[1] Rockefeller Univ, Lab Mol Immunol, New York, NY 10065 USA
[2] Inst Pasteur, Dept Immunol, Lab Humoral Response Pathogens, Paris, France
[3] CALTECH, Div Biol, Pasadena, CA 91125 USA
[4] Rockefeller Univ, Howard Hughes Med Inst HHMI, New York, NY 10065 USA