Safety and immunogenicity of a glycoprotein D genital herpes vaccine in healthy girls 10-17 years of age: results from a randomised, controlled, double-blind trial.

OBJECTIVE: The investigational AS04-adjuvanted herpes simplex virus type 2 (HSV-2) glycoprotein D (gD2) subunit prophylactic vaccine ('HSV vaccine'; GlaxoSmithKline Vaccines) has been shown to be well tolerated in adults, but limited data exist for pre-teen and adolescent girls, a likely target population. The primary objective of this study was to compare the occurrence of serious adverse events (SAEs) over 12 months between HSV vaccine recipients and saline recipients (placebo control group) in pre-teen and adolescent girls. The immunogenicity of the HSV vaccine was also assessed. METHODS: Healthy girls aged 10-17 years, stratified by age (10-15 years; 16-17 years), were randomised 2:1:1 to receive the HSV vaccine, a hepatitis A vaccine (Havrix™; HAV control) or placebo (saline) according to a 0-, 1-, 6-month schedule. Participants and study personnel not involved in the preparation or administration of vaccines were blinded to treatment. Safety and immunogenicity analyses were performed overall and by age (10-15 years; 16-17 years) and HSV serostatus. RESULTS: No statistically significant difference in the percentage of subjects with SAEs was observed between the HSV and saline group, or between the HSV and pooled control (HAV and saline) groups. The HSV vaccine was well tolerated, although a higher incidence of solicited local symptoms was observed in the HSV group than in the control group. Neither age nor HSV serostatus at the time of study entry had an impact on the safety profile of this vaccine. The HSV vaccine was immunogenic regardless of pre-vaccination HSV serostatus. Higher anti-gD geometric mean concentrations were observed in HSV-1 seropositive participants than in HSV-1 seronegative participants. CONCLUSION: The HSV vaccine had an acceptable safety profile, and was well tolerated and immunogenic when administered to girls aged 10-17 years regardless of age or HSV pre-vaccination serostatus.

Efficacy of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in women aged 15-25 years with and without serological evidence of previous exposure to HPV-16/18.

In the Phase III PATRICIA study (NCT00122681), the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine (Cervarix(®), GlaxoSmithKline Biologicals) was highly efficacious against HPV-16/18 infections and precancerous lesions in women HPV-16/18 deoxyribose nucleic acid (DNA) negative and seronegative at baseline. We present further data on vaccine efficacy (VE) against HPV-16/18 in the total vaccinated cohort including women who may have been exposed to HPV-16/18 infection before vaccination. In women with no evidence of current or previous HPV-16/18 infection (DNA negative and seronegative), VE was 90.3% (96.1% confidence interval: 87.3-92.6) against 6-month persistent infection (PI), 91.9% (84.6-96.2) against cervical intraepithelial neoplasia (CIN)1+ and 94.6% (86.3-98.4) against CIN2+ [97.7% (91.1-99.8) when using the HPV type assignment algorithm (TAA)]. In women HPV-16/18 DNA negative but with serological evidence of previous HPV-16/18 infection (seropositive), VE was 72.3% (53.0-84.5) against 6-month PI, 67.2% (10.9-89.9) against CIN1+, and 68.8% (-28.3-95.0) against CIN2+ [88.5% (10.8-99.8) when using TAA]. In women with no evidence of current HPV-16/18 infection (DNA negative), regardless of their baseline HPV-16/18 serological status, VE was 88.7% (85.7-91.1) against 6-month PI, 89.1% (81.6-94.0) against CIN1+ and 92.4% (84.0-97.0) against CIN2+ [97.0% (90.6-99.5) when using TAA]. In women who were DNA positive for one vaccine type, the vaccine was efficacious against the other vaccine type. The vaccine did not impact the outcome of HPV-16/18 infections present at the time of vaccination. Vaccination was generally well tolerated regardless of the woman's HPV-16/18 DNA or serological status at entry.

Sustained efficacy and immunogenicity of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine: analysis of a randomised placebo-controlled trial up to 6.4 years.

