Assessment of a combined testing strategy for detection of antibodies to human herpesvirus 8 (HHV-8) in persons with Kaposi's sarcoma, persons with asymptomatic HHV-8 infection, and persons at low risk for HHV-8 infection

Patterns of human herpesvirus-8 oral shedding among diverse cohorts of human herpesvirus-8 seropositive persons

Background

Human herpesvirus-8 (HHV-8), the etiologic agent of Kaposi sarcoma (KS), establishes lifelong latent infection with periodic lytic replication (“shedding”) at mucosal sites, especially the oropharynx. Patterns of HHV-8 shedding are not well understood, and require elucidation to better predict risk of HHV-8 related malignancies in those infected. We sought to characterize patterns of HHV-8 oropharyngeal shedding among diverse cohorts that enrolled HHV-8 seropositive persons.

Methods

We quantified HHV-8 oral shedding using PCR among HHV-8 seropositive persons who collected at least 14 days of oral swabs in 22 studies on 3 continents. We excluded persons taking antivirals during sampling or any prior use of antiretrovirals in those who were HIV-infected.

Results

248 participants were enrolled from the US, Peru, Cameroon, Uganda, and Kenya; 61 % were men, 58 % were HIV seropositive, and 16 % had KS. Overall, 3,123 of 10,557 samples (29.6 %) had HHV-8 detected. Quantity of virus shed was highly correlated with shedding rate, (ρ = 0.72, p < 0.0001). HHV-8 was detected in ≥1 sample in 55 % of participants with a median of 7 % of days in the US and Kenya, 0 % in Uganda and Peru, and 18 % in Cameroon. Median episode duration was three days, and episodes with high median quantity lasted longer (42 vs 3 days, p < 0.0001). In persons with multiple observations over time, 66 % of shedding rate variance was attributable to differences between individuals.

Conclusions

In HHV-8 infected individuals from diverse settings, oral mucosal shedding rate, quantity, and duration were correlated; individual shedding was highly variable. Studies are needed to determine factors accounting for between-person variation and the relationship of HHV-8 shedding to development of associated diseases.

Reduced human herpesvirus-8 oropharyngeal shedding associated with protease inhibitor-based antiretroviral therapy

BACKGROUND

Human herpesvirus 8 (HHV-8) replication increases the risk of Kaposi sarcoma (KS). Highly-active antiretroviral therapy (HAART) reduces the incidence of KS, and regimens that contain protease inhibitors (PIs) may be particularly effective.

OBJECTIVE

To determine whether PI-based HAART regimens may more effectively inhibit HHV-8 shedding compared to regimens without PIs.

STUDY DESIGN

Prospective, observational study of 142 HIV-1 and HHV-8 co-infected men conducted in Seattle, Washington. Quantitative HHV-8 PCR testing was performed on daily swabs of the oropharynx, the primary site of HHV-8 replication. Associations between antiretroviral regimen and detection of HHV-8 DNA in swabs were evaluated using generalized estimating equations.

RESULTS

HHV-8 DNA was detected in 3016 (26%) of 11,608 specimens collected. PI-based HAART was associated with a statistically significantly lower frequency of detection (RR 0.2; 95% CI 0.1-0.5) compared to ART-naïve persons, whereas HAART without a PI was not (RR 0.7; 95% CI 0.4-1.3). Compared to ART-naïve persons, there was also a trend toward lower quantities of HHV-8 detected during treatment with HAART regimens that contained a PI. These associations between PIs and measures of HHV-8 shedding could not be attributed to use of nelfinavir, which inhibits HHV-8 replication in vitro, and were independent of CD4 count and HIV plasma viral load (VL).

CONCLUSIONS

HAART regimens that contain PIs appear to decrease HHV-8 shedding compared to NNRTIs. Further study of PI-based HAART is warranted to determine the optimal regimens for prevention and treatment of KS.

Seroprevalence of human herpesvirus-8 in HIV-1 infected and uninfected individuals in Cameroon

We evaluated the prevalence of HHV-8 antibodies in 516 plasma samples collected from HIV positive and negative patients from blood banks and urban areas of Cameroon. Among HIV-1 positive samples, HHV-8 seropositivity rate was 61% based on combined reactivity using both ELISA and IFA techniques. HIV negative samples showed 62% seropositivity rate for HHV-8 antibodies. Our results indicate a high HHV-8 prevalence rate in both HIV infected and uninfected individuals in Cameroon.

