An unusual case of posttrabeculectomy conjunctival granuloma.

We report an unusual case of granulomatous inflammation that presented adjacent to bleb 3 weeks postoperatively after combined phacoemulsification and trabeculectomy surgery with mitomycin-C due to retained microfragments of methyl cellulose sponge. The commonly used antimetabolite delivery devices are made of cellulose. Methyl cellulose sponges are friable, and they are likely to leave behind microfragments in subconjunctival space. In our case, bleb integrity was maintained, unlike the earlier reported cases which presented with bleb leak. Hence, one should have high index of suspicion in unusual cases of postoperative inflammation not resolving conservatively. Although rare, retained sponge particles can be a cause of early bleb-related inflammation which can lead to bleb failure.

Role of Filopodia in HSV-1 Entry into Zebrafish 3-O-Sulfotransferase-3-Expressing Cells.

BACKGROUND: Heparan sulfate proteoglycans (HSPGs) modified by zebrafish (ZF) encoded glucosaminyl 3-O sulfotransferase-3 (3-OST-3) generate a receptor for herpes simplex virus type-1 (HSV-1) entry and spread. In order to elucidate the mechanism by which HSV-1 enters into ZF-3-OST-3 cells, we investigated the mode of viral entry. RESULTS: Under high resolution scanning electron microscopy (SEM), actin cytoskeleton changes were observed by a dramatic increase in the number of filopodia formed during early interactions of HSV-1 with the target cells. While the increase in number was common among all the infected cells, the highest numbers of filopodia was observed in cells expressing the 3-OST-3 modified form of heparan sulfate (HS) encoded either by human or ZF. The levels of viral infection and filopodia induction were reduced with the actin polymerization inhibitors, Cytochalasin-D and Lantriculin B, suggesting an important role for actin reorganization during ZF-3-OST-3 mediated HSV-1 entry. Supporting an interesting possibility of filopodia usage during HSV-1 spread, pre-treatment of cytochalasin D in ZF-3-OST-3 cells drastically reduced virus glycoprotein induced cell fusion. CONCLUSIONS: Taken together, our results provide new evidence on the involvement of filopodia during HSV-1 infection of ZF-3-OST-3 cells and confirm a role for modified heparan sulfate in cytoskeleton rearrangement during HSV-1 entry.

Contortrostatin, a homodimeric disintegrin isolated from snake venom inhibits herpes simplex virus entry and cell fusion.

BACKGROUND: Herpes simplex virus (HSV) causes significant health problems from periodical skin and corneal lesions to encephalitis. HSV entry provides a unique opportunity for therapeutic intervention. In this study, we evaluated contortrostatin (CN), an Arg-Gly-Asp motif containing disintegrin isolated from snake venom, as a novel therapeutic agent with ability to block HSV entry and related membrane fusion. METHODS: In vitro efficacy of CN against HSV was determined using an HSV type-1 (HSV-1) entry assay based on the measurement of ß-galactosidase reporter activity originating from the genome of a recombinant strain of HSV-1(KOS) gL86. HSV-1 glycoprotein-mediated cell-to-cell fusion was used to study the effect of CN on polykaryocyte formation. Primary as well as transformed cell lines were used for this study. RESULTS: Pre-treatment of Chinese hamster ovary (CHO-K1) cells expressing HSV-1 glycoprotein D receptors and primary cultures of human corneal fibroblasts (CF) with CN resulted in the inhibition of entry, cell-to-cell fusion, and polykaryocyte formation. Interestingly, a more pronounced anti-HSV-1 effect was observed in naturally susceptible CF than CHO-K1 cells. CONCLUSIONS: CN, a novel venom-derived peptide, exhibits the ability to block two key steps, entry and cell-to-cell fusion, in HSV infection. Showing strong promise for development as an anti-HSV agent, it also demonstrates better prophylactic efficacy in primary cells.

Herpes simplex virus type-1 (HSV-1) entry into human mesenchymal stem cells is heavily dependent on heparan sulfate.

Hematopoietic stem cells recipients remain susceptible to opportunistic viral infections including herpes simplex virus type-1 (HSV-1). The purpose of this investigation was to analyze susceptibility of human mesenchymal stem cells (hMSCs) to HSV-1 infection and identify the major entry receptor. Productive virus infection in hMSCs was confirmed by replication and plaque formation assays using a syncytial HSV-1 KOS (804) virus. To examine the significance of entry receptors, RT-PCR and antibody-blocking assays were performed. RT-PCR data showed the expression of gD receptors: nectin-1, 3-O sulfotransferase-3 (3-OST-3), and HVEM. Antibody-blocking assay together with heparinase treatment suggested an important role for HS and 3-O-sulfated heparan sulfate (3-OS HS), but not nectin-1 or HVEM, in mediating HSV-1 entry and spread in hMSCs. Taken together, our results provide strong evidence demonstrating that HSV-1 is capable of infecting hMSCs and HS and 3-OS HS serve as its entry receptors during this process.