Cytomegalovirus viremia increases with progressive immune deficiency in patients infected with HTLV-III

Assessing Anti-HCMV Cell Mediated Immune Responses in Transplant Recipients and Healthy Controls Using a Novel Functional Assay

HCMV infection, reinfection or reactivation occurs in 60% of untreated solid organ transplant (SOT) recipients. Current clinical approaches to HCMV management include pre-emptive and prophylactic antiviral treatment strategies. The introduction of immune monitoring to better stratify patients at risk of viraemia and HCMV mediated disease could improve clinical management. Current approaches quantify T cell IFNγ responses specific for predominantly IE and pp65 proteins ex vivo, as a proxy for functional control of HCMV in vivo. However, these approaches have only a limited predictive ability. We measured the IFNγ T cell responses to an expanded panel of overlapping peptide pools specific for immunodominant HCMV proteins IE1/2, pp65, pp71, gB, UL144, and US3 in a cohort of D+R- kidney transplant recipients in a longitudinal analysis. Even with this increased antigen diversity, the results show that while all patients had detectable T cell responses, this did not correlate with control of HCMV replication in some. We wished to develop an assay that could directly measure anti-HCMV cell-mediated immunity. We evaluated three approaches, stimulation of PBMC with (i) whole HCMV lysate or (ii) a defined panel of immunodominant HCMV peptides, or (iii) fully autologous infected cells co-cultured with PBMC or isolated CD8+ T cells or NK cells. Stimulation with HCMV lysate often generated non-specific antiviral responses while stimulation with immunodominant HCMV peptide pools produced responses which were not necessarily antiviral despite strong IFNγ production. We demonstrated that IFNγ was only a minor component of secreted antiviral activity. Finally, we used an antiviral assay system to measure the effect of whole PBMC, and isolated CD8+ T cells and NK cells to control HCMV in infected autologous dermal fibroblasts. The results show that both PBMC and especially CD8+ T cells from HCMV seropositive donors have highly specific antiviral activity against HCMV. In addition, we were able to show that NK cells were also antiviral, but the level of this control was highly variable between donors and not dependant on HCMV seropositivity. Using this approach, we show that non-viraemic D+R+ SOT recipients had significant and specific antiviral activity against HCMV.

Absence of interaction between porcine endogenous retrovirus and porcine cytomegalovirus in pig-to-baboon renal xenotransplantation in vivo

BACKGROUND

Studies of xenotransplantation from swine have identified porcine viruses as potential barriers to clinical trials. The biology of these viruses has not been extensively investigated in the in vivo xeno-environment. Enhancement of viral gene expression by viral and cellular factors acting in trans has been demonstrated for certain viruses, including bidirectional interactions between human herpesviruses and endogenous (HERV) and exogenous (HIV) retroviruses. Both porcine cytomegalovirus (PCMV) and porcine endogenous retrovirus (PERV) infections have been identified in xenografts from swine. PERV receptors exist on human cells with productive infection in vitro in permissive human target cell lines. PCMV is largely species-specific with infection restricted to the xenograft in pig-to-baboon transplants. It is unknown whether coinfection by PCMV affects the replication of PERV within xenograft tissues which might have implications for the risk of retroviral infection in the human host.

METHODS

A series of 11 functioning, life-supporting pig-to-baboon kidney xenografts from PERV-positive miniature swine were studied with and without PCMV co-infection. Frozen biopsy samples were analyzed using quantitative, real-time PCR with internal controls.

RESULTS

PERV replication was not altered in the presence of PCMV coinfection (P = .70). The absence of variation with coinfection was confirmed when PERV quantitation was expressed relative to simultaneous cellular GAPDH levels with or without PCMV coinfection (P = .59).

CONCLUSIONS

PCMV coinfection does not alter the replication of PERV in life-supporting renal xenotransplantation in vivo in baboons.

A novel pattern of pp65-positive cytomegalic endothelial cells circulating in peripheral blood from a renal transplant recipient

The present study reports a novel pattern of cytomegalic endothelial cells (CEC) in peripheral blood from a female renal transplant recipient infected with human cytomegalovirus (HCMV), which has not been reported previously. Localization of specific early antigen of HCMV, pp65 antigen, was examined by immunohistochemistry. Staining of an endothelial cell marker (CD34) was used to characterize endothelial cells. It is demonstrated that many leukocytes surrounded and adhered to a protein-like material, in which pp65-positive CEC were detected. The composition and function of this protein-like material are yet unknown. The patient lacked clinical symptoms of HCMV disease. Furthermore, similar localization patterns were found in other renal transplant recipients suffering from HCMV infections as determined by real-time PCR to detect HCMV DNA in blood. These patients showed no or only minor clinical symptoms of HCMV infection. It is suggested that these novel localization patterns of CEC may play a role in the host defense in patients infected with HCMV, but the exact relation between HCMV infection and CEC formation needs further investigation.

Cytomegalovirus and simian immunodeficiency virus coinfection: longitudinal study of antibody responses and disease progression

Antibody titers to rhesus cytomegalovirus (RhCMV) were prospectively analyzed over a period of 68 weeks in a longitudinal serosurvey of 17 RhCMV-seropositive rhesus macaques (Macaca mulatta) experimentally coinfected with simian immunodeficiency virus (SIV). These were compared with anti-RhCMV titers in 18 animals that were also naturally infected with RhCMV but not infected with SIV. Fluctuations in anti-RhCMV antibody titers were observed within 5 weeks of SIV inoculation, and two distinct patterns of RhCMV antibody response were observed in SIV-infected animals. Animals showing a progressive decline in anti-RhCMV immunoglobulin G (IgG) exhibited the most rapid disease progression, coincident with low anti-SIV and anti-tetanus toxoid IgG responses, high levels of p27 antigen in the plasma, and short survival. Animals exhibiting a more stable CMV-specific response after SIV inoculation had the least rapid disease course. Anti-RhCMV antibody titers in SIV-uninfected animals remained relatively stable during the period of study. Evidence that preinoculation immunologic measures predicted postinoculation outcome was equivocal.