Development of whole-virus multiplex luminex-based serological assays for diagnosis of infections with kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 homologs in macaques

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus 8 is a tumorigenic rhadinovirus that is associated with all forms of Kaposi's sarcoma. Current serological detection of KSHV is based on enzyme-linked immunosorbent or immunofluorescence assays that suffer from a variety of problems, including the lack of defined standards for test comparison. While KSHV is the only known human rhadinovirus, two lineages of KSHV-like rhadinoviruses are found in Old World primates: the RV1 lineage includes KSHV and retroperitoneal fibromatosis herpesvirus (RFHV) in macaques, and the RV2 lineage includes RRV and MneRV2 from different macaque species. To develop animal models of KSHV-associated diseases, we developed quantitative multiplex bead-based serological assays to detect antibodies against rhadinovirus antigens. Proteins from KSHV (RV1) and MneRV2 (RV2) virions were coupled to spectrally distinct fluorescent beads and used in Luminex flow cytometry-based assays to detect immune responses in macaques. Both assays showed large dynamic ranges with high levels of seroreactivity to both KSHV and MneRV2 proteins. A large set of macaque serum samples from the Washington National Primate Research Center was screened, and most of the samples (82%) were positive in both assays, consistent with the high level of RV1-RV2 coinfection detected by PCR. The macaque sera showed broad, variable, and unique serological responses to the different viral antigens, allowing an initial seroprevalence to be determined for the macaque viruses. The Luminex assays offer a novel multiplexed approach to assess rhadinovirus infection patterns in both humans and nonhuman primates. This will help advance our understanding of rhadinovirus biology and associated host immunological responses.

Treatment with valacyclovir, famciclovir, or antiretrovirals reduces human herpesvirus-8 replication in HIV-1 seropositive men

Human herpesvirus-8 (HHV-8) replication is a key factor in Kaposi sarcoma, primary effusion lymphoma, and Castleman disease pathogenesis. In vitro data suggest that antivirals inhibit HHV-8 replication, but little data exist in humans. Daily oropharyngeal swabs were analyzed from HIV/HHV-8 dually infected men enrolled in three previous clinical trials of valacyclovir and famciclovir for HIV-1 and/or HSV-2 suppression. Fifty-eight participants contributed 6,036 swabs. HHV-8 was detected in 1,128 (19%) of 6,036 swabs, including 618 (21%) of 2,992 on placebo, 323 (15%) of 2,221 on valacyclovir, and 187 (23%) of 823 on famciclovir. After adjusting for baseline HIV viral load and highly active antiretroviral therapy (HAART) use, an 18% reduction in HHV-8 shedding frequency (IRR 0.822; P = 0.011) was found in participants on valacyclovir and a 30% reduction (IRR 0.700; P < 0.001) on famciclovir. HAART was associated with an 89% (IRR 0.129; P = 0.048) reduction in HHV-8-shedding. Neither antiviral nor antiretroviral therapy was associated with decreased HHV-8 quantity. Valacyclovir and famciclovir were associated with modest but significant reductions in HHV-8 oropharyngeal shedding frequency. In contrast, HAART was a potent inhibitor of HHV-8 replication. Studies of whether antiviral therapy in combination with ART will prevent HHV-8-associated disease appear warranted.

Kaposi sarcoma herpes virus antibody response and viremia following highly active antiretroviral therapy in the Swiss HIV Cohort study

OBJECTIVE

To describe the effect of HAART on Kaposi sarcoma herpes virus (KSHV) antibody response and viremia among HIV-positive MSM.

DESIGN

A follow-up study of 272 HIV-positive MSM (including 22 with Kaposi sarcoma) who first initiated HAART between January 1996 and July 2004 in the Swiss HIV Cohort Study.

METHODS

For each individual, two serum samples, one at HAART initiation and another 24 months later, were tested for latent and lytic KSHV antibodies using immunofluorescence assays, and for KSHV viremia using PCR. Factors associated with changes in KSHV antibody titers and viremia were evaluated.

