Anti-CT83 (aa 25-113) polyclonal antibody

Photodynamic therapy (PDT) is a noninvasive, highly selective approach to the treatment of tumors. However, its therapeutic effect is limited by long-lasting skin phototoxicity. Therefore, to compromise this shortcoming, it is preferable to deliver photosensitizers selectively to tumor cells with the aid of antibodies specific against tumor-associated antigens. Cancer/testis antigens 83 (CT83), also called KK-LC-1 or CXorf61, recognized by cytotoxic T lymphocytes (CTL), has become a promising target for immunotherapy. Herein, we developed and characterized a novel mouse CT83 mAb 7G4 with a high affinity with Gallium (III) 5, 10, 15-tris (ethoxycarbonyl) corrole (1-Ga), a new and promising photosensitizer in PDT. The enzyme-linked immunosorbent assay (ELISA), flow cytometry and cytotoxicity activity assays revealed that 7G4-1-Ga was able to recognize human CT83 with high specificity. Furthermore, 7G4-1-Ga showed greater cytotoxicity to CT83-expressing human cancer cells in vitro than 1-Ga. These results suggest that the antibody-conjugated photosensitizer between anti-CT83 mAb and 1-Ga may have a good application in PDT, where the destruction of CT83-expressing tumor is required.

Central to the pathology of Alzheimer's disease (AD) is the profuse accumulation of amyloid-beta (A beta) peptides in the brain of affected individuals, and several amyloid precursor protein (APP) transgenic (Tg) mice models have been created to mimic A beta deposition. Among these, the PDAPP Tg mice carrying, the familial AD APP 717 Val -> Phe mutation have been widely used to test potential AD therapeutic interventions including active and passive anti-A beta immunizations. The structure and biochemistry of the PDAPP Tg mice A beta-related peptides were investigated using acid and detergent lysis of brain tissue, ultracentrifugation, FPLC, HPLC, enzymatic and chemical cleavage of peptides, Western blot, immunoprecipitation, and MALDI-TOF and SELDI-TOF mass spectrometry. Our experiments reveal that PDAPP mice produce a variety of C-terminally elongated A peptides in addition to A beta n-40 and A beta n-42, as well as N-terminally truncated peptides, suggesting anomalous proteolysis of both APP and A. Important alterations in the overall APP degradation also occur in this model, resulting in a striking comparative lack of CT83 and CT99 fragments, which may be inherent to the strain of mice, a generalized gamma-secretase failure, or the ultimate manifestation of the overwhelming amount of expressed human transgene; these alterations are not observed in other strains of APP Tg mice or in sporadic AD. Understanding at the molecular level the nature of these important animal models will pen-nit a better understanding of therapeutic interventions directed to prevent, delay, or reverse the ravages of sporadic AD.