[Changes of antibody and splenic plaque forming cell responses to mutans streptococci in the rats infected with S. sobrinus 6715].
The study was undertaken to examine the changes in humoral IgM, IgG and IgA antibodies and splenic plaque forming cell responses against Streptococcus sobrinus 6715 in rats infected with the same mutans streptococci. The serum samples were collected every week for 24 weeks after infection (20 day old, Sprague Dawley rats). Humoral anti-S. sobrinus 6715 IgG and IgA antibodies were determined by an enzyme-linked immunosorbent assay. In the separate experiment, rat splenic IgM, IgG and IgA anti-trinitrophenyl (TNP) conjugated S. sobrinus plaque-forming cell (PFC) responses were also determined from 1 to 12 weeks after the infection. The results obtained were as follows: 1. From 1 to 4 weeks after infection, a slight increase in serum IgG anti-S. sobrinus antibody response was observed in the group of rats infected with S. sobrinus 6715 when compared with the non-infected rat group. However, beyond the 5th week, there was no difference in serum antibody responses between these two groups. 2. Infected rats showed a 2-9 times higher serum anti-S. sobrinus IgA antibody response than those of uninfected rats for 6 weeks after the infection. After this period just as with the IgG response, no difference in the IgA titers was found between these two groups. 3. Splenic IgM, IgG and IgA anti-TNP-S. sobrinus PFC responses showed a remarkable decrease shortly after the infection. These results suggest that the infected rats would gradually acquire oral tolerance to S. sobrinus antigen after the infection.
Kitamura
K
K
Morisaki
I
I
Sobue
S
S
D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000276:immunology / Q000382:microbiology; D013295:Streptococcus mutans / Q000276:immunology*
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M