RESULTS

At HAART initiation, 69.1 and 75.0% of patients were seropositive to latent and lytic KSHV antibodies, respectively. Seropositivity was associated with the presence of Kaposi sarcoma, older age, lower CD8 cell count and higher CD4/CD8 ratio. Prevalence of KSHV viremia at HAART initiation was 6.4%, being significantly higher among patients with Kaposi sarcoma (35.0%), and those with HIV viral loads 100 000 copies/ml (11.7%) or higher. At 24-month follow-up, geometric mean titers (GMTs) among KSHV seropositive patients increased and antibody seroprevalence was higher. Having Kaposi sarcoma and/or CD4 cell counts less than 50 cells/microl at HAART initiation was associated both with higher probability for antibody titers to increase (including seroconversion) and larger increases in GMTs. Only one of 17 viremic patients at HAART initiation had viremia at 24-month follow-up.

CONCLUSION

HAART increases KSHV-specific humoral immune response and clearance of viremia among HIV-infected MSM, consistent with the dramatic protection offered by HAART against Kaposi sarcoma.

Prevalence and correlates of human herpesvirus 8 infection among Peruvian men who have sex with men

BACKGROUND

Infection with human herpesvirus 8 (HHV-8) is common among men who have sex with men (MSM) in North America and Europe and is also found to be endemic in some regions of South America. Little is known about HHV-8 prevalence and its correlates among MSM in the Andean region.

METHODS

We assessed HHV-8 seroprevalence among 497 MSM recruited for the 2002 Peruvian HIV sentinel surveillance program using a combined HHV-8 enzyme immunoassay and immunofluorescence assay algorithm. Logistic regression analysis was used to estimate odds ratios (ORs) and their 95% confidence intervals (CIs) to determine the association between selected covariates and HHV-8 seropositivity.

RESULTS

One hundred thirty-one (66.5%, 95% CI 63.1% to 69.9%) of 197 HIV-infected and 80 (26.7%, 95% CI 24.4% to 29.0%) of 300 HIV-uninfected MSM had serologic evidence of HHV-8 infection. Factors independently associated with HHV-8 infection were education<12 years (OR 1.7, 95% CI 1.1 to 2.7), anal receptive sex with the last partner (OR 2.0, 95% CI 1.2 to 3.3), self-reported sexually transmitted infection symptoms during the last year (OR 1.9, 95% CI 1.2 to 3.0), coinfection with HIV (OR 4.2, 95% CI 2.8 to 6.4) and chronic hepatitis B (OR 4.9, 95% CI 1.5 to 15.8). MSM with long-standing HIV infection were more likely to have serologic evidence of HHV-8 infection when compared with men with recently acquired HIV (OR 3.8, 95% CI 1.7 to 9.1).

CONCLUSIONS

HHV-8 infection is common among both HIV-infected and HIV-negative MSM in Lima, Peru. HHV-8 seropositivity is correlated with anal receptive sex, self-reported sexually transmitted infection symptoms, and HIV infection among these MSM and thus seems to be sexually transmitted. HHV-8 infection seems to be acquired after HIV infection, suggesting that future studies should evaluate the mode of HHV-8 transmission and prevention strategies among HIV-uninfected MSM.

Gamma delta+ T cells involvement in viral immune control of chronic human herpesvirus 8 infection

Little is known about what effector populations are associated with the control of human herpesvirus 8 (HHV-8) infection in vivo. We compared T lymphocyte subsets among HIV-HHV-8+ and HIV-HHV-8- infected human individuals. alphabeta+ T cells from HHV-8-infected individuals displayed a significantly higher percentage of differentiated effector cells among both CD4+ and CD8+ T cell subsets. HHV-8 infection was associated with significant expansion of gammadelta+ Vdelta1 T cells expressing a differentiated effector cell phenotype in peripheral blood. In vitro stimulation of PBMC from HHV-8-infected individuals with either infectious viral particles or different HHV-8 viral proteins resulted in gammadelta Vdelta1 T cell activation. In addition, gammadelta Vdelta1 T cells displayed a strong reactivity against HHV-8-infected cell lines and prevented the release of infectious viral particles following the induction of lyric replication. These data indicate that gammadelta T cells play a role in both innate and adaptive T cell responses against HHV-8 in immunocompetent individuals.

Frequent and asymptomatic oropharyngeal shedding of human herpesvirus 8 among immunocompetent men

BACKGROUND

Little is known about the clinical and virologic manifestations of human herpesvirus (HHV)-8 infection in immunocompetent persons in the absence of malignancy.

