Mucosal immunology
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Resident memory T cells (TRM) reside in the lung epithelium and mediate protective immunity against respiratory pathogens. Although lung CD8+ TRM have been extensively characterized, the properties of CD4+ TRM remain unclear. Here we determined the transcriptional signature of CD4+ TRM, identified by the expression of CD103, retrieved from human lung resection material. ⋯ Interestingly, the superior cytokine production appears to be because of an accessible interferon-γ (IFNγ) locus and was partially because of rapid translation of preformed mRNA. Our studies provide a molecular understanding of the maintenance and potential function of CD4+ TRM in the human lung. Understanding the specific properties of CD4+ TRM is required to rationally improve vaccine design.