West Nile Virus and Neuropathology


MUNE allowed for successful identification of cases of chronic neuropathy in hamsters infected spinal cords. Hamster models showed that long-term neurobiological sequela occurred because MUNE suppression was detected at 9 to 92 days in hamsters injected with WNV subcutaneously. Later correlations were established with the loss of neuronal function and 10 days of MUNE suppression. After 10 to 26 days of MUNE suppression alpha-motor neurons shown signs of death, but further neuronal death was not detected. An understanding of the correlations between phenotype disease and MUNE was established.

Values ​​detected pointing to the fact that the lowest of the MUNE suppression values ​​were linked to phenotypic disease like the paralysis of the limbs. Tests also showed that from 28 to 86 days of infection persistent WNV RNA and envelope-positive cells were identified in all of the central nervous systems of the hamsters. WNV or its products were thought to be the contributing factors in neuropathogenisis because of WMV-positive staining colocalized with the neuropathology. Thus results suggest that the main cause of dysfunction in WNV infections are its proteins, there is a association between WMV and chronic neuropathological lesions, and that MUNE can detect neurologically sequela efficiently.

Evaluation of MUNE as indication marker for paralysis of limbs was done by measuring the MUNE of WNV-infected hamsters that exhibited varying levels of hind limp paralysis. The MUNE value comparison from paralyzed and non paralyzed hamster limb shown a significant difference in MUNE values. Low MUNE values ​​were observed in paralyzed hamsters while non-paralyzed hamster limbs showed higher values ​​of MUNE shown. Also MUNE from the limbs of infected, but asymptomatic hamsters was found to be within considered normal ranges.

An important detail was found WNV viral RNA titers were found not to be correlated with MUNE values ​​or disease. But correlations between neuropathology or MUNE and the existence of viral proteins or particles were found. Further more the relationships between viral envelopes and their correlation with disease pathology were proved though immunohistochemistry.

An important question that needed to be answered was what would have the effect of disease pathology of the virus in the presence and absence of the viral envelope protein. The presence or absence of a gene of interest that codes for the viral envelope protein in viruses could have been the first step in understanding to what extent the viral envelope protein is involved in causing disease pathology and hamster hind-limb paralysis and how antiviral intervention could be used to fight WNV based on exploiting its weaknesses. Once an understanding of the virulence of the viral envelope protein involvement in disease pathology and limb paralysis has been established it would be beneficial to also understand where the WNV virus concentrates in cellular compartments which would help better understand where and how the virus behaves in the cell .

An experiment would need to be designed to answer the question as to what role the viral envelope protein plays in disease pathology and limb paralyses. An appropriably designed experiment would need to involve cloning a gene that expresses the WNV envelope protein and tranfecting that the gene of interest into tissue culture. This experiment would also need to include positive and negative controls as points of references to the experiment.

For the experiment the gene that codes for viral envelope protein would have to be cloned into a plasmid. After cloning, the plasmid should be redirected into tissue culture. Infecting the tissue culture with the gene of interest would allow observers to tell if the gene was the major cause for disease pathology. If there was no disease pathology most likely the viral envelope protein is not causing any effects, while if there was disease pathology the gene of interest was at fault.

A negative control would need to be set up because of the fact that possibly the plasmid caused some changed in the tissue culture. This could be done by just tansfecting non-infectious plasmids to the tissue culture. A good negative control should have no real change or noticeable disease pathology to the tissue culture. A positive control would also need to be set up in order to compare the experimental tissue culture to a normal WT infected tissue culture. A positive control could have been set up by simply infecting tissue culture with normal WT viruses which would have virulent proteins expressed from their genomes and should show significant disease pathology.

This experiment with the necessary controls will yield any results hypothesized about the involvement of viral envelope protein and its relationship to pathology and disease. If the experimental tissue culture signs of disease pathology are comparable to that of the positive control WT virus infection there is strong evidence that the gene encoding for proteins that cause disease including neurological lesions. If the experimental tissue culture shows little or no signs of disease pathology compared to the control WET virus infected tissue culture it can be concluded that the gene encoding for viral envelope protein is not involved with neurological lesions on the hamsters.

An immunofluorescence assay would need to be done to determine WNV enveloped protein concentrations in certain cellular compartments. If the gene encoding for the WNV envelope protein proved positive in the previous experiment providing to the cause disease pathology and limb paralysis in hamsters an immuofluorescence assay could have been done in order to tell where in the cell the viral WMN envelope proteins are most and could help further an understanding into how and where WNV works and infects which could lead to a better understanding on how to fight future WNV infections.

Tissue cultures from the experimental and positive and negative controls could have been exposed to monoclonal antibodies specifically for the epitopes of the WNV envelope protein and then exposed to Green fluorescent tagged anti-monoclonal antibodies. After the fluorescent tagged anti-monoclonal antibodies are added to the tissue culture already exposed to monoclonal antibodies, the positive should defiantly fluoresce while the negative control should not fluoresce at ll. The positive control should fluoresce because it defiantly has the WNV viral envelope proteins present during the negative control should have no fluoresce because it is no viral envelope protein presence. The experimental tissue culture should also fluoresce similar to the control experiment because of the presence of viral envelope protein presence.

From this experiment the positive control and the experiment test WNV enveloped protein concentrations in cellular compartments can be examined for similarities. This would be a very important test to do because if the previous experiment showed positive results for the experiment when compared to the positive results causing disease pathology and neurological lesions there can also be a definite answer to exactly what cellular compartment the WNV envelope protein concentrates.


Source by Gillian Smyth

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