Characterization of a human platelet antigen-1a-specific monoclonal antibody derived from a B cell from a woman alloimmunized in pregnancy.

Human platelet Ag (HPA)-1a, located on integrin β3, is the main target for alloantibodies responsible for fetal and neonatal alloimmune thrombocytopenia (FNAIT) in the white population. There are ongoing efforts to develop an Ab prophylaxis and therapy to prevent or treat FNAIT. In this study, an mAb specific for HPA-1a, named 26.

Polyreactivity of monoclonal antibodies made against human erythrocyte membranes with various pathogenic bacteria.

Glycophorins comprise the major sialoglycoproteins of the human erythrocyte membrane. Several years ago we described a murine monoclonal antibody (MAb), designated 124,D-7 (IgM), developed by in vitro immunization with human erythrocyte membranes as antigen. We found the MAb reacted with a neuraminidase-dependent epitope on glycophorin A.

A mutant human IgG molecule with only one C1q binding site can activate complement and induce lysis of target cells.

There are potentially two binding sites for C1q on IgG, one on each C(H)2 domain of the gamma heavy chains, close to the lower hinge region. It is not clear whether the presence and involvement of both the C1q binding sites is necessary to induce the activation signal of human IgG. In order to clarify this issue, we made a hybrid mutant IgG1/IgG3 molecule where the IgG1 half of the molecule was made unable to activate complement through the introduction of a P329A mutation.

Construction and functional activities of chimeric mouse-human immunoglobulin G and immunoglobulin M antibodies against the Neisseria meningitidis PorA P1.7 and P1.16 epitopes.

We studied the in vitro protective activities of human immunoglobulin G1 (IgG1), IgG3, and IgM antibodies against group B meningococci by constructing sets of chimeric mouse-human antibodies (chIgG1, chIgG3, and chIgM, respectively) with identical binding regions against the P1.7 and P1.16 epitopes on PorA.