BPI

Case study 1: Sigrid Bülow, 2018

Adequate perception of immunologically important pathogen-associated molecular patterns like lipopolysaccharide and bacterial lipoproteins is essential for efficient innate and adaptive immune responses. In the context of Gram-negative infection, BPI neutralizes endotoxic activity of lipopolysaccharides, and thus prohibits hyperactivation. So far, no immunological function of BPI has been described in Gram-positive infections.

In this study, a significant elevation of BPI in Gram-positive meningitis and a positive correlation between BPI and pro-inflammatory markers like TNFα were found. To clarify the underlying mechanisms, the team prepared recombinant BPI, bacterial lysates and various methods including BPI microtiter binding assay, nanoDSF experiments and microscale thermophoresis experiments. The results show that the interaction of BPI with these newly defined ligands significantly enhances the immune response in peripheral blood mononuclear cells (PBMCs) mediated by Gram-positive bacteria, and thereby ensures their sensitive perception.

Fig1. Competition of bLPs with lipopolysaccharide for binding to BPI. BPI binding assays with LPS biotin.

Fig2. Influence of BPI on TNFα secretion of PBMCs in response to bLPs and lysates of S. pneumoniae D39Δcps.

Case study 2: Fangchen Gong, 2021

Acute respiratory distress syndrome (ARDS) is one of the leading causes of death in patients with sepsis. As such, early and accurate identification of sepsis-related ARDS is critical. Bioinformatic analysis was used to explore the GEO datasets. ELISA method was used to detect the plasma or cellular supernatant of relevant proteins. Quantitative real-time PCR was used for mRNA measurements and Western blot was applied for protein measurements. Plasma expression of OLFM4 and LCN2 was also upregulated in sepsis-related ARDS patients compared to septic patients alone. In vitro data showed that OLFM4 expression in lung epithelial cells was downregulated upon LPS stimulation, whereas neutrophil media induced OLFM4 expression in lung epithelial cells. Furthermore, the increased levels of LDHA phosphorylation and the downstream NF-κB activation induced by LPS in epithelial cells were effectively diminished by OLFM4 overexpression and recombinant OLFM4 treatment via a reduction in ROS production and HIF1α expression.

Fig3. Analyses of ROC curves of critical DEGs in the GSE66890 dataset.

Fig4. BPI expressions were compared between healthy controls, septic patients, and sepsis-related ARDS patients using ELISA kit.

Fig1. BPI can alleviate cognitive impairment in diabetic mice by blocking the LPS-LBP-TLR4 signaling pathway. (Qin Sun, 2021)

Fig2. Interactions of BPI with Gram-negative bacteria in tissue settings. (Hendrik Schultz, 2007)

BPI involved in several pathways and played different roles in them. We selected most pathways BPI participated on our site, such as , which may be useful for your reference. Also, other proteins which involved in the same pathway with BPI were listed below. Creative BioMart supplied nearly all the proteins listed, you can search them on our site.

BPI has several biochemical functions, for example, lipopolysaccharide binding. Some of the functions are cooperated with other proteins, some of the functions could acted by BPI itself. We selected most functions BPI had, and list some proteins which have the same functions with BPI. You can find most of the proteins on our site.

BPI has direct interactions with proteins and molecules. Those interactions were detected by several methods such as yeast two hybrid, co-IP, pull-down and so on. We selected proteins and molecules interacted with BPI here. Most of them are supplied by our site. Hope this information will be useful for your research of BPI.