Donor-derived Kaposi's sarcoma in a liver-kidney transplant recipient.

Human herpes virus 8 (HHV-8), also known as Kaposi's sarcoma associated herpesvirus (KSHV), is an oncogenic virus that can cause Kaposi's sarcoma (KS). KS can develop following organ transplantation through reactivation of the recipient's latent HHV-8 infection, or less commonly through donor-derived infection which has higher risk for severe illness and mortality. We describe a case of probable donor-derived KS in the recipient of a liver-kidney transplant. The donor had multiple risk factors for HHV-8 infection. The KS was successfully treated by switching immunosuppression from tacrolimus to sirolimus. With an increasing number of human immunodeficiency virus (HIV)-positive persons seeking organ transplantation and serving as organ donors for HIV-positive recipients, HHV-8 prevalence among donors and recipients will likely increase and with that the risk for post-transplant KS. Predetermination of HHV-8 status can be useful when considering organ donors and recipients with risk factors, although there are currently no validated commercial tests for HHV-8 antibody screening.

Varicella zoster virus in American Samoa: seroprevalence and predictive value of varicella disease history in elementary and college students.

The epidemiology of varicella is believed to differ between temperate and tropical countries. We conducted a varicella seroprevalence study in elementary and college students in the US territory of American Samoa before introduction of a routine varicella vaccination programme. Sera from 515 elementary and 208 college students were tested for the presence of varicella-zoster virus (VZV) IgG antibodies. VZV seroprevalence increased with age from 76·0% in the 4-6 years group to 97·7% in those aged ⩾23 years. Reported history of varicella disease for elementary students was significantly associated with VZV seropositivity. The positive and negative predictive values of varicella disease history were 93·4% and 36·4%, respectively, in elementary students and 97·6% and 3·0%, respectively, in college students. VZV seroprevalence in this Pacific island appears to be similar to that in temperate countries and suggests endemic VZV circulation.

Molecular epidemiology of varicella zoster virus.

Varicella zoster virus has highly conserved genome 125,000 base pairs. The different molecular genetic methods of analyzing VZV genome are discussed, as well as their results with regards to the virus phylogenesis, geographic distributions, possible recombination and virulence of different VZV strains.

Inhibition of HSV-1-specific cytotoxic T lymphocytes by recombinant-derived gp120 of HIV-1.

The ability of human immunodeficiency virus type-1 (HIV-1) and recombinant HIV-1 gp120 to prevent target cell lysis by herpes simplex virus type 1 (HSV-1)-specific cytotoxic T lymphocytes (CTL) was assessed by limiting dilution analysis. Live and inactivated HIV-1 as well as recombinant-derived gp120 all substantially inhibited HSV-1-specific CTL. Soluble CD4 antigen reversed the inhibition by gp120 when simultaneously added with gp120 to the assay. In addition, the monoclonal anti-CD4 antibody a-Leu3a mimicked the effects of gp120 in these experiments. These data suggest that the observed decrease in measurable CTL activity is caused by direct or steric hindrance of the CD4-class II major histocompatibility complex interaction between the effector and target cells.

Inhibition of the in vitro generation of class II-restricted, HSV-1-specific, CD4+ CTL by HIV-1.

Previously, we demonstrated that cultures of human peripheral blood lymphocytes (PBL) stimulated with herpes simplex virus type 1 (HSV-1) generate antigen-specific, major histocompatibility complex (MHC) restricted cytotoxic T lymphocytes (CTL) that tend to be CD4+ and restricted to HLA-DR antigens. In this study, we present evidence that when HSV-1 stimulated human peripheral blood lymphocytes (PBL) are cocultured with human immunodeficiency virus type 1 (HIV-1), the generation of CD4+, DR-restricted CTL during the 5-day culture period is inhibited. In contrast, HIV-1 had no effect on either natural killer (NK) activity, or on the unrestricted NK-like killers which are often detected in HSV-1-stimulated cultures after the depletion of CD16+ cells. HIV-1 also failed to inhibit the generation of CTL against Epstein-Barr virus (EBV), a response that principally involves CD8+, CD4-, class I-restricted killers.

Genomic analysis of varicella-zoster virus: primers for individual open reading frames.