BACKGROUND: Prophylactic human papillomavirus (HPV) vaccines have to provide sustained protection. We assessed efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine up to 6.4 years. METHODS: Women aged 15-25 years, with normal cervical cytology, who were HPV-16/18 seronegative and oncogenic HPV DNA-negative (14 types) at screening participated in a double-blind, randomised, placebo-controlled initial study (n=1113; 560 vaccine group vs 553 placebo group) and follow-up study (n=776; 393 vs 383). 27 sites in three countries participated in the follow-up study. Cervical samples were tested every 6 months for HPV DNA. Management of abnormal cytologies was prespecified, and HPV-16/18 antibody titres were assessed. The primary objective was to assess long-term vaccine efficacy in the prevention of incident cervical infection with HPV 16 or HPV 18, or both. We report the analyses up to 6.4 years of this follow-up study and combined with the initial study. For the primary endpoint, the efficacy analysis was done in the according-to-protocol (ATP) cohort; the analysis of cervical intraepithelial neoplasia grade 2 and above (CIN2+) was done in the total vaccinated cohort (TVC). The study is registered with ClinicalTrials.gov, number NCT00120848. FINDINGS: For the combined analysis of the initial and follow-up studies, the ATP efficacy cohort included 465 women in the vaccine group and 454 in the placebo group; the TVC included 560 women in the vaccine group and 553 in the placebo group. Vaccine efficacy against incident infection with HPV 16/18 was 95.3% (95% CI 87.4-98.7) and against 12-month persistent infection was 100% (81.8-100). Vaccine efficacy against CIN2+ was 100% (51.3-100) for lesions associated with HPV-16/18 and 71.9% (20.6-91.9) for lesions independent of HPV DNA. Antibody concentrations by ELISA remained 12-fold or more higher than after natural infection (both antigens). Safety outcomes were similar between groups: during the follow-up study, 30 (8%) participants reported a serious adverse event in the vaccine group versus 37 (10%) in the placebo group. None was judged related or possibly related to vaccination, and no deaths occurred. INTERPRETATION: Our findings show excellent long-term efficacy, high and sustained immunogenicity, and favourable safety of the HPV-16/18 AS04-adjuvanted vaccine up to 6.4 years. FUNDING: GlaxoSmithKline Biologicals (Belgium).

Efficacy of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine against cervical infection and precancer caused by oncogenic HPV types (PATRICIA): final analysis of a double-blind, randomised study in young women.

BACKGROUND: The human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine was immunogenic, generally well tolerated, and effective against HPV-16 or HPV-18 infections, and associated precancerous lesions in an event-triggered interim analysis of the phase III randomised, double-blind, controlled PApilloma TRIal against Cancer In young Adults (PATRICIA). We now assess the vaccine efficacy in the final event-driven analysis. METHODS: Women (15-25 years) were vaccinated at months 0, 1, and 6. Analyses were done in the according-to-protocol cohort for efficacy (ATP-E; vaccine, n=8093; control, n=8069), total vaccinated cohort (TVC, included all women receiving at least one vaccine dose, regardless of their baseline HPV status; represents the general population, including those who are sexually active; vaccine, n=9319; control, n=9325), and TVC-naive (no evidence of oncogenic HPV infection at baseline; represents women before sexual debut; vaccine, n=5822; control, n=5819). The primary endpoint was to assess vaccine efficacy against cervical intraepithelial neoplasia 2+ (CIN2+) that was associated with HPV-16 or HPV-18 in women who were seronegative at baseline, and DNA negative at baseline and month 6 for the corresponding type (ATP-E). This trial is registered with ClinicalTrials.gov, number NCT00122681. FINDINGS: Mean follow-up was 34.9 months (SD 6.4) after the third dose. Vaccine efficacy against CIN2+ associated with HPV-16/18 was 92.9% (96.1% CI 79.9-98.3) in the primary analysis and 98.1% (88.4-100) in an analysis in which probable causality to HPV type was assigned in lesions infected with multiple oncogenic types (ATP-E cohort). Vaccine efficacy against CIN2+ irrespective of HPV DNA in lesions was 30.4% (16.4-42.1) in the TVC and 70.2% (54.7-80.9) in the TVC-naive. Corresponding values against CIN3+ were 33.4% (9.1-51.5) in the TVC and 87.0% (54.9-97.7) in the TVC-naive. Vaccine efficacy against CIN2+ associated with 12 non-vaccine oncogenic types was 54.0% (34.0-68.4; ATP-E). Individual cross-protection against CIN2+ associated with HPV-31, HPV-33, and HPV-45 was seen in the TVC. INTERPRETATION: The HPV-16/18 AS04-adjuvanted vaccine showed high efficacy against CIN2+ associated with HPV-16/18 and non-vaccine oncogenic HPV types and substantial overall effect in cohorts that are relevant to universal mass vaccination and catch-up programmes. FUNDING: GlaxoSmithKline Biologicals.

