Microarrays in the Diagnosis of Human Herpesvirus infections

Currently, there are nine known human herpesviruses and these viruses appear to have been a very common companion of humans throughout the millenia. Of human herpesviruses, herpes simplex viruses 1 and 2 (HSV-1, HSV-2), causative agents of herpes labialis and genital herpes, and varicella-zoster virus (VZV), causative agent of chicken pox, are also common causes of central nervous system (CNS) infections. In addition, human cytomegalovirus (CMV), Epstein-Barr virus (EBV) and human herpesviruses 6A, 6B, and 7 (HHV-6A, HHV-6B, HHV-7), all members of the herpesvirus family, can also be associated with encephalitis and meningitis. Accurate diagnostics and fast treatment are essential for patient recovery in CNS infections and therefore sensitive and effective diagnostic methods are needed. The aim of this thesis was to develop new potential detection methods for diagnosing of human herpesvirus infections, especially in immunocompetent patients, using the microarray technique. Therefore, methods based on microarrays were developed for simultaneous detection of HSV-1, HSV-2, VZV, CMV, EBV, HHV-6A, HHV-6B, and HHV-7 nucleic acids, and for HSV-1, HSV-2, VZV, and CMV antibodies from various clinical samples. The microarray methods developed showed potential for efficiently and accurately detecting human herpesvirus DNAs, especially in CNS infections, and for simultaneous detection of DNAs or antibodies for multiple different human herpesviruses from clinical samples. In fact, the microarray method revealed several previously unrecognized co-infections. The microarray methods developed were sensitive and provided rapid detection of human herpesvirus DNA, and therefore the method could be applied to routine diagnostics. The microarrays might also be considered as an economical tool for diagnosing human herpesvirus infections.

Human herpesvirus-6 infection in liver transplantation

Rejection and infections are the two most common complications after liver transplantation. Human herpesvirus-6 (HHV-6) belongs to the betaherpesviruses, together with its close relatives cytomegalovirus (CMV) and human herpesvirus-7 (HHV-7). The impact of CMV in liver transplantation is well characterized, but the roles of the other two betaherpesviruses have been acknowledged only recently. Although, HHV-6 reactivation after transplantation is usually asymptomatic, the virus may infect the liver transplant, cause an intragraft lymphocyte dominated inflammatory reaction and graft dysfunction. HHV-6 is also suggested to be associated with liver allograft rejection but the mechanisms are unclear. The aim of this study was to investigate the intragraft immunological processes associated with HHV-6, the involvement of HHV-6 in acute liver failure (ALF) and the hepatic HHV-6 infection of the same patients after transplantation. In addition, the occurrence of HHV-6 and HHV-7 was investigated in liver transplant patients with symptomatic CMV infection. HHV-6 infection of the liver graft was associated with portal lymphocyte infiltration and with a significant increase of adhesion molecules (ICAM-1 and VCAM-1) and the number of cells expressing their ligand molecules (LFA-1, VLA-4) and class II antigens. HHV-6 infection was associated with significant immunological changes, but the immune response was limited to lymphocyte infiltration and the adhesion molecule level. However, one third of these patients developed chronic rejection during the follow-up. Of the patients with ALF of unknown origin, most patients demonstrated HHV-6 antigens in the liver, whereas the opposite was seen in ALF patients with a known disease. After transplantation, HHV-6 recurrence was found in the liver transplant in half of these patients with pre-transplant HHV-6 infection of the liver, whereas no post-transplant HHV-6 infection of the liver was seen in patients without pre-transplant HHV-6. Our studies further demonstrated that both HHV-6 and HHV-7 antigenemia often appeared in association with CMV disease in liver transplant patients. The time-related occurrence of the viruses differed, as HHV-6 appeared early after transplantation and regularly preceded CMV whereas HHV-7 often appeared concurrently with CMV. In conclusion, these results indicate that all three betaherpesviruses are common after liver transplantation, often associated with each other. The immunological events caused by HHV-6 in the liver transplant may be involved in, or trigger mechanisms of allograft rejection. In addition, HHV-6 could be one of the causes of ALF, and pre-transplant HHV-6 infection in ALF patients is a risk factor for post-transplant HHV-6 infection of the graft. These results strongly support the clinical significance of HHV-6 in liver transplantation. Even though the reactivation is usually asymptomatic, in some individuals HHV-6 infection may lead to severe manifestations, such as liver failure or in transplant patients, graft dysfunction and rejection.

