Signaling pathway used by HSV-1 to induce NF-kappaB activation: possible role of herpes virus entry receptor A.

We have previously demonstrated that wild-type herpes simplex virus type 1 (HSV-1), as well as nonreplicating UV-inactivated HSV-1, promptly activates the nuclear factor-kappaB (NF-kappaB) in U937 monocytoid cells and that glycoprotein D (gD) of HSV-1 is sufficient by itself to exert a similar effect. We then investigated the signaling pathway used by HSV-1 to initiate NF-kappaB activation and, particularly, whether our observation could be related to the capability of HSV-1-gD to directly stimulate NF-kappaB through its interaction with the herpes virus entry receptor A (HveA). Here we report that: (a) co-cultivation of U937 cells with an adherent cell line expressing wild-type gD on its surface led to increased NF-kappaB activation, while co-cultivation with the same adherent cell line expressing a mutated form of gD, lacking the capability to bind HveA, did not cause the same effect; (b) exposure to UV-inactivated HSV-1 induced the activation of NF-kappaB in HveA-expressing U937 and THP-1 cells, but not in non-HveA-expressing HEp-2 cells; and (c) activation of NF-kappaB in U937 and THP-1 cells exposed to soluble gD was inhibited by an antibody able to interfere with gD-HveA interaction.

Synthesis of phosphonated carbocyclic 2'-oxa-3'-aza-nucleosides: novel inhibitors of reverse transcriptase.

Phosphonated carbocyclic 2'-oxa-3'-aza-nucleosides have been synthesized in good yields by 1,3-dipolar cycloaddition methodology. The cytotoxicity and the reverse transcriptase inhibitory activity of the obtained compounds have been investigated. Phosphonated carbocyclic 2'-oxa-3'-aza-nucleosides, while showing low levels of cytotoxicity, exert a specific inhibitor activity on two different reverse transcriptases, which is comparable with that of AZT, opening new perspectives on their possible use as therapeutic agents, in anti-retroviral and anti-HBV chemotherapy.

Protection by herpes simplex virus glycoprotein D against Fas-mediated apoptosis: role of nuclear factor kappaB.

Signals involved in protection against apoptosis by herpes simplex virus 1 (HSV-1) were investigated. Using U937 monocytoid cells as an experimental model, we have demonstrated that HSV-1 rendered these cells resistant to Fas-induced apoptosis promptly after infection. UV-inactivated virus as well as the envelope glycoprotein D (gD) of HSV-1, by itself, exerted a protective effect on Fas-induced apoptosis.