Lipoteichoic acid preparations of gram-positive bacteria induce interleukin-12 through a CD14-dependent pathway

• DOI: 10.1128/iai.64.6.1906-1912.1996
• Publication Date: 2020-01-06T18:58:50Z
• Authors: M G Cleveland; J D Gorham; T L Murphy; E Tuomanen; K M Murphy
• Keywords: Lipoteichoic acid; Muramyl dipeptide; Monocyte

Interleukin 12 (IL-12) strongly augments gamma interferon production by natural killer (NK) and T cells. IL-12 also promotes effective cell-mediated immune responses, which are particularly important against intracellular bacteria such as Listeria monocytogenes. While the lipopolysaccharide (LPS) of gram-negative induces monocyte IL-12, relevant gram-positive components induce uncharacterized. We used human monocytic cell line THP-1 to study induction bacteria. Muramyl dipeptides well major muramyl tetrapeptide component Streptococcus pneumoniae were inactive for inducing IL-12. In contrast, lipoteichoic acid (LTA), a predominant surface glycolipid bacteria, potently induced p40 gene expression. A competitive LPS antagonist, Rhodobacter sphaeroides LPS, inhibited LTA-induced production, suggesting common pathway LTA in activation. Pretreatment cells with anti-CD14 monoclonal antibody blocked both Thl development naive CD4 an IL-12-dependent mechanism, indicating direct physiologic levels Together, these results show that is potent structure monocytes through CD14-mediated pathway.