Difference in Expression of the Transfected Cell - Essay Example

There are different methodologies following this principle. One involves carefully cultivating RNA cells in a suitable medium mixed with HIV or HBV-infected cells or the virus itself and then meticulously determining changes in gene expression.

The cultivated RNA cells are analyzed for the specific genes that had differentially expressed themselves during the process of growth changes. This in vitro study is called transient transfection cell culture systems and has been used to establish sensitivity or cross-resistance to analogs. Imperative in this activity is the acquisition of quantitative real-time data and previous knowledge on the replication and pathogenesis of HIV or HBV. Any difference in the expression of the transfected cell is identified and analyzed.

Another approach is to introduce derivatives from certain sources that can serve as potent inhibitor of in vitro HIV or HBV replication. For example, synthetic DNA molecules called antisense oligodeoxynucleotides (ODN) were administered to cells transiently and stably transfected with HBV protein-encoding plasmids. The cells were observed for any HBV replication and pathogenesis for 48 hours. It was found that there ODN effectively inhibited viral protein expression and replication. ( Karayiannis, 2003) Animal models have also been very useful in understanding the replication and pathogenesis of the virus mentioned.

Many of the models are I've primates such as chimpanzees, rhesus macaques, and Aotus monkeys. HBV or HIV carrier animals are administered with potential cures. As there are significant genetic differences between humans and the animal models, specific processes are determined such as the action of DNA immunization. For the case of determining the role of outer membrane proteins (OMPs), a control and variable set-up must be established. Outer membrane proteins from pathogenic and non-pathogenic bacteria should be extracted and administered to cultured animal model cells.

There are different methods of extraction, administration and animal models but for the sake of example, I cite the study of Yang et al (2002) who extracted OMPS with the use of Triton X-114 and administered it to cultured mouse proximal tubule cells. The culture supernatant is then observed for a specified pperiodfor any differences in genetic expression using real-time analytical experiments and equipment. Yang et al (2002) used RT competitive-PCR experiments to determine if there were any differential expression between pathogenic and non-pathogenic Leptospira shermani.

They were able to show that 0.2 micron/ml OMPs produced an increase in the expression of Monocyte Chemoattractant Protein-1, Nitric Oxide Synthase, and TNF-alpha mRNA by 2.5-9.4 fold as compared to untreated cells. Note that they were very specific as they also recorded the dosage of OMPs administered mouse proximal tubule cells. This is due to the possibility that the results can be dose-dependent.

There are different methods of confirming which of the components is causing pathogenesis. One method adapted by Yang and his peers (2002) was to pin the pathogenesis to a 32 kD lipoprotein by introducing into the culture antibodies that specifically target or inhibit the said lipoprotein. Further verification involved introducing 32 kd lipoproteins in the control sample to determine to make sure that the component is responsible for causing pathogenesis.