A Genetic Variation of Lipopolysaccharide Binding Protein Affects the Inflammatory Response and Is Associated with Improved Outcome during Sepsis

LPS binding protein (LBP) is an important innate sensor of microbial cell wall structures. Frequent functionally relevant mutations exist and have been linked to influence susceptibility to and course of bacterial infections. We examined functional properties of a single nucleotide polymorphism resulting in an exchange of phenylalanine to leucine at position 436 of LBP (rs2232618) and compared the frequent variant of the molecule with the rare one in ligand binding experiments. We then stimulated RAW cells with bacterial ligands in the presence of serum obtained from individuals with different LBP genotypes. We, furthermore, determined the potential effects of structural changes in the molecule by in silico modeling. Finally, we analyzed 363 surgical patients for this genetic variant and examined incidence and course of sepsis following surgery. We found that binding of LBP to bacterial ligands was reduced, and stimulation of RAW cells resulted in an increased release of TNF when adding serum from individuals carrying the F436L variant as compared with normal LBP. In silico analysis revealed structural changes of LBP, potentially explaining some of the effects observed for the LBP variant. Finally, patients carrying the F436L variant were found to be similarly susceptible for sepsis. However, we observed a more favorable course of severe infections in this cohort. Our findings reveal new insights into LPS recognition and the subsequent activation of the innate immune system brought about by LBP. The identification of a genetic variant of LBP influencing the course of sepsis may help to stratify individuals at risk and thus reduce clinical complications of patients.Peer Reviewe

Accuracy of endometrial sampling in the diagnosis of endometrial cancer: a multicenter retrospective analysis of the JAGO-NOGGO

Abstract Background Accurate preoperative molecular and histological risk stratification is essential for effective treatment planning in endometrial cancer. However, inconsistencies between pre- and postoperative tumor histology have been reported in previous studies. To address this issue and identify risk factors related to inaccurate histologic diagnosis after preoperative endometrial evaluation, we conducted this retrospective analysis. Methods We conducted a retrospective analysis involving 375 patients treated for primary endometrial cancer in five different gynaecological departments in Germany. Histological assessments of curettage and hysterectomy specimens were collected and evaluated. Results Preoperative histologic subtype was confirmed in 89.5% of cases and preoperative tumor grading in 75.2% of cases. Higher rates of histologic subtype variations (36.84%) were observed for non-endometrioid carcinomas. Non-endometrioid (OR 4.41) histology and high-grade (OR 8.37) carcinomas were identified as predictors of diverging histologic subtypes, while intermediate (OR 5.04) and high grading (OR 3.94) predicted diverging tumor grading. Conclusion When planning therapy for endometrial cancer, the limited accuracy of endometrial sampling, especially in case of non-endometrioid histology or high tumor grading, should be carefully considered

The Crystal Structure of Lipopolysaccharide Binding Protein Reveals the Location of a Frequent Mutation that Impairs Innate Immunity

Item does not contain fulltextLipopolysaccharide (LPS) binding protein (LBP) is an acute-phase protein that initiates an immune response after recognition of bacterial LPS. Here, we report the crystal structure of murine LBP at 2.9 A resolution. Several structural differences were observed between LBP and the related bactericidal/permeability-increasing protein (BPI), and the LBP C-terminal domain contained a negatively charged groove and a hydrophobic "phenylalanine core." A frequent human LBP SNP (allelic frequency 0.08) affected this region, potentially generating a proteinase cleavage site. The mutant protein had a reduced binding capacity for LPS and lipopeptides. SNP carriers displayed a reduced cytokine response after in vivo LPS exposure and lower cytokine concentrations in pneumonia. In a retrospective trial, the LBP SNP was associated with increased mortality rates during sepsis and pneumonia. Thus, the structural integrity of LBP may be crucial for fighting infections efficiently, and future patient stratification might help to develop better therapeutic strategies