scholarly journals Binding of surfactant protein A (SP-A) to herpes simplex virus type 1-infected cells is mediated by the carbohydrate moiety of SP-A.

1992 ◽  
Vol 267 (35) ◽  
pp. 25039-25043 ◽  
Author(s):  
J.F. van Iwaarden ◽  
J.A. van Strijp ◽  
H Visser ◽  
H.P. Haagsman ◽  
J Verhoef ◽  
...  
1991 ◽  
Vol 261 (2) ◽  
pp. L204-L209 ◽  
Author(s):  
J. F. van Iwaarden ◽  
J. A. van Strijp ◽  
M. J. Ebskamp ◽  
A. C. Welmers ◽  
J. Verhoef ◽  
...  

In the present study we used flow cytometry to investigate the phagocytosis of fluorescein isothiocyanate-labeled herpes simplex virus type 1 (FITC-HSV-1) by rat alveolar macrophages and the effects of surfactant protein A (SP-A) on this process. The phagocytosis of FITC-HSV-1 by alveolar macrophages, which was studied as a model for virus phagocytosis in general, was strongly enhanced in the presence of SP-A. The SP-A-mediated phagocytosis was time and concentration dependent, reaching a maximal level after 15 min of incubation and at an SP-A concentration of 5 micrograms/ml. Using a fluorescence quenching technique, we could show that at least 65% of the viruses were indeed internalized by the macrophages. The addition of SP-A to the system was sufficient for the phagocytosis of FITC-HSV-1 by the alveolar macrophages, suggesting that SP-A acts as an opsonin. This hypothesis was further strengthened by the observation that F(ab')2 fragments of immunoglobulin G directed against SP-A could abolish FITC-HSV-1 phagocytosis by alveolar macrophages preincubated with SP-A. Comparing the opsonic capacity of serum and SP-A, SP-A proved to be twice as potent as serum in stimulating phagocytosis of FITC-HSV-1 by alveolar macrophages. Complement factor C1q, which is known to possess a similar collagen-like domain as SP-A, did not stimulate phagocytosis of FITC-HSV-1 by alveolar macrophages nor did it inhibit SP-A-mediated HSV-1 phagocytosis. This study demonstrates that SP-A may play an important role in the antiviral defenses of the lung.


2005 ◽  
Vol 150 (11) ◽  
pp. 2387-2395 ◽  
Author(s):  
E. Morency ◽  
Y. Couté ◽  
J. Thomas ◽  
P. Texier ◽  
P. Lomonte

1975 ◽  
Vol 23 (4) ◽  
pp. 283-288 ◽  
Author(s):  
L R Trusal ◽  
A Anthony ◽  
J J Docherty

Infection of human embryonic lung cells with herpes simplex virus type 1 (HSV-1) and herpes simplex type 1 (HSV-2) resulted in: (a) qualitative (nuclear cytopathologic) alterations and quantitative (nuclear area) differences in infected compared to control nuclei; (b) increased Feulgen-deoxyribonucleic acid (F-DNA) amounts in infected cells, probably due to viral DNA; (c) higher F-DNA levels in HSV-2 infected cells; and (d) increased rates of F-DNA hydrolysis in viral-infected as compared to uninfected nuclei.


1998 ◽  
Vol 72 (3) ◽  
pp. 2463-2473 ◽  
Author(s):  
Carmela Lamberti ◽  
Sandra K. Weller

ABSTRACT Six genes, including UL32, have been implicated in the cleavage and packaging of herpesvirus DNA into preassembled capsids. We have isolated a UL32 insertion mutant which is capable of near-wild-type levels of viral DNA synthesis; however, the mutant virus is unable to cleave and package viral DNA, consistent with the phenotype of a previously isolated temperature-sensitive herpes simplex virus type 1 mutant, tsN20 (P. A. Schaffer, G. M. Aron, N. Biswal, and M. Benyesh-Melnick, Virology 52:57–71, 1973). A polyclonal antibody which recognizes UL32 was previously used by Chang et al. (Y. E. Chang, A. P. Poon, and B. Roizman, J. Virol. 70:3938–3946, 1996) to demonstrate that UL32 accumulates predominantly in the cytoplasm of infected cells. In this report, a functional epitope-tagged version of UL32 showed that while UL32 is predominantly cytoplasmic, some nuclear staining which colocalizes with the major DNA binding protein (ICP8, UL29) in replication compartments can be detected. We have also used a monoclonal antibody (5C) specific for the hexon form of major capsid protein VP5 to study the distribution of capsids during infection. In cells infected with wild-type KOS (6 and 8 h postinfection), 5C staining patterns indicate that capsids are present in nuclei within replication compartments. These results suggest that cleavage and packaging occur in replication compartments at least at 6 and 8 h postinfection. Cells infected with the UL32 mutant exhibit a hexon staining pattern which is more diffusely distributed throughout the nucleus and which is not restricted to replication compartments. We propose that UL32 may play a role in “bringing” preassembled capsids to the sites of DNA packaging and that the failure to localize to replication compartments may explain the cleavage/packaging defect exhibited by this mutant. These results suggest that the UL32 protein is required at a step distinct from those at which other cleavage and packaging proteins are required and may be involved in the correct localization of capsids within infected cells.


