Cytomegalovirus: detection in human colonic and circulating mononuclear cells in association with gastrointestinal disease

Profiling of microRNAs modulating cytomegalovirus infection in astrocytoma patients

Astrocytoma is recognized as the most common neoplasm of the brain with aggressive progression. The therapeutic regime for glioblastoma, the most aggressive astrocytoma, often consists of aggressive chemo and radiotherapy. The present holistic approaches, however, have failed to influence the quality life of patients. Therefore, it is necessary to understand the underlying mechanisms of its progression for updated therapeutic evaluation. Human cytomegalovirus (HCMV) is reported to be associated with glioblastoma progression. The hypothesis still remains controversial due to the lack of concrete evidences. Here, we report the profile of miRNAs encoded by human host and the cytomegalovirus (CMV) involved in modulation of CMV infection in surgically resected human astrocytoma tissue samples of various malignancy grades (n = 24). Total RNA from the control brain and tumor tissues was extracted by TriZol reagent. The expression levels of the mature form of miRNA were detected by real-time PCR. Primarily, we found the upregulation of miR-210-3p, miR-155-5p, miR-UL-112-3p, miR-183-5p, and miR-223-5p in high-grade astrocytic tumors as compared with low-grade tumor tissues. miR-214-3p is significantly expressed in control brain tissues and its expression decreased with astrocytoma grade progression. This miRNA was reported to be associated with antiviral proprieties. Among CMV-encoded miRNA, miR-UL-112-3p was significantly upregulated in glioblastoma tissue samples and may be involved in providing immune escape to the virus as well as involved in modulating the immune microenvironment of glioblastoma. Taken together, we conclude the possible involvement of miRNAs in modulating the CMV dependent astrocytoma progression.

The evaluation of critically ill transplant patients with infectious diarrhea

PURPOSE OF REVIEW

The review summarizes the epidemiology, risk factors, clinical presentation, diagnosis and management of the most important etiologic agents of infectious diarrhea in critically ill transplant recipients.

RECENT FINDINGS

Diarrhea, frequently caused by infectious pathogens, can cause significant morbidity and mortality in transplant recipients. Diarrhea can lead to severe dehydration, acute renal failure, medication toxicity, rejection, graft-versus-host disease and impairs patients' quality of life. Opportunistic infectious pathogens can pose significant diagnostic and therapeutic challenges in immunocompromised hosts.

SUMMARY

In transplant recipients, it is vital to differentiate infectious from noninfectious diarrhea to adequately manage their therapeutic approach. Supportive measures and reduction in immunosuppression are essential for the treatment management.

Sepsis and Challenging Infections in the Immunosuppressed Patient in the Intensive Care Unit

In 2017, most intensive care units (ICUs) worldwide are admitting a growing population of immunosuppressed patients. The most common causes of pre-ICU immunosuppression are solid organ transplantation, hematopoietic stem cell transplantation, and infection due to human immunodeficiency virus. In this article, the authors review the most frequent infections that cause critical care illness in each of these 3 immunosuppressed patient populations.

Clinical relevance between human cytomegalovirus infection and colorectal cancer

AIM: To investigate the clinical relevance between human cytomegalovirus (HCMV) infection and colorectal cancer.

METHODS: The specific immunoglobulin G (IgG) and IgM antibodies against HCMV in sera of colorectal cancer patients (n = 60), patients with colorectal polyps (n = 60) and health controls (n = 60) were detected by chemiluminescence immunoassay. HCMV infection in colorectal cancer tissues and corresponding adjacent normal samples were determined through the detection of UL138 gene by nested PCR and in situ hybridization. The relationships between HCMV infection and clinical features of colorectal cancer were analyzed.

RESULTS: The positive rates of HCMV-IgG in the colorectal cancer group, colorectal polyps group and healthy control group were 95.0% (57/60), 98.3% (59/60), and 96.7% (58/60), respectively; the positive rates of HCMV-IgM were 5.0% (3/60), 1.7% (1/60) and 1.7% (1/60), respectively. There were no statistically significant differences in the positive rates of HCMV-IgG and HCMV-IgM among the three groups. However, there was a significant difference between colorectal cancer tissues and corresponding normal tissues in HCMV-UL138 detection. The positive rates of HCMV-UL138 were 65.6% (19/32) and 62.5% (20/32) in colorectal cancer tissues samples, and 12.5% (4/32) and 9.4% (3/32) in corresponding normal tissues as revealed by nested PCR detection and in situ hybridization, respectively. HCMV infection had no significant association with age, gender, location of mass, tumor size, histological differentiation, metastasis or Dukes stage.

