Effect of multiple herpesvirus infections on the progression of HIV disease in a cohort of HIV seroconverters

Human Herpesviruses as Copathogens of HIV Infection, Their Role in HIV Transmission, and Disease Progression

Of eight human herpesviruses (HHVs), often, only herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) find mention in medical literature as both of these viruses are commonly associated with genital lesions and oral ulcers, commonly known as cold sores. However, role of human herpesviruses as copathogens and in aggravation and in the transmission of other human diseases, especially the Acquired immunodeficiency syndrome (HIV/AIDS) has only very recently been recognized. Therefore, screening and treating subclinical HHV infections may offer slowing of HIV infection, disease progression, and its transmission. Beside HSV-1 and HSV-2, HHV-3 a causative agent of herpes zoster remained one of the first manifestations of HIV disease before the era of highly active antiretroviral therapy (HAART). HHV-5 also known as human Cytomegalovirus infection remains a significant risk factor for HIV-associated mortality and morbidity even in HAART era. It is proposed that Cytomegalovirus viremia could be a better predictor of HIV disease progression than CD4+ T-lymphocyte count. The role of HHV-4 or Epstein-Burr virus and HHV-6, HHV-7, and HHV-8 is still being investigated in HIV disease progression. This review provides insight into the current understanding about these 8 HHVs, their co-pathogenesis, and role in HIV/AIDS disease progression. The review also covers recent literature in favor and against administering anti-HHV treatment along with HAART for slower AIDS progression and interrupted sexual transmission.

Kaposi's sarcoma-associated herpesvirus ORF45 mediates transcriptional activation of the HIV-1 long terminal repeat via RSK2

Robust activation of human immunodeficiency virus type 1 (HIV-1) gene expression occurs upon superinfection with Kaposi's sarcoma-associated herpesvirus (KSHV), a common AIDS-associated pathogen. Though the mechanisms underlying this phenotype remain unknown, several KSHV-encoded factors have been reported to stimulate HIV-1 long terminal repeat (LTR) activity. Here, we systematically evaluated the ability of KSHV tegument proteins to modulate the activation of an integrated HIV-1 LTR and revealed that the most potent individual activator is ORF45. ORF45 directs an increase in RNA polymerase II recruitment to the HIV-1 LTR, leading to enhanced transcriptional output. ORF45 is a robust activator of the p90 ribosomal S6 kinases (RSK), and we found that this activity is necessary but not sufficient to increase transcription from the LTR. Of the three widely expressed RSK isoforms, RSK2 appears to be selectively involved in LTR stimulation by both KSHV ORF45 and HIV-1 Tat. However, constitutively active RSK2 is unable to stimulate the LTR, suggesting that ORF45 may preferentially direct this kinase to a specific set of targets. Collectively, our findings reveal a novel transcriptional activation function for KSHV ORF45 and highlight the importance of RSK2 in shaping the transcriptional environment during infection.

IMPORTANCE

Kaposi's sarcoma-associated herpesvirus (KSHV) is a prominent AIDS-associated pathogen. Previous studies have shown that infection of cells containing human immunodeficiency virus type 1 (HIV-1) with KSHV leads to potent stimulation of HIV-1 gene expression by activating the HIV-1 promoter, termed the long terminal repeat (LTR). Here, we compared the abilities of various KSHV proteins to activate gene expression from the HIV-1 LTR and found that KSHV ORF45 is the most potent activator. ORF45 is known to induce cell signaling through ribosomal S6 kinase (RSK) and enhance protein translation. However, we revealed that the activation of a specific isoform of RSK by ORF45 also leads to increased mRNA synthesis from the LTR by the host RNA polymerase. Collectively, our findings provide new insight into the interviral interactions between KSHV and HIV that may ultimately impact disease.

Prevalence of persistent and latent viruses in untreated patients infected with HIV-1 from Ghana, West Africa

