Comparison of HIV-1 pol and env sequences of blood, CSF, brain and spleen isolates collected ante-mortem and post-mortem.

OBJECTIVES: HIV-1 infects the central nervous system (CNS) early in the course of infection. However, it is not known to what extent the virus evolves independently within the CNS and whether the HIV-RNA in cerebrospinal fluid (CSF) reflects the viral population replicating within the brain parenchyma or the systemic infection. The aim of this study was to investigate HIV-1 evolution in the CNS and the origin of HIV-1 in CSF. MATERIALS AND METHODS: Longitudinally derived paired blood and CSF samples and post-mortem samples from CSF, brain and spleen were collected over a period of up to 63 months from three HIV-1 infected men receiving antiretroviral treatment and presenting with symptoms of AIDS dementia complex (ADC). RESULTS: Phylogenetic analyses of HIV-1 V3, reverse transcriptase (RT) and protease sequences from patient isolates suggest compartmentalization with distinct viral strains in blood, CSF and brain. We found a different pattern of RT and accessory protease mutations in the systemic infection compared to the CNS. CONCLUSIONS: We conclude that HIV-1 may to some extent evolve independently in the CNS and the viral population in CSF mainly reflects the infection in the brain parenchyma in patients with ADC. This is of importance in understanding HIV pathogenesis and can have implications on treatment of HIV-1 patients.

A randomized, double-blind, placebo-controlled MRI study of anti-herpes virus therapy in MS.

OBJECTIVE: To evaluate the effect of treatment with the antiherpes drug valacyclovir on MRI-evident lesions in patients with relapsing-remitting MS in a phase 2, randomized, double-blind, placebo-controlled study. BACKGROUND: It has been postulated from virologic studies that herpesvirus infection could play a role in the progression of MS. METHODS: Patients were eligible for the study if they had had two or more MS relapses in the 2-year period before enrollment. Seventy patients with Expanded Disability Status Scale scores of 0 to 5.5 were randomly assigned to receive 1 gram of valacyclovir (n = 36) or placebo (n = 34) three times daily for 24 weeks. Patients underwent MRI every fourth week for 32 weeks: twice during pretreatment, six times during treatment, and once after treatment. Scoring of neurologic disability was performed at the start and end of the treatment period. The primary endpoint was the number of new active MRI-evident lesions over 24 weeks of treatment. Secondary endpoints included other MRI measures and clinical endpoints. RESULTS: The mean number of new active lesions +/- SD per patient during 24 weeks of treatment with valacyclovir was 11.9 +/- 17.6 and that during placebo treatment was 14.5 +/- 21.4. A protocol-planned exploratory analysis stratified patients according to baseline activity; this analysis showed that patients with high levels of disease activity in the valacyclovir treatment group (n = 17) developed fewer new active lesions per scan than did those in the placebo treatment group (n = 11). The median number (Q(1), Q(3) range) of active lesions was 2.0 (1.38, 3.96) in the valacyclovir treatment group and 6.5 (2.63, 9.0) in the placebo treatment group. CONCLUSIONS: Valacyclovir treatment did not reduce the formation of active lesions in patients with relapsing-remitting MS who had two or more relapses during the previous 2-year period. In a subgroup of patients with high levels of disease activity who had more than one active MRI-evident lesion during 4 weeks, valacyclovir treatment was associated with a reduced number of new active MRI-evident lesions and with an increase in the number of scans free of new active lesions. The results of the exploratory subgroup analysis provide support for further studies of antiherpes therapy for patients with MS and high levels of MRI-evident disease activity.

Increased blood-brain barrier permeability in neuro-asymptomatic HIV-1-infected individuals--correlation with cerebrospinal fluid HIV-1 RNA and neopterin levels.

