Studies on the neutralization of herpes simplex virus. XI. Differences between slow-reacting complement-requiring neutralizing (s-CRN) antibodies in IgG and IgM.
Late IgG and IgM from a rabbit immunized with herpes virus were tested for ordinary neutralizing (N) antibody, complement-requiring neutralizing (CRN) antibody and in addition CRN antibody detectable by overnight sensitization at 0 C (s-CRN antibody). Heat stability tests showed that IgG s-CRN antibody was slightly less resistant to heating at 70 C than were N and CRN antibodies, whereas all three activities of IgM were quickly degraded at this temperature. Dose-response curves with varying amounts of complement (C) or anti-antibody revealed a marked difference between IgG s-CRN and IgM s-CRN antibodies. While 1-hr sensitization at 37 C was insufficient to detect IgG s-CRN antibody, it had the same effect as overnight sensitization at 0 C for IgM s-CRN antibody. When sensitization at 0 C was prolonged to 3 days, unexpectedly high endpoints exceeding 1:10,000 were obtained even with IgM. consequently, enhancement by C was several hundred-fold with IgM in contrast to 5- to 10-fold enhancement of IgG s-CRN antibody, which was similar to that after overnight sensitization. Also IgM obviously required more C than did IgG. These results suggest that IgM of late serum is slower reacting and more C-dependent than IgG s-CRN antibody. Tests with early rabbit sera indicated that the s-CRN antibody detectable by 3-day sensitization reaches a high level before the appearance of N antibody.
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology*; D000917:Antibody Formation; D003168:Complement Fixation Tests; D004306:Dose-Response Relationship, Immunologic; D006358:Hot Temperature; D007074:Immunoglobulin G / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D009500:Neutralization Tests; D011817:Rabbits; D018139:Simplexvirus / Q000276:immunology*; D013997:Time Factors
D000888:Antibodies, Anti-Idiotypic; D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M