APP Processing Induced by Herpes Simplex Virus Type 1 (HSV-1) Yields Several APP Fragments in Human and Rat Neuronal Cells

Lifelong latent infections of the trigeminal ganglion by the neurotropic herpes simplex virus type 1 (HSV-1) are characterized by periodic reactivation. During these episodes, newly produced virions may also reach the central nervous system (CNS), causing productive but generally asymptomatic infections. Epidemiological and experimental findings suggest that HSV-1 might contribute to the pathogenesis of Alzheimer's disease (AD). This multifactorial neurodegenerative disorder is related to an overproduction of amyloid beta (Aβ) and other neurotoxic peptides, which occurs during amyloidogenic endoproteolytic processing of the transmembrane amyloid precursor protein (APP). The aim of our study was to identify the effects of productive HSV-1 infection on APP processing in neuronal cells. We found that infection of SH-SY5Y human neuroblastoma cells and rat cortical neurons is followed by multiple cleavages of APP, which result in the intra- and/or extra-cellular accumulation of various neurotoxic species. These include: i) APP fragments (APP-Fs) of 35 and 45 kDa (APP-F35 and APP-F45) that comprise portions of Aβ; ii) N-terminal APP-Fs that are secreted; iii) intracellular C-terminal APP-Fs; and iv) Aβ1-40 and Aβ1-42. Western blot analysis of infected-cell lysates treated with formic acid suggests that APP-F35 may be an Aβ oligomer. The multiple cleavages of APP that occur in infected cells are produced in part by known components of the amyloidogenic APP processing pathway, i.e., host-cell β-secretase, γ-secretase, and caspase-3-like enzymes. These findings demonstrate that HSV-1 infection of neuronal cells can generate multiple APP fragments with well-documented neurotoxic potentials. It is tempting to speculate that intra- and extracellular accumulation of these species in the CNS resulting from repeated HSV-1 reactivation could, in the presence of other risk factors, play a co-factorial role in the development of AD

[Critical analysis of the 2-hour test in mass screenings for the early detection of diabetes].

Out of 500 random trial subjects, taken for a mass-screening for early detection of diabetes mellitus, the Authors tried a correlation between the reliability of the "two-hour test" and the 2 h OGTT. The latter method provides more reliable results, allowing us to diagnose a high percentage of cases which is not possible if the simple two-hour test were used. Research of glycosuria in the course of OGTT did not show any real reliability, whereas it did prove useful in the preliminary phase of our research in order to distinguish the subjects for whom a deeper investigation would be advisable

Comparative analysis of the virion polypeptides specified by Herpes simplex virus type 2 strains

This paper reports on the variability of structural polypeptides of 32 strains of Herpes simplex virus 2 (HSV-2) isolated from various locations in the United States and Italy. Most strains were passaged a limited number of times at low multiplicity outside the human host; a few strains were characterized by numerous passages at variable multiplicities in cell culture. The acrylamide gel electrophoresis of polypeptides from purified virions revealed very few differences. Considering these differences the HSV-2 strains analysed can be classified into 3 groups according to the variability of three polypeptides. The study of polypeptides in HSV-2 infected cells revealed more differences than those seen in the structural proteins. Comparisons of the structural proteins specified by HSV-2 and HSV-1 virions, revealed clear variant features of the electrophoretic profiles, especially when pH of main gel was 8.9

Limb reduction defects in Emilia Romagna, Italy: epidemiological and genetic study in 173,109 consecutive births.

Epidemiological and genetic variables in limb reduction defects (LRD) were analysed during the years 1978 to 1987 in a case control study in Emilia Romagna, northern Italy. During the observation period, 83 neonates out of 173,109 consecutive births had LRD (4.8 per 10,000). Cases were divided into five subgroups: transverse, intercalary, longitudinal, split, and multiple types of LRD. Of all cases, 64% were upper limb, 21% lower limb, and 15% both. Coexisting non-limb malformations were found in 10 cases (12%), five with recognised syndromes and five with other associated defects. About 7.2% of first degree relatives had defects involving the skeletal system. In two cases the mother had the same type of LRD (a split). No recurrence among sibs was observed. Risk factors correlated with LRD were found to be low birth weight (2500 g or less), vaginal bleeding, and threatened abortion

