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PubMed1989

Human T-lymphotropic virus I-infected T cells constitutively express lymphotoxin in vitro.

We have studied the pattern of expression of the lymphokines tumor necrosis factor (TNF alpha) and lymphotoxin (TNF beta) in T-cell lines established by transformation with human T-lymphotropic virus, type I (HTLV-I), the etiologic agent of adult T-cell leukemia (ATL). We report here that nine of nine HTLV-I-infected T-cell lines, established by in vitro infection with HTLV-I, including those with CD4+ or CD8+ as well as CD4-/CD8- phenotypes, constitutively produce high levels of TNF alpha and -beta mRNA and secrete biologically active TNF beta into the culture medium. Similar patterns of expression are seen in six of six HTLV-I-infected T-cell lines directly established from ATL patients. In contrast, several T-cell lines, either uninfected or infected with human immunodeficiency virus I, did not produce comparable levels of the TNF beta. Comparisons of a normal functional T-cell clone before and after infection with HTLV-I show that expression of TNF beta mRNA is induced in the infected cells. The high level expression in HTLV-I-infected cell lines dose not seem to involve perturbation of the TNF alpha/beta genetic loci by proviral integration. A cell line (81-66/45) nonproductively transformed with HTLV-I that produces tat-1 in the absence of viral structural proteins, produces both TNF alpha and -beta mRNA. This suggests that expression of these cytokines could be mediated in trans by the tat-1 gene product.

Blotting, Southern↗

PubMed1986

Human papillomavirus (HPV) infections of the female genital tract and their associations with intraepithelial neoplasia and squamous cell carcinoma.

Human papillomaviruses (HPV) consist of a heterogenic group of viruses (32 different HPV types currently recognized) known to induce a variety of squamous cell tumors (papillomas and warts) in the skin, and on mucous membranes of respiratory, gastrointestinal, and genitourinary tracts. The most familiar HPV manifestation in the genital tract is the venereal wart (condyloma acuminatum) recognized since antiquity, and shown to be a sexually transmitted disease (STD). In 1976, two other morphologically distinct HPV lesions were described in the uterine cervix, currently known as a flat and an inverted condyloma. Subsequently, these new HPV lesions were also shown to be an STD, and in addition, they frequently seem to occur concomitantly with CIN, CIS, and occasionally with invasive cervical carcinomas as well. These morphologic findings substantiated by the recent reports on malignant transformation of HPV lesions, as well as data from animal experiments and epidemiologic surveys, have lent support to the concept that HPV might be involved in the development of cervical (and other) human squamous cell carcinomas. Further evidence has been provided by the recent discoveries of HPV structural proteins (viral antigens) and HPV type 11 DNA in lesions of CIN, and HPV 16 and 18 DNA predominantly in invasive cervical carcinomas. So far, HPV 16 and HPV 18 seem to be the only HPV types with DNA capable of existing integrated in the host cell DNA. At the moment, cervical (and other) HPV lesions are the subject of intense study utilizing epidemiologic, morphologic, immunohistochemical, biochemical, and molecular biologic methods (recombinant gene technology) to provide further evidence of the suggested causal relationship between HPV and cancer. Prospective follow-up studies are also in progress to explore the natural history of cervical HPV lesions as well as the factors (e.g., immunologic, epidemiologic synergistic actions,) modifying them. In the light of present understanding, the factors linking HPV to cervical squamous cell carcinogenesis can be summarized as follows: (1) HPV infection in the uterine cervix is a sexually transmitted disease; (2) HPV lesions in the uterine cervix seem to be equivalent to CIN in their clinical behavior, i.e., possess the potential to progress towards CIS; (3) malignant transformation seems to depend on HPV type, being conditioned by integration of HPV DNA with the host cell DNA; (4) malignant transformation most probably requires synergistic effects between the virus and chemical or physical carcinogens, or other infectious agents; (5) genetic disposition (data available on animals only) significantly contributes to the process

Carcinoma, Squamous Cell↗

PubMed1988

Measles virus infection of unstimulated blood mononuclear cells in vitro: antigen expression and virus production preferentially in monocytes.

