Human herpesvirus 8 infection is associated with prostate cancer among IFNL4-ΔG carriers.

BACKGROUND: The dinucleotide germline variant, rs368234815-ΔG, in the IFNL4 gene (IFNL4-ΔG) has been associated with prostate cancer among men at increased risk of sexually transmitted infections and reported to impair viral clearance. Human herpesvirus 8 (HHV-8) seropositivity has been associated with prostate cancer in Tobago. METHODS: We examined whether the association of HHV-8 with prostate cancer is IFNL4-ΔG-dependent among 728 IFNL4-ΔG-genotyped cases and 813 genotyped population-based controls from the NCI-Maryland Prostate Cancer Case-Control study. Associations between HHV-8 and prostate cancer were assessed in multivariable unconditional logistic regression models. We calculated adjusted odds ratios (OR) and stratified the analysis into men harboring the IFNL4-ΔG-variant and non-carriers (ΔG/ΔG or ΔG/TT vs. TT/TT). RESULTS: HHV-8 seropositivity was higher in cases than controls (11% vs. 6%) and this association was restricted to carriers of the ΔG allele (OR 2.19: 95% CI:1.38-3.48) in both African American (OR 1.96; 95% CI:1.08-3.56) and European American men (OR 2.59; 95% CI:1.20-5.56). CONCLUSIONS: HHV-8 seropositivity is associated with increased odds of prostate cancer in men harboring the IFNL4 rs368234815-ΔG variant. This study describes HHV-8 infection as a candidate prostate cancer risk factor in men with the IFNL4-ΔG genotype and supports the hypothesis that IFNL4-ΔG is a susceptibility factor that contributes to prostate cancer.

Serum proteomics links suppression of tumor immunity to ancestry and lethal prostate cancer.

There is evidence that tumor immunobiology and immunotherapy response may differ between African American and European American prostate cancer patients. Here, we determine if men of African descent harbor a unique systemic immune-oncological signature and measure 82 circulating proteins in almost 3000 Ghanaian, African American, and European American men. Protein signatures for suppression of tumor immunity and chemotaxis are elevated in men of West African ancestry. Importantly, the suppression of tumor immunity protein signature associates with metastatic and lethal prostate cancer, pointing to clinical importance. Moreover, two markers, pleiotrophin and TNFRSF9, predict poor disease survival specifically among African American men. These findings indicate that immune-oncology marker profiles differ between men of African and European descent. These differences may contribute to the disproportionate burden of lethal prostate cancer in men of African ancestry. The elevated peripheral suppression of tumor immunity may have important implication for guidance of cancer therapy which could particularly benefit African American patients.

Assessment of factors associated with PSA level in prostate cancer cases and controls from three geographical regions.

It is being debated whether prostate-specific antigen (PSA)-based screening effectively reduces prostate cancer mortality. Some of the uncertainty could be related to deficiencies in the age-based PSA cut-off thresholds used in screening. Current study considered 2779 men with prostate cancer and 1606 men without a cancer diagnosis, recruited for various studies in New Zealand, US, and Taiwan. Association of PSA with demographic, lifestyle, clinical characteristics (for cases), and the aldo-keto reductase 1C3 (AKR1C3) rs12529 genetic polymorphisms were analysed using multiple linear regression and univariate modelling. Pooled multivariable analysis of cases showed that PSA was significantly associated with demographic, lifestyle, and clinical data with an interaction between ethnicity and age further modifying the association. Pooled multivariable analysis of controls data also showed that demographic and lifestyle are significantly associated with PSA level. Independent case and control analyses indicated that factors associated with PSA were specific for each cohort. Univariate analyses showed a significant age and PSA correlation among all cases and controls except for the US-European cases while genetic stratification in cases showed variability of correlation. Data suggests that unique PSA cut-off thresholds factorized with demographics, lifestyle and genetics may be more appropriate for prostate cancer screening.

Human Herpesvirus 8 Infects and Replicates in Langerhans Cells and Interstitial Dermal Dendritic Cells and Impairs Their Function.

