Human cytomegalovirus enhances chemokine production by lipopolysaccharide-stimulated lamina propria macrophages.

To elucidate the role of mucosal macrophages in intestinal human cytomegalovirus (HCMV) disease, primary lamina propria macrophages (LPM) were isolated from normal human jejunum, infected with HCMV, and studied for their cytokine responses. HCMV infection of LPM was confirmed by the presence of HCMV IE72 (UL123), pp65 (UL83), and glycoprotein B (UL55) proteins, which were detected by immunofluorescence, beginning at postinfection (pi) day 3, and were sustained through pi day 12 in 0.1%-0.5% of LPM. The late protein pp28 (UL99) was also detected up to pi day 12, consistent with productive infection. HCMV infection in LPM was characterized by quantitative competitive polymerase chain reaction, with maximum levels of HCMV DNA detected at pi day 7. HCMV infection of the LPM augmented lipopolysaccharide-inducible chemokine (interleukin [IL]-8 and macrophage inflammatory protein-1alpha) and cytokine (IL-6) production. These findings suggest that mucosal macrophages, via enhanced mediator production, play an important role in intestinal inflammation associated with HCMV infection.