CONCLUSION: HCMV infection is associated with colorectal cancer. Compared with corresponding normal epithelium, the neoplastic epithelium may be preferentially infected by the HCMV. This research suggests that HCMV infection may play a role in the occurrence and development of colorectal cancer.

Viral infections and colorectal cancer: a systematic review of epidemiological studies

Numerous studies have found the presence of viral DNA in colorectal tumor tissues. However, whether viral infections contribute to the risk of colorectal cancer (CRC) is still under debate. We aimed to provide an overview of published epidemiological studies on the association between viral infections and CRC. A systematic literature search was performed in PubMed to find relevant studies published until 8 May 2014. Information collected included study population, sample type, laboratory method and prevalence of viral infection in cancer or precancer patients and controls. We found 41 studies that fulfilled the selection criteria, all of which had cross-sectional or case-control designs, and most of which were of small to moderate size. Viral infections included human papillomaviruses (HPV), human polyomaviruses, human herpesviruses, human bocavirus and Inoue-Melnick virus. Inconsistent results were observed across studies. Many studies reported higher viral DNA prevalence in tumor tissues than in normal noncancerous tissues either in the same patients or in CRC-free controls. However, potential contamination or temporal sequence of the infection and cancer development were often unclear. Seroprevalence studies assessing antibody titers indicative of viral infections did not find statistically significant differences between CRC cases and healthy controls. Overall published evidence on the role of viral infections in CRC etiology remains limited. Given the potential importance of viral infections and their implication for prevention, there is a strong need for large, methodologically rigorous epidemiological studies.

Incidence, risk factors, and outcomes associated with cytomegalovirus disease in small bowel transplant recipients

Despite improved prophylaxis, monitoring, and more efficient immunosuppression, CMV infection remains a common opportunistic infection in transplant recipients. We assessed the incidence of CMV disease in pediatric SBT recipients, the timing of CMV disease after transplantation, and its impact on patient outcome. The medical records of 98 SBT recipients were reviewed. We performed descriptive analysis, regression analysis, and Kaplan-Meier curves to determine the time-to-event after transplantation. Fifty-three percent patients were male and 47% female, with a mean age of 38.3 months. Thirty-five percent of patients received prophylactic VGC, 55% GCV, 10% a combination of GCV/VGC, and 99% CMV immunoglobulins. A total of 24.5% recipients were CMV D+/R- (CMV serostatus donor positive/recipient negative). Seven (c. 7%) patients developed CMV disease. CMV disease was associated with 2.5 times (0.52-12.1; p = 0.25) higher rate of CMV mismatch and 11.1 times (1.3-95.9; p = 0.03) higher risk of death. CMV prophylaxis increased time-to-death (p = 0.074). Time-to-CMV disease was shorter in patients with enteritis (p < 0.0001), and CMV disease was associated with shorter time-to-death after transplantation (p = 0.001). CMV disease in SBT recipients was associated with an 11-fold mortality increase and a fourfold faster time-to-death. Time-to-death was significantly shorter with CMV enteritis.

The cytomegalovirus-encoded chemokine receptor US28 promotes intestinal neoplasia in transgenic mice

