Benzyloxycarbonyl-proline-prolinal (ZPP): Dual complementary roles for neutrophil inhibition.

Neutrophil influx and activation contributes to organ damage in several major lung diseases. This inflammatory influx is initiated and propagated by both classical chemokines such as interleukin-8 and by downstream mediators such as the collagen fragment cum neutrophil chemokine Pro-Gly-Pro (PGP), which share use of the ELR + CXC receptor family. Benzyloxycarbonyl-proline-prolinal (ZPP) is known to suppress the PGP pathway via inhibition of prolyl endopeptidase (PE), the terminal enzyme in the generation of PGP from collagen. However, the structural homology of ZPP and PGP suggests that ZPP might also directly affect classical glutamate-leucine-arginine positive (ELR+) CXC chemokine signaling. In this investigation, we confirm that ZPP inhibits PE in vitro, demonstrate that ZPP inhibits both ELR + CXC and PGP-mediated chemotaxis in human and murine neutrophils, abrogates neutrophil influx induced by murine intratracheal challenge with LPS, and attenuates human neutrophil chemotaxis to sputum samples of human subjects with cystic fibrosis. Cumulatively, these data demonstrate that ZPP has dual, complementary inhibitory effects upon neutrophil chemokine/matrikine signaling which make it an attractive compound for clinical study of neutrophil inhibition in conditions (such as cystic fibrosis and chronic obstructive pulmonary disease) which evidence concurrent harmful increases of both chemokine and matrikine signaling.

Phenotyping ciliary dynamics and coordination in response to CFTR-modulators in Cystic Fibrosis respiratory epithelial cells.

Personalized approaches for systematically assessing ciliary beat dynamics and for drug testing would improve the challenging task of diagnosing and treating respiratory disorders. In this pilot study, we show how multiscale differential dynamic microscopy (multi-DDM) can be used to characterize collective ciliary beating in a non-biased automated manner. We use multi-DDM to assess the efficacy of different CFTR-modulating drugs in human airway epithelial cells derived from subjects with cystic fibrosis (ΔF508/ΔF508 and ∆F508/-) based on ciliary beat frequency and coordination. Similar to clinical observations, drug efficacy is variable across donors, even within the same genotype. We show how our assay can quantitatively identify the most efficient drugs for restoring ciliary beating for each individual donor. Multi-DDM provides insight into ciliary beating responses following treatment with drugs, and has application in the broader context of respiratory disease and for drug screening.

The role of matrix metalloproteinases in cystic fibrosis lung disease.

Significant airway remodelling is a major component of the increased morbidity and mortality observed in cystic fibrosis (CF) patients. These airways feature ongoing leukocytic inflammation and unrelenting bacterial infection. In contrast to acute bacterial pneumonia, CF infection is not cleared efficiently and the ensuing inflammatory response causes tissue damage. This structural damage is mainly a result of free proteolytic activity released by infiltrated neutrophils and macrophages. Major proteases in this disease are serine and matrix metalloproteases (MMPs). While the role of serine proteases, such as elastase, has been characterised in detail, there is emerging evidence that MMPs could play a key role in the pathogenesis of CF lung disease. This review summarises studies linking MMPs with CF lung disease and discusses the potential value of MMPs as future therapeutic targets in CF and other chronic lung diseases.

Evolution of the capsular gene locus of Streptococcus pneumoniae serogroup 6.

Streptococcus pneumoniae expressing serogroup 6 capsules frequently causes pneumococcal infections and the evolutionary origins of the serogroup 6 strains have been extensively studied. However, these studies were performed when serogroup 6 had only two known members (serotypes 6A and 6B) and before the two new members (serotypes 6C and 6D) expressing wciN(ß) were found. We have therefore reinvestigated the evolutionary origins of serogroup 6 by examining the profiles of the capsule gene loci and the multilocus sequence types (MLSTs) of many serogroup 6 isolates from several continents. We confirmed that there are two classes of cps locus sequences for serogroup 6 isolates. In our study, class 2 cps sequences were limited to a few serotype 6B isolates. Neighbour-joining analysis of cps sequence profiles showed a distinct clade for 6C and moderately distinct clades for class 1 6A and 6B sequences. The serotype 6D cps profile was found within the class 1 6B clade, suggesting that it was created by recombination between 6C and 6B cps loci. Interestingly, all 6C isolates also had a unique wzy allele with a 6 bp deletion. This suggests that serotype switching to 6C involves the transfer of a large (>4 kb) gene segment that includes both the wciN(ß) allele and the 'short' wzy allele. The MLST studies of serotype 6C isolates suggest that the 6C cps locus is incorporated into many different pneumococcal genomic backgrounds but that, interestingly, 6C cps may have preferentially entered strains of the same genomic backgrounds as those of serotype 6A.