Stig Jeansson

Prevalence of antibodies to herpes simplex virus in pregnant women in Stockholm in 1969, 1983 and 1989: implications for STD epidemiology.

Prevalence of antibody to herpes simplex virus types 1 and 2 was assessed in consecutive serum samples from a total of 3700 women pregnant in 1969, 1983, or 1989 from the same catchment area in Stockholm. There was little change in seroprevalence of antibody to herpes simplex type 1 in the 3 groups, but age-adjusted herpes simplex virus type 2 antibody prevalence was 19, 33, and 33% respectively. Increase in type 2 seropositivity with age was slight and similar in 1969 and 1989, but steep in 1983, indicating a shift in sexual behaviour. However, rising prevalence in women will be mirrored by rising prevalence in their male partners. The increase from 1969 to 1989 will thus partly be due to higher risk of infection per partner, and cannot be taken as direct evidence of increased rate of partner change during this 20-year period.

Localization of a functional site on herpes simplex virus type 1 glycoprotein C involved in binding to cell surface heparan sulphate

The amino acid residues critical for interaction between herpes simplex virus type 1 (HSV-1) glycoprotein C (gC-1) and cell surface heparan sulphate (HS) were localized to two separate regions within antigenic site II of this glycoprotein. These amino acids were Arg-143, Arg-145, Arg-147 and Thr-150 in one region and Gly-247 in the other. This conclusion is based on the following observations. (i) Monoclonal antibodies defining gC-1 antigenic site II, and not those reactive with antigenic site I, inhibited HSV-1-induced haemagglutination and virus binding to susceptible cells. (ii) A number of HSV-1 mar mutants, altered at these critical residues, were impaired in attachment to cells. (iii) Synthetic peptides, corresponding to these two regions inhibited virus attachment to cells and infectivity. In addition these peptides were found to agglutinate red blood cells. This agglutination was inhibited by soluble HS, and was prevented by the pretreatment of red blood cells with heparitinase suggesting that cell surface HS was a site of peptide binding. The same was observed with the polycationic substances neomycin and poly-L-lysine. In conclusion, we propose that the regions of gC-1 represented by the HS-binding peptides may form a functional site of a polycationic nature, active in attachment to the polyanionic glycosaminoglycan chain of cell surface HS.

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.

Amplified ELISPOT assay for the detection of HIV-specific antibody-secreting cells in subhuman primates

A novel immunoenzyme amplification technique has been evaluated in an ELISPOT assay for the detection of antigen-specific antibody-secreting cells (ASC) in monkeys. In this assay, mononuclear cells containing putative ASC are incubated for a few hours in antigen-coated wells. Following removal of the cells, zones of solid phase bound antibodies secreted by individual ASC are visualized in four consecutive steps. First, a primary biotinylated anti-immunoglobulin (Ig) reagent is added followed by enzyme-labelled avidin. The amplification procedure comprises the addition of biotinylated anti-enzyme antibodies in the third stage, followed by enzyme-conjugated avidin and substrate. When evaluated in a modified ELISPOT assay for the detection of simian B cells secreting antibodies to the envelope glycoprotein gp120 of the human immunodeficiency virus type 1 (HIV-1), this amplification procedure proved to be suitable even when using anti-human Ig antisera as primary antibody reagents. This development should be useful for other ELISPOT assays where species specific anti-Ig reagents are not always available and, most importantly, for enumerating cells producing immunoreactive substances in such minute amounts that they may escape detection by conventional ELISPOT assays. Furthermore, a functional simian HIV-specific ELISPOT assay could prove valuable for assessing the humoral immunogenicity of future candidate vaccines against the acquired immunodeficiency syndrome (AIDS).

Production of Herpes Simplex Antisera with Increased Type Specificity in Guinea Pigs by Antibody Suppression

Summary Passive administration of heterologous antibody to guinea pigs infected with Herpes simplex virus type 1 and type 2 allowed a production of antisera of enhanced specificity. The anti Herpes simplex virus type 1 serum produced was of high specificity and potency and showed only minor reactions with Herpes simplex virus type 2. The anti-Herpes simplex virus type 2 serum produced was of moderate specificity, but clearly differentiated between Herpes simplex virus type 1 and type 2 in different immunological reactions. The procedure described is a simple method whereby relatively specific antisera for typing of Herpes simplex virus type 1 and type 2 strains can be produced. This investigation was supported by grants from foundations of Jorgen Schaumann, Finsen and Edward Welander. I thank Gun Carlstrom, Aberra Demissie, and Erling Norrby for valuable help, comments, and advice.