1996 ◽  
Vol 7 (2) ◽  
pp. 79-85 ◽  
Author(s):  
Kyoko Hayashi ◽  
Toshimitsu Hayashi

The antiviral activity of scopadulciol (SDC), a tetracyclic diterpenoid with a chemical structure related to that of aphidicolin, isolated from Scoparia dulcis, was studied in vitro against herpes simplex virus type 1 (HSV-1). SDC was found to inhibit the virus replication as shown by reduction of virus production. The action was not due to the inhibition of viral DNA polymerase activity and virus penetration, but might involve, at least in part, a virucidal effect. SDC did not suppress the viral protein synthesis of infected cells when added at an early stage of HSV-1 replication, but did when added later. When aciclovir (ACV) and SDC were evaluated in combination for antiviral activity against HSV-1 replication and cytotoxicity, these drugs inhibited viral replication in HeLa cells synergistically, but the same combination did not produce synergistic cytotoxicity in HeLa cells. Studies of the deoxynucleotide pool sizes revealed that SDC increased the intracellular dNTP pools and ACV triphosphate level significantly in infected cells when the cells were treated with the combination. These results could account for the synergistic action between SDC and ACV.


1996 ◽  
Vol 109 (1) ◽  
pp. 119-129 ◽  
Author(s):  
S. Besse ◽  
F. Puvion-Dutilleul

The localization of ribosomal RNA (rRNA) was investigated at the ultrastructural level in herpes simplex virus type 1 infected HeLa cells using three distinct biotinylated probes which bind in sequence to three different segments of the ribosomal genes. Comparison of the above with the signal levels obtained from non-infected cells reveals information about the effects of HSV-1 infection on ribosome biogenesis. A probe specific for the 5′ end portion of pre-rRNA labeled all nucleoli of both non-infected and infected cells in the same way, that is, it mainly labeled the dense fibrillar component and the border of the fibrillar centers but only slightly labeled the granular component. This indicates that the initial cleavage of pre-rRNA in herpes infection still occurs in the 5′ region of the 5′ external transcribed spacer. However, a probe specific for 18 S rRNA labeled the granular component of the nucleoli more intensely after infection. In addition, significant amounts of rRNA molecules were present within the intranuclear viral region, except over the enclosed viral dense bodies, and within the virus-enlarged clusters of interchromatin granules. The data indicate that the still enigmatic viral dense bodies, which are nucleolus-related structures, are excluded from the marked intranuclear retention of ribosomal RNAs and, in addition, reveal a possible role for the interchromatin granules of infected cells in the regulation of the export of the ribosomal subunits towards the cytoplasm.


2001 ◽  
Vol 75 (24) ◽  
pp. 12070-12080 ◽  
Author(s):  
Maryam Ahmed ◽  
Nigel W. Fraser

ABSTRACT During latency of herpes simplex virus type 1 in sensory neurons, the transcription of viral genes is restricted to the latency-associated transcripts (LATs). The stable 2-kb LAT intron has been characterized previously and has been shown to accumulate to high levels in the nuclei of infected neurons. However, in productively infected tissue culture cells, this unique intron is also found in the cytoplasm. Although deletion mutant analysis has suggested that the region of the gene from which the intron is spliced plays a role in maintenance of latency or in reactivation from latency, no well-defined function has been ascribed specifically to the 2-kb LAT intron. Nevertheless, previous work has shown that it associates with 50S particles in the cytoplasm of acutely infected cells. Our studies tested the ability of the 2-kb LAT to dissociate from cytoplasmic protein complexes under various salt conditions. Results indicated that this association, which had been speculated to be mRNA-like, is actually more similar to the affinity of rRNAs for translational complexes. Furthermore, by immunoprecipitation analysis, we demonstrate that the 2-kb LAT associates with ribosomal as well as with splicing complexes in infected cells. Our results suggest that the 2-kb LAT is processed similarly to mRNAs in the nuclei of infected cells. However, in the cytoplasm, the 2-kb LAT may play a structural role in the ribosomal complex, similar to that of the cellular rRNAs, and therefore affect the functioning of the translational machinery.


Sign in / Sign up

Export Citation Format

Share Document