Proteinaceous cysteine protease inhibitors.

Studies of proteinaceous cysteine protease inhibitors originated with the discovery of cystatins in the 1960s. Since that time, a rich and fascinating world of proteins that control and regulate a multitude of important physiological processes, ranging from the basics of protein turnover to development and brain function, has been uncovered. Failures in such important and complex systems inevitably lead to pathologies. Many threatening diseases such as cancer or neurological disorders, to mention only some, are attributed to deregulation of protease-inhibitor balance. Moreover, important aspects of infection pathology and host defense rely on proteolysis and protease inhibition. Recent advances in the field of protease inhibitors have drawn attention to the possible use of this collected knowledge to control related pathological processes. This review attempts to familiarize the reader with proteinaceous cysteine protease inhibitors by providing an overview of current knowledge. The work primarily highlights biological processes in which the inhibitors are involved and focuses on pathologies resulting from aberrant protease-inhibitor balance, pointing out emerging possibilities for their correction.

The potential epidemiological impact of a genital herpes vaccine for women.

BACKGROUND: In two phase III vaccine trials immunisation of women previously uninfected by herpes simplex virus provided protection against genital herpes disease. In deciding policy, an evaluation of the epidemiological impact of the partial protection provided by the vaccine should be considered. METHODS: A sex and sexual activity stratified deterministic differential and partial differential equation model of the natural history of herpes simplex virus type 2 (HSV-2) and the impact of vaccination is developed and analysed. To explore the role of vaccination, the pattern of viral shedding and the transmission of infection during sexual acts within sexual partnerships are described. RESULTS: Using literature derived estimates of parameter values and assuming efficacy in only 40% of women the impact of the vaccine depends on assumptions made about its action. The vaccine has a limited impact if it only prevents disease but a more substantial impact if it reduces asymptomatic viral shedding, which it could do indirectly by preventing infection or directly by modifying the biology of the infection. Concern over the implications of a vaccine that prevents disease but has no impact on viral shedding was addressed in a worst case scenario. Here there is a modest increase in the incidence of infection in both men and women but an increase in disease prevalence in men alone, since the virus directly protects some women from disease. CONCLUSIONS: Results suggest that a herpes vaccine should be used universally and that a vaccine that only protects HSV-1-/2- women can paradoxically have a significant epidemiological impact, the scale of which depends upon changes in patterns of viral shedding.

Molecular cloning and biochemical characterisation of proteases from Staphylococcus epidermidis.

We report the complete coding sequence and the partial amino acid sequence (determined by chemical sequencing) of Staphylococcus epidermidis extracellular cysteine (Ecp) and serine (Esp) proteases. The first enzyme shows an extended sequence similarity to Staphylococcus aureus cysteine protease (staphopain) and the second one resembles the serine protease produced by that species. The region directly upstream of the sequence coding for the mature protein in both enzymes displays significant homology to the profragments encoded by sspB and sspA, respectively, thus suggesting that the characterised enzymes may also be produced as proproteins. Furthermore, we report some biological properties of the cysteine protease, contributing to a better understanding of its role as a possible virulence factor. The proteolytic activity of this enzyme was rapidly and efficiently inhibited by human alpha-2-macroglobulin; however, human kininogen as well as cystatins (A, C and D) were not inhibitory. Moreover, the protease was capable of inactivating, by limited proteolysis, both alpha-1-antitrypsin and HMW-kininogen, but neither alpha-1-antichymotrypsin nor antithrombin III.

