Serotype b of Aggregatibacter actinomycetemcomitans increases osteoclast and memory T‐lymphocyte activation

This study aimed to investigate whether serotype b of A. actinomycetemcomitans induces higher Th17‐associated RANKL production, RANKL‐induced osteoclasts activation, and antigen‐specific memory T lymphocytes proliferation. On naïve CD4+ T lymphocytes stimulated with autologous dendritic cells primed with different A. actinomycetemcomitans serotypes, RANKL production, T‐bet, GATA‐3, RORC2, and Foxp3 expression, RORC2/RANKL intracellular double‐expression, TRAP+ osteoclast activation, and bone resorption were quantified. The frequency of proliferating memory T lymphocytes in response to A. actinomycetemcomitans serotypes was determined in periodontitis and healthy subjects. Naïve CD4+ T lymphocytes stimulated by serotype b‐primed dendritic cells elicited higher levels of RANKL, RORC2, TRAP+ osteoclasts, and bone resorption than the same cells stimulated with the other serotypes. RANKL positively correlated and co‐expressed with RORC2. Memory T lymphocytes responding to serotype b were more frequently detected in periodontitis patients than healthy subjects. These results indicate that serotype b of A. actinomycetemcomitans is associated with higher production of RANKL and these increased levels are associated with Th17 lymphocyte induction, osteoclast activation, and bone resorption. This article is protected by copyright. All rights reserved.
Source: Oral Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research