US28 is a constitutively active chemokine receptor encoded by CMV (also referred to as human herpesvirus 5), a highly prevalent human virus that infects a broad spectrum of cells, including intestinal epithelial cells (IECs). To study the role of US28 in vivo, we created transgenic mice (VS28 mice) in which US28 expression was targeted to IECs. Expression of US28 was detected in all IECs of the small and large intestine, including in cells expressing leucine rich repeat containing GPCR5 (Lgr5), a marker gene of intestinal epithelial stem cells. US28 expression in IECs inhibited glycogen synthase 3β (GSK-3β) function, promoted accumulation of β-catenin protein, and increased expression of Wnt target genes involved in the control of the cell proliferation. VS28 mice showed a hyperplastic intestinal epithelium and, strikingly, developed adenomas and adenocarcinomas by 40 weeks of age. When exposed to an inflammation-driven tumor model (azoxymethane/dextran sodium sulfate), VS28 mice developed a significantly higher tumor burden than control littermates. Transgenic coexpression of the US28 ligand CCL2 (an inflammatory chemokine) increased IEC proliferation as well as tumor burden, suggesting that the oncogenic activity of US28 can be modulated by inflammatory factors. Together, these results indicate that expression of US28 promotes development of intestinal dysplasia and cancer in transgenic mice and suggest that CMV infection may facilitate development of intestinal neoplasia in humans.

Sensitive detection of human cytomegalovirus in tumors and peripheral blood of patients diagnosed with glioblastoma

Human cytomegalovirus (HCMV) has been described to be associated with several human malignancies, though the frequency of detection remains controversial. It is unclear whether HCMV plays an active role in malignant tumor progression or becomes reactivated under pathologic conditions that result in chronic inflammation or immunosuppression. In this study, we report on the investigation of detecting HCMV in the tumors and peripheral blood of patients with newly diagnosed glioblastoma multiforme (GBM). Using immunohistochemistry, in situ hybridization, and polymerase chain reaction amplification of viral DNA, the detection of HCMV was investigated in tumor and blood specimens from patients with GBM as well as in the peripheral blood of normal volunteers and patients undergoing craniotomy for diagnoses other than GBM. We found that a high percentage (>90%) of GBM tumors, not surrounding normal brain, are associated with HCMV nucleic acids and proteins. Furthermore, a significant proportion of patients (80%) with newly diagnosed GBM have detectable HCMV DNA in their peripheral blood, while sero-positive normal donors and other surgical patients did not exhibit detectable virus, suggesting either a systemic reactivation of HCMV within patients with GBM or shedding of viral DNA from infected tumor cells into the periphery. These results confirm the association of HCMV with malignant gliomas and demonstrate that subclinical HCMV viremia (presence of viral DNA in blood without clinical symptoms of infection) is a previously unrecognized disease spectrum in patients with GBM.

Differential mutagen sensitivity of peripheral blood lymphocytes from smokers and nonsmokers: effect of human cytomegalovirus infection

We used the mutagen sensitivity assay to test the hypothesis that human cytomegalovirus (HCMV) infection modifies the sensitivity of cells to genetic damage from genotoxic agents. Chromosome aberration (CA) frequency in peripheral blood lymphocytes (PBLs) from 20 smokers who were matched with 20 nonsmokers by age (+/- 5 years), sex, and ethnicity was evaluated following in vitro exposure to bleomycin and/or HCMV infection. Bleomycin induced significant (P < 0.05) concentration-dependent increases in the frequency of aberrant cells, chromatid-type damage (breaks), and chromosome-type aberrations (deletions, rearrangements) in PBLs. The baseline (background) CA frequency was similar in both smokers and nonsmokers. Significantly higher frequencies of aberrant cells (P < 0.05) were observed in PBLs from smokers compared to nonsmokers at all bleomycin concentrations tested (10, 30 and 100 microg/ml). Infection of PBLs with HCMV induced a significant (P < 0.05) twofold increase in the frequency of CA (primarily chromatid breaks) in PBLs, regardless of the smoking status. PBLs from smokers and nonsmokers infected with HCMV prior to challenge with bleomycin demonstrated significant (P < 0.05) concentration-dependent increases in the levels of aberrant cells, chromatid-type damage (breaks), and chromosome-type aberrations (deletions, rearrangements) compared to noninfected cells challenged with bleomycin. The frequency of induced CA was consistently higher for PBLs derived from smokers relative to nonsmokers (P = 0.06 and 0.002). These data indicate that, individually, both smoking and HCMV infection significantly enhance the sensitivity of PBLs to bleomycin-induced genetic damage. More importantly, the data also suggest that smoking and HCMV infection interact synergistically to enhance the sensitivity of PBLs to such damage.