Colocalisation of human immunodeficiency virus and human cytomegalovirus infection in brain autopsy tissue from AIDS patients

We have examined 26 human AIDS brains obtained at post mortem for infection by human immunodeficiency virus (HIV) and human cytomegalovirus (HCMV), and for dual infection of cells by both viruses. The techniques used were enzyme-linked immunocytochemistry for HCMV and in situ hybridisation using a cDNA probe for HIV. Using these techniques, HCMV infection was detected in 14 brains, HIV infection in 14 brains, and coinfection with HIV and HCMV in 7 brains. Four case of dual HIV/HCMV infection were found where no colocalisation could be detected. In randomly chosen dually infected areas 19.2% of infected cells were coinfected with both viruses. Although cells identified morphologically as macrophages were the most common infected cell type, astrocytes and neurons were both singly and doubly infected with HIV and HCMV. Complete clinical data were available for 4 of the 7 cases with coinfection and each had AIDS dementia complex.

Cytomegalovirus infection of the brain in AIDS: a clinicopathological study

Based on neuropathological findings, a retrospective case control study of 39 patients with acquired immune deficiency syndrome (AIDS) and confirmed cytomegalovirus (CMV) infection of the brain is presented. Since 1989, the incidence has increased progressively and, in 1994, CMV was the most frequent opportunistic central nervous system (CNS) infection. Of the patients with CMV infections of the brain 16 had one or more coexisting secondary opportunistic and/or tumorous lesions in the CNS. Cerebral involvement by CMV was more frequent in patients with multiple extracerebral organ infections, while 7 among the 39 reported cases showed isolated CMV infection of the brain. The evaluation of the clinical records of 21 patients revealed neuropsychiatric signs and symptoms in 10, while these were absent in 11. All of these patients revealed various types of cerebral lesions related to CMV infection: ventriculitis, focal lesions, and microglial nodule encephalitis. The extent and distribution of cerebral lesions showed no significant correlations with clinical, radiological, or laboratory findings. Further clinicopathological studies are warranted to recognize CMV infections of the CNS and to allow earlier and more efficient treatment of this rather frequent complication of AIDS.

Cytomegalovirus viraemia in HIV infection: association with intercurrent infection

The aim of this retrospective study was to investigate the clinical significance of cytomegalovirus (CMV) viraemia in HIV-infected subjects (with or without AIDS) who had attended this hospital during a 45 month period. They were reviewed regularly and, when clinically indicated, tested for CMV viraemia. The blood of 105 subjects was cultured for CMV and 34 had at least one episode of CMV viraemia during the review period. The viraemia was present during CMV disease in nine of the 34 positive patients and was the only detectable infection in another two. In the remaining 23 patients, CMV viraemia occurred in association with intercurrent opportunistic infection. Among these 23 patients, the viraemia resolved in 12 after treatment (or natural resolution) of the intercurrent infection and only one of these 12 developed CMV disease (mean review period: 8 months). In another seven patients, CMV viraemia persisted despite treatment (or natural resolution) of the intercurrent infection and four subsequently developed CMV disease (mean review period: 4 months) (P = 0.08, Fisher's exact test). From the remaining four patients, no specimens for CMV culture were obtained after treatment of the intercurrent infection. The CD4 count was higher in the 12 patients in whom there was resolution of the viraemia [mean CD4 60 x 10(6)/l] compared with the seven in whom the viraemia persisted [mean CD4 45 x 10(6)/l]. These findings suggest that in some HIV-positive patients, CMV viraemia was potentiated by intercurrent infection with another micro-organism and that its treatment was sufficient to mitigate the CMV disease.

Longitudinal study of cytomegalovirus antibodies in individuals infected with the human immunodeficiency virus

Cytomegalovirus (CMV) antibody profiles were studied in 25 HIV-infected patients over periods of up to 56 months. Specific antibodies against CMV antigen components were monitored by complement-fixation (CF) test, EIA, Western blot and a neutralization assay. Three subjects remained CMV seronegative throughout the study. Marked fluctuations were observed in anti-CMV antibodies assayed by the CF test as compared to a control group. Fluctuations on immunoblots of purified virion antigens were also observed in the HIV-infected patients; neutralizing antibodies and anti-CMV nucleocapsid antibodies showed less variability. Seven of 22 individuals exhibited an increase in CF-test titre of up to 64-fold without clinically apparent CMV disease. On Western-blot testing of IgG reactivity with disrupted virions, ten individuals exhibited increasing reactivity to pp65, and only three of these also showed a titre rise in the CF test. In contrast, 7 of 22 showed low reactivity to the pp28 antigen. The homosexual patient group exhibited the highest levels of anti-CMV antibody. In conclusion, many asymptomatic HIV-infected subjects showed fluctuations at different levels of their antibody response to CMV, thought to be indicative of CMV reactivation/reinfection. Western-blot findings indicated that some CMV antibodies increased in level while others were lost.

Five myths about AIDS that have misdirected research and treatment

A number of widely repeated and factually incorrect myths have pervaded the AIDS research literature, misdirecting research and treatment. Five of the most outstanding are: 1) that all risk groups develop AIDS at the same rate following HIV infection; 2) that there are no true seroreversions following HIV infection; 3) that antibody is protective against HIV infection; 4) that the only way to treat AIDS effectively is through retroviral therapies; and 5) that since HIV is so highly correlated with AIDS incidence, it must be the sole necessary and sufficient cause of AIDS. A huge body of research, reviewed in this paper, demonstrates the falsity of these myths. 1) The average number of years between HIV infection and AIDS is greater than 20 years for mild hemophiliacs, 14 years for young severe hemophiliacs, 10 years for old severe hemophiliacs, 10 years for homosexual men, 6 years for transfusion patients of all ages, 2 years for transplant patients, and 6 months for perinatally infected infants. These differences can only be explained in terms of risk-group associated cofactors. 2) Seroreversions are common. Between 10 and 20 percent of HIV-seronegative people in high risk groups have T-cell immunity to HIV, and may have had one or more verified positive HIV antibody tests in the past. 3) Antibody, far from being protective against HIV, appears to be highly diagnostic of loss of immune regulation of HIV, and some evidence of antibody-enhancement of infection exists. 4) Non-retroviral treatments of HIV infection, including safer sex practices, elimination of drug use, high nutrient diets, and limited reexposure to HIV and its cofactors have proven to be effective means of preventing or delaying onset of AIDS. 5) Many immunosuppressive factors, including drug use, multiple concurrent infections, and exposure to alloantigens, are as highly correlated with AIDS risk groups as HIV. These data are more consistent with AIDS being a multifactorial or synergistic disease than a monofactorial one.

