Airoldi, M. | Search bioRxiv

bioRxiv2024

Effect of molecular weight of tyramine-modified hyaluronan on polarization state of peripheral blood mononuclear cells-derived macrophages

The immunomodulatory properties of hyaluronan and its derivatives are key to their use in medicine and tissue engineering. In this work we evaluated the capability of soluble tyramine-modified hyaluronan (THA) of two molecular weights (low Mw=280 kDa and high Mw=1640 kDa) for polarization of THP-1 and peripheral blood mononuclear cells (PBMCs)-derived macrophages (M{Phi}s). We demonstrate the polarization effects of the supplemented THA by flow cytometry and multiplex ELISA for the THP-1 derived M{Phi}s and by semi-automated image analysis from confocal microscopy, immunofluorescent staining utilising CD68 and CD206 surface markers, RT-qPCR gene expression analysis, as well as using the enzyme-linked immunosorbent assay (ELISA) for PBMCs-derived M{Phi}s. Our data indicate that supplementation with LMW THA drives changes in THP-1 derived M{Phi}s towards a pro-inflammatory M1-like phenotype, whereas supplementation with the HMW THA leads to a more mixed profile with some features of both M1 and M2 phenotypes, suggesting either a heterogeneous population or a transitional state. For cells directly sourced from human patients, PMBCs-derived M{Phi}s, results exhibit a higher degree of variability, pointing out a differential regulation of factors including IL-10 and CD206 between the two cell sources. While human primary cells add to the clinical relevance, donor diversity introduces wider variability in the dataset, preventing drawing strong conclusions. Nevertheless, the M{Phi}s profiles observed in THP-1 derived cells for treatments with LMW and HMW THA are generally consistent with what might be expected for the treatment with non-modified hyaluronans of respective molecular weights, confirming the known association holds true for the chemically tyramine-modified hyaluronan. We stipulate that these responses will provide basis for more accurate in vivo representation and translational immunomodulatory guidance for the use of THA-based biomaterials to a wider biomaterials and tissue engineering communities. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=114 SRC="FIGDIR/small/575241v3_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@899d95org.highwire.dtl.DTLVardef@c8b80aorg.highwire.dtl.DTLVardef@1aad98dorg.highwire.dtl.DTLVardef@1b0ce60_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2023

The antiphage defense system CBASS controls resistance and enables killing by antifolate antibiotics in Vibrio cholerae

Toxic bacterial modules, in particular toxin-antitoxin (TA) systems, have been long sought-after for their antimicrobial potential, although with limited success1-6. Here we show that the cyclic-oligonucleotide-based antiphage signaling system (CBASS), another example of a toxic module, increases sensitivity to well-established antifolate antibiotics, interferes with their synergy, and ultimately enables bacterial lysis by antifolates - classic bacteriostatic antibiotics, in Vibrio cholerae. We propose a molecular mechanism for the CBASS-antifolate interaction based on onset of cyclic-oligonucleotide production by the nucleotidyltransferase DncV upon folate depletion by antifolates. CBASS-antifolate interaction is specific to CBASS systems with closely related nucleotidyltransferases and similar folate binding. Altogether, our findings illustrate that toxic modules, such as the antiphage defense CBASS system, can dramatically impact antibiotic activity, and open the possibility that endogenous metabolites could also act as triggers/silencers of toxic modules under stress beyond antibiotic treatment, such as during phage infection, biofilm formation or disease environments.

microbiology↗