Acetylenic aromatic compounds from Stereum hirsutum.

Stereum hirsutum is a one of several fungi involved in a grapevine disease called esca. From the culture medium of this fungus, four new acetylenic compounds 1-3 and 6 have been isolated and identified. Structural elucidation and biological activity are reported.

In vivo immune evasion mediated by the herpes simplex virus type 1 immunoglobulin G Fc receptor.

Herpes simplex virus (HSV) glycoproteins gE and gI form an immunoglobulin G (IgG) Fc receptor (FcgammaR) that binds the Fc domain of human anti-HSV IgG and inhibits Fc-mediated immune functions in vitro. gE or gI deletion mutant viruses are avirulent, probably because gE and gI are also involved in cell-to-cell spread. In an effort to modify FcgammaR activity without affecting other gE functions, we constructed a mutant virus, NS-gE339, that has four amino acids inserted into gE within the domain homologous to mammalian IgG FcgammaRs. NS-gE339 expresses gE and gI, is FcgammaR-, and does not participate in antibody bipolar bridging since it does not block activities mediated by the Fc domain of anti-HSV IgG. In vivo studies were performed with mice because the HSV-1 FcgammaR does not bind murine IgG; therefore, the absence of an FcgammaR should not affect virulence in mice. NS-gE339 causes disease at the skin inoculation site comparably to wild-type and rescued viruses, indicating that the FcgammaR- mutant virus is pathogenic in animals. Mice were passively immunized with human anti-HSV IgG and then infected with mutant or wild-type virus. We postulated that the HSV-1 FcgammaR should protect wild-type virus from antibody attack. Human anti-HSV IgG greatly reduced viral titers and disease severity in NS-gE339-infected animals while having little effect on wild-type or rescued virus. We conclude that the HSV-1 FcgammaR enables the virus to evade antibody attack in vivo, which likely explains why antibodies are relatively ineffective against HSV infection.

Structural and antigenic analysis of a truncated form of the herpes simplex virus glycoprotein gH-gL complex.

The herpes simplex virus (HSV) gH-gL complex is essential for virus infectivity and is a major antigen for the host immune system. The association of gH with gL is required for correct folding, cell surface trafficking, and membrane presentation of the complex. Previously, a mammalian cell line was constructed which produces a secreted form of gHt-gL complex lacking the transmembrane and cytoplasmic tail regions of gH. gHt-gL retains a conformation similar to that of its full-length counterpart in HSV-infected cells. Here, we examined the structural and antigenic properties of gHt-gL. We first determined its stoichiometry and carbohydrate composition. We found that the complex consists of one molecule each of gH and gL. The N-linked carbohydrate (N-CHO) site on gL and most of the N-CHO sites on gH are utilized, and both proteins also contain O-linked carbohydrate and sialic acid. These results suggest that the complex is processed to the mature form via the Golgi network prior to secretion. To determine the antigenically active sites of gH and gL, we mapped the epitopes of a panel of gH and gL monoclonal antibodies (MAbs), using a series of gH and gL C-terminal truncation variant proteins produced in transiently transfected mammalian cells. Sixteen gH MAbs (including H6 and 37S) reacted with the N-terminal portion of gH between amino acids 19 and 276. One of the gH MAbs, H12, reacted with the middle portion of gH (residues 476 to 678). Nine gL MAbs (including 8H4 and VIII 62) reacted with continuous epitopes within the C-terminal portion of gL, and this region was further mapped within amino acids 168 to 178 with overlapping synthetic peptides. Finally, plasmids expressing the gH and gL truncations were employed in cotransfection assays to define the minimal regions of both gH and gL required for complex formation and secretion. The first 323 amino acids of gH and the first 161 amino acids of gL can form a stable secreted hetero-oligomer with gL and gH792, respectively, while gH323-gL168 is the smallest secreted hetero-oligomer. The first 648 amino acids of gH are required for reactivity with MAbs LP11 and 53S, indicating that a complex of gH648-gL oligomerizes into the correct conformation. The data suggest that both antigenic activity and oligomeric structure require the amino-terminal portions of gH and gL.