The objective of this study was to assess the frequency of blood-brain barrier (BBB) impairment, as measured by the albumin ratio, in neuro-asymptomatic HIV-1-infected individuals without antiretroviral treatment and the correlation between BBB disruption and intrathecal immune activation and HIV-1 RNA levels. Serum and cerebrospinal fluid (CSF) albumin, neopterin, and HIV-1 RNA levels were analysed in 110 neuro-asymptomatic HIV-1-infected individuals at different stages of disease; 63 classified as CDC A, 25 as CDC B, and 22 as CDC C. Increased BBB permeability was found in 17 of 110 (15%) of HIV-1-infected individuals. This proportion was sustained throughout the CDC stages. The albumin ratio was correlated with the CSF neopterin levels (r(s) = 0.36, P < 0.001), the serum neopterin levels (r(s) = 0.37, P < 0.001), and the CSF HIV-1 RNA levels (r(s) = 0.26, P < 0.01), but not with the plasma HIV-1 RNA levels. The correlations between the albumin ratio and the CSF and serum neopterin concentrations and the CSF HIV-1 RNA levels indicate that immune activation and, possibly, intrathecal HIV-1 virus replication are important factors associated with increased BBB permeability in HIV-1 infection.

Interleukin-12 (IL-12) and IL-18 are important in innate defense against genital herpes simplex virus type 2 infection in mice but are not required for the development of acquired gamma interferon-mediated protective immunity.

Using a combination of gene-targeted mice and neutralizing antibodies, we showed that interleukin-12 (IL-12) and IL-18 are important in the innate control of genital herpes simplex virus type 2 infection but were not found to be critical, either singly or in combination, for the development of a protective gamma interferon-mediated immune response.

The nontoxic tripeptide glycyl-prolyl-glycine amide inhibits the replication of human immunodeficiency virus type 1.

OBJECTIVE: To determine whether short peptides corresponding to the RGPGR motif of the V3 loop of gp 120 have anti-human immunodeficiency virus type 1 (anti-HIV-1) activity. DESIGN/METHODS: Short peptides were tested against the HIV-1 laboratory strains and clinical isolates. RESULTS: The tripeptide glycyl-prolyl-glycine amide (GPG-NH2) inhibited the replication of both laboratory strains and 47 clinical isolates, including 19 strains that were resistant to other drugs or that were from patients with failing therapy. The 50% inhibitory concentrations values were 2.7 to 37 microM. Phenotypic change of two isolates from nonsyncytia-inducing to syncytia-inducing did not change their sensitivity to GPG-NH2. The tripeptide added to the antiviral effect of both zidovudine and ritonavir. CONCLUSIONS: The tripeptide GPG-NH2 is a nontoxic compound that inhibits the replication of HIV-1 by an apparently new mode of action. Glycyl-prolyl-glycine-NH2 might prove useful by itself or as a lead compound for the treatment of drug-resistant HIV-1. Glycyl-prolyl-glycine-NH2 is currently undergoing phase I/II human clinical trials in Sweden.

The tripeptide glycyl-prolyl-glycine amide does not affect the early steps of the human immunodeficiency virus type 1 replication.

OBJECTIVE: To determine whether the peptide glycyl-prolyl-glycine amide (GPG-NH2) corresponding to a conserved motif in the tip of the third hypervariable region of gp120 affected the early events in the human immunodeficiency virus type 1 (HIV-1) replication. DESIGN/METHODS: Glycyl-prolyl-glycine amide was tested for its effect on HIV-1 adsorption, co-receptor usage, proviral DNA synthesis, messenger RNA (mRNA) synthesis and splicing, translation, tat/TAR transactivation, and virus protease activity. RESULTS: Glycyl-prolyl-glycine amide did not appear to affect the early events of the virus replication. HIV-1 having glycine-leucine-glycine instead of GPG in the V3 loop and the mutants deleted of the GPG motif were still inhibited by the peptide. Glycyl-prolyl-glycine-NH2 had no discernible effect on any of the other steps in the virus replication cycle tested. The only effect observed was an increased sodium dodecyl sulfate polyacrylamide amide gel electrophoresis mobility of gp160/120 at high concentrations of GPG-NH2. CONCLUSIONS: The tripeptide GPG-NH2 is a nontoxic compound that inhibits the replication of HIV-1 by an apparently new mode of action.

Protective vaccination against genital herpes simplex virus type 2 (HSV-2) infection in mice is associated with a rapid induction of local IFN-gamma-dependent RANTES production following a vaginal viral challenge.