Synthesis of measles virus antigens occurred only in a small percentage of peripheral blood mononuclear cells infected in vitro with measles virus without mitogenic stimulation. The infection cycle was restricted as only low amounts of infectious virus were released but all the major structural viral proteins were present as shown by immunofluorescence with monoclonal antibodies. Cells with viral antigen synthesis were characterized by double labelling and by infecting selectively depleted subpopulations. In 3-day cultures, up to 80% of the cells with measles virus antigen were shown to be monocytes by specific staining with anti-MMA and anti-Leu M3 monoclonal antibodies and up to 40% of the monocytes were infected. Less than 10% of the cells expressing virus antigens carried the lymphocyte marker OKT3, the majority of these cells belonging to the Leu3a (helper) population. Anti-alpha-interferon treatment increased the number of measles-positive cells and the release of infectious virus in preparations enriched for monocytes, but had no significant effect on infection of lymphocytes.

Antibodies, Monoclonal↗

PubMed1981

Zonal density gradient electrophoresis of influenza A virus.

Enzymatic activities associated with influenza A virus purified by sedimentation in sucrose density gradient were removed from the virions by sucrose density gradient electrophoresis. A rapidly migrating electrophoretic fraction contained both structural viral polypeptides and chick embryo allantoic fluid polypeptides.

Animals↗

PubMed1981

Resistance of Semliki forest virus protein synthesis to high salt treatment.

Selective translation of Semliki Forest virus-specific mRNA occurred in virus-infected cells exposed to hypertonic growth medium. The selective resistance of the virus-specific protein synthesis could be detected at a wide NaCl concentration range and was more significant at lowered incubation temperature (28 degrees C). It is suggested that the translation of the structural proteins encoding subgenomic 26 S RNA is more resistant to the hypertonic initiation block than the translation of the genomic 42 S RNA which codes for the non-structural viral proteins.

Animals↗

PubMedDate not supplied

Ultrastructural aspects of herpetoviruses.

Thin-section electron microscopy of several herpetovirus strains recovered in the laboratory from human hosts and rodents visualized typical spherical particles when the strains were propagated in vitro at a temperature corresponding to the body temperature of their natural host. In contrast, viral growth at a suboptimal temperature often resulted in aberrant viral structures.

Animals↗

PubMed1984

Mammary carcinoma arising in mice undergoing a chronic graft-versus-host reaction.

A graft-versus-host reaction (GVHR) was induced in 30 (CBA X A)F1 mice by the iv injection of 50 X 10(6) parental strain A lymphoid cells. Solid tumors emerged in 5 of 10 experimental animals that survived beyond 14 months after the GVHR was initiated. The neoplasms were judged to be mammary carcinomas by light and electron microscopic examinations. C-type RNA viral structures were observed in some tumor cells. The neoplasms were successfully transplanted into syngeneic animals by either sc or ip injections of tumor cell suspensions. Tumor transfer to syngeneic mice was not possible if only spleen cells from tumor-bearing animals were transferred. No tumors developed in an age-matched control group that received no treatment.

Animals↗

PubMed1983

Gamma-ray-enhanced reactivation of irradiated adenovirus in Xeroderma pigmentosum and Cockayne syndrome fibroblasts.

A gamma-ray-enhanced reactivation (gamma RER) of uv-irradiated as well as of gamma-irradiated human adenovirus type 2 (Ad 2) was detected following infection of normal, Xeroderma pigmentosum (XP), and Cockayne syndrome (CS) fibroblasts that had been preirradiated with gamma rays. Gamma-irradiated or nonirradiated fibroblasts were infected with either nonirradiated or irradiated Ad 2, and 48 hr after infection cells were examined for the presence of viral structural antigens (Vag) using immunofluorescent staining. Results obtained using seven different normal fibroblast strains showed that irradiation of host monolayers with 1 krad immediately prior to infection resulted in a gamma RER factor +/- SE of 4.5 +/- 1.6 for uv-irradiated virus and 4.3 +/- 1.3 for gamma-irradiated virus. CS fibroblasts, as well as excision repair-deficient XP fibroblasts from complementation groups A and D, were all found to be capable of expressing gamma RER of irradiated Ad 2. XP variant cells expressed lower levels of gamma RER compared to most normal strains, suggesting a possible role for cellular postreplication repair in the mechanism responsible for ER in human cells. An excision-deficient XP fibroblast strain belonging to complementation group A, but derived from a patient afflicted with the severe De Sanctis-Cacchione form of XP, although proficient in gamma RER of gamma-irradiated Ad 2, yielded barely detectable levels of gamma RER for uv-irradiated Ad 2.

