Heterogeneity in the immune response to serotype b LPS of Actinobacillus actinomycetemcomitans in inbred strains of mice.
We investigated the heterogeneity of the humoral immune responses to whole cells and lipopolysaccharide (LPS) of Actinobacillus actinomycetemcomitans serotype b and production of cytokines in inbred strains of mice. Nine such strains were tested: A/J (H-2(a)), C57BL/6 (H-2(b)), BALB/c (H-2(d)), DBA/2 (H-2(d)), B10.BR (H-2(k)), C3H/He (H-2(k)), C3H/HeJ (H-2(k)), DBA/1 (H-2(q)) and B10.S (H-2(s)). Mice were immunized intraperitoneally with whole cells of A. actinomycetemcomitans ATCC 43718 (serotype b) in phosphate buffered saline (PBS; pH 7.2) emulsified with an equal volume of Freund's incomplete adjuvant. Serum immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM) levels against A. actinomycetemcomitans were measured by an ELISA system. ELISA analysis, using LPS fractions from serotype a, b or c strains of A. actinomycetemcomitans as the coating antigens, revealed that mice strains C3H/He, C3H/HeJ, B10.BR and B10.S had an extremely high-IgM response against serotype b LPS. High-IgM titer sera contain also elevated levels of IgA antibodies to the antigen. To compare the cytokine production among inbred mice, the amounts of interleukin-4 (IL-4), interleukin-5 (IL-5), and interleukin-6 (IL-6) released from mouse splenocytes were measured using ELISA systems specific for these cytokines. A. actinomycetemcomitans serotype b LPS stimulation induced IL-6 release from murine splenocytes of all tested strains. However, IL-4 and IL-5 were detected only in high-IgM/IgA responders to A. actinomycetemcomitans serotype b LPS, not in low-IgM/IgA responders. Thus, we found a relationship between the humoral immune response to LPS of A. actinomycetemcomitans serotype b and production of type 2 cytokines by splenocytes.
Kato
T
T
Oral Health Science Center, Department of Microbiology, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba, Japan.
Honma
K
K
Yamanaka
A
A
Miura
T
T
Okuda
K
K
D000189:Actinobacillus Infections / Q000276:immunology / Q000382:microbiology; D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification / Q000276:immunology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D016207:Cytokines / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007114:Immunization; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D012703:Serotyping
D000907:Antibodies, Bacterial; D016207:Cytokines; D008070:Lipopolysaccharides