The gH-gL complex of herpes simplex virus (HSV) stimulates neutralizing antibody and protects mice against HSV type 1 challenge.

The herpes simplex virus type 1 (HSV-1) gH-gL complex which is found in the virion envelope is essential for virus infectivity and is a major antigen for the host immune system. However, little is known about the precise role of gH-gL in virus entry, and attempts to demonstrate the immunologic or vaccine efficacy of gH and gL separately or as the gH-gL complex have not succeeded. We constructed a recombinant mammalian cell line (HL-7) which secretes a soluble gH-gL complex, consisting of gH truncated at amino acid 792 (gHt) and full-length gL. Purified gHt-gL reacted with gH- and gL-specific monoclonal antibodies, including LP11, which indicates that it retains its proper antigenic structure. Soluble forms of gD (gDt) block HSV infection by interacting with specific cellular receptors. Unlike soluble gD, gHt-gL did not block HSV-1 entry into cells, nor did it enhance the blocking capacity of gD. However, polyclonal antibodies to the complex did block entry even when added after virus attachment. In addition, these antibodies exhibited high titers of complement-independent neutralizing activity against HSV-1. These sera also cross-neutralized HSV-2, albeit at low titers, and cross-reacted with gH-2 present in extracts of HSV-2-infected cells. To test the potential for gHt-gL to function as a vaccine, BALB/c mice were immunized with the complex. As controls, other mice were immunized with gD purified from HSV-infected cells or were sham immunized. Sera from the gD- or gHt-gL-immunized mice exhibited high titers of virus neutralizing activity. Using a zosteriform model of infection, we challenged mice with HSV-1. All animals showed some evidence of infection at the site of virus challenge. Mice immunized with either gD or gHt-gL showed reduced primary lesions and exhibited no secondary zosteriform lesions. The sham-immunized control animals exhibited extensive secondary lesions. Furthermore, mice immunized with either gD or gHt-gL survived virus challenge, while many control animals died. These results suggest that gHt-gL is biologically active and may be a candidate for use as a subunit vaccine.

Relationship of cytomegalovirus to salivary gland dysfunction in HIV-infected patients.

In a previous retrospective study of HIV-infected patients we detected a relationship between xerostomia and the presence of cytomegalovirus in saliva. This prospective study compares 13 patients with HIV and a complaint of xerostomia and low salivary flow rates with a control group of 7 patients with HIV without xerostomia and normal salivary flow rates. Both groups were evaluated for the presence of cytomegalovirus in saliva, peripheral blood mononuclear cells, and labial minor salivary glands. Viral cultures, polymerase chain reaction, and histopathologic examination were used to detect cytomegalovirus. Xerostomia and low salivary flow rates were associated with the presence of CMV in saliva. The virus was detected in 10 of 13 xerostomia patients and 2 of 7 controls (p = 0.05, Fisher's exact test). Cytomegalovirus was detected in the saliva of patients who did not also have it in their blood suggesting a local source of virus replication such as the salivary glands. The minor salivary glands were not a major site of cytomegalovirus. Culture was more sensitive then polymerase chain reaction in detecting salivary cytomegalovirus as a result of the presence of inhibitors to the reaction in saliva. These results suggest a link between cytomegalovirus in saliva and salivary gland dysfunction in HIV-infected patients.

Mapping regions of herpes simplex virus type 1 glycoprotein I required for formation of the viral Fc receptor for monomeric IgG.