Adenoviruses, Human↗

PubMed1981

An unusual wart-like skin lesion found in a renal allograft recipient.

Immunosuppressed renal allograft recipients have an increased tendency to acquire warts. While studying such patients, we found a virus-induced, wart-like lesion that had an unusual histologic picture. Light microscopic studies showed bizarre keratinocytes with cytoplasmic, juxtanuclear, giant, crescentic bodies and round, nuclear inclusions, By electron microscopy, the giant cytoplasmic bodies were found to be composed of tonofilaments, and the nuclear inclusions were found to be composed of papillomavirus-like particles in a filamentous matrix. Typical papillomavirus particles were observed in a wart extract by the negative-staining method. Although virus was abundant in infected cells, no structural viral antigens of the human papillomavirus (HPV) types 1, 2, 3, or 5 could be detected by immunofluorescence microscopy, indicating infection by HPV 4 or some other, as yet undescribed, HPV type.

Adult↗

PubMed1975

[Subacute spongiform encephalopathy and Creutzfeldt-Jakob disease. Apropos of 1 case].

The authors describe a case of sub-acute spongiform encephalopathy with an ultrastructural study in a man of 65 with associated dementia, extra-pyramidal syndrome, myoclonia, optical disorders, pyramidal syndrome and speech disorders, rapidly leading to death one and a half months later. Electroencephalograms were at first disorganized with persistent delta and theta activity and only in the last record did short runs of repetitive activity appear. Histologically, there was severe status spongiosus, a moderate degree of neuronal depopulation with a noticeable astrocytary gliosis. Under the electron microscope, the neuropile in the astrocytes was found to be pitted with numerous cavities and so were, to a lesser extent, the axonal projections. The vessels were normal. Nothing was found to indicate viral structures. Attention is drawn to the nosological connection between this type of observation and Creutzfeldt-Jakob disease.

Aged↗

PubMed1995

Autoantibodies directed against CD43 molecules with an altered glycosylation status on human immunodeficiency virus type 1 (HIV-1)-infected CEM cells are found in all HIV-1+ individuals.

Autoantibodies to lymphocytes have been detected in sera from human immunodeficiency virus type 1 (HIV-1)-infected individuals, and several autoantigens have been described. Among them, hyposialylated CD43 has been shown to be a target for autoantibodies in up to 47% of HIV+ individuals. However, the corresponding autoantigen (ie, the incompletely sialylated CD43) has not been isolated from blood cells of HIV-1-infected individuals. Recently, we have observed in vitro that HIV-1 productively or latently infected CEM cells (CEMLAI/NP) express CD43 molecules with modified glycosylation (mogly CD43). Using CEMLAI/NP cells, which do not express any structural viral antigen, we show now that all of the tested HIV+ sera from asymptomatic individuals, and up to 86% of those from subjects at the acquired immunodeficiency syndrome stage contain antibodies (mainly IgM and, to a lesser degree, IgG) that recognize the surface of CEMLAI/NP cells, and precipitate mogly CD43 molecules from the cells lysates. Taken together with our previous demonstration of altered glycosylation of CD43 from HIV-1-infected CEM cells in vitro, the constant antimogly CD43 autoimmune response observed from asymptomatic HIV-1+ subjects is likely to illustrate the occurrence of an altered glycosylation in vivo of the major lymphocyte surface CD43 glycoprotein, associated with HIV-1 infection.