PROBLEM: To investigate the production of the CC chemokines RANTES. MCP-1, and MlP-1alpha in the vaginal mucosa following HSV-2 challenge in vaccinated and unvaccinated mice. METHOD OF STUDY: The concentrations of the chemokines were determined in the vagina of HSV-2-vaccinated as well as unvaccinated mice after HSV-2 challenge using a PERFEXT method combined with ELISA. RESULTS: HSV-2 infection did not induce any measurable levels of MIP-1alpha, whereas high levels of RANTES and MCP-1 were detected in unvaccinated animals at 48 hr post challenge. The vaccinated mice developed a more rapid induction of RANTES, but not of MCP-1, appearing as early as 24 hr post challenge. The local induction of RANTES production was preceded by a vaginal IFN-gamma response. Furthermore, vaccinated IFN-gamma-/- mice did not produce any enhanced levels of RANTES following HSV-2 challenge. CONCLUSIONS: The protective immune response against genital HSV-2 infection is associated with a rapid induction of local IFN-gamma-dependent RANTES production.

Conservation of type-specific B-cell epitopes of glycoprotein G in clinical herpes simplex virus type 2 isolates.

Glycoprotein G (gG-2) of herpes simplex virus type 2 (HSV-2) is cleaved to a secreted amino-terminal portion and to a cell-associated, heavily O-glycosylated carboxy-terminal portion that constitutes the mature gG-2 (mgG-2). The mgG-2 protein is commonly used as a type-specific antigen in the serodiagnosis of HSV-2 infection. As the amino acid sequence variability of mgG-2 in clinical isolates may affect the performance of such assays, the gG-2 gene was sequenced from 15 clinical HSV-2 isolates. Few mutations were identified, and these were mostly localized outside the epitope regions described earlier. Five isolates were identical to different laboratory strains, indicating that the gG-2 gene is highly conserved over time. In the search for HSV-2 isolates harboring mutations within the immunodominant region of mgG-2, a pool of 2,400 clinical HSV-2 isolates was tested for reactivity with two anti-mgG-2 monoclonal antibodies (MAbs). Ten MAb escape HSV-2 mutants, which all harbored structurally restricted single- or dual-point mutations within the respective epitopes explaining the loss of binding, were identified. Sera from corresponding patients were reactive to mgG-2, as well as to a peptide representing the immunodominant region, suggesting that the point mutations detected did not diminish seroreactivity to mgG-2. The conservation of the gG-2 gene reported here further supports the use of mgG-2 as a type-specific antigen in the diagnosis of HSV-2 infections.

Herpes simplex virus types 1 and 2 differ in their interaction with heparan sulfate.

Cell surface heparan sulfate (HS) serves as an initial receptor for many different viruses, including herpes simplex virus types 1 and 2 (HSV-1 and 2, respectively). Glycoproteins C and B (gC and gB) are the major components of the viral envelope that mediate binding to HS. In this study, purified gB and gC homologous proteins as well as purified HSV-1 and HSV-2 virions were compared for the ability to bind isolated HS receptor molecules. HSV-1 gC and HSV-2 gC bound comparable amounts of HS. Similarly, HSV-1 gB and its HSV-2 counterpart showed no difference in the HS-binding capabilities. Despite the similar HS-binding potentials of gB and gC homologs, HSV-1 virions bound more HS than HSV-2 particles. Purified gC and gB proteins differed with respect to sensitivity of their interaction with HS to increased concentrations of sodium chloride in the order gB-2 > gB-1 > gC-1 > gC-2. The corresponding pattern for binding of whole HSV virions to cells in the presence of increased ionic strength of the medium was HSV-2 gC-neg1 > HSV-1 gC(-)39 > HSV-1 KOS 321 > HSV-2 333. These results relate the HS-binding activities of individual glycoproteins with the cell-binding abilities of whole virus particles. In addition, these data suggest a greater contribution of electrostatic forces for binding of gB proteins and gC-negative mutants compared with binding of gC homologs and wild-type HSV strains. Binding of wild-type HSV-2 virions was the least sensitive to increased ionic strength of the medium, suggesting that the less extensive binding of HS molecules by HSV-2 than by HSV-1 can be compensated for by a relatively weak contribution of electrostatic forces to the binding. Furthermore, gB and gC homologs exhibited different patterns of sensitivity of binding to cells to inhibition with selectively N-, 2-O-, and 6-O-desulfated heparin compounds. The O-sulfate groups of heparin were found to be more important for interaction with gB-1 than gB-2. These results indicate that HSV-1 and HSV-2 differ in their interaction with HS.

