An Example of Tissue Cross-Reactivity study for animal model selection
Background: Molecule A is known to express on the epithelial cell membrane in human gastric mucosa and certain carcinomas. Two types (mouse and human) of monoclonal antibodies were generated against the human type molecule A. In order to set up an animal model for preclinical validation of the molecule, it was important to determine: 1. whether the antibodies reacted with molecule A in the stomach of cyno monkey, rat and mouse; 2. whether the specificity of the human monoclonal antibody was comparable to that of the mouse monoclonal antibody. Both antibodies were biotinylated for IHC analysis.
IHC result analysis
Mouse antibody (MMab) to molecule A showed specific cell membrane staining in the gastric mucosa of rat, cyno and human. Human antibody (HMab) showed similar staining pattern but with non-specific background. Negative control remained negative
IHC with mouse and human antibodies to molecule A in mouse and rat gastric mucosa
Mouse antibody to molecule A (left panel) was negative in mouse stomach (left upper), but showed staining on gastric epithelial cell membrane of the rat (left down). Human antibody (right panel) showed similar patterns with non-specific background staining.
IHC with mouse and human antibodies to molecule A in cyno monkey and human gastric mucosa
Mouse antibody to molecule A (left panel) showed strong membrane staining on both cyno (left upper) and human (left down) gastric epithelial cells. Human antibody showed similar patterns with non-specific background staining.
Both mouse and human monoclonal antibodies recognized molecule A from rat, cyno monkey and human. Neither of the antibodies recognized mouse form of molecule A. The mouse antibody showed specific cell membrane staining in the gastric mucosa, while, in addition to the membrane staining, human antibody also reacted with non-specific epitopes in different types of cells.