Acquired Immunodeficiency Syndrome↗

PubMed1994

Virus-specific cytotoxic T lymphocyte responses in patients infected with the human immunodeficiency virus, HIV-1.

A vigorous virus-specific cytotoxic response has been detected in individuals infected by the human immunodeficiency virus (HIV). ADCC and CTL activities specific to the envelope glycoproteins could be measured at the same time from the same donor. CTL response have been shown directed to most viral structural and non-structural proteins. The p24gag protein is the most frequent target of HIV-specific CTL. The characterization of CTL epitopes at the level of the human population is of importance for vaccine strategy. The mechanism of control of virus replication by CD8+ T lymphocytes is not elucidated but HIV-specific CTL have been shown to mediate this antiviral activity. The biological relevance of CTL in vivo is discussed.

Antibody-Dependent Cell Cytotoxicity↗

PubMed1994

The role of human T-cell lymphotropic viruses (HTLV-I and II) in cutaneous T-cell lymphomas.

Although an association between the human T cell lymphotropic viruses (HTLV-I and II) and cutaneous T cell lymphoma (CTCL) has long been suspected, only a minor fraction of patients with this disease have antibodies to the viral structural proteins. However, the consistent finding of HTLV-like particles in cultures of peripheral blood mononuclear cells (PBMC) from such patients has prompted a continued effort to find evidence linking the virus to this disease. Capitalizing on the increased sensitivity afforded by combining PCR amplification with detection by Southern blot hybridization, it became possible to demonstrate HTLV tax and/or pol proviral sequences in freshly isolated PBMC of most patients with mycosis fungoides. These observations suggest a possible role of the virus in the pathogenesis of CTCL, and may impact on diagnostic and therapeutic measures in the future.

HTLV-I Infections↗

PubMedDate not supplied

Neuro-Behçet's disease.

We are reporting a case of Behçet's disease without vasculitis, but with acute neutrophilic inflammation which involved the brain and other organs. The patient exhibited waxing and waning neurological deficits which were unresponsive to treatment. The neuroradiologic findings simulated those of multiple sclerosis. The neuropathological examination revealed an acute, focal, though disseminated encephalitis involving the frontal lobe, internal capsule, basal ganglia, cerebellum, and brain stem. The acute inflammation consisted of a neutrophilic and eosinophilic infiltration of the perivascular spaces and parenchyma without evidence of vasculitis, fibrinoid necrosis, or thrombosis. Cultures and special stains for microbial organisms were negative. Ultrastructural examination revealed no viral structures or other microorganisms. In situ hybridization for Epstein-Barr virus (EBV), herpes simplex virus type I (HSVI), and cytomegalovirus (CMV) was negative. In this case, the lack of inflammation in the vessel walls points out that the necrotizing lesions in neuro-Behçet's disease need not be the result of vasculitis and superimposed thrombosis, but may occur as a result of primary, acute neutrophilic inflammation.

Adult↗

PubMed1996

Human herpesvirus 6 and Epstein-Barr virus in Hodgkin's disease: a controlled study by polymerase chain reaction and in situ hybridization.