METHODS

A total of 46 human immunodeficiency virus-negative, HHV-8-seropositive men collected saliva daily, and 25 recorded 15 common symptoms daily (gastrointestinal, constitutional, and oropharyngeal) and absences from work or school. Quantitative polymerase chain reaction measured HHV-8 DNA in saliva.

RESULTS

Some 44 (96%) of 46 men reported having sex with men (MSM). Of the 44 MSM, 27 (61%) had HHV-8 detected in saliva on > or = 1 day; heterosexual men also shed HHV-8. In analyses restricted to MSM, HHV-8 DNA was detected on 636 (22%) of 2897 days. Among MSM with HHV-8 detected in saliva, the median rate was 20% (range, 1%-100%), with 30% shedding on > 50% of days, and the median quantity was 4.5 log10 copies/mL (range, 2.0-7.3 log10 copies/mL). The quantity of HHV-8 shed was lower in nonwhites (P<.001) and younger participants (P=.03). The frequency of HHV-8 detection and quantity were correlated (r=0.62; P<.001). Symptoms were reported on 10 (9%) of 114 days when HHV-8 was present, compared with 78 (9%) of 830 days without (odds ratio, 0.93 [95% confidence interval, 0.30-2.88]; P=.9).

CONCLUSIONS

HHV-8 is detected frequently and intermittently in the saliva of chronically infected immunocompetent MSM, but this infection is asymptomatic.

HIV serodiscordant sex partners and the prevalence of human herpesvirus 8 infection among HIV negative men who have sex with men: baseline data from the EXPLORE Study

OBJECTIVES

Human herpesvirus 8 (HHV-8) infection is common among men who have sex with men (MSM), especially those infected with HIV, and is frequently detected in saliva. We sought to determine whether oral or anogenital contact with HIV discordant, or unknown serostatus sexual partners is associated with HHV-8 seroprevalence among HIV negative MSM.

METHODS

HIV negative MSM participating in a behavioural intervention trial for the prevention of HIV infection (the EXPLORE study) were recruited from the Seattle and Denver areas for participation in this cross sectional study. Participants completed detailed questionnaires regarding sexual behaviour, focusing on activities with possible exposure to the oropharynx. Serum samples from study enrollment were tested for the presence of HHV-8 antibodies using whole virus enzyme immunoassay and immunofluorescence assay to latent and lytic proteins.

RESULTS

198/819 MSM (24.3%) were HHV-8 antibody positive. Exposure to saliva with HIV positive and HIV unknown serostatus sex partners was reported by 83% and 90% of all men, respectively. In a multivariate model, reporting more than the median number of lifetime sex partners (OR 2.2, p = 0.03) or lifetime sex partners of unknown HIV status (OR 1.7, p = 0.03), and the performance of oro-anal sex ("rimming") on partners whose HIV status is unknown (OR 2.7, p = 0.04) were independently associated with HHV-8 infection.

CONCLUSIONS

The oropharynx may be an important anatomical site in HHV-8 acquisition, and contact with HIV serodiscordant or unknown sex partners is associated with higher HHV-8 seroprevalence among HIV negative MSM.

Correlations between synthetic peptide-based enzyme immunoassays and immunofluorescence assay for detection of human herpesvirus 8 antibodies in different Argentine populations

Human herpesvirus 8 (HHV-8) antibody tests vary in sensitivity and specificity, depending on the population tested and on the type of assay. In this study, we evaluated the sensitivity and specificity of two peptide enzyme immunoassays using a multiple antigenic peptide (PK8.1-MAP) or a chimeric peptide (PK8.1-orf65) as the antigens and determined the HHV-8 seroprevalence in different Argentine populations using an immunofluorescence assay (IFA) as reference. For analysis, when either or both of the peptide EIAs were positive, the specimen was considered positive (PEIA). We estimated the sensitivity and specificity of PEIA to be 97% using Kaposi's sarcoma (KS) patients and healthy individuals as positive and negative controls respectively. Then, we expanded the control groups to include IFA positive men who have sex with men (MSM) and IFA negative blood donors. The sensitivity decreased to 83% but specificity remained high at 98%. Concordance between PEIA and IFA was 77% for 1/40 IFA titers and increased to 90% for titers >or=1/160. Seroprevalences for HHV-8 performed in the HIV positive MSM were (IFA 73.1%; PEIA55.2%); heterosexuals (52.5%, 22.2%), which includes injecting drug users (IDU) (54.0%, 32.4%) and non-IDU (51.6%, 16.1%). The inclusion of non-KS HHV-8 IFA positive individuals to the positive controls may be a substantial improvement towards the realistic assessment of assay sensitivity. These peptide EIAs can be used for trends in populations with high probability of being HHV-8 infected and negative results should be confirmed by IFA. IFA test is still the most suitable test for populations with low probabilities of being infected.

