title: Antibody classes and subclasses in circulating immune complexes isolated from mice infected with lactic dehydrogenase virus.
abstract: A chronological study of circulating immune complexes (CIC) in lactic dehydrogenase virus (LDV)-infected mice has been performed. The results demonstrate that CIC containing immunoglobulin of the IgM class were isolated between days 3 and 9 post-LDV infection and corresponded to an increase in serum IgM. IgG1-containing CIC were also transient in the serum of LDV-infected mice in that they were isolated only between days 5 and 13. The occurrence of IgG1 CIC did correlate with an increase in total IgG1 in the serum, however, it did correlate with a small (1:10) increase in IgG1 anti-LDV activity. In contrast, CIC containing immunoglobulin of the serum IgG2 subclass were not isolated from LDV-infected serum until 15 days post infection. This chronological appearance of IgG2 CIC did not correlate with the observed increase in total IgG2 concentration in LDV-infected mice on day 7, however, was analogous to the rapid increase in free serum LDV-specific antibody. We propose that the non-specific suppression of the immune response and tumour enhancement during the acute phase of LDV infection could be due to the immunoregulatory properties of IgG1 CIC.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D000918:Antibody Specificity; D000936:Antigen-Antibody Complex / Q000276:immunology* / Q000302:isolation & purification; D007074:Immunoglobulin G / Q000032:analysis / Q000145:classification; D007075:Immunoglobulin M / Q000032:analysis; D007772:Lactate dehydrogenase-elevating virus / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D014777:Virus Diseases / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007075:Immunoglobulin M