Human herpesvirus-6 (HHV-6), a T-lymphotropic double-stranded DNA virus highly endemic in human populations, has been suggested to play a possible role in the development of lymphoid neoplasms, especially Hodgkin's disease. To investigate this point, we evaluated the presence and distribution of HHV-6 DNA by Southern blot, nested polymerase chain reaction, and in situ hybridization in a series of lymphoproliferative disorders including 73 Hodgkin's disease cases, 15 non-Hodgkin lymphomas, and 19 reactive lymph nodes. A high prevalence of HHV-6 infection was observed within the Hodgkin's disease category by polymerase chain reaction (38 of 52, 73%) and in situ hybridization (47 of 57, 82.4%); however, a similar prevalence was found in non-Hodgkin's lymphomas (10 of 15, 66.6%) and reactive lymph nodes (13 of 19, 68.4%). In no case did Southern blot detect viral DNA, suggesting that the neoplastic tissue contained a low number of HHV-6 copies. In situ hybridization showed that the HHV-6 positivity was restricted to lymphocytes, whereas Hodgkin and Reed-Sternberg cells were consistently negative. Immunohistochemical staining with specific monoclonal antibodies against viral structural proteins was also negative, indicating the absence of a productive infection. No relationship was observed between HHV-6 positivity and histological type, clinical parameters, and outcome of the disease. In the same series, a high proportion of cases (39 of 52, 75%) showed the presence of the Epstein-Barr virus (EBV) genome by polymerase chain reaction; In situ hybridization for Epstein-Barr-virus-encoded small RNA and immunohistochemical detection of latent membrane protein-1 gave similar results (73.6% of positive cases with both methods). In 54.9% of the cases, both sequences of HHV-6 and Epstein-Barr virus DNA were found, suggesting that a synergism of the two viruses may occur. However, the lack of detectable HHV-6 DNA in Reed-Sternberg and Hodgkin's cells seems to argue against such an interpretation. Based on these results, HHV-6 does not appear to play a specific role in the pathogenesis of Hodgkin's disease.

Blotting, Southern↗

PubMedDate not supplied

Neuro-Behçet's disease.

We are reporting a case of Bechçet's disease without vasculitis but with acute neutrophilic inflammation which involved the brain and other organs. The patient exhibited waxing and waning neurological deficits which were unresponsive to treatment. The neuroradiologic findings simulated those of multiple sclerosis. The neuropathological examination revealed an acute, focal, though disseminated encephalitis involving the frontal lobe, internal capsule, basal ganglia, cerebellum, and brainstem. The acute inflammation consisted of a neutrophilic and eosinophilic infiltration of the perivascular spaces and parenchyma without evidence of vasculitis, fibrinoid necrosis, or thrombosis. Cultures and special stains for microbial organisms were negative. Ultrastructural examination revealed no viral structures or other microorganisms. In situ hybridization for Epstein-Barr virus (EBV), herpes simplex virus type I (HSV-I), and cytomegalovirus (CMV) was negative. In this case, the lack of inflammation in the vessel walls points out that the necrotizing lesions in neuro-Bechçet's disease need not be the result of vasculitis and superimposed thrombosis, but may occur as a result of primary, acute neutrophilic inflammation.

Acute Disease↗

PubMedDate not supplied

Genetic heterogeneity and properties of hepatitis C virus.

Hepatitis C virus (HCV) is a member of the Flaviviridae family. Its genome is a positive single-stranded RNA molecule which comprises three distinct regions: a 5' non coding region, a long open reading frame encoding both the structural and non structural viral proteins, and a 3' non coding region. HCV circulates in infected individuals as complex mixtures of genetically distinct but closely related variants referred to as "quasispecies". The quasispecies nature of HCV genomes appears to play a major role in viral persistence, cell tropism of viral variants, pathogenicity and resistance to antiviral therapy.

Genetic Heterogeneity↗

PubMedDate not supplied

Absence of porcine interferon alpha secreting cells in severe combined immunodeficiency (SCID) mice inoculated with porcine leukocytes.

A low frequency leukocyte subpopulation, referred to as natural interferon producing cells (NIPC) is able to produce high amounts of interferon alpha (IFN-alpha) following contact with noninfectious viral structures. In order to examine the possible leukocytic nature and bone marrow origin of NIPC, severe combined immunodeficiency (SCID) mice were reconstituted with porcine leukocyte populations, including bone marrow cells. At different times after reconstitution, enriched CD4 and CD45 positive porcine cells were isolated from various mouse organs and tested for the presence of porcine NIPC by porcine IFN-alpha specific ELISPOT assay, after in vitro stimulation by UV inactivated transmissible gastroenteritis virus (TGEV). Although engraftment of porcine cells in SCID mice was shown by flow cytometry and by the production of pig immunoglobulins, no IFN-alpha secreting cells could be detected. This result suggests that NIPC do not derive from bone marrow precursor cells, or that growth factors needed for in vivo expansion of porcine NIPC were absent in mice.

Animals↗