Tumor necrosis factor alpha promotes replication and pathogenicity of rat cytomegalovirus

We investigated the role of tumor necrosis factor alpha (TNF-alpha) in the pathogenesis of rat cytomegalovirus (RCMV) infection. TNF-alpha levels found in the sera of radiation-immunosuppressed rats in the course of infection (> 350 pg/ml) correlated with the development of RCMV disease. Administration of anti-TNF-alpha antibodies strongly reduced the severity of pneumonia and led to a reduction in virus titers. In immunocompetent rats, anti-TNF-alpha antibodies also significantly suppressed viral replication. Conversely, administration of TNF-alpha augmented RCMV replication and aggravated the disease signs. In vitro, TNF-alpha enhanced RCMV replication in the macrophage, whereas a reduction of viral replication was observed in fibroblasts, indicating that the effect on viral replication is cell type specific. Besides activation of viral replication and exacerbation of RCMV disease, TNF-alpha also favored lymphoid and hematopoietic tissue reconstitution after irradiation, which may contribute to antiviral resistance and survival. This finding demonstrates the protean nature of TNF-alpha, with both beneficial and adverse effects for the host. Our results suggest that TNF-alpha plays an important role in modulating the pathogenesis of RCMV infection.

Activation of the human immunodeficiency virus type 1 long terminal repeat by transforming mutants of human p53

We have studied the effects of human wild-type and mutant p53s on the long terminal repeat (LTR) promoter of human immunodeficiency virus type 1 (HIV). HeLa cells were cotransfected with a wild-type or mutant p53 expression plasmid and a plasmid containing a chloramphenicol acetyltransferase reporter gene under HIV LTR promoter control. As expected, expression of wild-type p53 inhibited promoter function. Expression of a p53 mutated at any one of the four amino acid positions 175, 248, 273, and 281 correlated with a significant increase of the HIV promoter activity. The HIV LTR was also significantly activated in Saos-2 cells that do not express endogenous p53. This finding suggests a gain-of-transactivation function by mutation of the p53 gene. Cotransfection of wild-type and mutant p53-281G expression plasmids indicated that either the wild type or the mutant was dominant in inhibiting or enhancing promoter activity, respectively, when transfected in excess of the other. Transfection experiments showed transactivation even when the Sp1, NF-kappa B, and TATA sites in the LTR were individually mutated. Synthetic minimal promoter constructs containing two Sp1 sites or two NF-kappa B sites or an ATF site are also significantly activated by the mutant p53-281G. Thus, the mutant protein may activate transcription through interaction with either a general transcription factor or a common factor that bridges the basal transcription machinery and the transcription factors Sp1, NF-kappa B, and ATF.

Antiviral susceptibility testing of cytomegalovirus from primary culture using shell vial assay to detect the late viral antigen

Susceptibility testing of 68 cytomegalovirus (CMV) peripheral blood isolates to Ganciclovir (DHPG) and 11 blood isolates to Foscarnet (PFA), was performed on primary culture isolates using the shell vial assay methodology (SVA-IFA, that is, quantitation of fluorescent focus units, FFUs), with an anti-CMV monoclonal antibody to the late viral antigen. A positive reaction in monolayer cultures of MRC-5 cells was characterized by cytoplasmic fluorescence with inclusions at both or more commonly off one end of the elongated fibroblast nucleus. Isolates from conventional MRC-5 tube cultures displaying a 1+ (10% cytopathic effect) were inoculated into shell vials containing DHPG concentrations of 0, 1.5, 3, 6, 12, or 24 microliters/ml shell vials containing 400, 500, 800, or 1200 microM PFA. The optimal readability of monolayers (expressed as FFUs per monolayer) occurred at 96 h after treatment with DHPG and at 36-48 h with PFA. Resistance to DHPG was determined at the concentration of antiviral agent necessary to reduce the number of FFUs to 90% or 50% of the control [that is, the 90% minimum inhibitory concentration (MIC90) or MIC50]. Six of 68 isolates showed an MIC90 > 12 or an MIC50 > 1.5 microgram/ml, and were considered DHPG resistant. Three of the six isolates were from AIDS patients with late-stage disease who had never received DHPG therapy. All but one (specimen 2400) DHPG-resistant isolates revealed MIC90 values to a PFA concentration of 500 microM, which is considered an achievable peak plasma level in patients undergoing PFA therapy. The single DHPG- and FPA-resistant isolate was obtained from a patient displaying marked clinical resistance to both drugs.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions between HIV-1 and cytomegalovirus in human osteosarcoma cells carrying both viruses

Cytomegalovirus (CMV) and the human immunodeficiency virus type 1 (HIV-1) may interact in the pathogenesis of AIDS. We compared CMV replication in human osteosarcoma (HOS) cells to that in HOS cells genetically engineered to contain an envelope-deficient HIV-1 proviral construct (designated HOS-HXG). Following acute CMV infection of each cell line, HOS-HXG cells contained higher numbers of intranuclear CMV nucleocapsids than did HOS cells. Infectious CMV could be persistently detected in culture supernatant fluids of the CMV-infected HOS-HXG cells, whereas CMV was lost over several weeks from HOS cells infected with CMV in parallel. HIV-1 CMV pseudotypes were not detected in supernatant fluids from CMV-infected HOS-HXG cells. On day 119 after CMV infection, these cultures were superinfected with HIV-1. These dually infected HOS-HXG cells produced infectious HIV-1 and exhibited markedly enhanced CMV replication compared to parental CMV-infected HOS-HXG cells. Two different HIV-1 tat gene function antagonists, Ro24-7429 and chemically modified antibodies to the Tat protein, did not inhibit the replication of CMV in either acute or persistent infections of HOS-HXG cells at concentrations that inhibited HIV-1 replication.

