Haas KM, Hasegawa M, Steeber DA, Poe JC, Zabel MD, Bock CB, Karp DR, Briles DE, Weis JH, Tedder TF. Complement receptors CD21/35 link innate and protective immunity during Streptococcus pneumoniae infection by regulating IgG3 antibody responses. Immunity. 2002 Dec; 17(6):713-23.