Gingival Transcriptomics of Follicular T Cell Footprints in Progressing
Periodontitis
Abstract
Follicular helper T cells (Tfh) cells are generally considered critical
in secondary lymphoid tissues; however, they are also identified in the
circulation and in tertiary lymphoid structures in chronic inflammation.
Gingival tissues with periodontitis reflect chronic inflammation so
genomic footprints of Tfh cells should occur in these tissues and may
differ related to aging effects. Methods: Macaca mulatta monkeys were
used in a model of ligature-induced periodontitis [adult group (12-23
years of age); young group (3-7 years)]. Gingival tissue and
subgingival microbiome samples were obtained at matched healthy sites,
sites during ligature-induced disease, and in samples after clinical
resolution. Microarray analysis examined Tfh genes (n=40) and the
microbiome samples were examined using 16S MiSeq. Results: An apparent
increase in the major transcription factor of Tfh cells, BCL6, was found
with disease in both adult and young animals, while the master
transcription markers of other T cell subsets were either decreased or
showed minimal change. A number of the Tfh related genes, including
surface receptors, secreted products and transcription factors were also
significantly increased during disease. Unique microbial complexes
showed patterns of interactions with Tfh genes that differed in health
and disease. Conclusions: An increase in Tfh cell responsiveness
occurred later in the progression of periodontitis, affected by age and
strongly related to specific microbial complexes. The capacity of
gingival Tfh cells to contribute to localized B cell activation and
active antibody responses, including affinity maturation may be critical
for controlling periodontal lesions and contributing to limiting and/or
resolving the lesions.