Implicações imunobiológicas da infecção a herpesvirus em tumores malignos : pesquisa e análise quantitativa de herpesvirus humanos no astrocitoma pilocítico

RESUMO: As infecções virais podem contribuir para o desenvolvimento do cancro, estando vários tumores malignos associados aos Herpesvirus (HHV). O vírus de Epstein-Barr (EBV) e o Herpesvirus 8, dois Herpesvirus, foram reconhecidos como agentes etiológicos de várias neoplasias. O astrocitoma pilocítico do cerebelo é um dos tumores cerebrais mais frequentes na criança, adolescentes e jovens adultos e a proliferação astrocitária ocorre geralmente após vários tipos de agressão, nomeadamente a infecção viral. Para investigar esta eventual interligação, estudámos 35 astrocitomas pilocíticos, pesquisando a presença dos 8 Herpesvirus. Neste estudo, foram utilizadas 10 amostras de biópsias do cerebelo de doentes que faleceram por doenças não relacionadas com infecção ou patologia tumoral. A maioria dos astrocitomas (33) eram tumores de baixa malignidade. As amostras foram analisadas por PCR (Polymerase Chain Reaction) quantitativa em tempo real (qPCR), com amplificação do gene da DNA polimerase viral. Treze astrocitomas e 7 controles revelaram pequenas quantidades de DNA viral (1-100 cópias/100ng DNA) de todos os Herpesvirus, com excepção do HHV6 A e B que estava ausente nas amostras. O EBV foi identificado em 9 dos 35 astrocitomas (26%) e em 7 dos 10 controles (70%) estando muito mais presente nos controles. As amostras positivas para o EBV foram também analisadas por imunohistoquímica, não tendo sido imunoreactivas para os anticorpos utilizados. A PCR com CODEHOP (consensus-degenerated hybrid oligonucleotide primers) foi utilizada para investigar a presença de um eventual Herpesvirus novo nestas amostras. Não foi identificada nenhuma sequência indicativa de um novo HHV por este método. 24. Em conclusão, os dados apontam para a presença de Herpesvirus, com particular relevância para o EBV, em tecido de cerebelo normal e em tumores cerebrais, embora em níveis demasiado baixos para poderem ser responsabilizados pela indução tumoral. A presença de sequências de DNA de Herpesvirus, nomeadamente do EBV, no Sistema Nervoso Central vem enriquecer a discussão sobre o significado da infecção viral na oncogénese humana, particularmente na neuro-oncogénese. ABSTRACT: Viral infections can contribute to the development of human cancer. Several human malignancies are linked with Human Herpesviruses (HHVs). Epstein-Barr virus and HHV8, two hHerpesvirus, have been recognized as etiologic agents of several neoplasms. Pilocytic astrocytoma of the cerebellum is one of the most common brain tumour in children, adolescents and young adults and astrocytary proliferation generally occurs after several types of injury, namely viral infection. To further explore this association, we have searched the tissue from 35 pilocytic astrocytoma, for all the 8 HHV. In this study, ten brain biopsies (cerebellum) from patients who died of unrelated diseases were used as controls. Most of the astrocytomas (33) were of low grade malignity. Samples were assessed by Real-time quantitative Polymerase Chain Reaction (q PCR) amplification of viral DNA polymerase gene. Thirteen astrocytoma and 7 controls showed low viral DNA levels (1-100 copies/100ng DNA) for all HHVs, with the exception of HHV6 that was absent. EBV was identified in 9 of the 35 astrocytoma (26 %) and in 7 of the 10 controls (70%) being more present in controls. EBV positive samples were also assessed by Immunohistochemistry (IHC) but none showed immunoreactivity for the antibodies used. PCR with consensus-degenerated hybrid oligonucleotide primers (CODEHOP) were also used to look for novel HHVs in these samples and no sequence indicative of a new HHV was detected. 26 Altogether the data indicate the presence of HHVs, with relevance for EBV in normal cerebellum tissue and also in brain tumours but at too low levels to be considered responsible for tumour induction. The presence of HHV DNA sequences, particularly EBV, in the studied brain tumours and control samples, further enriches the discussion about the relevance of viral infection in human oncogenesis, particularly neuro-oncogenesis.RÉSUMÉ: Les infections virales peuvent contribuer au développement du cancer. Les vírus de type Herpès sont associés à plusieurs néoplasies. Il est par exemple établi que les vírus Epstein-Barr et « human Herpesvirus 8 » (HHV-8) sont responsables de plusieurs tumeurs malignes. L´astrocytome pilocitique du cervelet est l’une des tumeurs les plus fréquentes chez les enfants, adolescents et adultes jeunes. En général la prolifération des astrocytes se produit en réponse à une agression. Posant l’hypothèse d’une agression d’origine virale, nous avons recherché la présence des 8 vírus Herpès dans les tissus de 35 astrocytomes. Dans cette étude, 10 échantillons de biopsie de cervelet de patients décédés suite à d’autres pathologies, ont été utilisés comme contrôles. La majorité des astrocytomes étaient de très basse malignité. Les échantillons ont été étudiés par PCR quantitative en temps réel, en amplifiant le gène de l’ADN-polymérase virale. Treize astrocytomes sur 35 (37%) et 7 contrôles sur 10 (70%) ont été trouvés positifs pour tous les HHV sauf l´HHV6, toujours avec un nombre de copies de polymérase virale bas (< 100 copies/100 ng d’ADN). Notamment l’EBV a été identifié 7 fois dans les contrôles (70%) et 9 fois dans les astrocytomes (26%). Les échantillons positifs pour l`EBV ont aussi été étudiés par immuno-histochimie. Aucun signal n’a été observé avec les anticorps utilisés. Enfin, une technique de PCR avec oligonucléotides dégénérés (CODEHOP ou consensus degenerated hybrid oligonucleotide primers) a été utilisée pour rechercher la présence d´un éventuel nouveau vírus Herpès dans les échantillons d’astrocytome. Aucun nouveau vírus n’a été identifié. 28 En résumé, nous avons établi la présence de vírus Herpès, en particulier l´EBV, dans le cervelet normal et dans les tumeurs du cerveau. Les quantités d’ADN viral retrouvées sont faibles et ne permettent pas d’attribuer à ces vírus la responsabilité de l’induction des tumeurs. Cependant, la présence d’ADN de vírus Herpès dans le cerveau sain ou pathologique vient enrichir la discussion sur le signification de l´infection virale dans les processus d´oncogenèse en général, et dans la neuroonco-genèse en particulier.

