Gingival Biopsies and Saliva Collection from Healthy and HIV+ Cohorts

Human samples (gingival biopsies and saliva) were obtained with informed consents from healthy and HIV+ (PLWH) cohorts under a protocol approved by the University Hospitals Cleveland Medical Center Institutional Review Board, complying with all relevant ethical regulations^{4 (link)}. Participants of both sexes were enrolled. The characteristics of enrolled participants for obtaining gingival biopsies and saliva are described in Supplementary Table 1. Gingival biopsies were processed fresh for flow cytometry. Discarded palatine tonsils were obtained from tonsillectomy surgeries performed at University Hospitals Cleveland Medical Center through the Histology Tissue Procurement Facility following a separate IRB-approved protocol (Non-Human research). A single-cell suspension of gingival tissues and tonsils was prepared by Collagenase 1A digestion (0.5 mg/ml; Sigma C9891), with subsequent Ficoll-Paque PLUS (GE17-1440-02; Millipore Sigma) centrifugation at 900 g and washing with PBS. Tonsil cells were processed fresh for HTOC cultures. Some tonsil cells were processed fresh for CD4 cell purification for cell culture or flow cytometry. Saliva samples were collected in sterile tubes and stored at −80 °C until processing for metabolome and ELISA analyses.