The predominant types of dendritic cells (DC) in the skin and mucosa are Langerhans cells (LC) and interstitial dermal DC (iDDC). LC and iDDC process cutaneous antigens and migrate out of the skin and mucosa to the draining lymph nodes to present antigens to T and B cells. Because of the strategic location of LC and iDDC and the ability of these cells to capture and process pathogens, we hypothesized that they could be infected with human herpesvirus 8 (HHV-8) (Kaposi's sarcoma [KS]-associated herpesvirus) and have an important role in the development of KS. We have previously shown that HHV-8 enters monocyte-derived dendritic cells (MDDC) through DC-SIGN, resulting in nonproductive infection. Here we show that LC and iDDC generated from pluripotent cord blood CD34+ cell precursors support productive infection with HHV-8. Anti-DC-SIGN monoclonal antibody (MAb) inhibited HHV-8 infection of iDDC, as shown by low expression levels of viral proteins and DNA. In contrast, blocking of both langerin and the receptor protein tyrosine kinase ephrin A2 was required to inhibit HHV-8 infection of LC. Infection with HHV-8 did not alter the cell surface expression of langerin on LC but downregulated the expression of DC-SIGN on iDDC, as we previously reported for MDDC. HHV-8-infected LC and iDDC had a reduced ability to stimulate allogeneic CD4+ T cells in the mixed-lymphocyte reaction. These results indicate that HHV-8 can target both LC and iDDC for productive infection via different receptors and alter their function, supporting their potential role in HHV-8 pathogenesis and KS.IMPORTANCE Here we show that HHV-8, a DNA tumor virus that causes Kaposi's sarcoma, infects three types of dendritic cells: monocyte-derived dendritic cells, Langerhans cells, and interstitial dermal dendritic cells. We show that different receptors are used by this virus to infect these cells. DC-SIGN is a major receptor for infection of both monocyte-derived dendritic cells and interstitial dermal dendritic cells, yet the virus fully replicates only in the latter. HHV-8 uses langerin and the ephrin A2 receptor to infect Langerhans cells, which support full HHV-8 lytic replication. This infection of Langerhans cells and interstitial dermal dendritic cells results in an impaired ability to stimulate CD4+ helper T cell responses. Taken together, our data show that HHV-8 utilizes alternate receptors to differentially infect and replicate in these tissue-resident DC and support the hypothesis that these cells play an important role in HHV-8 infection and pathogenesis.

Modified Terminal Restriction Fragment Analysis for Quantifying Telomere Length Using In-gel Hybridization.

There are several different techniques for measuring telomere length, each with their own advantages and disadvantages. The traditional approach, Telomere Restriction Fragment (TRF) analysis, utilizes a DNA hybridization technique whereby genomic DNA samples are digested with restriction enzymes, leaving behind telomere DNA repeats and some sub-telomeric DNA. These are separated by agarose gel electrophoresis, transferred to a filter membrane and hybridized to oligonucleotide probes tagged with either chemiluminescence or radioactivity to visualize telomere restriction fragments. This approach, while requiring a larger quantity of DNA than other techniques such as PCR, can measure the telomere length distribution of a population of cells and allows measurement expressed in absolute kilobases. This manuscript demonstrates a modified DNA hybridization procedure for determining telomere length. Genomic DNA is first digested with restriction enzymes (that do not cut telomeres) and separated by agarose gel electrophoresis. The gel is then dried and the DNA is denatured and hybridized in situ to a radiolabeled oligonucleotide probe. This in situ hybridization avoids loss of telomere DNA and improves signal intensity. Following hybridization, the gels are imaged utilizing phosphor screens and the telomere length is quantified using a graphing program. This procedure was developed by the laboratories of Drs. Woodring Wright and Jerry Shay at the University of Texas Southwestern1,2. Here, we present a detailed description of this procedure, with some modifications.

Epinephrine promotes COX-2-dependent immune suppression in myeloid cells and cancer tissues.

Activation of the sympathetic nervous system (e.g., due to stress) has been implicated in cancer progression and recurrence, but its cancer-promoting effects have been variable between different studies. Here, we report that although catecholamines, mediators of systemic sympathetic activity, display only weak immunosuppressive impact on their own, their combination with inflammatory signals leads to the induction of COX-2 and multiple COX-2-dependent suppressive factors in human myeloid cells and cancer tissues. Human macrophages exposed to epinephrine and TNFα, or macrophages generated in 6day cultures in the presence of epinephrine, expressed high levels of COX-2, IDO and IL-10, and strongly suppressed both the proliferation and IFNγ production of CD8+ T cells. These suppressive effects of epinephrine were counteracted by celecoxib, a selective inhibitor of COX-2 activity, which inhibited the induction of immunosuppressive factors (including the elevated expression of COX-2 itself) and the ability of epinephrine-exposed macrophages to suppress CD8+ T cell responses. The activation of the COX-2/PGE2 system and COX-2-dependent suppressive events were also observed in ex vivo human breast and colon cancer explant cultures and were similarly counteracted by celecoxib. Our preliminary data also indicate elevated COX-2 expression in mammary tumors of chronic stress-exposed mice. The current demonstration of the interplay between inflammation and the induction of immunosuppressive factors by catecholamines suggest a contextual impact of stress, helping to explain variable results of epidemiologic studies of the link between sympathetic activity and cancer progression, and implicating COX-2 blockade as a potential means to mitigate stress-related immune suppression.