Treatment-dependent loss of polyfunctional CD8+ T-cell responses in HIV-infected kidney transplant recipients is associated with herpesvirus reactivation.

Antiretroviral-therapy has dramatically changed the course of HIV infection and HIV-infected (HIV(+)) individuals are becoming more frequently eligible for solid-organ transplantation. However, only scarce data are available on how immunosuppressive (IS) strategies relate to transplantation outcome and immune function. We determined the impact of transplantation and immune-depleting treatment on CD4+ T-cell counts, HIV-, EBV-, and Cytomegalovirus (CMV)-viral loads and virus-specific T-cell immunity in a 1-year prospective cohort of 27 HIV(+) kidney transplant recipients. While the results show an increasing breadth and magnitude of the herpesvirus-specific cytotoxic T-cell (CTL) response over-time, they also revealed a significant depletion of polyfunctional virus-specific CTL in individuals receiving thymoglobulin as a lymphocyte-depleting treatment. The disappearance of polyfunctional CTL was accompanied by virologic EBV-reactivation events, directly linking the absence of specific polyfunctional CTL to viral reactivation. The data provide first insights into the immune-reserve in HIV+ infected transplant recipients and highlight new immunological effects of thymoglobulin treatment. Long-term studies will be needed to assess the clinical risk associated with thymoglobulin treatment, in particular with regards to EBV-associated lymphoproliferative diseases.

Detección molecular y aislamiento del herpesvirus bovino 1 (BoHV-1) en sementales de hatos bovinos del noreste de México.

Tesis (Maestría en Ciencias Veterinarias con Especialidad en Salud Animal) UANL, 2011.

Identification of a novel herpesvirus associated with a penile proliferative lesion in a beluga (Delphinapterus leucas).

The carcass of an adult male beluga (Delphinapterus leucas) was found beach cast in 2008 on the shore of the St. Lawrence Estuary at Rivière-Ouelle, Quebec, Canada. The carcass was transported to the Faculté de médecine vétérinaire of the Université de Montréal for postmortem examination. Aspiration pneumonia was the probable cause of death. Necropsy revealed a focal papilloma-like penile lesion, characterized by focal mucosal thickening with disorganization of the epithelial layers and lymphoplasmacytic infiltration. A pan-herpesvirus nested PCR assay on frozen tissue from the penile lesion was positive. The PCR product sequencing revealed a partial herpesvirus DNA polymerase (DPOL) gene sequence of 600 nucleotides. Its nearest nucleotide identity was with the partial DPOL gene of an alphaherpesvirus, bovine herpesvirus 5 (79.5% identity). It also shared high identity with several other marine mammal herpesviruses (50.2 to 77.3% identity). This new herpesvirus was tentatively named beluga whale herpesvirus (BWHV). Virus isolation was unsuccessful. The pathogenic potential of BWHV is unknown, but the evaluation of archived tissues suggests that the virus is endemic in the St. Lawrence Estuary beluga population.

Identification of a novel herpesvirus associated with cutaneous ulcers in a fisher (Martes pennanti).