Cerebrospinal fluid and plasma viral load in HIV-1-infected patients with various anti-retroviral treatment regimens.

Highly active anti-retroviral therapy (HAART) effectively decreases HIV-1 RNA in cerebrospinal fluid (CSF) and plasma in controlled clinical trials. To study the virological effect in CSF and plasma achieved in routine practice, HIV-1 RNA levels were analysed retrospectively in 27 patients on mono-nucleoside reversed transcriptase inhibitor (NRTI) treatment, 27 on dual-NRTI-treatment and 45 on HAART using a Roche Amplicor HIV-1 monitor quantitative PCR. A significant difference was found in the proportion of patients with a CSF viral load below 20 copies/ml between patients treated with 1 (0%) and 2 NRTIs (41%) as well as between those treated with 2 NRTIs and HAART (69%). The proportion of patients with plasma viral load below 20 copies/ml differed significantly between patients on HAART (47%) and those on 2 NRTIs (0%), but not between those with 1 (0%) or 2 NRTIs. In multivariate regression analysis, treatment regimen and prior anti-retroviral experience (but not treatment time) were independently associated with the CSF viral load. Plasma viral load was independently associated with treatment regimen and treatment time, but not with anti-retroviral experience. Dual-NRTI-treatment affects the CSF viral load substantially, while HAART is required to achieve an essential decline in plasma viral load.

Higher HIV-1 RNA cutoff level required in cerebrospinal fluid than in blood to predict positive HIV-1 isolation.

HIV-1 can be isolated from the vast majority of blood samples taken from HIV-1-seropositive patients not treated with antiretroviral drugs. Isolation rates from cerebrospinal fluid (CSF) samples are considerably lower, ranging between 20-70%. The objective of this study was to determine the cutoff levels for HIV-1 RNA that would yield a positive predictive value > or =90% for positive virus isolation from CSF and blood. Quantitative HIV-1 RNA PCR (Amplicor HIV monitor, version 1.0, Roche Diagnostic Systems) and virus isolation were used to examine 303 CSF samples and 278 paired blood samples from 157 HIV-1-seropositive patients. Patients on antiretroviral treatment provided 140 of the CSF samples and 131 of the blood samples. CSF samples that were positive by culture numbered 137 of 303 (45%), as compared with 216 of 278 (78%) blood samples. In the case of samples taken from patients with antiretroviral treatment, 28% were positive by culture from CSF and 63% from blood. As expected, mean HIV-1 RNA levels were higher in CSF and blood samples positive by culture than in samples negative by culture. A cutoff level of >5,000 HIV-1 RNA copies/ml was required to yield a positive predictive value for positive virus isolation from CSF samples of > or =90%, whereas the cutoff level for blood samples was just above the detection limit of the assay (>200 HIV-1 copies/ml).

Increased cerebrospinal fluid protein tau concentration in neuro-AIDS.

OBJECTIVES: Assessment of cerebrospinal fluid (CSF) levels of protein tau in human immunodeficiency virus type 1 (HIV-1) infection. MATERIAL AND METHODS: CSF tau levels were analyzed in 52 HIV-1-infected patients, 37 of whom had no neurological symptoms, eight had aquired immunodeficiency syndrome (AIDS) dementia complex (ADC), and seven had AIDS with other neurological complications. RESULTS: A significantly higher mean CSF tau concentration was found in patients with ADC (380 pg/ml) compared with patients with neuroasymptomatic HIV-1 infection (120 pg/ml, P<0.01) and HIV-negative controls (150 pg/ml, P<0.05). No difference in CSF tau levels was found between patients with ADC and patients with AIDS with other neurological complications. CONCLUSION: CSF tau might be used as a biochemical marker for axonal degeneration and might be of use to identify HIV-1-infected patients with ADC and other neurological complications, but it cannot discriminate between ADC and other neurological complications in HIV-1-infection.

