Pharmacology and Immunopathology Core – Hackensack Meridian Health ABSTRACT The pharmacology and ImmunoPathology Shared Resource Core will serve the Projects and the Clinical Core of this TBRU Consortium to deliver (1) standardized high-dimensional immunophenotyping of mouse and human samples, including data analysis and dimensional reduction, and (2) drug quantitation in plasma and sputum to identify immunologic and pharmacokinetic determinants of post-treatment persistent infection and relapse. High dimensional immunophenotyping: a significant subset of apparently cured TB patients present with non- resolving and intensifying lesions on PET–CT images along with the presence of Mtb mRNA in sputum and bronchoalveolar lavage samples, up to 1 year after a standard 6-month treatment. This suggests that even apparently curative TB treatment may not eradicate all Mtb bacteria in most patients and reveals an important role for the immune response in maintaining a disease-free state. The Clinical Core will recruit a cohort of 500 subjects with active TB and at high risk of relapse due to cavitary disease and high bacterial burden in sputum. To mimic the phenomenon of post-treatment persistent infection in humans and identify determinants of relapse, Project 3 (Ehrt et al.) has developed and optimized a mouse model of paucibacillary TB. We will apply high- dimensional immune-phenotyping with samples collected from the cohort of 500 subjects recruited by the Clinical Core, and the mouse model of PTPI, to identify immunologic determinants of relapse. Five wild-derived mouse strains with diverse genetic backgrounds and a broad spectrum of responses to TB infection will be studied in the model of PTPI to study the impact of host genetics on disease progression and outcome in mice, and identify mouse strains that develop immune responses closer to humans (Project 3). We will also apply deep immunophenotyping to samples from subjects with inborn errors of immunity (Project 2) to confirm the impact of candidate mutations and associated deficiencies on the immune response. Pharmacokinetic determinants of relapse: Leveraging the cohort of 500 TB patients at high risk of relapse, we will measure drug concentrations in plasma, sputum and saliva, during chemotherapy with the first line agents: rifampicin, isoniazid, pyrazinamide and ethambutol. Together with pharmacogenetic profiling (Project 2), the results will be analyzed using population PK approaches to determine whether inter-individual pharmacokinetic variability contributes to clinical relapse and microbiome dysbiosis (Project 1). We have access to large BioSafety Level 3 facilities where TB infected rodents are routinely housed for extended periods, with an integrated platform for high-dimensional immunophenotyping allowing the simultaneous profiling of up to 28 immune markers in mouse or human cells processed in a BSL-3 facility, and associated dimension reduction algorithms. Our analytical platform houses...