Herpes simplex virus latency in immunosuppressed mice

Export | Download | Add to List | More... Microbiologica Volume 7, Issue 3, July 1984, Pages 219-227 Herpes simplex virus latency in immunosuppressed mice. (Article) Rotula, A., Di Luca, D., Gerna, G., Manservigi, R., Tognon, M., Cassai, E. Abstract To determine the role of antibodies in establishing Herpes simplex virus (HSV) latency, immunosuppressed Swiss mice were experimentally infected in the right hind footpad with a HSV-1 x HSV-2 recombinant (C6D) with low virulence. Immunosuppression was induced by repeated intraperitoneal inoculations of Cyclophosphamide (CY) and the production of antibodies to C6D in immunosuppressed animals was monitored by Enzyme Linked Immunosorbent Assay (ELISA). Within 21 days after inoculation, C6D was able to establish a latent infection of lumbosacral spinal ganglia in both normal and CY-treated immunosuppressed animals. The data presented indicate that detectable production of antibodies is not necessary to induce HSV latency in spinal ganglia

Transformation by defined regions of herpes simplex virus DNA.

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Herpes simplex virus and human cancer. III: Search for relationship of herpes simplex antibodies and cervical dysplasia and labial neoplasia

We employed the enzyme-linked immunosorbent assay (ELISA), indirect hemagglutination (IHA), and complement fixation (CF) methods to measure antibody titer to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in patients affected by labial tumors or cervical dysplasias. No relationship of antibody titer to HSV-1 and labial tumors was detected by any of the three methods. Association between antibody titer to HSV-2 and cervical dysplasias was revealed by IHA (p less than 0.05) and ELISA (p less than 0.001); CF tests were negative. Moreover, we assayed for HSV-specific antigens in cell cultures derived from labial tumors and cervical dysplasias. In cultures from labial tumors, it was not possible to detect HSV-specific antigens. Of the 25 cultures derived from cervical dysplasias, HSV antigens were found in only 3 cultures

Sequences homologous to two separate transforming regions of herpes simplex virus DNA are linked in two genital tumors

Ten human genital invasive squamous cell carcinomas and five human premalignant tissues were analyzed for the presence of selected sets of herpes simplex virus 2 (HSV-2) DNA sequences. Two vulvar tumors and one vulvar dysplastic tissue were found to contain DNA sequences homologous to the BglII O fragment (coordinates 0.38-0.42) and the BglII N fragment (coordinates 0.58-0.63) of HSV-2 DNA. These two fragments overlap the subsets of HSV-1 and HSV-2 DNA sequences (respectively) shown previously to transform cells in culture. Sequences homologous to an additional HSV-2 DNA probe (BglII G) were not detected in the same tumors. Surprisingly, in each of the two positive vulvar tumors, the BglII N and BglII O sequences appeared to be linked, whereas in the standard HSV-2 genome the two fragments are separated by approximately 26 kb. This finding suggested that the two sets of sequences may have rearranged prior to or following the association of the HSV DNA sequences with the tumor cells. The same set of 10 tumors were analyzed for the presence of sequences complementary to human papillomavirus 16 (HPV16) DNA. The HPV16 DNA probe hybridized to three of six cervical tumors, whereas no hybridization was detected with the two vulvar tumors which contained the HSV DNA sequences

HSV-1 virions engineered for specific binding to cell surface receptors

Expression of specific peptide epitopes on the surface of virions has significant potential for studying viral biology and designing vectors for targeted gene therapy. In this study, an HSV-1 amplicon plasmid expressing a modified glycoprotein C (gC), in which the heparan sulfate binding domain was replaced with a His-tag, was used in generating HSV-1 virions. Western blot analysis demonstrated the presence of modified gC in the purified virions. The amplicon vectors were packaged using a gC-, lacZ+ helper virus to generate a mixture of high-titer helper virus (lacZ+) and amplicon vectors (GFP+), which expressed modified gC in the virion envelope. His-tagged virions bound to 293 6H cells expressing a cell surface pseudo-His-tag receptor four-fold more efficiently than to parental 293 cells and also proved more effective than wild-type virus in binding to both cell types. Binding resulted in productive infection by the modified virions with expression of reporter genes and cytopathic effect comparable to those of wild-type virions. Thus, not only can HSV-1 tropism be manipulated to recognize a non-herpes simplex binding receptor, but it is also possible to increase the infective capacity of the vectors beyond that of the wild-type virus via specific ligand receptor combinations