Bacterial Lysate “lantigen B” Induces Proliferation of B and NK Cells and the Release of Related Cytokines

Background: The present is an exploratory study, to evaluate the immune effect of a bacterial chemical lysate: Lantigen-B (Lan-B). PBMCs were stimulated with the concentration of the drug utilized in the clinical setting to evaluate its effects on lymphocyte subpopulation and cytokine release. Methods: PBMCs, from 7 healthy donors, were cultured alone or incubated with Lan-B at 199.45 Antigen Units/mL concentrations. Lymphocyte subpopulations were evaluated by Facs-Scan and cytokines by Cytometer. Results: A significant increase of IL-1b, IFN-g, TNF-a, IL-17, and IL-18 release and of CD19+ and CD16+/56+cells proportion was found in stimulated compared to unstimulated cultures along with a significant decrease of MCP1 and a trend for an increase of CD8+ cells and IL12-p40. Conclusions: The study shows that Lantigen-B drives a Th1-reaction and stimulates the differentiation/activation of B and NK cells. Changes in lymphocyte subpopulations and in cytokines are well correlated. The observed changes can result in a state of “prealert” of the immune system able to successfully fight infections also induced by bacteria and viruses different from those administered, the so-called “Trained Immunity”. Finally, the reduction of MCP1, which drives a Th2 reaction, can explain the beneficial effects on allergies observed in some clinical studies.