Recombinant human monoclonal Fab fragments against rotavirus from phage display combinatorial libraries

We prepared and characterized human monoclonal Fab fragments to rotavirus f rom IgG(1) x combinatorial libraries (designated as N and O) constructed fr om peripheral blood lymphocytes (PBLs) from two healthy individuals. Approx imately 30-fold enrichment in eluted phage was obtained in these libraries after five rounds of panning against rabbit polyclonal antibody-captured hu man rotavirus (HRV) Wa strain. Forty-eight clones from each library. were t ested for reactivity to HRV Wa in an enzyme-linked immunosorbent assay (ELI SA), and the identities of positive clones were determined by BstNI fingerp rinting, As a result, eight individual clones (five from N library and thre e from O library) were isolated. In testing the cross-reactivity of Fabs ag ainst a panel of self- or non-self antigens, all Fab clones were found to b e specific for HRV Wa, Fab clones from the two libraries showed distinct ch aracteristics with respect to their reaction patterns with Wa and crossreac tivities with rotavirus strains, and displayed variable heavy (V-H) chain g ene usage, although they recognized the VP6 protein as determined by immuno blotting, The distinct epitope recognition by Fabs from two libraries sugge sts different courses of humoral immune response to rotavirus during infect ion in the two individuals.