Regulatory T Cell Effect on CD8+ T Cell Responses to Human Herpesvirus 8 Infection and Development of Kaposi's Sarcoma.

We assessed CD8+ T cell reactivity to human herpesvirus 8 (HHV-8; Kaposi's sarcoma [KS]-associated herpesvirus) and the role of CD4+CD25hiFoxP3+ regulatory T cells (Treg) in HHV-8- and HIV-coinfected participants of the Multicenter AIDS Cohort Study who did or did not develop KS. There were similarly low CD8+ T cell interferon-γ responses to MHC class I-restricted epitopes of HHV-8 lytic and latent proteins over 5.7 years before KS in participants who developed KS compared to those who did not. T cell reactivity to HHV-8 antigens was low relative to responses to a combination of cytomegalovirus, Epstein-Barr virus and influenza A virus (CEF) peptide epitopes, and dominant HIV peptide epitopes. There was no change in %Treg in the HHV-8- and HIV-coinfected participants who did not develop KS, whereas there was a significant increase in %Treg in HHV-8- and HIV-coinfected participants who developed KS beginning 1.8 years before development of KS. Removal of Treg enhanced HHV-8-specific T cell responses in HHV-8- and HIV-coinfected participants who did or did not develop KS, with a similar pattern observed in response to CEF and HIV peptides. Thus, long-term, low levels of anti-HHV-8 CD8+ T cell reactivity were present in both HHV-8- and HIV-coinfected men who did and did not develop KS. This was related to moderately enhanced Treg function.

Elevated Serum PSA is Associated With Human Herpesvirus 8 Infection and Increased Circulating Cytokine Levels in Men From Tobago.

BACKGROUND: Serum-prostate specific antigen (PSA) levels have been used for many years as a biomarker for prostate cancer. This usage is under scrutiny due to the fact that elevated PSA levels can be caused by other conditions such as benign prostatic hyperplasia and infections of or injury to the prostate. As a result, the identification of specific pathogens capable of increasing serum levels of PSA is important. A potential candidate responsible for elevated PSA is human herpesvirus 8 (HHV-8). We have reported previously that HHV-8 is capable of infecting and establishing a latent infection in the prostate. In this current study we test the hypothesis that HHV-8 infection is associated with elevated PSA levels. Circulating cytokine levels between men with elevated PSA and controls are also compared. METHODS: HHV-8 serostatus was determined among men with elevated serum PSA (≥4 ng/ml; n = 168, no prostate cancer on biopsy) and age-matched controls (PSA <4 ng/ml; n = 234), Circulating cytokine levels were determined among a subset of each group (116 with elevated PSA and 85 controls). RESULTS: Men with an elevated serum PSA were significantly more likely to be HHV-8 seropositive (42.9%) than the age-matched cancer-free men (22.2%; OR 2.51; 95%CI 1.48-4.29, P = 00001). Comparison of circulating cytokine levels between men with elevated serum PSA and controls indicated that elevated serum PSA is associated with a pro-inflammatory response with a mixed Th1/Th2 response while HHV-8 infection was associated with significantly higher levels of IL12p70, IL-10, and IL-13 indicating a Th2 immune response. CONCLUSIONS: We found a significant association between HHV-8 infection and increased levels of serum PSA. In an age of patient-centered medicine, men with an elevated serum PSA should be considered for HHV-8 serology testing to determine if HHV-8 is responsible for the elevated PSA. Prostate 77: 617-624, 2017. © 2017 Wiley Periodicals, Inc.

Human herpesvirus 8 infection contributes to a T helper 2 immune response in men from Tobago with prostate cancer.