Only limited epidemiological data, pertaining to the prevalence of common persistent viruses has been reported in Ghana. This study was conducted to determine the prevalence of persistent viruses in individuals with untreated HIV-1 infection and uninfected blood donors. Paired plasma and cellular samples from HIV-negative blood donors, asymptomatic HIV and symptomatic/AIDS cohorts were screened by multiplex PCR then qPCR for parvovirus B19 (B19V), hepatitis B virus (HBV), GB virus-C (GBV-C), cytomegalovirus (CMV), Epstein-Barr virus (EBV), human herpesvirus-8 (HHV-8) and varicella-zoster virus (VZV). IgG antibodies specific to each target virus were tested to determine exposure rates. No evidence of viraemia was found for B19V and VZV in any group. Prevalence of GBV-C plasma viraemia was significantly higher in asymptomatic and symptomatic HIV infection (16.7%) and (16.2%) than in blood donors (4%) P < 0.005. Occult HBV infection was significantly more frequent in symptomatic HIV infection (10.9%) compared to asymptomatic HIV (3.6%) and blood donors (1.6%) P < 0.005. Although there was a high background of EBV viraemia in cellular fractions of blood donors (8.3%), it was significantly higher in asymptomatic (44.6%) and symptomatic HIV (14.6%) P < 0.0001. For CMV, the significantly increased prevalence of viraemia was only observed in the plasma fraction of the symptomatic HIV-1/AIDS patients (7.6%) compared to asymptomatic individuals (1.8%) and blood donors (0.8%) P < or = 0.001. The background seroprevalence in blood donors was high for B19V (> or =64%), HBV (> or =70%), CMV and EBV (> or =90%) and was significantly increased in HIV infections for HBV, CMV, VZV (symptomatic HIV), and HHV-8 (asymptomatic and symptomatic HIV).

A replication-competent, neuronal spread-defective, live attenuated herpes simplex virus type 1 vaccine

Herpes simplex virus type 1 (HSV-1) produces oral lesions, encephalitis, keratitis, and severe infections in the immunocompromised host. HSV-1 is almost as common as HSV-2 in causing first episodes of genital herpes, a disease that is associated with an increased risk of human immunodeficiency virus acquisition and transmission. No approved vaccines are currently available to protect against HSV-1 or HSV-2 infection. We developed a novel HSV vaccine strategy that uses a replication-competent strain of HSV-1, NS-gEnull, which has a defect in anterograde and retrograde directional spread and cell-to-cell spread. Following scratch inoculation on the mouse flank, NS-gEnull replicated at the site of inoculation without causing disease. Importantly, the vaccine strain was not isolated from dorsal root ganglia (DRG). We used the flank model to challenge vaccinated mice and demonstrated that NS-gEnull was highly protective against wild-type HSV-1. The challenge virus replicated to low titers at the site of inoculation; therefore, the vaccine strain did not provide sterilizing immunity. Nevertheless, challenge by HSV-1 or HSV-2 resulted in less-severe disease at the inoculation site, and vaccinated mice were totally protected against zosteriform disease and death. After HSV-1 challenge, latent virus was recovered by DRG explant cocultures from <10% of vaccinated mice compared with 100% of mock-vaccinated mice. The vaccine provided protection against disease and death after intravaginal challenge and markedly lowered the titers of the challenge virus in the vagina. Therefore, the HSV-1 gEnull strain is an excellent candidate for further vaccine development.

Human herpesvirus 8 enhances human immunodeficiency virus replication in acutely infected cells and induces reactivation in latently infected cells

Human herpesvirus 8 (HHV-8) is etiologically associated with Kaposi sarcoma (KS), the most common AIDS-associated malignancy. Previous results indicate that the HHV-8 viral transactivator ORF50 interacts synergistically with Tat protein in the transactivation of human immunodeficiency virus (HIV) long terminal repeat (LTR), leading to increased cell susceptibility to HIV infection. Here, we analyze the effect of HHV-8 infection on HIV replication in monocyte-macrophage and endothelial cells, as potential targets of coinfection. Primary or transformed monocytic and endothelial cells were infected with a cell-free HHV-8 inoculum and subsequently infected with lymphotropic or monocytotropic strains of HIV. The results show that HHV-8 coinfection markedly increases HIV replication in both cell types. HHV-8 infection induces also HIV reactivation in chronically infected cell lines and in peripheral blood mononuclear cells (PBMCs) from patients with asymptomatic HIV, suggesting the possibility that similar interactions might take place also in vivo. Furthermore, coinfection is not an essential condition, since contiguity of differently infected cells is sufficient for HIV reactivation. The results suggest that HHV-8 might be a cofactor for HIV progression and that HHV-8-infected endothelial cells might play a relevant role in transendothelial HIV spread.

Cutaneous markers of HIV infection

Despite the development of laboratory methods, dermatological symptoms are a basic index of the presence and physical course of HIV infection. HIV infection usually undergoes a long latent period, proceeds to a period of immunodeficiency-related symptoms, and ends in an advanced immunodeficiency state characterized by opportunistic infections and neoplasms. Occasionally, dermatological manifestations can be the first signs of asymptomatic disease, indices of advanced immunodeficiency, or symptoms of opportunistic infections or neoplasms. The variety of symptoms and signs for the skin during the course of HIV infection is a consequence of the progressing immunodeficiency and therefore indicates the underlying disorder. The use of these manifestations is a challenge for clinical praxis.