CD4+ and CD8+) that returned to the normal range within 48 h. Catumaxomab physiologically activated T cells in vitro (increased CD69 expression) and induced cytokine release (TNFα, IFNγ). TNFα increased expression of adhesion molecules CD54 and CD62E on endothelial cells. Furthermore, catumaxomab dose-dependently enhanced adhesion of T cells to endothelial cells. Adhesion was further increased when endothelial cells were preactivated with TNFα. Conclusions Catumaxomab increases adhesion of T cells to endothelial cells due to antibody-mediated activation of T cells and production of T cell cytokines that up-regulate endothelial cell adhesion molecules. These results provide a mechanistic rationale for the transient, reversible decrease in lymphocyte counts observed following catumaxomab administration in patients, which is likely to be due to redistribution of lymphocytes.