Bioimmunoassays (BIAs) of Human Interferon

Abstract Simple, sensitive, and reproducible assay systems for measurement of the biological activity of interferon are described. The methods used are based on the quantification of cell membrane-bound viral and cellular antigens in interferon-treated cells by enzyme immunoassays. To measure the antiviral activity, samples of human interferon are titrated in microplates with human or bovine cells. After incubation with challenge virus (vesicular stomatitis or herpes simplex virus) the cells are fixed with glutaraldehyde and assayed for viral antigens by enzymelabeled antibodies. This assay permits the detection of less than 0.1 unit of interferon per milliliter, after optimization of several factors, such as type of cell, multiplicity of infection, temperature, and period of incubation. The effect of interferon on cellular antigens is measured in a similar way, by using peroxidase-labeled antibodies directed against β2-microglobulin. The two types of assays described appear suitable for kinetic experiments and for detection of interferons of different specificities in body fluids.

An evaluation of a hemagglutination-inhibition test for the detection of antibodies to herpes simplex virus type 1

BACKGROUND We have recently demonstrated the ability of herpes simplex virus type 1 (HSV-1) to agglutinate mouse red blood cells, and identified glycoprotein C (gC-1) as a major virus hemagglutinin. Based on this a classical hemagglutination-inhibition (HI) assay was developed. OBJECTIVES Regarding significant structural differences between HSV-1 gC-1 and its herpes simplex virus type 2 (HSV-2) counterpart, gC-2, the possibility of application of a classical HI assay for the detection of HSV-1-specific antibodies was explored. STUDY DESIGN HI antibody titers were compared with those of gC-1-specific enzyme-linked immunoassay (ELISA), and with the results of the standard gG-1- and gG-2-specific immunodot enzymatic assays for the detection of type-specific antibodies to HSV-1 and HSV-2 respectively. RESULTS The sensitivity of HI test was 89% and 97% of that gC-1-ELISA and gG-1-immunodot respectively. Approximately 21% of serum specimens, defined as containing antibodies specific for only HSV-2, showed low HI titers. Heterotypic reactivity with purified gC-1 antigen was also observed in both ELISA and immunoblot assays. CONCLUSION Antibodies detectable in HI assay were mainly HSV-1-specific; however, a limited degree of serologic reactivity between HSV-2-specific sera and HSV-1 hemagglutinin also occurred. Thus, our results confirmed prevalent opinion about the presence of a limited number of antigenic determinants shared by HSV-1 gC-1 and HSV-2 gC-2.

Systematic identification of T-cell activating epitopes on the human immunodeficiency virus type 1 envelope glycoprotein gp120 in primates immunized with synthetic peptides.

Because T-cell responses are critical for defence against viral infections, an ideal vaccine should stimulate these cells. The authors have examined a series of forty overlapping synthetic peptides covering the entire amino acid sequence of the envelope protein gp120 from the human immunodeficiency virus type 1 (HIV-1) HTLV-IIIB isolate, for harbouring putative T-cell recognition sites. The peptide-induced proliferative responses and IL-2 production by blood mononuclear cells were studied from 40 macaques previously immunized with ovalbumin-conjugated HIV-1 peptide(s). These analyses disclosed four major areas of T-cell recognition, including one novel T-cell activating region (located between amino acids 152 and 176) which was also found to harbour a domain recognized by HIV-1 neutralizing antibodies. Recognition of the latter region by CD4+ T cells did not appear to be subject to strong genetic restriction. The results of these studies have obvious implications for the development of synthetic subunit vaccines against the acquired immunodeficiency syndrome (AIDS).

Herpesviridae: Herpes Simplex Virus

Disease: Herpes simplex virus infections. Etiologic Agents: Herpes simplex virus types 1 and 2. Source: Human to human spread of infection.

ON THE TREATMENT WTH PROFLAVINE OF HERPES SIMPLEX OR VACCINIA INFECTED GMK CELLS

Green monkey kidney (GMK) cells were inoculated with vaccinia or herpes simplex virus, and the effect of photodynamic treatment with proflavine and light was studied in the electron microscope. Whereas virions were abundant in all untreated cultures (incubated with virus for 15 hours or more), no virus particles could be found in the treated ones. Proflavine and light, in the amounts used, seemed to exert a certain degree of toxicity on the GMK cell cultures, but virus reproduction was effectively stopped by the treatment. Preliminary results on photodynamic treatment of human herpes keratitis are mentioned.