Restraining the virus is done in two ways, either by macrophages and phagocytes, or by killer T cells. Macrophages and phagocytes both contain the virus by engulfing and breaking them down with the help of enzymes and lysosomes (Delves). Killer T cells “recognize antigens from the pathogen” and kills the cell by inducing apoptosis, thus “preventing the spread of the infection to neighboring cells” (Mayer, Nyland). Killer T cells also immobilize infected cells by injecting a substance called perforin, which enters the wall of the infected cell and makes a hole, causing the cell to leak fluids and electrolytes and ultimately lead to their death (Menche, et al). Antibodies also play a vital role in the neutralizing viruses.
Special cells called Dendritic cells and macrophages are white blood cells that try to fight off infection before it becomes a major problem. T-Cells of the humoral immune response are the second line of defense... • Second line of defense: T-Cells o Once a virus has invaded the body, T-Cells (CD4 cells) relay signals to the rest of the immune system, which causes the immune system to activate by sending out the “reinforcements.” These T-killer cells (CD8 cells) do exactly what the name suggests, they “kill” almost any foreign invader, through apoptosis or programmed cell death. Other CD4 activated cells are part of your body's line of defenses... • Other Cells activated by CD4 Cells o B-Cells- Once activated, B-cells / Plasma cells begin producing antibodies against a virus o Natural Killer Cells (NK)- Help your body by destroying infected cells Introduction to HIV Cont. All viruses must be able to bind to a cell in order to enter it. In the case of HIV, the virus has a cell membrane with embedded viral proteins that enables it to do so, but this works only when it binds with two specific receptors.
See a diagram depicting this process. Some of the different types of viruses used as gene therapy vectors: Retroviruses - A class of viruses that can create double-stranded DNA copies of their RNA genomes. These copies of its genome can be integrated into the chromosomes of host cells. Human immunodeficiency virus (HIV) is a retrovirus. Adenoviruses - A class of viruses with double-stranded DNA genomes that cause respiratory, intestinal, and eye infections in humans.
The virus then finds the protein by using the nucleic acid. Several new RNA or DNA strands are made. Once the cell has exceeded the maximum number of strands, it then bursts open and the new particles find new host cells. The process is then repeated.3 The following is a list of the many ways viruses can be classified: 1.) Whether viral particles contain RNA or DNA strands.
A retrovirus is a single-stranded RNA virus that stores its nucleic acid in the form of an mRNA genome and targets a host cell as an obligate parasite. The virus uses an enzyme reverse transcriptase to make DNA from its RNA strand as it enters the host cell. The newly formed virus DNA is incorporated in the host’s DNA using an enzyme called integrase. After it is inserted in the host’s genome, it is called a provirus. The cell then unknowingly transcribes the virus’ DNA and translated proteins necessary for the virus.
This complex binds to the helper T cell receptors and unfolds itself to facilitate the fusion of their membranes. HIV enters the capsule releasing two RNA strands and three essential enzymes which were surrounded by an envelope. HIV is unable replicate on its own and instead leverages on the machinery of the host cell to produce new viral particles. Once the virus has infected a T cell, integrase(protein complex) transcribes its RNA into double helix DNA copy by means of viral enzyme reverse transcriptase. Reverse transcriptase lacks it’s ‘filtering’ function that other DNA synthesizing have, mutations arise as it replicates and handicap the immune system’s ability to fight the virus.
HIV Mechanisms Viruses are microscopic particles that act like parasitic agents. Viruses reproduce themselves by integrating into the host cell and making viral copies. A virus forms the genetic blueprint for the structure of the Human Immunodeficiency Virus (HIV). A drawing that shows receptors on HIV HIV is a retrovirus, which reverses the usual flow of genetic information within the host cell. This allows the virus to reproduce.
Once the virus is in the cell, it then uncoats itself freeing viral genes and enzymes. After the uncoating stage the virus then goes through the fourth stage, called reverse transcription, in this stage copies of viral RNA and DNA are produced. Once the DNA is copied it then enters the nucleus of the cell and undergoes what is called genome integration where the viral integrase splices viral DNA into cellular DNA. Once the cellular DNA is made, the cell then uses the new DNA as a template for reproducing the HIV RNA genome.
These cells are located by the mouth, vagina, rectum, and penis. The cells then transport the virus from the where the infection is to the lymph nodes where it also infects other immune system cells. Once inside the cell, the virus turns RNA into DNA, and then makes its way to the cells nucleus. The HIV weakens the immune system. The infected HIV cells convert into the messenger RNA then it is transferred outside the nucleus and is used to make more HIV infected cells.
Biosynthesis follows, viral components are synthesized and the host cell starts replicating the virus. After biosynthesis is maturation. In maturation the viral components assembly, meaning that all the virus structures come together to prepare for the next stage of release. Finally, there is release, where the new viruses leave the host cell to infect more cells. Some of the things different betwee... ... middle of paper ... ...ic wasting disease : Wsj."