Genome-Scale Meta-analysis of Host Responses to Staphylococcus aureus Identifies Pathways for Host-Directed Therapeutic Targeting.

Background: Staphylococcus aureus infections are frequently complicated by metastatic foci, recurrence, and death. Antimicrobial resistance and intracellular bacterial persistence limit the effectiveness of conventional antimicrobials. Host-directed therapies could improve outcomes, but the interpretive complexity of pathogen-host interactions impedes identification of critical responses suitable for therapeutic targeting. To address this, we performed a meta-analysis of genome-scale studies aiming to prioritize host responses to S aureus.

Methods: Lists of genes associated with host responses to S aureus were retrieved from systematically identified genome-scale studies, then integrated using the meta-analysis by information content (MAIC) algorithm. This generated a single aggregated gene list, ranked based on the cumulative evidence supporting each gene.

Results: MAIC prioritized 3867 host genes. Myeloid cell immune responses were enriched with specific hubs including TLR2, IL-17, IFN-γ, and IL-1β. Noncanonical effector pathways were also enriched: autophagy (specific factors including mTOR and LAMP2), apoptosis (including BAD and BID), ferroptosis and iron metabolism (TFRC ranked 8/3876), and proteasomal antimicrobial responses (including PSME3 and the novel antimicrobial peptide PPP1CB). Prioritized genes were associated with genome-wide association study traits related to platelet count. In a cohort of patients with S aureus bacteremia, platelet count was differentially associated with clinical outcomes. Targets with immediate therapeutic relevance included S aureus/fibrin/platelet microthrombus formation (VWF, GP11b), S aureus-induced platelet loss (ASGR2), autophagy (mTOR), BID-mediated apoptosis, and intracellular bacterial killing (IFN-γ).

Conclusions: This in silico analysis identifies cytokine hubs associated with the response to S aureus infection and prioritizes additional host responses including apoptosis, autophagy, iron metabolism, and thrombosis as therapeutic targets.