TAR-independent transactivation of the murine cytomegalovirus major immediate-early promoter by the Tat protein

Tat is a transactivator of human immunodeficiency virus type 1 (HIV-1) that stimulates gene expression via an RNA target sequence (TAR) by augmenting transcriptional initiation and/or elongation from the HIV-1 long terminal repeat promoter. Here we show that Tat is able to transactivate the murine cytomegalovirus (MCMV) major immediate-early promoter (MIEP), which lacks sequence similarity with the HIV-1 long terminal repeat TAR element. Surprisingly, deletion of the upstream enhancer region (-610 to -146) of the MCMV MIEP abrogated Tat responsiveness. This result suggests that Tat requires a DNA target for function. Quantitation of RNA and protein indicates that Tat stimulates expression from the MCMV MIEP at both the transcriptional and translational levels. Deletion analysis of the MIEP indicates that there is likely to be interplay between the enhancer region, a sequence upstream of the known enhancer which negatively affects expression, and the Tat protein.

AIDS dementia complex complicated by cytomegalovirus encephalopathy

We have studied longitudinally ten patients with AIDS encephalopathy with respect to pathogenetic roles of human immunodeficiency virus (HIV) and cytomegalovirus (CMV). Three patients manifested typical AIDS dementia complex (ADC) (initially without retinitis and with slowly progressive cognitive, motor and behavioral abnormalities which were zidovudine-responsive, and relatively preserved CD4+ T cells), and seven patients presented with AIDS dementia complex complicated by CMV encephalopathy (ACE) (with CMV retinitis, peripheral neuropathy, altered sensorium, and rapidly declining clinical and immunological status). Whereas only HIV antibody was elevated in the spinal fluid of patients with ADC, both virus infections were active in the central nervous system of patients with ACE as shown by HIV p24 antigenemia and antigenrrhachia, elevated HIV and CMV antibody in the spinal fluid, disseminated CMV infection with retinitis, and basilar ventriculoencephalitis with multinucleated cytomegalic cells containing CMV and HIV proteins and CMV DNA. The recognition of ADC and ACE is important, since some patients with ACE may respond to ganciclovir or foscarnet.

High levels of circulating cytomegalovirus DNA reflect visceral organ disease in viremic immunosuppressed patients other than marrow recipients

Although viremia is a hallmark of disseminated cytomegalovirus (CMV) infection, not all viremic patients have visceral organ CMV disease. We used blot hybridization with a cloned subgenomic probe to quantitate viral DNA in blood leukocytes of 60 viremic patients (25 with solid organ transplants, 20 with AIDS, and 15 marrow recipients) who had different clinical manifestations of CMV infection. The results are expressed as pg of viral DNA/10 micrograms of leukocyte DNA. Patients with AIDS or with solid organ transplants who had CMV visceral organ disease had the largest amounts of viral DNA in their granulocytes (median 632 and 237 pg, respectively). These amounts were significantly greater than those in similar viremic patients without CMV visceral disease (17 and 21 pg; P < 0.005 and 0.002, respectively). All patients in the study with > 150 pg of CMV DNA in their granulocytes had visceral CMV disease. The amounts of viral DNA in granulocytes of AIDS and organ transplant patients with CMV retinitis were low (median 22 pg). Marrow transplant patients were unique in that the amounts of CMV DNA in granulocytes were low whether CMV visceral organ disease was present (17 pg) or absent (14 pg). We conclude that high levels of circulating CMV DNA in viremic AIDS and solid organ transplant patients reflect viral involvement of visceral organs but not the retina. In marrow recipients, the severity of CMV disease, even when fatal, is not reflected quantitatively in peripheral blood leukocytes.

Enhanced shedding of cytomegalovirus in semen of human immunodeficiency virus-seropositive homosexual men

Site-specific shedding of cytomegalovirus (CMV) was assessed in a longitudinal study of homosexual and bisexual men. At initial testing, CMV was cultured from the semen of 33% (19 of 58) of asymptomatic and mildly symptomatic men who were seropositive for human immunodeficiency virus (HIV) at the time of entry into the study, whereas it was cultured from the semen of 17% (10 of 58) of the men who were HIV seronegative. CMV was isolated much more frequently from semen than from urine or throat washing specimens, and it was rarely recovered from stool or blood, regardless of the subject's HIV serostatus. CMV was cultured from the semen of 31% (16 of 52) of the men relatively early after seroconversion to HIV (mean, 12.8 months). CMV was persistently isolated from the semen of a greater proportion of the HIV-seropositive men than from the semen of the HIV-seronegative men during a 4.5-year follow-up period (52 of 110 - [47%] and 15 of 58 [26%] men, respectively). There was an increased relative risk for shedding of CMV in semen in association with decreased CD4+ cell numbers and increased levels of serum immunoglobulin A. However, there was no association of CMV shedding with an increased risk for the development of AIDS.

Antibodies to Epstein-Barr virus and cytomegalovirus in relation to CD4 cell number in human immunodeficiency virus 1 infection

Interaction between herpesviruses and human immunodeficiency virus (HIV)1 is postulated in the progression of HIV disease. In order to evaluate the specific antibody responses directed to Epstein-Barr virus (EBV) and cytomegalovirus (CMV) and to provide serological evidence suggesting reactivation of these viruses able to accelerate the immunodeficiency, we studied IgA and IgG titres to EBV and CMV in the serum of HIV positive patients in relation to the CD4 cell number. The titres of IgG antibodies to EBV and the prevalence of IgG to CMV were significantly higher in HIV positive patients compared to control high risk HIV negative subjects. In HIV infected patients, anti-VCA IgG antibodies increased and anti-EBNA IgG antibodies decreased progressively in relation to the decline of CD4 cell number whereas anti-CMV IgG antibodies did not varied significantly at the same time. Anti-VCA IgA and anti-EA IgG antibodies were found uncommonly and with low titres. IgA antibodies to EA and CMV were not detected in any patient. The variations in EBV antibody response that we describe in HIV infection were previously reported in other immunodeficiency states and could be distinctive of these diseases.