Glycoprotein E (gE) and glycoprotein I (gI) of herpes simplex virus type 1 (HSV-1) form a complex that binds the Fc domain of monomeric IgG. In this study, we used two approaches to map the regions of gI-1 required for formation of the HSV-1 Fc receptor for monomeric IgG. First, we constructed six plasmids encoding gD-1/gI-1 fusion proteins. Each fusion protein contains a large gI-1 peptide inserted into the ectodomain of gD-1. gD-1/gI-1 fusion proteins were coexpressed with gE-1 using a transfection-infection assay in which cells were transfected with individual fusion protein constructs and then infected with a gE+/gI- virus. Cells were then assayed for monomeric IgG binding using immunofluorescence microscopy. Transfection-infection with two of six fusion proteins conferred monomeric IgG binding activity to cells, whereas cells infected with gE+/gI- virus alone failed to bind IgG monomers. The smallest gI-1 peptide to confer monomeric IgG binding activity contained amino acids 43 to 192. To more precisely map the region of gI-1 required for monomeric IgG binding, we constructed a panel of 10 gI-1 linker insertion mutants. Transfection-infection studies identified two mutants containing linker insertions at gI-1 amino acids 128 and 145, which failed to bind monomeric IgG. The other eight mutants demonstrated wild-type IgG binding activity. Taken together, these results indicate that the region of gI-1 between amino acids 128 and 145 is required for formation of the HSV-1 Fc receptor for monomeric IgG.

Expression of herpes simplex virus type 1 glycoprotein L (gL) in transfected mammalian cells: evidence that gL is not independently anchored to cell membranes.

We expressed herpes simplex virus type 1 glycoprotein L (gL) in transfected cells to investigate whether it is independently anchored to plasma membranes or is membrane associated as a result of complex formation with gH. gL was detected by immunofluorescence microscopy at the surfaces of cotransfected cells when it was expressed with gH but not when it was expressed in the absence of gH or with a truncated form of gH, gHTrunc(792), which lacks the membrane-spanning region and terminates at amino acid 792. Immunoprecipitation studies of transfected-cell culture media revealed that gL was secreted from cells when expressed in the absence of gH and was secreted from cotransfected cells complexed with gHTrunc(792). These observations demonstrate that gL is not independently anchored to plasma membranes but is membrane associated as a result of complex formation with gH.

Failure of culture and polymerase chain reaction to detect human immunodeficiency virus (HIV) in seronegative steady sexual partners of HIV-infected individuals.

Because of concern that steady sexual partners of patients infected with human immunodeficiency virus (HIV) may be infected despite negative results in tests for antibody to HIV, we studied 50 sexually active couples with discordant antibody results, assessing the agreement between these serological results and those obtained by p24 antigen testing, the polymerase chain reaction (PCR), and culture. Forty-nine of 50 seropositive sexual partners were also positive for HIV by PCR; the remaining seropositive partner was positive by culture. All seronegative partners also had negative results in the other three tests. Moreover, seronegative partners continued to have negative results in all tests for a mean follow-up period of 17 months despite ongoing sexual relations with their seropositive partners. Seronegative infection was not documented in these partners at risk for sexual transmission of HIV. HIV-negative individuals in stable, monogamous sexual relationships with HIV-infected partners apparently do not have a high incidence of infection despite continued sexual exposure.

Relationship of oral disease to the presence of cytomegalovirus DNA in the saliva of AIDS patients.

Cytomegalovirus is an important pathogen in persons infected with human immunodeficiency virus. In this study a thorough oral examination was done and blood and urine cultures for cytomegalovirus were obtained from a group of 31 patients with acquired immunodeficiency syndrome with CD4 lymphocyte counts less than 150 cells/mm3. Whole saliva was also collected for detection of cytomegalovirus deoxyribonucleic acid (DNA) via the polymerase chain reaction. The presence of cytomegalovirus DNA in the saliva specimens was not related to the presence of cytomegalovirus in the urine, which suggests a local source of cytomegalovirus from salivary gland and kidney parenchyma. There was also a strong statistical relationship between salivary cytomegalovirus DNA and xerostomia (p = 0.0004), which suggests that cytomegalovirus may be a cause of salivary gland dysfunction in patients with acquired immunodeficiency syndrome with low CD4 counts.

Characterization of regions of herpes simplex virus type 1 glycoprotein E involved in binding the Fc domain of monomeric IgG and in forming a complex with glycoprotein I.

