The Bacterial Commercial Lysate, Pulmonarom®, Induces Dendritic Cell Activation In Vitro Through the Induction of the Expression of TLRs and Cytokines

Background Evidence shows bacterial lysates may participate in the immune response against respiratory infections. However, few studies have been conducted on dendritic cells, and, to our knowledge, none on human dendritic cells, and few have analyzed certain TLRs and cytokines. Materials and Methods Monocytes were obtained from the buffy coat and subsequently differentiated into dendritic cells (moDCs). The protein of commercial bacterial lysate Pulmonarom® was lyophilized and quantified. Ultrastructural changes induced by Pulmonarom® were evaluated in moDC by electron microscopy, and the expression of TLRs and some cytokines in these cells was evaluated by flow cytometry. Results Pulmonarom®-stimulated moDCs showed increased numbers of dendrites and the presence of lysosomes; they also showed increased expression of MHC-II and TLRs 2, 3, 6, and 7, IL-4, IL-6, IL-8, and MCP-1. Major conclusions The effects of Pulmonarom® on moDC correlate with an increased capacity to mobilize to lymph nodes and present antigens, initiating an effective adaptive immune response. Lysosomal activity and maturation of moDC, increased expression of TLR2, TLR3, TLR6, and TLR7 receptors, and increased production of the cytokines IL-8, MCP-1, IL-6, and IL-4, indicate a training process in moDC after their activation with Pulmonarom® bacterial lysate. This suggests that Pulmonarom® could enhance responses against viruses and bacteria by activating moDC. To our knowledge, this is the first study to address the effect of Pulmonarom® on one of the most important cells orchestrating the innate and acquired immune responses.