A discrete cis element in the human immunodeficiency virus long terminal repeat mediates synergistic trans activation by cytomegalovirus immediate-early proteins

The major immediate-early (IE) promoter of human cytomegalovirus directs the expression of several differentially spliced and polyadenylated mRNAs that encode isoformic proteins with apparent molecular masses of 55, 72, and 86 kDa. All of these proteins are potent transcriptional regulatory proteins. We are interested in the collateral interactions between human cytomegalovirus and human immunodeficiency virus (HIV) in the context of dual infection of a cell. The roles of the specific IE protein isoforms and their respective response elements involved in trans activation of the HIV long terminal repeat (LTR) are not known. Here we present evidence that major IE proteins IE86, IE72, and IE55 are capable of trans-activating the HIV LTR in a T-cell line, HUT-78. The IE55 isoform noncooperatively stimulates the HIV LTR in the presence of either isoform IE72 or IE86. Interactions between isoforms IE72 and IE86, however, result in strong synergistic activation of the LTR. Our results suggest that a specific 155-amino-acid protein domain that is unique for the IE86 protein participates in this synergic interaction. Point mutational analysis of the LTR identified a distinct cis-acting target site, located between nucleotide positions -174 and -163, that mediates exclusively synergistic trans activation by the IE72 and IE86 proteins. Finally, this study underscores the role of a cellular intermediate(s) for communicating the synergic interactions between two IE trans activators.

Cytomegalovirus IgG and IgA serum antibodies in a study of HIV infection and HIV related diseases in homosexual men

The significance of serum IgG and IgA antibodies to cytomegalovirus (CMV) at various stages of human immune deficiency virus (HIV) infection was studied in 175 homosexual men. Sera were obtained from 123 HIV seropositives [41 asymptomatic, 29 with lymphadenopathy associated syndrome (LAS), 22 with AIDS related complex (ARC), and 31 AIDS patients], 17 HIV seroconverters, and 35 HIV asymptomatic seronegatives. The sera were tested blindly for CMV IgA and IgG antibodies using the immunoperoxidase assay (IPA) and CMV infected human embryo cells. Cross-sectional analysis of CMV IgG antibodies at a titer of greater than or equal to 20 showed 87% and 100% prevalence in the HIV seronegative groups and in the HIV seropositive groups, respectively (P less than 0.05). CMV IgG antibodies at a titer of greater than or equal to 80 were present in significantly higher proportions among the HIV seropositive subjects of the various groups as compared with the HIV seronegative homosexual men. However, in the HIV seronegatives who later seroconverted to HIV, a significantly higher prevalence of CMV antibodies (35%) was detected before HIV seroconversion, as compared with the persistently HIV seronegative subjects (14.3%) (P less than 0.05). The HIV seronegatives pre-HIV seroconversion also exhibited a significantly higher geometric mean titer (GMT) of CMV IgG antibodies (62.17 +/- 0.64) as compared with the persistently HIV seronegatives (34.0 +/- 0.6) (P = 0.03). Significantly higher GMTs of CMV IgG antibodies were detected in all the HIV seropositive groups as compared with the persistently HIV seronegative group. CMV IgG antibodies were not detected in the HIV seronegative subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Human immunodeficiency virus type 1 antigenaemia is enhanced in patients with disseminated cytomegalovirus infection and deficient T lymphocytes

We have studied 61 patients with the acquired immunodeficiency syndrome (AIDS) regarding the relationships between disseminated cytomegalovirus (CMV) infection with CMV retinitis, HIV1 antigenaemia and CD4+ and CD8+ T-cell deficiency. HIV1 p24 antigenaemia was present in all patients with CMV retinitis (at a high concentration), but in only 28% of patients without retinitis (at a low concentration). Compared to patients without retinitis, those patients who developed retinitis had lower CD4+ and CD8+ prior to and during AIDS. CMV may contribute to deficiencies of T lymphocytes in patients with AIDS.

Early virus isolation, early structural antigen detection and DNA amplification by the polymerase chain reaction in polymorphonuclear leukocytes from AIDS patients with human cytomegalovirus viraemia

Fifty AIDS patients were investigated for human cytomegalovirus (HCMV) viraemia when potentially HCMV-related clinical symptoms or syndromes were observed. Nine patients underwent prolonged virologic follow-up, while 41 additional patients were examined only once or sporadically. Concentrated preparations of polymorphonuclear leukocytes (PMNL) from 153 blood samples were obtained for monitoring: (1) early virus isolation in cell cultures 24 h p.i. (viraemia); (2) early structural antigen detection in cytospin preparations (antigenemia); and (3) HCMV DNA in blood (DNAemia) through DNA amplification by the polymerase chain reaction (PCR). Viraemia and antigenemia were quantitated, whereas evaluation of DNAemia was only qualitative. A good correlation between levels of viraemia and antigenemia was consistently found except during ganciclovir treatment. HCMV-related clinical symptoms were observed when the number of infected PMNL was greater than 100 per 2 x 10(5) cells examined. All 56 blood samples positive for viraemia and antigenemia were also PCR-positive, whereas 44 samples (39 of which taken from patients with ascertained HCMV infection in blood) were positive by PCR only. Viraemia and antigenemia were often unrelated to HCMV organ syndromes, such as retinitis, in which only DNAemia was often detected. Prolonged ganciclovir treatment kept viraemia, antigenemia and even DNAemia at a low or negative level, yet drug discontinuation led to rapid progression of HCMV infection in blood. In addition, prolonged antiviral treatment could induce appearance of ganciclovir-resistant HCMV strains, requiring alternative foscarnet therapy. In conclusion, determination of viraemia and antigenemia appears essential for correct clinical management and antiviral treatment of disseminated HCMV infections in AIDS patients. However, PCR is the most sensitive method for diagnosis and monitoring of HCMV infections in blood at a pre-clinical stage.

Modulation of T-cell activation through protein kinase C- or A-dependent signalling pathways synergistically increases human immunodeficiency virus long terminal repeat induction by cytomegalovirus immediate-early proteins

By using human CD4+ lymphoblastoid T cells transiently cotransfected with human immunodeficiency virus (HIV) and cytomegalovirus (CMV), we tested whether modulation of T-cell activation through the protein kinase C (PKC) or the protein kinase A (PKA) pathway synergized with CMV immediate-early (IE) proteins in HIV long terminal repeat (LTR) transactivation. Stimulation with phorbol myristate acetate, tumor necrosis factor, or cross-linked antibodies to CD3 and CD28 resulted in modest enhancement (two- to fourfold) of the activity of a luciferase expression vector under control of the HIV LTR. Cotransfection of a vector expressing the CMV IE1 and IE2 proteins under the control of their own promoter enhanced HIV LTR activity 16- to 49-fold. Combination of any one of the above stimuli and CMV IE expression amplified HIV LTR activity 99- to 624-fold. Stimulation of PKA-dependent pathways with forskolin, 8-bromo cyclic AMP, or prostaglandin E2 had a minimal effect on HIV LTR activity, whereas such stimuli resulted in synergistic amplification in cells cotransfected with CMV IE (three- to fivefold increases over the effects of CMV IE alone). This synergism was independent of the NF-kappa B binding motifs within the HIV LTR. CMV IE2, but not IE1, protein induced HIV transactivation and synergized with signals modulating T-cell activation. The intense synergism observed was superior to the increase in IE protein expression following PKC activation by phorbol myristate acetate. Treatment of cells with PKC inhibitor GF109203X blocked most of the observed synergism.(ABSTRACT TRUNCATED AT 250 WORDS)