Herpes simplex virus type 2 glycoprotein G-negative clinical isolates are generated by single frameshift mutations.

Herpes simplex virus (HSV) codes for several envelope glycoproteins, including glycoprotein G-2 (gG-2) of HSV type 2 (HSV-2), which are dispensable for replication in cell culture. However, clinical isolates which are deficient in such proteins occur rarely. We describe here five clinical HSV-2 isolates which were found to be unreactive to a panel of anti-gG-2 monoclonal antibodies and therefore considered phenotypically gG-2 negative. These isolates were further examined for expression of the secreted amino-terminal and cell-associated carboxy-terminal portions of gG-2 by immunoblotting and radioimmunoprecipitation. The gG-2 gene was completely inactivated in four isolates, with no expression of the two protein products. For one isolate a normally produced secreted portion and a truncated carboxy-terminal portion of gG-2 were detected in virus-infected cell medium. Sequencing of the complete gG-2 gene identified a single insertion or deletion of guanine or cytosine nucleotides in all five strains, resulting in a premature termination codon. The frameshift mutations were localized within runs of five or more guanine or cytosine nucleotides and were dispersed throughout the gene. For the isolate for which a partially inactivated gG-2 gene was detected, the frameshift mutation was localized upstream of but adjacent to the nucleotides coding for the transmembranous region. Thus, this study demonstrates the existence of clinical HSV-2 isolates which do not express an envelope glycoprotein and identifies the underlying molecular mechanism to be a single frameshift mutation.

Cerebrospinal fluid viral load, intrathecal immunoactivation, and cerebrospinal fluid monocytic cell count in HIV-1 infection.

To assess the association between cerebrospinal fluid (CSF) viral load, intrathecal immunoactivation, and immunosuppression in HIV-1-infected individuals with no antiretroviral treatment experience a cross-sectional study of stored frozen CSF and plasma samples were conducted. The study population included a total of 120 antiretroviral-naive HIV-1-infected patients, 110 neuroasymptomatic patients, and 10 with neurologic complications. HIV-1 RNA was quantified in cell-free CSF and plasma using polymerase chain reaction (PCR; Roche Amplicor HIV-1 Monitor version 1.5, Roche Diagnostic Systems, Hoffmann-La Roche, Inc., Base, Switzerland). Immunoactivation was measured by CSF-serum IgG index, CSF neopterin concentrations, and CSF monocytic cell count. The CSF HIV-1 RNA load did not differ significantly between patients with or without neurologic complications. In patients without neurologic symptoms, the CSF monocytic cell counts were correlated to the CSF viral load (r(s) = 0.40, p < .001), whereas IgG index and CSF neopterin concentrations were correlated to the viral load only in the subgroup of patients with CD4 counts > or =200 x 10(6) cells/L. In this subgroup of patients, the peripheral CD4 cell count was, as expected, inversely correlated to the CSF viral load (r. = -0.36, p < .01), whereas in patients with CD4 counts <200 x 10(6) cells/L, an unexpected, significant positive correlation (r(s) = 0.43, p < .01 ) was found. In HIV-1-infected patients with neurologic complications, no significant correlations were found between immune activation, CSF viral load, and immunosuppression.

The N-linked glycan of the V3 region of HIV-1 gp120 and CXCR4-dependent multiplication of a human immunodeficiency virus type 1 lymphocyte-tropic variant.

We have previously shown that an N-glycosylation site of N306 of HIV-1 gp120 is not necessary for the HIV-1 infectivity but protects HIV-1 from neutralising antibodies. In contrast Nakayama et al. [FEBS Lett. (1998) 426, 367-372], using a virus with an identical V3 region, suggested that elimination of this particular glycan reduced the ability of T-tropic HIV to bind to CXCR4 and hence its ability to infect T cell lines. We therefore re-examined the ability of a mutant virus, lacking the N306 glycan, to replicate in various types of cells and found no change in co-receptor usage for mutant virus. The ability of mutant virus to replicate or to induce syncytia in infected cells was similar to that of wild type virus. These results corroborate our original observation, confirming that the induced mutation in the N306 glycosylation site neither impairs nor improves the ability of mutant virus to replicate in permissive cells.