The genome of varicella-zoster virus (VZV) contains nearly 125,000 bp. Preliminary genomic analysis has revealed that VZV may be less immutable than once thought. Through the investigation of the VZV genome using specifically designed oligonucleotides, it has been learned that sequence variation within VZV open reading frame 62 can distinguish between vaccine and wild-type virus. Additionally, the presence of single nucleotide polymorphisms within the VZV genome has identified distinct VZV populations originating from circumscribed geographic locations. In order for future studies of VZV genetic diversity to be carried out, amplifying and sequencing primers for individual VZV genes have been catalogued. Additionally, this report will facilitate the selection of VZV primers by which to distinguish clinical VZV isolates from vaccinia virus isolates.

Analysis of herpes simplex virus 1 and 2 infection in women with high risk sexual behaviour in Mexico.

BACKGROUND: This paper describes the seroprevalence and risk factors of Herpes simplex virus (HSV) infection in a group of female prostitutes from Mexico City. METHODS: Women who consented to participate in the study voluntarily attended a sexually transmitted disease (STD) clinic during 1992. A standardized questionnaire was administered and a blood sample was obtained from each participant. Type-specific Western blot serology was performed to determine the serostatus of HSV-1 and HSV-2 for participants. Bivariate and multivariate analyses were applied to identify variables associated with an increased risk for HSV infection. RESULTS: Prevalences of infection among the 997 prostitutes studied were 93.9% for HSV-1 and 60.8% for HSV-2. Only 1.8% of the women were seronegative for both viruses. The only variable associated with HSV-1 seropositivity was crowding index. The following variables were associated with an increased risk for infection with HSV-2: age, level of education, working site, born outside Mexico City and increasing time as a prostitute. CONCLUSIONS: This is the first assessment of HSV infection in Mexico and may be useful for the development and application of control and preventive measures among the prostitute population at risk of acquiring and transmitting human immunodeficiency virus (HIV) and other STD.

Seroprevalence and incidence of sexually transmitted diseases in a rural Ugandan population.

The aim of the study was to determine in a rural population the age- and sex-specific prevalence and incidence rates of serological reactivity of 5 common sexually transmitted diseases (STDs) and their association with HIV-1 antibody status. Of the adult population of two villages (529 adults aged 15 years or more) 294 provided an adequate blood specimen both on enrollment and at 12 months. The sera were tested at 3 collaborating laboratories for antibodies against HIV-1, Treponema pallidum, Haemophilus ducreyi, Chlamydia trachomatis and herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). A sample of 45 children were tested for HSV-1 and HSV-2. Seroprevalence rates in adults on enrollment were 7.8% for HIV-1, 10.8% for active syphilis, 10.4% for H. ducreyi, 66.0% for C. trachomatis, 91.2% for HSV-1 and 67.9% for HSV-2. Males were significantly more likely than females to be seropositive for H. ducreyi (15.6% versus 6.6%), but less likely to be HSV-2 antibody positive (57.0% versus 74.4%). Reactivity to H. ducreyi, C. trachomatis and HSV-2 rose with increasing age. In contrast, active syphilis showed no age trend. All STDs tended to be more common in those HIV-1 seropositive. Incidence rates over the 12 months were nil for HIV-1, 0.5% for syphilis, 1.2% for H. ducreyi, 11.3% for C. trachomatis, and 16.7% for HSV-2. The results of this exploratory study indicate that all STDs included are common in this rural population. The high HSV-2 prevalence rate among adolescents suggests that HSV-2 may be an important risk factor for HIV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: A seroprevalence survey conducted in rural Uganda revealed a high potential for interaction between sexually transmitted diseases (STDs) such as herpes simplex virus type 2 (HSV-2) and human immunodeficiency virus (HIV). Venous blood samples were collected at baseline and one year later from 294 randomly selected adults aged 15 years or over from two neighboring villages. At baseline, 23 (7.8%) adults were HIV-positive; no seroconversion occurred during the one-year study period. STD prevalence rates were 10.8% for syphilis, 10.4% for Hemophilus ducreyi, 66.0% for Chlamydia trachomatis, and 91.2% for HSV-1 and 67.9% for HSV-2. More females (74.4%) than males (57.0%) were HSV-2 antibody-positive. Reactivity to H. ducreyi, C. trachomatis, and HSV-2 rose with increasing age, but there was no such trend for syphilis. HIV prevalence rates were 0.0% among those with no serologic evidence of previous STDs, 2.6% among those with one or two prior STDs, and 20.0% among those with three or four STD markers. Of particular concern was the high rate of HSV-2 prevalence among adolescents (85% among females aged 20-24 years and 82% in males aged 25-29 years). It is suggested that age-specific HSV-2 seroprevalence can provide an accurate marker of premarital sexual activity among Ugandan adolescents since it lacks the potential for bias associated with self-reporting in this population.