Jejunal perforation associated with cytomegalovirus infection in a patient with adult T-cell leukemia-lymphoma

A patient with adult T-cell leukemia-lymphoma suffered a jejunal perforation, which we believe was directly attributable to cytomegalovirus (CMV) infection. In the areas of ulceration and perforation in the small bowel, blood vessels penetrating the muscularis propria showed extensive lining of cytomegalic endothelial cells with CMV inclusions, accompanied by occasional disruption of the walls, partial occlusion of the lumina, fibrin thrombi, and hemorrhage. The CMV-induced vascular damage seemed to be closely related to the occurrence of ulcers and perforation. The recognition of CMV as a cause of lethal gastrointestinal lesions in immunocompromised hosts has become more important with the advent of anti-CMV therapy.

Activation of cellular oncogenes by clinical isolates and laboratory strains of human cytomegalovirus

The effect on cellular (c) oncogene RNA levels was investigated after infection of permissive cells with cell culture adapted strains (AD-169, C-87, Davis) and unadapted clinical isolates (82-1, 84-2, 85-1) of human cytomegalovirus (HCMV). The results indicate that both adapted and unadapted strains of HCMV induce substantial increases in c-oncogene RNA levels for fos, jun, and myc measured by Northern blot hybridization. Elimination of immediate early (IE) protein synthesis between 0 and 3 hrs or reduction of virus infectivity (99.99%) by UV-irradiation did not reduce the increase in c-oncogene RNA levels. Inhibition of viral and cellular protein synthesis by cycloheximide resulted in a high abundance (superinduction) of specific RNAs which hybridized to c-oncogene probes after infection with either adapted or unadapted strains of HCMV. These data suggest that IE viral gene expression is not essential for activation of c-oncogenes. Inhibition of DNA-dependent RNA synthesis by blocking RNA elongation with actinomycin-D or by inhibiting the activity of RNA polymerase II with alpha-amanitin significantly reduced the increase in c-oncogene RNA levels, suggesting that activation of cellular genes by HCMV is controlled at the level of transcription. Activation of c-oncogenes by HCMV may be particularly important because their protein products appear to be involved in initiation and regulation of viral and cellular gene expression.

Colorectal carcinogenesis

It is generally accepted that genetic and environmental factors combine in the aetiology of bowel cancer. Epidemiological studies have shown that the environmental factors effects are shown more clearly in the left colon, and that they are related to living in western societies whose diets contain high levels of protein, fat and energy. There has been recent awareness that consumption of alcoholic beverages, particularly beer, may be causally related to cancers of the left colon and rectum. This review attempts to relate the general epidemiological data to more specific mechanisms of colorectal carcinogenesis. Dimethylhydrazine (DMH) and N-nitroso chemicals are potent colorectal carcinogens in animals. They have not been thought very relevant to humans because their existence in appropriate forms in the environment has been debatable and analytical methods for the specific detection of non-volatile nitrosamines and nitrosamides have not been available. Recently, however, relevant alkylating activity has been detected in foods incubated in quasi-gastric conditions, and several epidemiological studies have shown a protective effect for Vitamin C, which may inhibit the development of rectal cancer through beer consumption. As Vitamin C prevents nitrosation and as precursors of nitrosamides are present in prepared foods, further dietary studies with hypotheses based on N-nitroso carcinogenesis are required. Unfortunately, these studies will probably not show clear dose-response relationships. Many of the complex reasons for this are discussed; however, one of the most important could be related to an interplay between inherited and environmental factors. The inherited factors demonstrated by chromosomal analysis in cancer and polyposis syndromes are a reminder that other genetic (oncogenetic) changes may occur in sporadic colorectal cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Meconium aspiration syndrome

Background

A possible association between human cytomegalovirus (HCMV) infection and colorectal cancer progression has been inferred by the identification in tumour tissues of HCMV antigens and specific viral DNA or RNA sequences. To further investigate the relationship between HCMV and colorectal cancers we developed qualitative and quantitative PCR assay to detect HCMV DNA in 56 formalin-fixed paraffin-embedded (FFPE) tissue samples from patients belonging to 4 different histological phenotypes: adenoma; poorly, moderately and well differentiated adenocarcinomas.