Shedding of human herpesvirus 8 in oral and genital secretions from HIV-1-seropositive and -seronegative Kenyan women

Polymerase chain reaction was used to determine the prevalence and correlates of human herpesvirus 8 (HHV8) in saliva, mouth, cervical, vaginal, plasma, and peripheral-blood mononuclear cell (PBMC) samples from 174 HHV8-seropositive female prostitutes in Mombasa, Kenya. The prevalence of detection of HHV8 was 32% in saliva samples, 28% in mouth swabs, 4% in cervical swabs, 2.3% in vaginal swabs, 9% in plasma samples, and 18% in PBMC samples. Human immunodeficiency virus type 1 (HIV-1) seropositivity was associated with detection of HHV8 from any mucosal surface (odds ratio, 2.1 [95% confidence interval, 1.1-4.0]). In HIV-1-seropositive women, there was no association between detection of HHV8 and either CD4 count or HIV-1 viral load.

Human herpesvirus 8 seroconversion in Kenyan women by enzyme-linked immunosorbent assay and immunofluorescence assay

BACKGROUND

Human herpesvirus 8 (HHV-8) antibody tests vary in reported sensitivity and specificity, depending on the population tested and the assay.

OBJECTIVE

The purpose of this study was to compare the ability to detect seroconversion to HHV-8 in a cohort of HHV-8 seronegative female commercial sex workers in Kenya using three tests: HHV-8 viral lysate-based enzyme-linked immunosorbent assay (ELISA), an immunofluorescence assay for HHV-8 lytic antigens (IFA-lytic) and IFA for latent nuclear antigens (IFA-LANA).

STUDY DESIGN

By ELISA, 16 women from a prospective cohort of commercial sex workers were identified as seroconverting to HHV-8. A total of 124 post-enrollment samples from these 16 women as well as the enrollment samples were tested for HHV-8 antibodies by all three assays to monitor seroconversion.

RESULTS

Of 16 women with apparent seroconversion by ELISA, 8 had a rise in IFA-lytic titers either concomitant with or prior to the first positive ELISA sample and no initial LANA by IFA. Five of the 16 women were IFA-LANA positive at entry, indicating prior infection with HHV-8. Three women had no evidence of seroconversion by either IFA-lytic or IFA-LANA and two of these three had increased ELISA reactivity concomitant with HIV-1 infection.

CONCLUSIONS

Conversion from a negative to a positive ELISA result for HHV-8 antibody indicated seroconversion in only half of the study cohort of 16 women when IFA-lytic and IFA-LANA results were considered. The IFA-lytic assay was more sensitive than ELISA for early antibody responses. The IFA-LANA was positive in some women who had neither IFA-lytic nor ELISA antibodies suggesting it may be a marker for latent infections. Presumptive identification of incident HHV-8 infection by ELISA screening followed by IFA-lytic testing to confirm the positive test and IFA-LANA to rule out prior infection provides the most accurate documentation of HHV-8 seroconversion.