OBJECTIVES: To compare the cytokine profile between human herpesvirus 8 seropositive and seronegative men with and without prostate cancer. METHODS: The study sample was obtained from the Tobago Prostate Survey, an ongoing study of prostate cancer in the Caribbean island of Tobago. Participants in the study were recruited mostly by public service announcement and by word of mouth. For analyses of circulating levels of pro-inflammatory cytokines, participants with biopsy-confirmed prostate cancer (n = 79) were compared with control participants (n = 87). RESULTS: Cytokine analyses showed a T helper 2 response with suppressed T helper 1 response in prostate cancer patients, as evidenced by significantly increased levels of interleukin-13 and reduced levels of interleukin-12p70. Herpesvirus 8 seropositive men showed significantly increased levels of interleukin-13 and interleukin-10. At logistic regression analyses, interleukin-12p70 predicted prostate cancer in 94.4% of human herpesvirus 8 seropositive men. CONCLUSIONS: These findings show that prostate cancer elicits an antitumor, T helper 2 response with a suppressed T helper 1 response. Human herpesvirus 8 infection results in a similar immune response supporting the hypothesis that in Tobago, human herpesvirus 8 establishes a chronic infection that can contribute to an immune response favoring the formation and survival of prostate cancer.

Human herpesvirus 8 establishes a latent infection in prostates of Tobago men resulting in increased macrophage infiltration.

BACKGROUND: The Caribbean island of Tobago, which is 97% African ancestry, has one of the highest rates of prostate cancer in the world. We have previously reported that human herpesvirus 8 (HHV-8) infection is significantly associated with prostate cancer in Tobago. In this study, we extend those results testing the hypothesis that HHV-8 seropositive Tobagonian men have a chronic HHV-8 infection in their prostates that is associated with increased inflammation. METHODS: Prostate sections were screened by immunohistochemistry for the expression of HHV-8 proteins K8.1 and LANA-1 and for presence of B cells (CD20) and macrophages (CD68). RESULTS: HHV-8 antigen expression representing lytic and latent infections was seen in 73.9% of prostates from HHV-8 seropositive subjects. Latent infections were seen predominantly in glandular epithelia whereas lytic gene expression was seen mainly in macrophages in prostate stroma. Macrophage infiltrates were significantly increased in sections expressing HHV-8 proteins. CONCLUSION: HHV-8 establishes a chronic latent infection in the prostate, which is associated with an increased macrophage infiltrate.

Merkel Cell Polyomavirus Small T Antigen Induces Cancer and Embryonic Merkel Cell Proliferation in a Transgenic Mouse Model.

Merkel cell polyomavirus (MCV) causes the majority of human Merkel cell carcinomas (MCC) and encodes a small T (sT) antigen that transforms immortalized rodent fibroblasts in vitro. To develop a mouse model for MCV sT-induced carcinogenesis, we generated transgenic mice with a flox-stop-flox MCV sT sequence homologously recombined at the ROSA locus (ROSAsT), allowing Cre-mediated, conditional MCV sT expression. Standard tamoxifen (TMX) administration to adult UbcCreERT2; ROSAsT mice, in which Cre is ubiquitously expressed, resulted in MCV sT expression in multiple organs that was uniformly lethal within 5 days. Conversely, most adult UbcCreERT2; ROSAsT mice survived low-dose tamoxifen administration but developed ear lobe dermal hyperkeratosis and hypergranulosis. Simultaneous MCV sT expression and conditional homozygous p53 deletion generated multi-focal, poorly-differentiated, highly anaplastic tumors in the spleens and livers of mice after 60 days of TMX treatment. Mouse embryonic fibroblasts from these mice induced to express MCV sT exhibited anchorage-independent cell growth. To examine Merkel cell pathology, MCV sT expression was also induced during mid-embryogenesis in Merkel cells of Atoh1CreERT2/+; ROSAsT mice, which lead to significantly increased Merkel cell numbers in touch domes at late embryonic ages that normalized postnatally. Tamoxifen administration to adult Atoh1CreERT2/+; ROSAsT and Atoh1CreERT2/+; ROSAsT; p53flox/flox mice had no effects on Merkel cell numbers and did not induce tumor formation. Taken together, these results show that MCV sT stimulates progenitor Merkel cell proliferation in embryonic mice and is a bona fide viral oncoprotein that induces full cancer cell transformation in the p53-null setting.

Association between free testosterone levels and anal human papillomavirus types 16/18 infections in a cohort of men who have sex with men.