Results

Of the 56 FFPE tested tissue samples, 6 (11%) were positive for HCMV nested PCR amplification, and more precisely 1 (5%) of 20 cases of adenoma and 5 (21%) of 24 cases of moderately differentiated adenocarcinoma. No PCR positivity was obtained in samples from well and poorly differentiated adenocarcinomas.

Conclusion

Our observations suggest that there is no evidence of a direct association between HCMV and colorectal cancer. Moreover, the results obtained are not supportive of a causal role of HCMV in the processes of carcinogenesis and/or progression of colorectal cancer. However, the fact that the virus may present a "hit and run" like-mechanism and HCMV can thus only be detectable at a particular stage of a processing adenocarcinoma, suggests that a significant number of colorectal cancers might have been the subject of HCMV infection that could contribute to trigger the oncogenic differentiation. Our analysis does not exclude the possibility of HCMV infection subsequent viral clearance.

Viral infections in the acquired immunodeficiency syndrome

The following communication is a tripartite synopsis of the role of viral infection in the acquired immunodeficiency syndrome (AIDS). The first section describes the impact of viral opportunistic infection in AIDS; for each virus, clinical presentation and diagnosis, laboratory diagnostic approaches (with emphasis on electron microscopy), and therapeutic interventions attempted to date are discussed. The second segment explores current theories on the pathogenesis of AIDS, and describes diagnostic and therapeutic approaches to the syndrome itself. The final section catalogues ultrastructural anomalies in the cells of AIDS patients, many of which have been mistakenly identified as etiologic agents.

Detection of human cytomegalovirus DNA in human tonsillar lymphocytes

The human cytomegalovirus (HCMV) was first isolated in cell cultures from the oropharynx, which is thought to be a site of primary infection. Although HCMV can be recovered from the oropharynx during reactivation phases, its exact site of latency is not known. In the present study we demonstrated evidence suggesting the presence of latent HCMV in this anatomic region--in the palatine tonsils. Samples from 30 tonsils obtained by tonsillectomy were screened for the presence of HCMV. Out of the 30 tonsil donors, 23 were seropositive for HCMV. Three methods were used in attempts to demonstrate HCMV's presence in the tonsils: (1) viral isolation attempts on various cell cultures, (2) immunohistochemical staining--immunoperoxidase method--designed to detect viral antigens, and (3) DNA dot hybridization with a HCMV-DNA probe designed to detect viral DNA. Neither infectious HCMV nor other viruses were isolated in cell cultures. No viral antigens were detected by immunoperoxidase staining in the tonsillar tissue. Four out of the 30 tonsils studied were found to contain viral DNA. In one case in which the tonsillar mononuclear (MN) fraction was separated from the polymorphonuclear (PMN) fraction, only the first fraction contained the viral DNA.

Nucleic acid probes in clinical microbiology

The infectious disease applications of nucleic acid probe have been described. In addition, the basic procedures of nucleic acid probe technology have been discussed, as have the factors affecting implementation of probe technology in diagnostic laboratories. Despite the questions raised, nucleic acid probes will become part of the diagnostic laboratory in the near future. Commercial interests are developing and marketing new probes, reagents, and kits which will expedite the employment of this technology. High-volume reference laboratories will first use probes as part of a battery of tests which will include ELISA and monoclonal antibody methods. In all probability, probes will replace methods: that have proven to be ineffective, difficult, or costly such as culturing for some enteric pathogens and Legionella, that require long incubation periods, such as mycobacteria, or that have high costs and low yields, such as virology.

Elution of cytomegalovirus antibodies from adenocarcinoma of the colon

Eluates were prepared by high salt extraction from normal colonic mucosa and adenocarcinomatous tissue from 28 patients, eight more from unmatched colonic tissue and five from patients with other gastrointestinal disease. Immunoglobulins were detected by ELISA: IgG was present in 24% eluates from normal colon and 21% from carcinomas; IgA in 55% eluates from normal colon and 39% from carcinomas; IgM in 55% from normal colon and 37% from carcinomas. Cytomegalovirus-specific antibody was found in 15% eluates from normal colon and in 18% carcinomas. Out of the 28 matched specimens, cytomegalovirus-specific IgG was detected in one normal and four tumour eluates, specific IgA in two normal and four tumour eluates, and specific IgM in two normal and two tumour eluates. In two instances cytomegalovirus-specific antibody was present in the eluates prepared from the normal and tumour tissue of the same patient. Of those eluates which contained cytomegalovirus-specific antibodies by ELISA, two were positive by anti-complement immunofluorescence of human embryo fibroblasts infected with cytomegalovirus strain AD-169. It seems possible, therefore, that cytomegalovirus antigens on colonic cells may be masked by complexing with anti-cytomegalovirus antibodies, and may not therefore be detected by techniques such as immunofluorescence.

