The pro-inflammatory macrophages interacted with T8_rms and plasma cells via the CXCL10-CXCR3 axis.<h4>Conclusions</h4>The lung interstitial-to-airway/alveolar cross-compartment sharing pattern of activated immune cells (Pattern 1a) provide a robust working hypothesis for clinical and translational research for severe pneumonia. The gene discussed is CXCL10; the disease is pneumonia.