biostudies-literatureMiller LMNHLBI NIH HHSe188342https://www.ebi.ac.uk/biostudies/studies/S-EPMC12352901biostudies-literatureUnknown135(16)Influenza-associated bacterial superinfections in the lung lead to increased morbidity and mortality. Nearly all people have preexisting memory to influenza virus, which can protect against subsequent infection in the lung. This study explored the role B cells play in protection against bacterial (Staphylococcus aureus or Klebsiella pneumoniae) superinfection with previous heterotypic influenza memory. B cell deficiency resulted in an increased inflammatory lung environment and lung tissue injury during superinfection. Loss of B cells increased populations of memory CD8+ T cells in the lung, and these CD8+ T cells were transcriptionally and functionally distinct from those of WT mice. Use of antibody-deficient mouse models showed that this phenotype was specifically due to loss of antibodyThe Journal of clinical investigationB cell deficiency induces cytotoxic memory CD8+ T cells during influenza-associated bacterial pneumonia.PMC12352901R01 HL107380Gupta AAlcorn JFCipolla EMMiller LMDresden BPRago FParenteau KLDuray AMfalseB cell deficiency induces cytotoxic memory CD8+ T cells during influenza-associated bacterial pneumonia.Influenza-associated bacterial superinfections in the lung lead to increased morbidity and mortality. Nearly all people have preexisting memory to influenza virus, which can protect against subsequent infection in the lung. This study explored the role B cells play in protection against bacterial (Staphylococcus aureus or Klebsiella pneumoniae) superinfection with previous heterotypic influenza memory. B cell deficiency resulted in an increased inflammatory lung environment and lung tissue injury during superinfection. Loss of B cells increased populations of memory CD8+ T cells in the lung, and these CD8+ T cells were transcriptionally and functionally distinct from those of WT mice. Use of antibody-deficient mouse models showed that this phenotype was specifically due to loss of antibody2025-01-01T00:00:00Z2025 Aug2026-05-29T17:01:44.462Z2026-04-08T05:25:23.935ZS-EPMC123529014049342210.1172/JCI188342