BACKGROUND: Human papillomavirus (HPV) types 16 and 18 cause invasive cervical cancer and most invasive anal cancers (IACs). Overall, IAC rates are highest among men who have sex with men (MSM), especially MSM with HIV infection. Testosterone is prescribed for men showing hypogonadism and HIV-related wasting. While there are direct and indirect physiological effects of testosterone in males, its role in anal HPV16/18 infections in men is unknown. METHODS: Free testosterone (FT) was measured in serum from 340 Multicenter AIDS Cohort Study (MACS) participants who were tested for anal HPV16/18-DNA approximately 36 months later. The effect of log10-transformed current FT level on anal HPV16/18 prevalence was modeled using Poisson regression with robust error variance. Multivariate models controlled for other HPV types, cumulative years of exogenous testosterone use, race, age, lifetime number of receptive anal intercourse partnerships, body mass index, tobacco smoking, HIV-infection and CD4+ T-cell counts among HIV-infected, and blood draw timing. RESULTS: Participants were, on average, 60 (+5.4) years of age, White (86%), and HIV-uninfected (56%); Twenty-four percent tested positive for anal HPV16 and/or 18-DNA (HPV16 prevalence=17.1%, HPV18=9.1%). In adjusted analysis, each half-log10 increase of FT was associated with a 1.9-fold (95% Confidence Interval: 1.11, 3.24) higher HPV16/18 prevalence. Additionally, other Group 1 high-risk HPVs were associated with a 1.56-fold (1.03, 2.37) higher HPV16/18 prevalence. Traditional risk factors for HPV16/18 infection (age, tobacco smoking; lifetime number of sexual partners, including the number of receptive anal intercourse partnerships within 24 months preceding HPV testing) were poorly correlated with one another and not statistically significantly associated with higher prevalence of HPV16/18 infection in unadjusted and adjusted analyses. CONCLUSIONS: Higher free testosterone was associated with increased HPV16/18 prevalence measured approximately three years later, independent of sexual behavior and other potential confounders. The mechanisms underlying this association remain unclear and warrant further study.

Human herpesvirus 8 seroconversion in a population-based cohort of men in Tobago.

Human herpesvirus 8 (HHV-8) is the causal agent of Kaposi's sarcoma (KS). In Tobago, KS is not common; however, HHV-8 seropositivity has been reported to be 39.9% in men with prostate cancer compared to <22.9% in healthier women and men. To understand HHV-8 transmission, we examined HHV-8 seroconversion and seroreversion, and risk factors for these changes in Tobago men. Serum specimens from a sub-cohort of Tobago Prostate Survey men, aged 40-81 years (n = 381/442), were collected at baseline and a subsequent visit between 3 and 9 years and tested for HHV-8 seropositivity using an immunofluorescence assay for antibodies against HHV-8 lytic antigens. Poisson distribution was used to calculate HHV-8 seroconversion and seroreversion rates and their 95% confidence intervals. Differences in baseline characteristics between HHV-seroconverters versus persistent HHV-8 seronegative men and HHV-8 seroreverters versus HHV-8 seropositive men were examined. HHV-8 seropositivity was 12.3% (N = 381) at baseline, with HHV-8 seropositivity significantly higher in increasing age groups, 40-49 (4.0%) to 70-81 (37.5%) years (P-value trend <0.0001). HHV-8 seroconversion and seroreversion rates were 0.23 per 100 person-years (95% C.I., 0.06-0.58) and 2.42 per 100 person-years (95% C.I., 0.89-5.26), respectively. There were significantly more HHV-8 seroconverters who reported "ever smoked cigarettes of >6 months" at baseline compared to HHV-8 persistent seronegative men (P-value = 0.03). Baseline characteristics of HHV-8 seroreverters did not differ from persistent seropositive men. Low HHV-8 seroconversion and seroreversion rates were found. Data suggest that HHV-8 transmission occurred at earlier ages, <40 years, in Tobago men.

Prospective study of human herpesvirus type 8 serostatus and prostate cancer risk in the placebo arm of the Prostate Cancer Prevention Trial.

