Cloning and sequencing of genes that express bone proteins recognized by monoclonal antibodies produced from human osteosarcoma cells (MG-63)

• Grant number: 11/07691-3
• Support type: Regular Research Grants
• Duration: July 01, 2011 - June 30, 2014
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal researcher: Luciene Machado dos Reis
• Grantee: Luciene Machado dos Reis
• Home Institution: Faculdade de Medicina (FM). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Assoc. researchers: Rosa Maria Affonso Moysés ; Vanda Jorgetti ; Verônica Do Carmo Neves de Gouveia

Abstract

We obtained monoclonal antibodies against human osteosarcoma cells and osteoblastic like cells by immunizing mice with MG-63. After several steps of tests we sub cloned three monoclonal antibodies: PSP 4-5, PSP 42-22 and PSP 85-9. These antibodies recognize antigens which size are 100, 20 and 16 kDa, respectively. We evaluated the antigen expression in cryostat sections of undecalcified normal bone, cartilage, adipocyte and cardiac muscle from fetus. We tested also in cells obtained from normal bone biopsies and from patients with metabolic bone disease (adinamic bone disease, osteitis fribosa and osteoporosis) and normal fibroblasts from human skin. The three antibodies showed antigen expression in periosteum of undecalcified bone sections with different pattern of expression. Moreover, we observed antigen expression in osteoblasts, osteocytes, condrocytes and other tissues showing that they are not tissue specific. Tests in cells revealed that the PSP 4-5 had expression in normal cells and in patients with metabolic bone disease, however with distinct intensity (score). In contrast, the PSP 42-22 showed weak reactivity in all cells tested. The PSP 85-9 was expressed in all cells however with low intensity in cells from patients with osteoporosis. With these preliminary results the objective of the present study is to identify the antigens recognized by these antibodies by means of cloning and sequencing of genes that express them. (AU)