Influence of proinflammatory cytokines on Actinobacillus actinomycetemcomitans specific IgG responses.
OBJECTIVE
High levels of serum anti-Actinobacillus actinomycetemcomitans immunoglobulin G (IgG) correlate with reduced extent and severity of periodontal disease and the present study was undertaken to begin testing the hypothesis that proinflammatory cytokines are important in the induction of optimal anti-A. actinomycetemcomitans IgG responses.


BACKGROUND
Studies with pokeweed mitogen indicate that interleukin-1alpha (IL-1alpha) and IL-1beta are necessary for optimal IgG1 and IgG2 production and that prostaglandin E(2) (PGE(2)) and interferon-gamma (IFN-gamma) selectively promote IgG2, which is a major component of the anti-A. actinomycetemcomitans response in vivo. The pokeweed mitogen results suggest that these proinflammatory cytokines would also be necessary for optimal production of IgG specific for A. actinomycetemcomitans.


METHODS
Peripheral blood mononuclear cells from A. actinomycetemcomitans-seropositive subjects with localized aggressive periodontitis were stimulated with A. actinomycetemcomitans in immune complexes capable of binding follicular dendritic cells that participate in the induction of recall responses in vivo. Cultures were manipulated with anti-IL-1alpha, anti-IL-1beta, anti-IFN-gamma, anti-IL-12, anti-CD21, indomethacin, and PGE(2). Actinobacillus actinomycetemcomitans specific IgG production was monitored by enzyme-linked immunosorbent assay (ELISA).


RESULTS
Addition of follicular dendritic cells to peripheral blood mononuclear cells cultures resulted in follicular dendritic cell-lymphocyte clusters and increased anti-A. actinomycetemcomitans IgG responses (3-40-fold increases) compared with controls lacking follicular dendritic cells. Anti-IL-1alpha, anti-IL-1beta, anti-IFN-gamma, anti-IL-12, anti-CD21 and indomethacin suppressed anti-A. actinomycetemcomitans IgG production by half or more. PGE(2) restored IgG responses suppressed by indomethacin.


CONCLUSIONS
The cytokines IL-1alpha, IL-1beta, IFN-gamma, IL-12, and PGE(2) were all necessary for optimal production of human anti-A. actinomycetemcomitans and the need for proinflammatory cytokines including the T helper 1 (Th1) cytokines is consistent with a response with a significant IgG2 component.
Tanaka
S
S
Clinical Research Center for Periodontal Diseases, School of Dentistry, Medical College of Virginia Campus/Virginia Commonwealth University, Richmond, VA 23298-0678, USA.
Fakher
M
M
Barbour
S E
SE
Schenkein
H A
HA
Tew
J G
JG
D000189:Actinobacillus Infections / Q000097:blood; D016976:Aggregatibacter actinomycetemcomitans / Q000276:immunology*; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D000936:Antigen-Antibody Complex / Q000276:immunology; D016207:Cytokines / Q000276:immunology*; D020566:Dendritic Cells, Follicular / Q000276:immunology; D015232:Dinoprostone / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D007213:Indomethacin / Q000494:pharmacology; D018836:Inflammation Mediators / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology; D007375:Interleukin-1 / Q000276:immunology; D018664:Interleukin-12 / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010518:Periodontitis / Q000097:blood / Q000382:microbiology; D017464:Receptors, Complement 3d / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000936:Antigen-Antibody Complex; D016207:Cytokines; D007074:Immunoglobulin G; D018836:Inflammation Mediators; D007375:Interleukin-1; D017464:Receptors, Complement 3d; D018664:Interleukin-12; D007371:Interferon-gamma; D015232:Dinoprostone; D007213:Indomethacin