Infecção pelo citomegalovírus em pacientes com síndrome da imunodeficiência adquirida (AIDS): relações clínico-virológicas e anatomopatológicas

Com o objetivo de determinar a prevalência da infecção pelo Citomegalovírus (CMV) em pacientes com AIDS, bem como relacionar os achados clínico-virológicos decorrentes desta infecção com as repercussões anatomopatológicas, estudamos 50 pacientes adultos atendidos entre abril de 1986 a junho de 1987, em dois hospitais públicos de São Paulo (HSP e HSPE). Estes pacientes foram acompanhados clínica e laboratorialmente, por período médio de 2 meses com coletas seriadas de sangue, urina e saliva. Foram realizados isolamento do CMV em monocamadas de fibroblastos humanos e testes sorológicos de Imunofluorescência Indireta (IFI-IgG/IgM) e Reação Imunoenzimática (ELISA-IgG). No momento da admissão no estudo 20% (10/50) dos pacientes apresentavam anticorpos IgM CMV específicos e 100% (50/50) deles anticorpos IgG (IFI). Durante o acompanhamento, 5 pacientes inicialmente IgM negativos tornaram-se IgM positivos, sugerindo reativação ou reinfecção pelo CMV. O CMV foi isolado de sangue periférico em 12,5%, da urina em 23,2%, da saliva em 21,9% dos pacientes. Exames anatomopatológicos foram realizados em 24 pacientes, correspondendo a 60% dos pacientes que evoluiram para óbito durante o período de estudo. Corpúsculos de inclusão citomegálica característicos foram observados em 50% das necrópsias, sendo o aparelho digestivo, pulmões e supra-renais os sítios mais acometidos. Não se observou uma relação estatisticamente significante entre os achados clínicos e os achados virológicos e anatomopatológicos.

Prevalence of antibodies to human herpesviruses and hepatitis B virus in patients at different stages of human immunodeficiency virus (HIV) infection

The results of antibody assays for viruses of the herpes group (HSV, EBV, VZV and CMV) and for hepatitis B virus (HBV) were retrospectively evaluated in 439 HIV-seropositive patients classified into different stages of HIV infection. The prevalence of specific IgG, IgM and IgA antibodies in these groups was compared with that of a control group of HIV-negative unselected hospital patients. Antibodies to herpes viruses and HBV were more prevalent amongst HIV-seropositives, especially LAS and AIDS patients than in controls. However, marked differences were found only with CMV-IgG and anti-HBc-IgG, both with a comparatively low prevalence in HIV-negative persons (64.5% and 23.2%). Significantly more seropositives were found among asymptomatic HIV carriers (83.3% and 50%) and still more in patients with full-blown AIDS (95.4% and 82.5%). The increased frequency of CMV and HBV antibodies, already seen in asymptomatic HIV patients reflects their higher risk for sexually transmitted infections. Moreover, IgA antibodies to CMV were detected in 25.4% of LAS and 37.3% of AIDS patients, respectively, but only in 7.6% of the controls. Elevated CMV-IgA titres were found exclusively in HIV-infected persons. The differences in the antibody patterns found in this cross-sectional study may reflect the progression of the HIV disease. However, prospective follow-up studies are required to assess the value of these markers as indicators of prognosis in HIV-infected subjects.

Pathological features of virus infections of the central nervous system (CNS) in the acquired immunodeficiency syndrome (AIDS)

Neurological disorders are a common cause of morbidity and mortality in the acquired immunodeficiency syndrome (AIDS). In this report we describe the neuropathological changes associated with both human immunodeficiency virus (HIV) infection and with the major opportunistic virus infections, cytomegalovirus (CMV), JC papovavirus (JCV) and herpes simplex virus (HSV) seen in AIDS. In addition "in situ" hybridization studies have been employed for the detection of virus genomic material in each case and the usefulness of this method in supporting the pathological diagnosis is demonstrated. Mechanisms whereby HIV infection results in leukoencephalopathy and the possible contributing roles of the three opportunistic virus infections are discussed.

Multi-step pathogenesis of AIDS--role of cytomegalovirus

Human immunodeficiency virus (HIV) has been shown to be the initial aetiological agent of the acquired immune deficiency syndrome (AIDS). The recent clinical, epidemiologic, pathological, immunological and molecular data presented in this review point to a multi-step pathogenesis of AIDS involving HIV as an initial cause leading to reactivation of cytomegalovirus (CMV), human herpesvirus-6 (HH-6) and other immunosuppressive organisms. Although the onset of CMV reactivation is not precisely known, it may be related to the transition from AIDS-related complex to AIDS. The molecular interactions between CMV and HIV occur in both directions. Although transcriptional activation of HIV by CMV infection (possibly via induction of NF chi B) is better known, the enhancement of CMV replication by HIV is clinically as important. The interactions between HIV or simian immunodeficiency virus (SIV) and CMV appear to be more specific than between HIV or SIV and other herpes viruses, and are also cell-type-dependent. CMV-induced immune suppression (possibly of variable magnitude with different strains) may be an additional co-factor in AIDS. In a rhesus monkey model, the interaction of SIV with rhesus CMV appears contributory to the reproduction of the full-blown simian AIDS. Patients with AIDS and disseminated CMV infection display the maximum activation of HIV p24 antigenaemia and the greatest deficiency of CD8+ T lymphocytes. Defects in CD4+ and CD8+ T cells, including HIV- and CMV-specific cytotoxic T cells, are crucially important in the progression to terminal AIDS and are related not only to HIV but also to CMV and HH-6 infections of lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Pseudotyping with human T-cell leukemia virus type I broadens the human immunodeficiency virus host range