HIV infection and human herpesvirus-8 oral shedding among men who have sex with men

Human herpesvirus-8 (HHV-8) is frequently detected in oropharyngeal secretions from HIV-infected men who have sex with men (MSM), and contact with saliva may be an important mode of HHV-8 transmission. A total of 196 MSM were followed over 2 years to determine the correlates of HHV-8 oropharyngeal shedding. A total of 134 (68%) of 196 participants were HHV-8 seropositive upon enrollment, and 9 (15%) of 62 participants seroconverted to HHV-8 during follow-up. HHV-8 DNA was detected in 43 (22%) of 196 participants: 39 (27%) of 134 HHV-8 seropositive, 4 (8%) of 53 HHV-8 seronegative, and 5 (56%) of 9 seroconverters to HHV-8. HHV-8 was detected in 101 (15%) of 696 total oral specimens: 84 (17%) of 481 samples from HHV-8-seropositive men, 6 (3%) of 180 samples from HHV-8-seronegative men, and 11 (31%) of 35 samples from seroconverters. Using adjusted marginal structural models, HHV-8 shedding was higher in men not receiving highly active antiretroviral therapy (odds ratio 2.4, 95% CI 1.0-6.0, P = 0.06), with CD4 counts > 200 cells/mm (odds ratio 4.8, 95% CI 1.0-22.8, P = 0.05), or with detectable oral leukocyte esterase (odds ratio 5.0, 95% CI 2.0-12.5, P < 0.01). CD4 count, antiretroviral therapy, and oral inflammation may influence HHV-8 oropharyngeal shedding.

Correlates of human herpesvirus-8 seropositivity among U.S. military members recently infected with human immunodeficiency virus

BACKGROUND

Human herpesvirus 8 (HHV-8), the cause of Kaposi's sarcoma, is common among HIV-infected persons. The exact route of transmission of HHV-8 in various populations is still debated.

GOAL

The goal was to define the correlates of HHV-8 infection among men recently infected with human immunodeficiency virus.

STUDY DESIGN

Three hundred forty-two HIV-infected U.S. military men were evaluated using a questionnaire regarding potential risk factors and laboratory data, including HHV-8, herpes simplex virus 2 (HSV-2), syphilis, hepatitis B, and hepatitis C serologies.

RESULTS

The seroprevalence of HHV-8 was 32%. HHV-8 was significantly associated with hepatitis B seropositivity (odds ratio [OR], 2.44; 95% confidence interval [CI], 1.5-4.1), and black ethnicity was negatively associated with HHV-8 (OR, 0.6; 95% CI, 0.3-0.9) in the multivariate analysis. HHV-8 was not associated with drug use or hepatitis C seropositivity. Among men who have sex with men (MSM), HHV-8 infection correlated with hepatitis B seropositivity (OR, 2.2; 95% CI, 1.1-4.3) and HSV-2 (OR, 2.6; 95% CI, 1.4-4.9). Among heterosexuals, the correlates of HHV-8 were different; blacks as compared with whites (OR, 0.3; 95% CI, 0.1-0.8) and married versus single status (OR, 0.4; 95% CI, 0.2-0.9) were associated with a lower rate of HHV-8 infection. Among heterosexuals, hepatitis B, HSV-2, and sexual behaviors were not associated with HHV-8.

CONCLUSION

This study suggests that the seroprevalence of HHV-8 is increased in both MSM and heterosexual men with HIV infection, and that the route(s) of HHV-8 acquisition might be different between MSM and heterosexuals.

Molecular genetics of Kaposi's sarcoma-associated herpesvirus (human herpesvirus-8) epidemiology and pathogenesis

Kaposi's sarcoma had been recognized as unique human cancer for a century before it manifested as an AIDS-defining illness with a suspected infectious etiology. The discovery of Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus-8, in 1994 by using representational difference analysis, a subtractive method previously employed for cloning differences in human genomic DNA, was a fitting harbinger for the powerful bioinformatic approaches since employed to understand its pathogenesis in KS. Indeed, the discovery of KSHV was rapidly followed by publication of its complete sequence, which revealed that the virus had coopted a wide armamentarium of human genes; in the short time since then, the functions of many of these viral gene variants in cell growth control, signaling apoptosis, angiogenesis, and immunomodulation have been characterized. This critical literature review explores the pathogenic potential of these genes within the framework of current knowledge of the basic herpesvirology of KSHV, including the relationships between viral genotypic variation and the four clinicoepidemiologic forms of Kaposi's sarcoma, current viral detection methods and their utility, primary infection by KSHV, tissue culture and animal models of latent- and lytic-cycle gene expression and pathogenesis, and viral reactivation from latency. Recent advances in models of de novo endothelial infection, microarray analyses of the host response to infection, receptor identification, and cloning of full-length, infectious KSHV genomic DNA promise to reveal key molecular mechanisms of the candidate pathogeneic genes when expressed in the context of viral infection.