Viral Delivery Systems And Its Effects

In making PNA a prospect for drugs, researchers have demonstrated proof of concept for using PNA oligomers to activated or suppress the transcription, replication, or repair of specific genes by binding DNA is various ways. PNA oligomers and conventional nucleic acids have the same problem of poor bioavailability because they are large water loving molecules making it difficult for them to enter cells. The productions of PNA based drugs awaits the development of suitable chemical modifications or pharmaceutical formulations to improve PNA bioavailability. Researchers believe this is the only thing holding back this medical breakthrough.

Originally in Takahashi and Yamanaka’s experiment, retroviruses were used as a vector to introduce factors that triggers reprogramming, however with evidences from further researches shown that retroviruses may cause insertional mutagenesis, where the host’s DNA is mutated due to the virus integrating into the host’s genome, and potentially cancerous nature of the iPSCs made this technique ill suited to further iPSC developments.(5) Therefore, other methods have been developed and used nowadays to minimise these issues and they include protein transduction, the use of

This article covers the Seneca Valley Virus (SVV-001) as a hopeful for an oncolytic treatment of certain cancer types. More specifically those with neuroendocrine properties such as rhabdomyosarcoma, Wilms tumor, glioblastoma, neuroblastoma, and adult small-cell lung cancer. Each of which effect smooth/skeletal muscle cells, kidneys/adrenal glands (mainly in children), astrocytes of the brain, nerve cells of a fetus, and lung cells in adults respectively. The virus was discovered by accident in a contaminated cell culture that contained bovine serum to promote growth. The virus was later discovered to be almost exclusively found in farm animals such as cows and pigs, due to the presence of neutralizing antibodies that were later to only ever have been found in one human sample. Just as important as that, the virus only targets the cells of the above-mentioned cancers/tumors, is a self-replicating RNA virus, and its inability to infect other cells in the body all come together to result in the lysis of these specific cancer cells. These properties alone give great hope for SVV-001 as a treatment for those infected by these diseases, and prompted for more research into its medicinal possibilities.

Everyday science is advancing and researchers are working hard to examine and investigate all the different possible ways to develop new viruses to cure cancer. A research paper published recently suggests that a genetically engineered poxvirus called JX-594 shows the greatest clinical potential for a couple of reasons. It spreads and replicates fast, does not mix into host DNA, easy to manipulate genetically, very immunogenic, and remarkably safe in both animal models and initial human clinical trials [19].

To create the best version of virotherapy, scientists are discovering two ways to be confident the viruses hit target cells with no other harm to other cells. One strategy virotherapy researchers are exploring is called transductional targeting. With this form of targeting cancer cells, researchers are modifying the viruses used so they are only attracted to only cancerous cells to contaminate them. To prevent the viruses from entering normal cells, transductional targeting works by binding “adapter” molecules onto the antibodies, proteins on the outside of virus, or tweaking the antibodies so that they will not allow viruses to enter normal cells and rather let them gain up on tumor cells. The second strategy discussed in the article is named transcriptional targeting. The goal of this form of targeting is to modify the viruses

Herpesvirus has been discussed to cause periodontal pathosis as a direct result of the virus infection and replication, or as a result of virally induced impairment of the host defense. Herpesvirus-mediated periodontopathogenicity may take place through at least five mechanisms, operating alone or in combination.

People can contract H.I.V. from contact with blood, semen, vaginal fluids, and drug use. (CDC.gov) A misconception about H.I.V. is that it doesn't survive outside the body. Therefore it can not spread by normal contact such as kissing or sharing drinking glasses with an infected person.

Another impressive dimension that adds to the efficacy of Ad-Apoptin-hTERT-E1a is the adenoviruses’ ability to attack tumor cells through the addition of the therapeutic transgene expression Apoptin. Apoptin is a protein that is known to induce the process of apoptosis specifically within malignant cells, but not in regular cells [3]. Apoptosis is often called “programmed cell death” because it is a process in which cells that are no longer needed within an organism are recognized and then destroyed. Inserting this transgene expression into the genome of Ad-Apoptin-hTERT-E1a creates a cancer specific adenovirus equipped with dual threat potential. With these transgene expressions inserted into the genome of an adenovirus, Ad-Apoptin-hTERT-E1a, is a genetically modified oncolytic adenovirus that has been created which can theoretically eradicate cancer cells through both lysis and apoptosis, but not negatively effect normal cells within the host.

In addition, there is another enzyme carried virus called integrate, for adenovirus the virus carry genetic material as double stranded DNA when virus infect the target cell, that exposure the DNA molecule in the target host, then the DNA left free in nucleus and not compound with target cell genome and this extra DNA molecule transcribed for other gene, for non-viral there are naked DNA, DNA complex with cation lipid and DNA condense cation polymers. For physical needle injection directly. Gupta, Singh et al. (2015)

The benefits of using virotherapy have multiple advantages for treating cancer. This treatment eliminates the potential lack of cross-resistance as well as being able to cause much more deterioration to tumors. Leaving minimal to no negative effects on normal cells within the body. Not only does it leave minimal effects it is less invasive and accommodate it for everyone’s liking.Furthermore, cancer gene therapy does not require long-term transgene expression, unlike gene therapy for many non-cancer diseases.

The uses of viruses to treat cancer have been talked about since the 1900’, but only due to the recent advances in microbiology, immunology, and virology, have we been able to understand how it reduces the size of cancerous tumors. One of the earliest recorded cases of viruses killing cancer was in 1896. A 42-year-old woman just recovering from influenza, when the doctors realized that her cancer was going into remission.

Viruses are not simply taken into cells. They must first attach to a receptor on the cell surface. Each virus has its specific receptor, usually a vital component of the cell surface. It is the distribution of these receptor molecules on host cells that determines the cell-preference of viruses. For example, the cold and flu virus prefers the mucus lining cells of the lungs and the airways.

The first interaction is the entry of the virus into the host cell; this is through “initiation by the knob domain of the fiber protein binding to the host cell receptor” (Boundless, 2016). The type of receptor depends on which strain type so it could be CD46 receptor for group B human adenovirus serotypes, and if not that it is the coxsackievirus adenovirus receptor for all the other serotypes. The next interaction is through a specialized motif in the penton bases which interact with alpha-v integrin, thus kickstarting internalization of the adenovirus through clathrin coated pits. After this interaction of internalization, the virion enters the host cell through an endosome (Boundless,

The first type is a viral vector, which is a genetically altered virus that specifically targets injury sites. Here the genes that are used by the virus to duplicate themselves are detached and substituted with the anticipated growth factor gene. Viral vector systems remain the most efficient vehicles to achieve long-term stable gene expression in the CNS (Bower, 2011). Afterwards the virus attaches itself to the injured targets using receptors. Next, viral and/or cellular proteins will allocate the genetic code (rDNA) for the wanted growth factor within the cytoplasm and into the nucleus. Manifestation of the growth factor by the genetically transformed target cells can promptly be commenced.

Despite the promise of such approaches, a number of difficulties remain to be overcome, the most important of which is the need for more efficient systems of gene delivery. No gene transfer system is 100% efficient, unless germ-line therapy is contemplated. During the past two decades, there have been major advances in our understanding of how cancer develops, proving that cancer has a genetic basis (2). A series of genetic abnormalities that accumulate in one cell may result in a pattern of abnormal clonal proliferation. Our growing understanding of the genetic basis of cancer offers new opportunities for the molecular prevention and treatment of cancer. There has been a