Disseminated herpes simplex virus infection during pregnancy. A case report.

Hepatitis due to herpes simplex virus (HSV) developed in a pregnant women at 38 weeks' gestation. She delivered a live-born infant who had serologically documented HSV 2 infection but did well with acyclovir therapy. The mother, however, died five days postpartum from fulminant hepatic failure despite antiviral treatment, and HSV was demonstrated in the liver. Twenty-three reported cases clearly establish pregnancy as a condition that can predispose to disseminated HSV infection. The majority of cases have been due to HSV 2, and primary infection in the latter part of pregnancy appears to constitute the greatest risk. The major disease manifestations appear to be hepatitis and encephalitis. Historically, maternal and fetal mortality rates have been high, but there is a trend toward improved survival in the acyclovir era.

The human MHC-restricted cellular response to herpes simplex virus type 1 is mediated by CD4+, CD8- T cells and is restricted to the DR region of the MHC complex.

The nature of the in vitro human cytotoxic T-cell responder population to HSV type 1 (HSV-1) was studied. In 5-day HSV-1-stimulated cultures that contained MHC-restricted activity, two phenotypically distinct populations of cells were present that were capable of lysing HSV-1-infected B cell lines in a 5-h 51Cr-release assay. The first was CD4+, CD8-, CD16- cell typical of class II-restricted T cells, whereas the other population bore a CD4-, CD8-, CD16+ NK-cell phenotype. Elimination of the NK cell fraction from bulk cultures by using anti-CD16 plus C frequently resulted in cell populations that killed in an Ag-specific, HLA-DR-restricted fashion. In some cases the anti-CD16-pretreated cultures retained a killing population that was unrestricted to MHC products. In no instance were any cytotoxic T cells that were restricted to class I Ag in evidence. Limiting dilution analysis of precursor frequency indicated that about 1 in 4000 to 1 in 8000 cells from peripheral blood are specific for HSV-1 in seropositive individuals. Comparisons of HLA class I-matched and HLA class II-matched targets with the autologous target by using limiting dilution analysis yielded results entirely consistent with those obtained in the bulk culture assay system.

T cell responses to herpes simplex viruses in humans.

Much of the evidence that implicates cytotoxic T lymphocytes (CTLs) in the control of infections due to herpes simplex virus (HSV) is circumstantial. However, the ease of induction of HSV-specific CTLs in vitro, the evidence from clinical observations in humans, and the protection afforded by adoptively transferred CTLs all tend to support an important role for CTLs in the resolution of HSV disease. One salient feature of the response of human CTLs to HSV that has emerged quite clearly is the presence of CD4+ T cells as a predominant killer cell phenotype. Given the importance of CD4+ T cells in mediating delayed type hypersensitivity responses and in clearing local infections on adoptive transfer, this T cell subset probably plays a critical role in the resolution of HSV recrudescent disease. Moreover, it is tempting to speculate that viral agents that impair the function of CD4+ T cells, such as human immunodeficiency virus type 1, may predispose patients to severe local infections.

Cellular interactions in the cytotoxic T lymphocyte response to herpes simplex virus antigens: differential antigen activation requirements for the helper T lymphocyte and cytotoxic T lymphocyte precursors.

