Microbial community composition in subgingival plaques and heterogeneity of tumor tissue TCRβ CDR3 repertoire in patients with moderate-to-severe periodontitis and oral squamous cell carcinoma.

The human oral cavity contains over 700 types of bacteria that may protect the body against colonization by exogenous pathogens and maintain relative homeostasis. However, alterations in the immune status can disrupt the balance between microorganisms and the host, inducing various diseases such as oral cancer and diabetes mellitus. The mechanism underlying this process is not clearly understood. The purpose of this study was to investigate the relationships between subgingival bacteria, T-cell receptor β-chain complementarity-determining region 3 (TCRβ CDR3), and the development oforal squamous cell carcinoma (OSCC). We grouped patients as “healthy periodontal” (H), “moderate-to-severe chronic periodontitis” (C), and “moderate-to-severe chronic periodontitis with OSCC” (T). Bacterial groups were “subgingival plaque” (bp) and “gingival/tumor tissue” (g). We also recorded patients’ age, gender, attachment level (AL), bleeding on probing (BOP), and probing depth (PD). We extracted and sequenced RNA from plaques, gingival tissues, tumors, and teeth. We performed high-throughput sequencing on TCRβ CDR3 and plaque bacteria.<italic>Synergistetes</italic> and <italic>Veillonella parvula</italic> were more abundant in the H group than in the T group. <italic>Granulicatella</italic>, <italic>Peptostreptococcus</italic>, and <italic>Streptococcus infantis</italic> were enriched in the T-bp group. AL, BOP, and PD were positively correlated with <italic>Granulicatella</italic>, <italic>Peptostreptococcus</italic>, and <italic>Pseudomonas</italic> but negatively correlated with <italic>Prevotella nigrescens</italic> and <italic>V. parvula</italic>. TCRβ CDR3 diversity was C > H > T. <italic>TCR β-chain Variable gene (TRBV)20-1</italic> usage varied among the H, C, and T groups. <italic>TRBV2</italic> and <italic>TRBV5-1</italic> usage was greater in the T group than in the C group. <italic>TRBJ1-1</italic>, <italic>TRBJ1-2</italic>, <italic>TRBJ2-2</italic>, <italic>TRBJ2-7</italic>, and <italic>TRBJ2-5</italic> were most frequently used. These trends and the reduction of gingival <italic>Synergistetes</italic> were correlated with OSCC. TCRβ CDR3 diversity was the lowest in patients in the T group, and there were considerable changes in the expression of <italic>TRBV2</italic> and <italic>TRBJ</italic>. Therefore, plaque bacterial composition can influence TCRβ CDR3. [ABSTRACT FROM AUTHOR]