Several epidemiologic and clinical studies suggest that patients coinfected with human immunodeficiency virus (HIV), the primary etiologic agent in AIDS, and other viruses, such as cytomegalovirus or human T-cell leukemia virus (HTLV), have a more severe clinical course than those infected with HIV alone. Cells infected with two viruses can, in some cases, give rise to phenotypically mixed virions with altered or broadened cell tropism and could therefore account for some of these findings. Such pseudotypes could alter the course of disease by infecting more tissues than are normally infected by HIV. We show here that HIV type 1 (HIV-1) efficiently incorporates the HTLV type I (HTLV-I) envelope glycoprotein and that both HIV-1 and HTLV-II accept other widely divergent envelope glycoproteins to form infectious pseudotype viruses whose cellular tropisms and relative abilities to be transmitted by cell-free virions or by cell contact are determined by the heterologous envelope. We also show that the mechanism by which virions incorporate heterologous envelope glycoproteins is independent of the presence of the homologous glycoprotein or heterologous gag proteins. These results may have important implications for the mechanism of HIV pathogenesis.

Immune responses to fractionated cytomegalovirus (CMV) antigens after HIV infection. Loss of cellular and humoral reactivity to antigens recognized by HIV-, CMV+ individuals

In order to delineate the molecular pathogenesis of the increased susceptibility to CMV disease in HIV infection, the patterns of antigen responsiveness in HIV-infected and non-infected individuals were investigated. CMV was fractionated by SDS-PAGE and electroblotted onto nitrocellulose. Lymphoproliferative responses of healthy HIV-, CMV+ individuals and HIV+, CMV+ asymptomatic patients to a whole CMV antigen preparation and to 20 fractions of nitrocellulose-bound CMV were then compared. Three fractions of approximate molecular weight of 130-165, 65-75, and 55-65 kD appeared to contain the major T cell stimulating antigens for HIV-, CMV+ individuals. A statistically significant depression of responses to fractions containing antigens in the ranges of 130-165 kD and 55-65 kD but not to whole CMV was seen in HIV+ individuals compared with controls. In healthy controls, the sum of the proliferative responses as measured by 3H-thymidine uptake to these three major fractions was approximately equal to the response to a whole CMV antigen preparation, whereas it was less than half of this response in five out of six HIV+ subjects. When antibody activities to CMV antigens were analysed by immunoblotting of sera from the two subject groups and also sera of ARC and AIDS patients, a selective loss of reactivity was revealed in 10 out of 19 HIV+ subjects to a band of 26-28 kD whereas all 15 HIV-, CMV+ controls recognized this band. Serum IgG and IgM values were both significantly higher in HIV+ individuals than in controls. These findings suggest that specific lesions in the repertoire of immune responsiveness to CMV antigens occur in HIV+ individuals.

Predictive value of cytomegalovirus viraemia for the occurrence of CMV organ involvement in AIDS

In HIV-infected patients, the presence of cytomegalovirus (CMV) viraemia is predictive of the development of acquired immunodeficiency syndrome (AIDS), but it is not known whether it predicts further occurrence of CMV organ involvement. To assess the predictive value of CMV viraemia in the occurrence of CMV organ involvement, CMV blood cultures were performed at the onset of AIDS in 71 patients. They were prospectively followed up for at least 6 months, with a mean of 16.6 +/- 7 months (6-36 months). CMV viraemia was present in 28/71 patients (39.5%) at the onset of AIDS. CMV organ involvement occurred in 18/71 patients (25.4%) after 8.7 +/- 3.3 months. Fourteen of the 28 patients (50%) with early CMV viraemia developed CMV organ involvement after 7.7 +/- 6.3 months as compared with 4/43 patients (9.3%) who were not viraemic at the onset of AIDS with a mean follow-up of 11.8 +/- 3.8 months (P less than 0.001). At the time of CMV organ involvement, CMV viraemia, however, was present in 94.4% of the cases. No differences in survival was observed between initially viraemic and non-viraemic patients. No difference has found in mean CD4 cell count between viraemic and non-viraemic patients. This high predictive value of early CMV viraemia in AIDS for the occurrence of CMV organ involvement underlines the need for repeated search for CMV organ involvement when CMV viraemia is detected, and for less toxic antiviral drugs that might be used earlier.

Role of primary and secondary maternal viremia in transplacental guinea pig cytomegalovirus transfer

The modulation of the outcome of intrauterine guinea pig cytomegalovirus (GPCMV) infection by maternal viremia was investigated in the guinea pig model. Virus assay and in situ hybridization were used to study GPCMV infection of maternal blood, placentas, and fetuses following inoculation of pregnant guinea pigs by the subcutaneous, intracardiac, or intranasal route. Animals were inoculated in early gestation and were evaluated every 7 to 10 days throughout pregnancy. Although placental and fetal infections occurred in all groups examined, transfer of GPCMV to placentas and fetuses was most efficient in mothers inoculated subcutaneously. Primary viremia was followed by virus clearance from blood and by an episode of secondary viremia in the three groups of mothers examined. Placental and fetal infections in animals infected subcutaneously or intracardially were first detected at the time of primary viremia, persisted throughout gestation, and increased during secondary viremia. In contrast, placental and fetal infections in animals inoculated intranasally were demonstrated primarily during secondary viremia. Fetal infection was detected in all mothers with detectable primary and secondary viremia but in only 33% of mothers that experienced only primary viremia. These results suggest that secondary maternal viremia is associated with increased placental and fetal GPCMV infections.

HIV susceptibility conferred to human fibroblasts by cytomegalovirus-induced Fc receptor

The main receptor for the human immunodeficiency viruses type 1 and 2 (HIV-1 and HIV-2) on T and B lymphocytes, monocytes and macrophages is the CD4 antigen 1-3. Infection of these cells is blocked by monoclonal antibodies to CD4(1,2) and by recombinant soluble CD4(4-9). Expression of transfected CD4 on the surface of HeLa and other human cells renders them susceptible to HIV infection 10. HIV-antibody complexes can also infect monocytes and macrophages by means of receptors for the Fc portion of immunoglobulins (FcR)11-13), or complement receptors 14,15. The expression of IgG FcRs can be induced in cells infected with human herpes viruses such as herpes simplex virus type 1 (HSV-1)16,17 and human cytomegalovirus (CMV)18-21. Here we demonstrate that FcRs induced by CMV allow immune complexes of HIV to infect fibroblasts otherwise not permissive to HIV infection. Infection was inhibited by prior incubation with human IgG, but not by anti-CD4 antibody or by recombinant soluble CD4. Once HIV had entered CMV-infected cells by means of the FcR, its replication could be enhanced by CMV transactivating factors. Synergism between HIV and herpes viruses could also operate in vivo, enhancing immunosuppression and permitting the spread of HIV to cells not expressing CD4.