The role and induction requirements of helper T lymphocyte responses to herpes simplex virus type 1 (HSV-1) was examined. Splenocytes from mice that had been primed in vivo with infectious HSV-1 can be restimulated in vitro with live or partially UV-inactivated HSV-1 to generate high levels of herpes virus-specific cytotoxic T lymphocyte (CTL) activity. By comparison, naive splenocytes or splenocytes taken from mice primed with heat-inactivated HSV-1 failed to generate CTL after in vitro viral stimulation. In addition, infectious HSV-primed splenocytes can be rendered unresponsive to secondary in vitro restimulation by pretreatment with anti-Lyt-1 antiserum plus complement. Spleen cells were taken from mice that had been primed and restimulated in vivo with infectious HSV-1. Two days after the second priming, splenocytes were prepared and irradiated. These cells were capable of assisting in the generation of CTL to varying degrees in all of the above unresponsive populations of cells. The irradiated cells did not produce detectable levels of CTL activity when cultured alone with antigen. Also, if the irradiated splenocytes were treated with anti-Lyt-1 plus complement before their addition to cultures, all restorative activity was ablated. In contrast, irradiated splenocytes from mice that had been primed and restimulated in vivo with either heat-inactivated or UV-inactivated HSV-1 were unable to provide help to naive or helper-depleted cultures. The failure to supply helper activity appears not to involve the preferential activation of suppressor cells, as evidenced by cell mixing experiments and the addition of concentrated, antigen-stimulated spleen cell supernatant fluids to secondary anti-HSV-1 splenocyte cultures. Proliferative assays using interleukin 2- (IL 2) dependent cell lines as a measure of relative helper activity indicated that the inactivated forms of HSV-1 were incapable of effectively enlisting helper activity. These experiments therefore suggest that the observed failure of heat-inactivated or UV-inactivated HSV-1 preparations to induce anti-HSV CTL responses reflects the inability of the HSV-1-specific subset of helper T lymphocytes to recognize these forms of the antigen.

DNA fragmentation: manifestation of target cell destruction mediated by cytotoxic T-cell lines, lymphotoxin-secreting helper T-cell clones, and cell-free lymphotoxin-containing supernatant.

A Lyt-2+, trinitrophenyl-specific, lymphotoxin-secreting, cytotoxic T-cell line, PCl 55, mediates the digestion of target cell DNA into discretely sized fragments. This phenomenon manifests itself within 30 min after effector cell encounter as measured by the release of 3H counts from target cells prelabeled with [3H]deoxythymidine and occurs even at very low effector to target cell ratios (0.25:1). A Lyt-1+, ovalbumin-specific, lymphotoxin-secreting T-helper cell clone, 5.9.24, is also able to mediate fragmentation of target cell DNA over a time course essentially indistinguishable from the cytotoxic T lymphocyte-mediated hit. Cell-free lymphotoxin-containing supernatants also cause release of DNA from targets, although they require a longer time course, on the order of 24 hr. In contrast, lysis of cells by antibody plus complement or Triton X-100 does not result in DNA release even after extended periods of incubation (24 hr). All three treatments that result in the release of DNA from cells cause fragmentation of that DNA into discretely sized pieces that are multiples of 200 base pairs. The results thus suggest that cytotoxic T cells, lymphotoxin-secreting helper clones with cytolytic activity, and lymphotoxin all effect target cell destruction by means of a similar mechanism and that observed differences in time course and the absence of target cell specificity in killing mediated by lymphotoxin may simply reflect differences in the mode of toxin delivery.

In vitro enhancement of natural killer cell activity against herpesvirus-infected targets in patients with acute lymphocytic leukemia.

The present study was carried out to determine whether natural killer (NK) activity against virus-infected target cells could be enhanced in peripheral blood lymphocytes (PBL) taken from patients with acute lymphocytic leukemia. Nonspecific cell-mediated killing of heterologous herpesvirus-infected B lymphoblastoid targets could be enhanced by pretreating PBL with interferons-alpha or -gamma, or with interleukin-2. NK activity was substantially enhanced over that of untreated cells, and virtually all cytolytic activity was attributable to CD16+ NK cells. Pretreatment of PBL with a combination of cytokines resulted in additive, but never synergistic enhancement of NK activity. The results suggest that cytokine therapy may provide a useful means for treating severe varicella zoster infections in immunocompromised children.

The role of accessory cells and T cell-growth factor in induction of cytotoxic T lymphocytes against herpes simplex virus antigens.

The roles of accessory cells and T cell-growth factor (TCGF) in the in vivo induction of herpes simplex type 1 (HSV) specific cytotoxic lymphocytes (CTL) were evaluated. Spleen cells from animals infected with HSV 4-6 weeks previously were depleted of adherent cells by passage over Sephadex G10. Unlike intact cells, such depleted spleen cells failed to respond by producing H-2 restricted virus-specific CTL upon culture for 5 days with infectious HSV. The CTL response could be restored either by adding normal genetically compatible peritoneal cells as accessory cells or by the addition of TCGF. To obtain optimum restoration accessory cells needed to be added soon after culture initiation but with TCGF addition, partial restoration was evident when added as late as 72 hr after culture. TCGF also permitted intact spleen cells to respond to heat-inactivated virus. The results are interpreted to indicate that accessory cells are essentially required for the presentation of virus to specific helper cells with such cells responding by the production of TCGF. The results also indicate that certain forms of virus may trigger the response of CTL precursors but not the response of helper cells.

