Biology subjects

van der Lans, S. P. A.

Publications and source records attributed to van der Lans, S. P. A..

3 recordsLinked to original sources

bioRxiv2024

Longitudinal fluctuations in protein concentrations and higher-order structures in the plasma proteome of kidney failure patients subjected to a kidney transplant

Using proteomics and complexome profiling we evaluated over a period of a year longitudinal variations in the plasma proteome of kidney failure patients, prior to and after a kidney transplantation, comparing this data with two healthy controls. The post-transplant period was complicated by numerous bacterial infections, resulting in dramatic changes in the plasma proteome, mostly related to an acute phase condition. As positive acute phase proteins, being elevated upon inflammation, we observed the well-described C-reactive protein (CRP) and Serum Amyloid A (SAA1 and SAA2), but our analyses added to that Fibrinogen (FGA, FGB and FGG), Haptoglobin (HP), Leucine-rich alpha-2-glycoprotein (LRG1), Lipopolysaccharide- binding protein (LBP), Alpha-1-antitrypsin (SERPINA1), Alpha-1-antichymotrypsin (SERPINA3), Protein S100 (S100A8, S100A9), Complement protein C4, C4b-binding protein alpha chain (C4BPA), Complement factor B (CFB) and Monocyte differentiation antigen CD14. As negative acute phase proteins, being downregulated upon inflammation, we identified the well-documented Serotransferrin (TF) and Transthyretin (TTR), but add on to that Kallistatin (SERPINA4), Heparin cofactor 2 (SERPIND1), Inter-alpha-trypsin inhibitor heavy chain H1 and H2 (ITIH1, ITIH2). For a patient with the most severe acute phase response, we furthermore performed plasma complexome profiling by SEC-LC-MS on all longitudinal samples. We observe that several plasma proteins displaying alike concentration patterns, co- elute and putatively form macromolecular complexes. These include a) FGA, FGB and FGG (as expected, b) ITIH1 and ITIH2, c) HP together with Hemoglobin (HB), d) the small acute phase biomarker proteins SAA1 and SAA2 with the Apolipoproteins A-I, A-II, A-IV (APOA1, APOA2, APOA4). By complexome profiling we expose how SAA1 and SAA2 become incorporated into high-density lipid particles, thereby replacing partly APOA1 and APOA4. Overall, our data highlight that the combination of in-depth longitudinal plasma proteome and complexome profiling can shed further light on the correlated variations in the abundance of several plasma proteins upon inflammatory events.

molecular biology↗

bioRxiv2023

Direct mass spectrometry-based detection and antibody sequencing of Monoclonal Gammopathy of Undetermined Significance from patient serum - a case study.

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell disorder, characterized by the presence of a predominant monoclonal antibody (i.e., M-protein) in serum, without clinical symptoms. Here we present a case study in which we detect MGUS by liquid-chromatography coupled with mass spectrometry (LC-MS) profiling of IgG1 in human serum. We detected a Fab-glycosylated M-protein and determined the full heavy and light chain sequences by bottom-up proteomics techniques using multiple proteases, further validated by top-down LC-MS. Moreover, the composition and location of the Fab-glycan could be determined in CDR1 of the heavy chain. The outlined approach adds to an expanding mass spectrometry-based toolkit to characterize monoclonal gammopathies such as MGUS and multiple myeloma, with fine molecular detail. The ability to detect monoclonal gammopathies and determine M-protein sequences straight from blood samples by mass spectrometry provides new opportunities to understand the molecular mechanisms of such diseases.

immunology↗

bioRxiv2022

Colistin resistance mutations in phoQ sensitize Klebsiella pneumoniae to IgM-mediated complement killing

The Gram-negative bacterium Klebsiella pneumoniae is notorious for a strong increase of infections with antibiotic resistant strains. To treat infections with antibiotic resistant K. pneumoniae, clinicians increasingly need to use the last resort antibiotic colistin. K. pneumoniae can develop colistin resistance by modifying its membranes. During infection the membranes of Gram-negative bacteria are also targeted by the human immune system via the complement system. Gram-negative bacteria have an outer and inner membrane separated by a thin cell wall. Activation of the complement system leads to the formation of the membrane attack complex (MAC), a pore that inserts into the outer membrane, and ultimately leads to lysis of the bacterium. As both colistin and the MAC interact with the outer membrane of Gram-negative bacteria, we wondered if developing colistin resistance influences MAC-mediated killing of K. pneumoniae. Using clinical isolates that developed colistin resistance, we found that the strain Kp209_CSTR became more sensitive to MAC-mediated killing compared to the wild-type strain. MAC-mediated membrane permeabilization of Kp209_CSTR required antibody dependent activation of the classical complement pathway. Strikingly, Kp209_CSTR was bound by IgM in human serum that did not recognise the wild-type strain. Depletion of Kp209_CSTR-specific antibodies from serum prevented MAC-mediated membrane permeabilization, which was restored by adding back IgM. Genomic sequence comparison revealed that Kp209_CSTR has a deletion in the phoQ gene. RNAseq analysis suggested that this mutation locks PhoQ in a constitutively active state. These results indicate that PhoQ activation in Kp209_CSTR leads to both colistin resistance and sensitivity to MAC-mediated killing. Together, our results show that developing colistin resistance can sensitize K. pneumoniae to killing by the immune system.

microbiology↗