Participation of 3‐O‐sulfated heparan sulfates in the protection of macrophages by herpes simplex virus‐1 glycoprotein D and cyclophilin B against apoptosis

Abstract

Heparan sulfates (HS) are involved in numerous biological processes, which rely on their ability to interact with a large panel of proteins. Although the reaction of 3‐O‐sulfation can be catalysed by the largest family of HS sulfotransferases, very few mechanisms have been associated with this modification and to date, only glycoprotein D (gD) of herpes simplex virus‐1 (HSV‐1 gD) and cyclophilin B (CyPB) have been well‐described as ligands for 3‐ O ‐sulfated HS. Here, we hypothesized that both ligands could induce the same responses via a mechanism dependent on 3‐ O ‐sulfated HS. First, we checked that HSV‐1 gD was as efficient as CyPB to induce the activation of the same signalling events in primary macrophages. We then demonstrated that both ligands efficiently reduced staurosporin‐induced apoptosis and modulated the expression of apoptotic genes. In addition to 3‐ O ‐sulfated HS, HSV‐1 gD was reported to interact with other receptors, including herpes virus entry mediator (HVEM), nectin‐1 and ‐2. Thus, we decided to identify the contribution of each binding site in the responses triggered by HSV‐1 gD and CyPB. We found that knock‐down of 3‐ O ‐sulfotransferase 2, which is the main 3‐ O ‐sulfated HS‐generating enzyme in macrophages, strongly reduced the responses induced by both ligands. Moreover, silencing the expression of HVEM rendered macrophages unresponsive to either HSV‐1 gD and CyPB, thus indicating that both proteins induced the same responses by interacting with a complex formed by 3‐ O ‐sulfated HS and HVEM. Collectively, our results suggest that HSV‐1 might hijack the binding sites for CyPB in order to protect macrophages against apoptosis for efficient infection.

The heparan sulfate 3-O-sulfotransferases (HS3ST) 2, 3B and 4 enhance proliferation and survival in breast cancer MDA-MB-231 cells

“…Among them, cyclophilin B (CypB) was described to interact with 3- O -sulfated HS at the surface of T lymphocytes and monocytes/macrophages [ 23 , 31 ]. We recently demonstrated that it is capable of protecting macrophages against apoptosis, via a mechanism dependent on the expression of HS3ST2 [ 26 ]. HS3ST2-modified HS were also reported to enhance the binding of neuropilin-1 and to regulate its activity in neurons and endothelial cells [ 13 ].…”

“…All of them amplified only one fragment of expected size, for which the sequence was confirmed (GATC Biotech, Constance, Germany). Real-time PCR amplifications were performed using an Mx3000P Multiplex Quantitative PCR system (Agilent Technologies, Santa Clara, CA, USA), as described in [ 26 ]. The transcript of HPRT was used as a control to normalize the expression of our genes of interest.…”

“…Cell apoptosis was evaluated by measuring phosphatidylserine externalization and caspase-3 activation, essentially as described in [ 26 ]. Briefly, apoptosis was induced in transfected MDA-MB-231 cells (2×10 5 cells per point) by the addition of 100 ng/mL of anti-Fas antibody (Merck Millipore) plus 100 ng/mL TNF-α (PeproTech) for 24 h at 37°C, or by the addition of 1 μM staurosporin (Merck Millipore) for 4 h at 37°C.…”

The Pro-Tumoral Activity of Heparan Sulfate 3-O-Sulfotransferase 3B (HS3ST3B) in Breast Cancer MDA-MB-231 Cells Is Dependent on the Expression of Neuropilin-1

“…They amplified only one fragment of expected size, for which the sequence was confirmed (GATC Biotech, Constance, Germany). Real-time PCR amplifications were performed using an Mx3000P Multiplex Quantitative PCR system (Agilent Technologies, Santa Clara, CA, USA), as described in [ 49 ]. The transcript of HPRT was used as a control to normalize the expression of our genes of interest.…”

High resolution MALDI-TOF-MS and MS/MS: Application for the structural characterization of sulfated oligosaccharides

“…17 3- O -sulfation, the rarest modification of HS molecules, has been reported to play a critical role in cancer, 18 neurodegenerative disorders, 19 immune responses, 20 and viral infection. 21 Hence, a 3- O -sulfated heparin octasaccharide has been successfully used against HSV-1 infection, with a higher affinity than one lacking the 3- O -sulfate. 22 Moreover, infection can be blocked by saturating the HSV envelope glycoprotein gD using the active octasaccharide.…”