Its involvement in the innate and adaptive immune systems has been studied, suggesting a possible role for NGAL in immune tolerance. HLA-G is a non-classical HLA class I molecule with an important role at the fetal-maternal interface, preventing fetus recognition and abortion. The genetic diversity, expression, structure, and function of HLA-G differs from HLA I molecules: it does not appear to significantly stimulate the immune system. However, like HLA class I molecules, HLA-G is able to bind to inhibitory receptors. It is currently considered a key molecule in the complex still not entirely understood phenomenon of tolerance. The aims of the present study were to evaluate the potential immunomodulatory role of NGAL. In particular, we tested the effect of NGAL in an in vitro model of peripheral blood mononuclear cells. We evaluated the expression of human leukocyte antigen G, a well-known tolerogenic molecule, and the presence of a FoxP3+ T-regulatory cell subset. Antibiotics have saved the lives of millions of people, greatly improving human and animal health in the twentieth century. Hundreds of thousands of deaths occur annually due to antibiotic treatment failures. At present, the routine approach to addressing this crisis is to develop novel antibiotics. However, novel antibiotics are limited, and pathogens will gradually evolve resistance to these novel antibiotics. Based on the inevitable trend towards bacterial resistance, it is necessary to explore new treatment strategies for effectively killing and eliminating bacterial pathogens. Limiting the evolution of bacterial resistance and using new and existing antibiotics may constitute a new strategy for antibacterial therapy. Antimicrobial peptides have been studied for the development of new antibacterial drugs due to their high antibacterial activity and low drug resistance. Although AMPs represent a potentially new source of antimicrobials for the treatment of various bacterial infections, conventional antibiotics remain a primary resource for antibacterial therapy and cannot be fully replaced at present. Therefore, combining conventional antibiotics and AMPs can prolong the life spans of many antibiotics. Nisin, an AMP from Lactococcus lactis, Staurosporine consists of 34 amino acid residues and is minimally toxic, odorless, colorless, and tasteless. Nisin possesses high antimicrobial activity against a wide range of Gram-positive bacteria, even against some antibiotic-resistant pathogens. Some papers have reported the anti-pathogen activity of antibiotics in combination with nisin. Antibiotic-resistant enterococci are one of major causes of hospital-acquired infections, as enterococci are common residents in the gastrointestinal tracts of a wide range of humans and animals. In Enterococcus spp, Enterococcus faecalis ranks among the leading causes of nosocomial infections worldwide.