BACKGROUND: Human herpesvirus type 8 (HHV-8), a gamma herpesvirus associated with Kaposi's sarcoma, has been proposed as a candidate risk factor for prostate cancer (PCa) because of its detection in benign and malignant prostate specimens, and its relation with histologic prostatic inflammation. We investigated the possible relation between pre-diagnostic HHV-8 infection and PCa risk in a case-control study sampled from the placebo arm of the Prostate Cancer Prevention Trial. METHODS: We defined cases as men with a confirmed diagnosis of PCa after visit 2 (n = 315) and controls as men not diagnosed with PCa during the trial who also had a negative end-of-study prostate biopsy (n = 315). We tested sera from visit 2 for IgG antibodies against HHV-8 using a monoclonal antibody-enhanced immunofluorescence assay against multiple lytic HHV-8 antigens. RESULTS: The adjusted seroprevalence of HHV-8 infection was 11.6 % for cases and 11.0 % for controls (p = 0.81). No association was observed between HHV-8 seropositivity and PCa risk (OR 1.06, 95 % CI 0.65-1.76). CONCLUSION: Our findings of a null association between HHV-8 seropositivity and PCa risk do not support an association between HHV-8 infection and PCa development, consistent with the general tendency of the epidemiologic literature to date.

Human herpesvirus 8 induces polyfunctional B lymphocytes that drive Kaposi's sarcoma.

UNLABELLED: Kaposi's sarcoma (KS) is an unusual neoplasia wherein the tumor consists primarily of endothelial cells infected with human herpesvirus 8 (HHV-8; Kaposi's sarcoma-associated herpesvirus) that are not fully transformed but are instead driven to excess proliferation by inflammatory and angiogenic factors. This oncogenic process has been postulated but unproven to depend on a paracrine effect of an abnormal excess of host cytokines and chemokines produced by HHV-8-infected B lymphocytes. Using newly developed measures for intracellular detection of lytic cycle proteins and expression of cytokines and chemokines, we show that HHV-8 targets a range of naive B cell, IgM memory B cell, and plasma cell-like populations for infection and induction of interleukin-6, tumor necrosis factor alpha, macrophage inhibitory protein 1α, macrophage inhibitory protein 1ß, and interleukin-8 in vitro and in the blood of HHV-8/HIV-1-coinfected subjects with KS. These B cell lineage subsets that support HHV-8 infection are highly polyfunctional, producing combinations of 2 to 5 of these cytokines and chemokines, with greater numbers in the blood of subjects with KS than in those without KS. Our study provides a new paradigm of B cell polyfunctionality and supports a key role for B cell-derived cytokines and chemokines produced during HHV-8 infection in the development of KS. IMPORTANCE: Kaposi's sarcoma (KS) is the most common cancer in HIV-1-infected persons and is caused by one of only 7 human cancer viruses, i.e., human herpesvirus 8 (HHV-8). It is unclear how this virus causes neoplastic transformation. Development and outgrowth of endothelial cell lesions characteristic of KS are hypothesized to be dependent on virus replication and multiple immune mediators produced by the KS cells and inflammatory cells, yet the roles of these viral and cell factors have not been defined. The present study advances our understanding of KS in that it supports a central role for HHV-8 infection of B cells inducing multiple cytokines and chemokines that can drive development of the cancer. Notably, HIV-1-infected individuals who developed KS had greater numbers of such HHV-8-infected, polyfunctional B cells across a range of B cell phenotypic lineages than did HHV-8-infected persons without KS. This intriguing production of polyfunctional immune mediators by B cells serves as a new paradigm for B cell function and classification.

Dendritic cells: key players in human herpesvirus 8 infection and pathogenesis.

Human herpesvirus 8 (HHV-8; Kaposi's sarcoma-associated herpesvirus) is an oncogenic gammaherpesvirus that primarily infects cells of the immune and vascular systems. HHV-8 interacts with and targets professional antigen presenting cells and influences their function. Infection alters the maturation, antigen presentation, and immune activation capabilities of certain dendritic cells (DC) despite non-robust lytic replication in these cells. DC sustains a low level of antiviral functionality during HHV-8 infection in vitro. This may explain the ability of healthy individuals to effectively control this virus without disease. Following an immune compromising event, such as organ transplantation or human immunodeficiency virus type 1 infection, a reduced cellular antiviral response against HHV-8 compounded with skewed DC cytokine production and antigen presentation likely contributes to the development of HHV-8 associated diseases, i.e., Kaposi's sarcoma and certain B cell lymphomas. In this review we focus on the role of DC in the establishment of HHV-8 primary and latent infection, the functional state of DC during HHV-8 infection, and the current understanding of the factors influencing virus-DC interactions in the context of HHV-8-associated disease.

Human herpesvirus 8 glycoprotein B binds the entry receptor DC-SIGN.