Role of Ia antigen expression and secretory function of accessory cells in the induction of cytotoxic T lymphocyte responses against herpes simplex virus.

Splenocytes from mice which have been primed in vivo with herpes simplex virus type 1 (HSV-1) can be restimulated in vitro with infectious or UV-inactivated HSV-1 to generate HSV-specific, H-2-restricted cytotoxic T lymphocytes (CTL). HSV-primed splenocytes which have been depleted of adherent cells by sequential incubation on plastic, nylon wool, and Sephadex G-10 are not able to respond with a CTL response when restimulated in vitro. A variety of Ia-positive and Ia-negative (Ia(+) and Ia(-)) cell populations were assessed for their ability to supply accessory cell functions to spleen cells which had been exhaustively depleted of adherent cells, as measured by the restoration of a CTL response to HSV-1. Of these, only those populations which included Ia(+) cells were capable of providing accessory cell function. The ineffective populations were devoid of Ia antigens, except for B lymphocytes, which are Ia(+) and still incapable of serving as accessory cells. Splenic adherent cells and resident peritoneal cells were both proficient at restoring anti-HSV CTL responses, although splenic adherent cells were clearly superior at limiting cell numbers. Neither population was capable of accessory cell activity, however, if it was pretreated with anti-Ia antiserum plus complement or if anti-Ia serum was present during induction. Peritoneal cells lose virtually all of their membrane-associated Ia antigen after a brief period of in vitro culture (24 to 48 h). Cultured peritoneal cells, as well as P388D(1) cells (normally Ia(-)), can be induced to express Ia antigens within 48 h if they are cultured with concanavalin A-stimulated spleen cell supernatants. Ia(+) P388D(1) cells without the extraneous macrophage factor are not able to restore CTL responsiveness to HSV-1 in vitro, whereas Ia(+) cultured macrophages are fully competent accessory cells. When Ia(+) P388D(1) cells were supplemented with the macrophage-derived soluble factor interleukin 1, they displayed a modest, but significant, capacity to restore secondary anti-HSV CTL responses. In addition, glutaraldehyde-fixed, HSV-1-infected Ia(+) peritoneal cells, which could not restore the CTL response alone, were capable of providing accessory cell function if extraneous interleukin 1 was provided. In contrast, Ia(-) cultured peritoneal cells, Ia(-) P388D(1) cells, and various other Ia(-) cell lines were unable to participate in the generation of CTL even in the presence of interleukin 1. The adherent cell population would therefore appear to be making at least two essential contributions to the process of CTL development, namely, the secretion of interleukin 1 and the presentation of antigen in the context of membrane-associated Ia antigen.

A comparison of lysis mediated by Lyt 2+ TNP-specific cytotoxic-T-lymphocyte (CTL) lines with that mediated by rapidly internalized lymphotoxin-containing supernatant fluids: evidence for a role of soluble mediators in CTL-mediated killing.

A series of Lyt 2+, trinitrophenyl (TNP)-specific T-cell lines are shown to lyse 51Cr-labeled target cells in an antigen-specific, H-2-restricted fashion in a 4-hr assay. These cells also produce lymphotoxin, in addition to other factors, upon stimulation with TNP-haptenated syngeneic splenocytes. A technique for introducing macromolecules into the cytoplasm of fibroblasts by inducing the cells to pinocytose the molecule in hypertonic medium, and then lysing the newly formed pinocytic vesicles with a mild hypotonic shock was used to assess the role of soluble mediators in the cytotoxic T lymphocyte (CTL)-mediated lytic process. The technique itself has little effect on cell growth rate or viability. A minimum of 24 hr, and more frequently 48-72 hr is required for lymphotoxin to manifest it's lethal effect when it is merely included in the culture medium of growing fibroblasts. In contrast, supernatant fluids from the Lyt 2+ cells kill 51Cr-labeled fibroblasts in a dose-dependent fashion during a 4-hr assay when they are rapidly internalized via the osmotic procedure. The data serve as preliminary evidence of a role for soluble mediators such as lymphotoxin in T-cell-mediated lysis, and suggest that the cytotoxic-T-cell lethal hit may include a mechanism for rapidly internalizing a toxin into appropriate target cells.