Cytomegalovirus (CMV) encephalomyeloradiculitis and human immunodeficiency virus (HIV) encephalitis: presence of HIV and CMV co-infected multinucleated giant cells

A 25-year-old homosexual male with AIDS presented with a cauda equina syndrome clinically suggestive of cytomegalovirus (CMV) myeloradiculitis. He was treated with ganciclovir with transient improvement of neurological signs and died 4 months after onset of neurological signs. Neuropathological examination revealed human immunodeficiency virus (HIV) encephalitis, CMV subependymal encephalitis and CMV myeloradiculitis. The latter was characterised by myelin loss, Schwann cell proliferation and presence of CMV early antigens in the nuclei of S-100 protein-positive cells in the spinal roots. In the subependymal regions, morphologically characteristic multinucleated giant cells, positive for CD68, contained early CMV antigens (E13) in their nuclei and HIV antigens (gp41 and p24) in their cytoplasm. The observation that HIV and CMV can co-infect the same cell in vivo raises the possibility of a direct synergistic interaction of both viruses at cell level. This suggests that CMV may play a role as a co-factor in the pathogenesis of HIV encephalopathy.

Cytomegalovirus enhances lysis of HIV-infected T lymphoblasts

A T4+ lymphoblastoid cell line (CR-10) persistently infected with the human immunodeficiency virus (HIV) and designated CR-10/NIT was superinfected with cytomegalovirus (CMV) isolated from peripheral blood mononuclear cells of a patient with AIDS. A productive CMV cycle in the CR-10/NIT lymphoblasts was demonstrated by fluorescent antibody staining (IF) using a monoclonal antibody (MAb) to the 150-kDa major capsid protein, by infectivity assays and by electron microscopy (EM). Two-color IF analysis showed that a small percentage of the CR-10/NIT cells were producing both CMV and HIV at any one time. EM studies revealed that all doubly infected cells were lysed whereas most cells infected only with HIV appeared intact. Cell lysis appeared 24 hr after superinfection of the CR-10/NIT cells with CMV and progressed to complete destruction of the cell culture between days 9 and 10. Our results suggest that CMV may convert a mildly cytopathic HIV infection of T lymphoblasts into a highly lytic process.

Rapid (24h) neutralization assay for the detection of antibodies to human cytomegalovirus using a monoclonal antibody to an HCMV early nuclear protein

Neutralizing antibodies to human cytomegalovirus (HCMV) may play an important role during the course of an HCMV infection but yet detection with conventional methods remains difficult and time consuming. A new neutralization test has been developed basically corresponding to the known microtitre technique. A monoclonal antibody to an HCMV early nuclear protein is utilized to detect HCMV (AD169) infected fibroblasts by biotin/streptavidin-enhanced immunoperoxidase staining. The test procedure was thereby confined to only 24 h. Evaluation of the new neutralization test (24h-NT) was done in comparison to the conventional method (NT). Preselected serum samples (n = 217), of which n = 169 were HCMV-seropositive in ELISA (reciprocal titre greater than or equal to 40), were tested for neutralizing antibodies (NAbs) to HCMV. ELISA titres were measured by a commercially available kit (Behring, F.R.G.). NAbs could be detected in 107 sera by 24h-NT (reciprocal titre greater than or equal to 5) and in 110 sera determined by NT (reciprocal titre greater than or equal to 5). Those sera were exclusively positive in ELISA. ELISA negative sera (n = 48; reciprocal titre less than 40) yielded no detectable neutralizing titres. This specific and rapid test should facilitate HCMV-NAbs detection for a wide variety of applications including routine virology diagnostics, evaluation of HCMV hyperimmunoglobulins and medical research.

Detection of cytomegalovirus in bronchial lavage and urine using a monoclonal antibody to an HCMV early nuclear protein

Laboratory diagnosis of 24 cases of human cytomegalovirus (HCMV) infection in patients with the acquired immunodeficiency syndrome, renal transplant recipients and premature infants was achieved. These results were obtained by a rapid, sensitive and versatile HCMV-antigen detection method, which combined cell culture and immunoperoxidase staining with a monoclonal antibody to an HCMV "early" nuclear protein. The results were compared with HCMV isolation by the conventional cell culture method. While some of these immunocompromised patients lacked a significant antibody response, infective HCMV could be detected in the patients' urine and bronchial lavage fluid. The diagnostic procedure took no longer than 24 h. The usefulness of this antigen test for an effective diagnosis in immunocompromised individuals was demonstrated. We recommend routine analysis of various specimens, since recent developments in chemotherapy of HCMV infection and the risks of long-term damage demand immediate management of the patients concerned.

Value of necropsy in acquired immunodeficiency syndrome

Necropsy findings in 101 adult patients with the acquired immunodeficiency syndrome (AIDS) from two metropolitan hospitals were compared retrospectively with the antemortem clinical diagnoses. 94% of the patients were male and 68% were homosexual or bisexual. 75 (74%) patients had AIDS-related diseases at necropsy that were not suspected clinically. The commonest of the unsuspected AIDS-related diseases were cytomegalovirus infection (49% of all cases), systemic fungal infection (20%), systemic Kaposi's sarcoma (14%), Mycobacterium avium intracellulare infection (11%), and systemic herpes infection (9%). Cryptococcal infection and cytomegalovirus retinitis were always diagnosed antemortem; and Pneumocystis carinii pneumonia went undiagnosed in only 5 of 58 (9%) patients who had proven infection either clinically or at necropsy. 8 patients who died with fungal pneumonia had undergone bronchoscopy; however, in only 1 patient was it diagnosed antemortem. Tuberculosis was undiagnosed in 4 patients. 4 cases of central nervous system lymphoma diagnosed only at necropsy had been treated empirically for toxoplasmosis. Bacterial pneumonias contributed considerably to mortality in 30% of the patients.