We have previously shown that human herpesvirus 8 (HHV-8) uses DC-SIGN as an entry receptor for dendritic cells, macrophages and B cells. The viral attachment protein for DC-SIGN is unknown. HHV-8 virions contain five conserved herpesvirus glycoproteins, a single unique glycoprotein, and two predicted glycoproteins. Previous studies have shown that DC-SIGN binds highly mannosylated glycoproteins. The HHV-8 glycoprotein B (gB) has been reported to be highly mannosylated, and therefore we hypothesized that gB will bind to DC-SIGN. In this report we confirm that gB has a high mannose carbohydrate structure and demonstrate for the first time that it binds DC-SIGN in a dose-dependent manner. We also identify key amino acids in the DC-SIGN carbohydrate recognition domain that are required for HHV-8 infection and compare these results with published binding regions for ICAM-2/3 and HIV-1 gp120. These results clarify some of the initial events in HHV-8 entry and can be used for the design of targeted preventive therapies.

Preoperative inflammatory biomarkers and neurovegetative symptoms in peritoneal carcinomatosis patients.

BACKGROUND: Inflammation plays a central role in peritoneal carcinomatosis (PC) etiology and progression, and circulating levels of inflammatory biomarkers prior to surgery predict progression-free and overall survival in PC patients. Depression and fatigue are prevalent among PC patients, and experimental research shows that these symptoms may be mediated by proinflammatory cytokines. As yet unstudied is the possibility that the heightened levels of inflammatory markers in PC patients may contribute to their experience of common neurovegetative symptoms. METHODS: Validated self-report measures of fatigue, depressive symptoms, and quality of life were administered to 64 patients scheduled to undergo aggressive surgical treatment for PC. Serum samples were collected the morning of surgery, and ELISAs were conducted to quantify circulating IL-6, CRP, and TNF-α levels. RESULTS: Consistent with hypotheses, higher IL-6 levels were associated with more severe fatigue (ß=-.39, p<.01) and neurovegetative symptoms of depression (ß=.30, p<.05). IL-6 was also related to poorer physical quality of life (ß=-.28, p<.05). CRP showed similar significant relationships with fatigue and physical quality of life. Inflammatory biomarkers were not significantly related to emotional symptoms of depression or to emotional or social functioning aspects of quality of life, and TNF-α levels were not related to patient-reported measures. CONCLUSION: Preoperative inflammatory activity may contribute to patients' experiences of fatigue and neurovegetative depressive symptoms as well as impaired quality of life. These biological mechanisms warrant consideration in the clinical management of neurovegetative symptoms in PC patients.

Effects on DNA Damage and/or Repair Processes as Biological Mechanisms Linking Psychological Stress to Cancer Risk.

Considerable research effort in the past several decades has focused on the impact of psychological stress, and stress hormones, on cancer progression. Numerous studies have reported that stress hormone treatment or in vivo stress exposure can enhance the growth of tumor cell lines in vitro, as well as tumors in animal models, and have begun to explore molecular mechanisms. Comparatively little research has focused on the impact of psychological stress and stress hormones on cancer initiation, in part due to inherent methodological challenges, but also because potential underlying biological mechanisms have remained obscure. In this review, we present a testable theoretical model of pathways by which stress may result in cellular transformation and tumorigenesis. This model supports our overarching hypothesis that psychological stress, acting through increased levels of catecholamines and/or cortisol, can increase DNA damage and/or reduce repair mechanisms, resulting in increased risk of DNA mutations leading to carcinogenesis. A better understanding of molecular pathways by which psychological stress can increase the risk of cancer initiation would open new avenues of translational research, bringing together psychologists, neuroscientists, and molecular biologists, potentially resulting in the development of novel approaches for cancer risk reduction at the population level.

Downregulation of IRF4 induces lytic reactivation of KSHV in primary effusion lymphoma cells.

Primary effusion lymphoma (PEL), associated with the latent infection by KSHV, constitutively expresses interferon-regulatory factor 4 (IRF4). We recently showed that IRF4 differentially regulates expression of cellular interferon-stimulated genes (ISGs) and viral genes (Forero et al., 2013). Here, using inducible IRF4 knockdown, we demonstrate that IRF4 silencing results in enhanced transcription of KSHV replication transactivator RTA. As a result viral transcription is increased leading to virus reactivation. Taken together, our results show that IRF4 helps maintain the balance between latency and KSHV reactivation in PEL cells.