Glycoprotein E (gE) and glycoprotein I (gI) of herpes simplex virus type 1 form a molecular complex that binds the Fc domain of monomeric IgG. Two approaches were used to define regions of gE-1 involved in monomeric IgG binding and complex formation with gI-1. First, we constructed 22 in-frame gE-1 linker-insertion mutants and, in cotransfection experiments with gI-1, assayed each mutant for IgG monomer binding and the ability to complex with gI-1. Nine mutants with insertions between gE-1 amino acids 235 and 380 failed to bind IgG monomers, whereas mutants outside this region retained binding activity. Each mutant reacted with several gE-1 mAbs, was detected at the cell surface, and was fully processed. Only two gE-1 mutants with insertions at residues 235 and 264 lost the ability to co-immunoprecipitate with gI-1, which defines a region of gE-1 that complexes with gI-1. As an additional approach, we assayed 8 gE-1/gD-1 fusion proteins containing large overlapping gE-1 peptides inserted within the ectodomain of gD-1 for binding of IgG monomers and complex formation with gI-1. Three fusion proteins containing gE-1 peptides that overlap at residues 183-402 bound monomeric IgG. This region of gE-1 includes the Fc binding region defined by linker insertion mutagenesis. Five fusion proteins containing gE-1 peptides that overlap at residues 183-288 were co-immunoprecipitated with gI-1, confirming results of gE-1 linker insertion mutagenesis. These studies define two regions on gE-1 involved in Fc binding activity, one that interacts with gI-1, and another that binds IgG.

Infection due to parvovirus B19 in patients infected with human immunodeficiency virus.

Parvovirus B19 has been described as a cause of chronic anemia in immunosuppressed patients, including those infected with human immunodeficiency virus (HIV). In this study serological assays and the polymerase chain reaction (PCR) were used to establish the prevalence of both prior and active infection due to parvovirus B19 among a general population of 105 HIV-infected individuals (cohort I) and among 22 HIV-infected patients with anemia (cohort II). Eight individuals in cohort I (7.6%) had IgG antibodies to parvovirus B19, while none had B19-specific IgM antibodies. In cohort II, four patients (18.2%) had B19-specific IgG antibodies and none had IgM antibodies. Only one person in cohort I (0.95%) and one person in cohort II (4.5%) had evidence on PCR of persistent infection with parvovirus B19; both of these patients lacked IgG and IgM antibodies to parvovirus. Both individuals with B19 viremia were anemic and had CD4 lymphocyte counts suggesting advanced immunosuppression (< 50/mm3). The observed low prevalences of B19 seropositivity and active B19 infection differ from the rates documented in previous studies and indicate that infection with parvovirus B19 is uncommon in some groups of HIV-infected patients.

Characterization of domains of herpes simplex virus type 1 glycoprotein E involved in Fc binding activity for immunoglobulin G aggregates.

Herpes simplex virus type 1 glycoproteins gE and gI form receptors for the Fc domain of immunoglobulin G (IgG) which are expressed on the surface of infected cells and on the virion envelope and which protect the virus from immune attack. Glycoprotein gE-1 is a low-affinity Fc receptor (FcR) that binds IgG aggregates, while gE-1 and gI-1 form a complex which serves as a higher-affinity FcR capable of binding IgG monomers. In this study, we describe two approaches used to map an Fc binding domain on gE-1 for IgG aggregates. First, we constructed nine plasmids encoding gE-1/gD-1 fusions proteins, each containing a large gE-1 peptide inserted into the ectodomain of gD-1. Fusion proteins were tested for FcR activity with IgG-sensitized erythrocytes in a rosetting assay. Three of the fusion proteins containing overlapping gE-1 peptides demonstrated FcR activity; the smallest peptide that retained Fc binding activity includes gE-1 amino acids 183 to 402. These results indicate that an Fc binding domain is located between gE-1 amino acids 183 and 402. To more precisely map the Fc binding domain, we tested a panel of 21 gE-1 linker insertion mutants. Ten mutants with insertions between gE-1 amino acids 235 and 380 failed to bind IgG-sensitized erythrocytes, while each of the remaining mutants demonstrated wild-type Fc binding activity. Taken together, these results indicate that the region of gE-1 between amino acids 235 and 380 forms an FcR domain. A computer-assisted analysis of the amino acid sequence of gE-1 demonstrates an immunoglobulin-like domain contained within this region (residues 322 to 359) which shares homology with mammalian FcRs.