CXCL13 production in B cells via Toll-like receptor/lymphotoxin receptor signaling is involved in lymphoid neogenesis in chronic obstructive pulmonary disease.

Rationale: Little is known about what drives the appearance of lymphoid follicles (LFs), which may function as lymphoid organs in chronic obstructive pulmonary disease (COPD). In animal infection models, pulmonary LF formation requires expression of homeostatic chemokines by stromal cells and dendritic cells, partly via lymphotoxin.Objectives: To study the role of homeostatic chemokines in LF formation in COPD and to identify mechanism(s) responsible for their production.Methods: Peripheral lung homeostatic chemokine and lymphotoxin expression were visualized by immunostainings and quantified by ELISA/quantitative reverse transcriptase–polymerase chain reaction in patients with COPD with and without LFs. Expression of lymphotoxin and homeostatic chemokine receptors was investigated by flow cytometry. Primary lung cell cultures, followed by ELISA/quantitative reverse transcriptase–polymerase chain reaction/flow cytometry, were performed to identify mechanisms of chemokine expression. Polycarbonate membrane...