On December 8, 2008, a male fisher (Martes pennanti) housed in a quarantine enclosure at the St-Félicien Zoo was found dead with multiple skin ulcers on the muzzle and plantar pads. At necropsy, no major findings were found, and a specific cause of death was not determined microscopically. However, at the borders of ulcerated sites, there were increased numbers of koilocytes, with perinuclear vacuolation and nuclear enlargement. A pan-herpesvirus nested polymerase chain reaction (PCR) assay was conducted, and an expected PCR product of 230 nucleotides was obtained within tissues collected from around the skin ulcers. Other tissues, including intestines and pool of lung, liver, and kidney, tested negative. The obtained PCR amplicon was sequenced and was highly related to the partial viral DNA polymerase (DPOL) gene of Mustelid herpesvirus 1. Virus isolation was negative, and no virion was detected by electron microscopy. The pathogenic potential of this novel herpesvirus and its role in the death of the fisher are unknown.

Seroprevalence of Human Herpesvirus 8 Infection in Individuals From Health Care Centers in Mozambique: Potential for Endemic and Epidemic Kaposi`s Sarcoma

Human herpesvirus 8 (HHV-8) infection is common in sub-Saharan Africa, but its prevalence in Mozambique is unknown. The seroprevalence of HHV-8 in a cohort of individuals seen at public health centers in Northern (n = 208), Central (n = 226), or Southern (n = 318) Mozambique was examined. All individuals were interviewed to obtain socioeconomic, demographic and clinical data and were tested for serum anti-HHV-8 antibodies using an immunofluorescence assay. The overall frequency of HHV-8 antibodies was 21.4% and, in spite of the diversity of epidemiological characteristics of the tested individuals, did not differ significantly among regions: 18.7%, 24.3% and 21.4% in the North, Center, and South, respectively (chi(2), 2.37; P = 0.305). The variables that were associated significantly with the presence of HHV-8 antibodies were gender, age, level of education, number of siblings and HIV serostatus, but these differed across the regions. In the North, although tested individuals lived under poor socioeconomic conditions, no association between HHV-8 infection and household variables was detected, with the exception of the number of siblings (P = 0.042). In the Central region, HHV-8 infection was associated with gender (P = 0.010), the number of household members (P = 0.031), and the place of attendance (P = 0.021). In the South, HHV-8 infection was associated with the number of siblings (P = 0.023) and HIV status (P = 0.002). The overall prevalence of HHV-8 seropositivity increased with age. These results demonstrate that Mozambique is another country in Africa with endemic HHV-8 infection, and, because of the AIDS epidemic, continued access to antiretroviral treatment is necessary to avert an outbreak of AIDS-Kaposi`s sarcoma. J. Med. Virol. 82:1216-1223, 2010. (C) 2010 Wiley-Liss, Inc.

A Comparative Study of the Frequency of Antibody and Titers Against Human Herpesvirus 8 Latent and Lytic Antigens in ""At-Risk"" Individuals and Among Patients With Kaposi`s Sarcoma

Differences in the prevalence of human herpesvirus 8 (HHV-8) and Kaposi`s sarcoma (KS) have been described, depending on the study population and their geographic origin. A cross-sectional study aimed at detecting the frequency and titers of antibodies against HHV-8 latent and lytic antigens in serum samples from individuals with different risk-factors for HHV-8 infection, as well as predictive marker identification in patients with KS, was conducted. Serum samples were collected from seven groups of individuals: 75 patients with AIDS-KS, 5 with classic KS, 16 with African KS, 495 with HIV/AIDS, 805 patients with chronic kidney disease, 683 handicapped individuals, and 757 health care workers. Samples were evaluated for the presence and titers of HHV-8-specific antibodies to latent and lytic antigens using ""in house"" immunofluorescence assays. The results were analyzed by the Chi-square, Fisher`s exact test, Kruskal-Wallis and/or Mann-Whitney U-tests. The frequencies of HHV-8 antibodies were as follows: 87.5-100% in patients with KS, 20.4% in patients with HIV/AIDS, 18% in patients with chronic kidney disease, 1.6% in handicapped individuals, and 1.1% in health care workers. A greater number of samples were antibody positive to lytic antigens. Elevated titers of antibodies to latent and lytic antigens, mostly among patients with KS, were detected. Using established serological assays, different ""at-risk"" populations for HHV-8 infection/disease were detected in this geographic area, confirming HIV/AIDS and identifying patients with chronic kidney disease as high-risk groups. It is suggested that a longitudinal evaluation of antibody titers in patients with chronic kidney disease be undertaken to confirm their predictive value in the development of KS. J. Med. Virol. 81: 1292-1297, 2009. (C) 2009 Wiley-Liss, Inc.