Cytomegalovirus DNA in colorectal carcinoma tissues

Numerous studies had linked human cytomegalovirus (HCMV) infections with neoplasia. Among various other malignant tumors, colonic carcinoma tissues were reported to contain DNA sequences hybridizing with DNA extracted from virus particles. Gene technology allowed us to use a cloned viral DNA library to measure HCMV in colorectal tumors more specifically. Four of 38 tissue specimens did contain DNA sequences homologous to cloned viral DNA probes; however, in each of those cases, identical hybridization patterns were seen with specimens from non-infiltrated surrounding intestinal wall. The amount of HCMV DNA in normal tissues was at least as much as in tumor biopsies. We conclude that nucleic acid hybridizations at high sensitivity with moleculary cloned HCMV DNA did not support the notion of a correlation between colorectal carcinomas and human cytomegalovirus.

Spontaneous activation of latent cytomegalovirus from murine spleen explants. Role of lymphocytes and macrophages in release and replication of virus

Cytomegalovirus (CMV) is a major pathogen in the compromised host where many infections result from activation of latent virus. Because latent CMV infection has been difficult to study in humans, murine models have been developed and investigated. Here, we describe the events involved in activation of latent murine CMV (MCMV) from spleen explants in vitro. Infectious virus was no longer detectable in murine organs 4 mo after inoculatioN of 10(5) plaque-forming units of MCMV. 8-10 d after establishment of spleen explants, phagocytic macrophages covered 70-80% of the surface of tissue culture dishes, and lymphocytes were continuously released, reaching titers of 10(6) cells/ml. MCMV was produced spontaneously after 12-18 d from spleen explant cultures of 33 of 34 mice. Virus replicated to titers above 10(4) plaque-forming units/ml, remained at that level for 4-5 wk, and gradually disappeared as macrophages were lysed. Although MCMV was shown to be replicating in macrophages, these cells were never found to be the source of latent virus. Cell separation studies indicated that latent virus was initially released from 70% of lymphocyte cultures and was associated with the B cell enriched fraction. We conclude that MCMV establishes nonreplicating dormant infection in B lymphocytes, activates from these cells in spleen explant cultures, and is augmented in titer by replication in permissive macrophages.

Cytomegalovirus and Kaposi's sarcoma in young homosexual men

10 homosexual men with Kaposi's sarcoma (KS) were studied for evidence of cytomegalovirus (CMV) infection. IgG and IgM antibodies to CMV were detected in 9 out of 9 and in 7 out of 9 of these patients, respectively. CMV was recovered from body secretions or peripheral blood of 7 patients. Viral cultures of KS tumour biopsy specimens were negative in 8 out of 8 patients, but CMV RNA was detected by in-situ hybridisation in 2 out of 3 and CMV antigen(s) by immunofluorescence in 6 out of 9. Normal tissue specimens from 3 KS patients were negative for CMV antigen. These observations suggest an association of CMV with KS.

Cloning of the complete human cytomegalovirus genome in cosmids

Purified virion DNA (155 X 10(6) Mr) of human cytomegalovirus (CMV) strain Ad169 was partially cleaved with restriction endonucleases HindIII and EcoRI and cloned in the respective cleavage sites of cosmid pHC79. A complete gene library was established in a set of clones containing the viral DNA in long overlapping segments. Restriction maps for HindIII (29 fragments) and EcoRI (36 fragments) were constructed from the linkage of cosmid-cloned fragments, from double digestions of cloned DNA, and from blot hybridization of labeled cloned viral DNA with restriction fragments of virion DNA and singly or doubly cleaved cosmid clones.