The present invention provides chimeric and humanized versions of anti-CD22 mouse monoclonal antibody, HB22.7. The anti-CD22 antibodies of the invention comprise four human or humanized framework regions of the immunoglobulin heavy chain variable region ('VH') and four human or humanized framework regions of the immunoglobulin light chain variable region ('VK'). The invention further comprises heavy and/or light chain FW regions that contain one or more backmutations in which a human FW residue is exchanged for the corresponding residue present in the parental mouse heavy or light chain. Human or humanized VH framework regions of antibodies of the invention may comprise one or more of the following residues: a valine (V) at position 24 of framework region 1, a glycine (G) at position 49 of framework region 2, and an asparagine (N) at position 73 of framework region 3, numbered according to Kabat. The invention further relates to pharmaceutical compositions, immunotherapeutic compositions, and methods using therapeutic antibodies that bind to the human CD22 antigen and that preferably mediate human ADCC, CDC, and/or apoptosis for: the treatment of B cell diseases and disorders in human subjects, such as, but not limited to, B cell malignancies, for the treatment and prevention of autoimmune disease, and for the treatment and prevention of graft- versus-host disease (GVHD), humoral rejection, and post-transplantation lymphoproliferative disorder in human transplant recipients.
