Rabbit Anti-Human CEACAM5 Monoclonal Antibody, clone CQ7196

Purpose: To detect anti-CEACAM5 targeted superparamagnetic iron oxide (SPIO) particles in vitro on the cell surface by quantitative magnetic resonance (MR) imaging and to compare with flow cytometry. Materials and Methods: The monoclonal mouse antibody T84.1 and an appropriate IgG isotype antibody were conjugated to dextran-coated SPIO particles. HT29 cells expressing carcinoembryonic antigen (CEACAM5) were treated with antibody-conjugated SPIO particles. Purified cell samples were examined on a 3.0-T MR scanner using a multi-echo spin-echo sequence for MR relaxometry. Aliquots of the cell samples were further treated with a fluorescein isothiocyanate (FITC) anti-dextran antibody and an Alexa Fluor 488 anti-mouse antibody for the corresponding flow cytometry. Results: MR relaxometry revealed a dose-dependent binding of T84.1-conjugated SPIO particles with a positive correlation between R(2) relaxation rate of cell samples and SPIO particle concentration during incubation (r=0.993, P<.01). Positive correlations were also observed between R(2) relaxation rate and flow cytometry (geometric mean) with both fluorescent antibodies (r=0.972 and r=0.953, both P<.01), respectively. Conclusion: The study revealed the feasibility of quantitative MR imaging of targeted SPIO particles on the cell surface comparable to flow cytometry. (C) 2010 Elsevier Inc. All rights reserved.

Carcinoembryonic antigen-related cellular adhesion molecules (CEACAMs) are glycoproteins produced in epithelial, endothelial, lymphoid, and myeloid cells. Carcinoembryonic antigen-related cellular adhesion molecules mediate cellcell contact and hostpathogen interactions. The aims of this study were to map the distribution and examine the regulation of CEACAMs in human gingival sites. Quantitative real-time PCR performed on human gingival biopsies from periodontitis sites revealed mRNA coding for CEACAM1, -5, -6, and -7. Immunohistochemistry showed that CEACAMs were not found in oral gingival epithelium, except for CEACAM5 in periodontitis. Carcinoembryonic antigen-related cellular adhesion molecules 1, 5, and 6 were present in the oral sulcular epithelium of periodontitis but not in that of healthy gingiva. In junctional epithelium, all three molecules were present in healthy gingiva, but in periodontitis only CEACAM1 and -6 were detected. Staining for CEACAM1 and -6 was also seen in the inflammatory cell infiltrate in periodontitis. No staining for CEACAM7 was found. Proinflammatory mediators, including lipopolysaccharide (LPS), tumour necrosis factor-a (TNF-a)/interleukin-1 beta (IL-1 beta), and interferon-? (IFN-?), increased the expression of CEACAM1 and CEACAM6 mRNAs in cultured human oral keratinocytes. CEACAM1 and CEACAM6 mRNAs were also strongly up-regulated upon stimulation with lysophosphatidic acid. In conclusion, the distribution of different CEACAMs was related to specific sites in the gingiva. This might reflect different functional roles in this tissue.