Effect of Herpesvirus Inhibition on Primary SIV Infection in Cynomolgus Monkeys

Foscarnet and (-)9-[4-hydroxy-2-(hydroxymethyl)butyl] guanine (H2G) have already been shown to inhibit herpesviruses in vitro and also to inhibit viral antigen production in primary SIV infection in monkeys. Attempts have been made to determine if these invivo effects on SIV were due to a direct effect on SIV or were mediated through inhibition of endogenous transactivating herpesviruses. The possible involvement of herpesviruses in primary SIVsm infection in monkeys was studied by the use of various inhibitors of herpesvirus replication. Subcutaneous injections of 3 × 5 mg kg−1 day−1 of aciclovir, 3 × 5 mg kg−1 day−1 of ganciclovir and 3 × 28 mg kg−1 day−1 of phosphonoacetic acid had no effect on primary SIVsm infection in cynomolgus monkeys. These doses of aciclovir, ganciclovir and phosphonoacetic acid are inhibitory to several herpesviruses. The results suggest that the effects of foscarnet and H2G on primary SIVsm infection in monkeys are direct and not mediated through inhibition of a replicating herpesvirus.

Human retinal and brain cell lines: A model of HCMV retinitis and encephalitis

Although HIV is accepted as the etiologic agent in AIDS, other factors have been implicated in accelerating the disease. Human cytomegalovirus (HCMV) in particular has been implicated as a cofactor in the progression from AIDS-related complex (ARC) to AIDS. HCMV infection of the central nervous system (CNS) (brain, retina) has been reported in at least 50% of AIDS patients, and has been implicated in producing encephalitis and sight-threatening retinitis. HCMV exhibits strict species specificity and animal models for human HCMV are conspicuous by their absence. We have developed a human brain cell line (mixed glial/neuronal) and a multipotential human retinal precursor cell line (neuronal in nature). We have tested the suitability of these cell lines as models for the study of HCMV infectibility. In this study, we report that these cell lines are optimal for the study of HCMV infectibility and pathogenesis in tissues of neural origin and appropriate to study HIV-HCMV interaction. Immortalized human brain and retinal cell lines were infected with a laboratory strain of HCMV (AD 169, Towne) at a multiplicity of infection moi (1-5) and viral infectibility and cell specificity monitored by: (a) phenotypic analysis (multinucleate cells, syncytium formation, etc.), (b) antigen expression (IE, E, late) by immunohistochemistry, Western blot analysis, (c) presence of viral particles by TEM, and (d) expression of indicator plasmids (HIV-LTR-CAT). We report that both human retinal and brain cell lines are permissive for HCMV infectibility. Cell specificity was not seen; both cells expressing glial/neuronal cell markers were positive for the presence of HCMV early/late antigens. Formation of multinucleate giant cells with nuclear inclusion bodies and syncytia were seen. Productive viral infection was confirmed by the ability of cell-free supernatant from the third passage of infected cells to produce pathogenicity and express viral particles, when added to fresh cultures. Using indicator plasmids, HIV-LTR, and CAT, we have shown that HIV and HCMV interact at the cellular level. We have also shown that HIV production in retinal and brain cell lines transfected with cloned HIV was enhanced by HCMV-IE genes. We did not see any differences in HCMV. AD 169, Towne isolate, and data from both strains is presented in this paper. This model could prove extremely useful for the study of cell specificity/cellular and molecular interaction between HIV/HCMV and to test antiviral therapies.

Use of the polymerase chain reaction to detect genomes of human immunodeficiency virus and cytomegalovirus in post-mortem tissues

The polymerase chain reaction (PCR) was used to amplify a 149 base-pair region of the cytomegalovirus (CMV) genome and a 551 base-pair region of the HIV-1 proviral long terminal repeat (LTR) present in DNA extracted from post-mortem tissue. Multiple tissues (n = 116) obtained from 16 patients which were subjected to PCR were also subjected to cell culture and histopathological analyses. One hundred and seven samples (92%) contained CMV DNA and 66/116 (57%) contained HIV proviral DNA at a level of > or = 10 genomes. Both viruses were detected in 60/116 (51.7%) of samples, with co-infection most frequent in the lung (69%). Cell culture for CMV detected 9.3% of the PCR-positive samples, whilst histology identified CMV inclusions in 15.9% of samples, all of which were CMV PCR-positive. CMV was most frequently detected in adrenal and lung tissues by histology. These results show that co-infection with CMV and HIV is a common occurrence in organs from AIDS patients and provide further evidence for a role of cytomegalovirus in the pathogenesis of AIDS.

No direct relationship between HIV1/2 infection and HHV-6 antibody response in a large-scale European and African trial

BACKGROUND

Tropism of both human herpesvirus-6 (HHV-6) and human immunodeficiency virus (HIV) for CD4+ lymphocytes, and several studies on HIV enhancer transactivation by HHV-6 have suggested that HHV-6 could be implicated as a cofactor in the progression of HIV infection to AIDS.

OBJECTIVES

To determine if there is any relationship between HHV-6 infection and the course of HIV infection.

STUDY DESIGN

527 French and 558 African sera (210 from Senegal, 348 from Ivory Coast) were tested for HHV-6 titers by immunofluorescence assay (IFA). For each country, patients studied were divided into several groups; those with AIDS, those who were HIV-seropositive but symptomless, and HIV-seronegative patients.

RESULTS

No statistical difference could be found between HHV-6 prevalences or HHV-6 geometric mean titers obtained for each geographical area in the different HIV-1- and/or HIV-2-positive and HIV-negative groups. HIV patients with clinical manifestations of AIDS did not differ in percent seropositivity or distribution of titers from the HIV-asymptomatic patients or HIV-seronegative patients.

CONCLUSION

These findings suggest that there is no correlation between HHV-6 antibodies and HIV seropositivity or with the stage of HIV infection.

Impact of herpesvirus infections in the future

Numerous diverse, often opposing, trends will determine the frequency (and severity) of herpesvirus infections in the future. A major factor is the growing population of iatrogenically immunocompromised patients, accruing especially from large increases in organ and autologous bone marrow transplantation. Of even greater importance is the immense number of human immunodeficiency virus (HIV)-infected patients for whom herpesviruses may: (1) have been a cofactor in acquisition of HIV infection; (2) contribute to in vivo activation of HIV; (3) cause severe infections. Another factor influencing severe herpesvirus infections is the aging of populations in developed countries; this will be associated with a greater prevalence, and more morbid manifestations, of herpes zoster. Sociologic changes will also be important. The consequences of these, such as attempts to influence sexual practices, will be difficult to predict. Other changes, such as more frequent use of early child care facilities, will predictably lead to early acquisition of most herpesviruses, thereby decreasing the incidence of severe disease in adulthood. Factors that will reduce the incidence and/or severity of herpesvirus infections include vaccines (varicella, herpes simplex, cytomegalovirus); prophylactic strategies for immunocompromised hosts (passive immunization, antiviral drugs, blood product selection); more rapid and sensitive diagnostic methods; and suppressive or early antiviral therapy for common infections, such as genital herpes simplex and varicella.(ABSTRACT TRUNCATED AT 250 WORDS)