Typing of clinical herpes simplex virus type 1 and type 2 isolates with monoclonal antibodies.

The purpose of this study was to evaluate the performance of a herpes simplex virus (HSV) type 1-specific anti-glycoprotein C-1 monoclonal antibody (MAb) and a type 2-specific anti-glycoprotein G-2 MAb for typing of 2,400 clinical HSV-1 isolates and 2,400 clinical HSV-2 isolates, respectively, using an enzyme immunoassay. The anti-HSV-1 MAb showed sensitivity and specificity of 100%, and the anti-HSV-2 MAb showed a sensitivity of 99.46% and 100% specificity, indicating that these MAbs are suitable for typing of clinical HSV isolates.

Kinetics of HIV-1 in cerebrospinal fluid and serum after zidovudine treatment.

Two patients with HIV-1 infection associated with neurological complications were repeatedly followed with cerebrospinal fluid (CSF) and serum analyses before, and 1 to 2.5 years after single zidovudine treatment. Retrospectively, HIV-RNA levels were analyzed with quantitative PCR assay. The number of HIV-RNA copies in CSF was decreased already 1 week after initiation of zidovudine, and continued to decrease during 5 months of follow up, while the serum levels increased during the same period. The difference between HIV levels in CSF and serum compartments following zidovudine treatment indicates that the CSF viral load does not merely reflect blood levels. Single zidovudine treatment did not reduce the viral load in CSF to non-detectable levels but had a better and more long-lasting anti-HIV effect in CSF than in peripheral blood.

Localization of type-specific epitopes of herpes simplex virus type 2 glycoprotein G recognized by human and mouse antibodies.

Glycoprotein G is a major target for the humoral immune response against herpes simplex virus (HSV) and a prototype antigen for type-specific serodiagnosis discriminating HSV-1 and HSV-2 infections. The mature part of HSV-2 glycoprotein G-2 (gG-2) contains a unique stretch suspected to mediate type specificity, and in addition a region homologous to HSV-1 glycoprotein G-1 (gG-1). Antigenic determinants of the mature gG-2 were mapped by testing the reactivity of mouse anti-gG-2 monoclonal antibodies (MAbs) and purified human anti-gG-2 antibodies with synthetic peptides coupled to cellulose membranes. The anti-gG-2 MAbs bound to four epitopes localized in a narrow cluster within a gG-2 segment delimited by amino acids (aa) 552 and 611. This cluster was located between the predicted O-glycan-rich region and the transmembrane anchor sequence. The epitopes of the human anti-gG-2 antibodies were localized within three stretches of amino acids, two of which were overlapping with those recognized by anti-gG-2 MAbs. One of these stretches, delimited by aa 552 and 574, showed reactivity to all human HSV-2 sera tested, but not to HSV-1 sera or to purified anti-gG-1 antibodies. Neither the anti-gG-2 MAbs nor the purified human anti-gG-2 antibodies were cross-reactive to gG-1 peptides or HSV-1 antigen, although most of the epitopes were localized within the part of gG-2 which was homologous to gG-1. The findings concerning HSV-2 type-specific human antibody response to a defined stretch within gG-2 may be of importance for the further development of type-discriminating serodiagnosis.

Cerebrospinal fluid viral load in HIV-1-infected patients without antiretroviral treatment: a longitudinal study.

HIV-1 RNA and neopterin levels were observed longitudinally for 20 to 68 months (mean, 37.5 months) in cerebrospinal fluid (CSF) and serum in 15 HIV-1-infected patients not receiving antiretroviral treatment. During the course of infection the HIV-1 RNA levels increased significantly in CSF, from a mean of 3.08 to 3.51 log10 copies RNA/ml (p < .01). A significant positive correlation was found between the CSF levels of HIV-I RNA and neopterin (rs = 0.54; p < .001), which increased from 13.6 to 19.6 nmol/L (p < .01). No significant changes in HIV-1 RNA or neopterin levels were found in serum. We suggest that the increase of CSF viral load with time in HIV-1 infection triggers an intrathecal immune activation reflected by increased CSF levels of neopterin. These results are in accordance with the theory that a chronic immune stimulation within the central nervous system (CNS) is involved in the pathogenesis of neurologic HIV-1 disease.