The effect of gramicidin, a topical contraceptive and antimicrobial agent with anti-HIV activity, against herpes simplex viruses type 1 and 2 in vitro.

PIP: Symptomatic human herpes simplex virus type 1 (HSV-1) infections are rather benign in immunocompetent individuals. The primary clinical manifestations of HSV-2 infection, which is mainly transmitted sexually, are anogenital lesions. Genital herpes simplex affects one third of the world's population, and possibly 80% of those infected with HIV. HSV infections are especially severe and even life-threatening in people with AIDS. Only 20% of herpes simplex seropositive persons have symptomatic infection, with the remainder asymptomatic but able to shed the virus. HSV infections are usually treated with nucleoside analogs such as Acyclovir (ACV), but HSV eventually becomes resistant to ACV due to the loss or mutation of the viral thymidine kinase (TK) or changes in viral DNA polymerase. Gramicidin has recently been identified as a potent nontoxic anti-HIV agent 3-5 times more active than nonoxynol-9. Findings are reported from an assessment of the effect of gramicidin upon the replication of HSV-1 and HSV-2. Human WI-38 fibroblasts were inoculated with either HSV type in the presence of serial dilutions of gramicidin, while reduction in viral yield was measured by ELISA. The 50% inhibitory dose (IC50) of gramicidin against 3 HSV-1 and 4 HSV-2 isolates was equal to 0.3 mcg/ml and was comparable to the efficacy of ACV. The IC50 of gramicidin required to protect WI-38 from the cytolytic effect of HSV was 10 mcg/ml at day 5 postinfection, indicating that gramicidin was less active than ACV. Gramicidin nonetheless suppressed the replication of ACV-resistant thymidine kinase and DNA polymerase HSV mutants at doses effective against ACV-sensitive strains. These results suggest that gramicidin could be used against STDs and to prevent sexually transmitted HIV and HSV infections.

Nectin2alpha (PRR2alpha or HveB) and nectin2delta are low-efficiency mediators for entry of herpes simplex virus mutants carrying the Leu25Pro substitution in glycoprotein D.

The receptors for entry of herpes simplex viruses 1 and 2 (HSV-1 and -2), widely expressed in human cell lines, are members of a subset of the immunoglobulin superfamily exemplified by herpes simplex virus entry mediator C (HveC) and the herpes simplex virus immunoglobulin-like receptor (HIgR). This report focuses on two members of this subset, herpes simplex virus entry mediator B (HveB), recently designated nectin2/PRR2alpha, and its splice variant isoform, nectin2/PRR2delta. Nectin2alpha and -delta share the ectodomain but differ in the transmembrane and cytoplasmic regions. HveB was reported to enable entry of HSV-1 carrying mutations in glycoprotein D (gD) and of HSV-2, but not of wild-type (wt) HSV-1. We report that (i) both nectin2alpha and -delta served as receptors for the entry of HSV-1 mutant viruses HSV-1(U10) and -(U21) and AP7(r) that carry the Leu25Pro substitution in gD but not for HSV-1 mutants U30 and R5000 that carry the Ser140 or Ala185 substitution in gD. All of these mutants were able to overcome the block to entry mediated by expression of wt gD. (ii) Infection of cells expressing nectin2alpha or -delta required exposure to multiplicities of infection about 100-fold higher than those required to infect cells expressing HveC or HIgR. (iii) gD from HSV-1(U21) bound in vitro soluble forms of nectin2. The association was weaker than that to the soluble form of HveC/HIgR. Binding of wt HSV-1 gD to soluble nectin2 was not detectable. (iv) A major region of nectin2 functional in virus entry mapped to the V domain, located at the N terminus.

Experimental transmission of a herpes simplex virus in Greek tortoises (Testudo graeca).

An experimental transmission study aimed at fulfilling Koch's postulates for a herpes simplex virus-associated stomatitis-rhinitis in Mediterranean tortoises is presented. Clinical, pathologic, serologic, and molecular studies were performed linking tortoise herpes simplex virus with the pathogenesis of stomatitis-rhinitis. Four adult Greek tortoises received either intranasally or intramuscularly two tortoise herpes simplex virus isolates by primary experimental infection and secondary challenge 11 months later. After the primary experimental infection and the secondary challenge, clinical signs of illness developed, which included conjunctivitis, diphtheritic oral plaques, and oral discharge. At 4 weeks after the secondary challenge, all tortoises were humanely euthanatized and evaluated. Although neutralizing antibodies developed after the primary experimental infection, they apparently did not prevent the later development of recurrent clinical signs. Polymerase chain reaction (PCR) and reverse transcription-PCR analyses allowed sensitive characterization of the systemic distribution of the herpes simplex virus DNA sequences and their presence in the cranial nerves and brains of the infected tortoises. Despite the failure to recover the herpes simplex viruses used in the transmission study, the findings support the premise that tortoise herpes-virus is a primary pathogen of Greek tortoises.

Herpes Simplex encephalitis treated with Acyclovir: diagnosis and long term outcome.

OBJECTIVES: The frequency and characteristics of the long term sequelae of herpes simplex encephalitis were assessed after treatment with Acyclovir. METHODS: Patients were included if they were treated with Acyclovir and the diagnosis of herpes simplex encephalitis was confirmed by culture of herpes simplex virus (HSV) from the brain, an increase in the CSF HSV antibody titre, or detection of HSV deoxyribonucleic acid in the CSF. Each patient's medical records were reviewed and surviving patients were interviewed and examined. RESULTS: A diagnosis of herpes simplex encephalitis was confirmed in 42 patients. Five patients (12%) died in the first month. Three patients (7%) had severe neurological sequelae and died after a longer interval. All but one of the 34 surviving patients had neurological symptoms, an abnormal neurological examination, or both. Twenty patients (48%) performed everyday activities as well as before herpes simplex encephalitis; nine patients (21%) were living independently, but were functioning at a lower level than before the illness; and five patients (12%) had a severe neurological deficit. Twenty nine of the 34 survivors were assessed six months to 11 years after herpes simplex encephalitis. The most common long term symptoms were memory impairment (69%), personality and behavioural abnormalities (45%), and epilepsy (24%). Short term memory impairment (70%), anosmia (65%), and dysphasia (41%) were the most common signs. CONCLUSIONS: Although Acyclovir has reduced the mortality of herpes simplex encephalitis, 30% of this group of patients either died or had a severe neurological deficit. The other 70% of the patients regained independence in activities of daily living, but most of these people had persistent neurological symptoms, signs, or both.