HCMV is capable of infecting an extensive range of cell types in vivo. According to Compton (2004), the infection of a fibroblast begins with an initial tethering of a virion to cell surface - heparan sulfate proteoglycans. Then the HCMV glycoprotein, gB, is directly fused to cellular receptors such as epidermal growth factor receptor (EGFR) and cellular integrins occurs at neutral pH (Compton, 1992). The fusion with the envelope is followed by attachment of the virion and release into the cytoplasm (Roizman & Pellet, 2001). HCMV entry into epithelial and endothelial cells occurs through endocytosis in a low-pH condition (Ryckman et al., 2006) using the viral glycoproteins UL131-128 (Hahn et al., 2004). Infected cells show several characteristics which are nuclear swelling, chromatin margination and the formation of both intra-nuclear and intra-cytoplasmic inclusions (Pass, 2001). Once the HCMV enter the cell, the tegument proteins remain associated with the capsid which is transported along microtubules to the nucleus (Kalejta, 2008).
In HCMV there are three phases of gene expression sequence which are immediate early (IE), early (E), and late (L). The IE phase is short and its products are derived from three major genes which are IE1, IE2, and IE3 (Keil et al., 1987). The expression of both E and L genes need the prior expression of one or more IE gene products which function as transcriptional activators (Messerle et al., 1992). Generally the IE genes are responsible for regulating the production of host cell products, the E genes control the production of daughter virions, and the L genes are involved in the synthesis of proteins that form the structural components of the virion (Griffiths & Grundy, 1987). The process of HCM...
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...teins (Gibson, 1996). In the maturation process, the nuclear lamina is dissolved to generate delaminated infoldings of the inner nuclear membrane that form long intranuclear tubules (Buser et al., 2007). Nucleocapsids attach to the membranes and obtain a putative primary tegument and a temporary membrane. Then these virions are transported along the intranuclear tubules to the nuclear periphery where it fuses with the outer nuclear membrane (Buser et al., 2007). The primary membrane is later lost throughout de-envelopment at the outer nuclear membrane resulting in the release of a naked nucleocapsid into the cytoplasm. The final phase of maturation occurs in the trans-Golgi membrane where the capsid obtains a secondary tegument and undergoes a second envelopment process (Buser et al., 2007). The mature virions are then transported to the plasma membrane for release.
Zielinski, Sarah (22 January 2010). Cracking The Code of The Human Genome. Smithsonian.com. Retrieved from www.smithsonianmag.com/science-nature/henrietta-lacks-immortal-cells-6421299/?no-ist
Cytomegalovirus (CMV) is the most common virus in the United States that can infect almost any individual. Cytomegalovirus is also referred to as Herpesvirus-5, which belongs to a branch of Herpesviridae family. Herpesviridae has a spherical shape that contains four significant elements that are important to the viron. The four elements are the core, tegument, capsid and the envelope. Alphaherpesvirinae, Betaherpesvirinae and Gammaherpesvirinae are three subfamilies which belong to Herpesviridae. Cytomegalovirus belongs to the Betaherpesvirinae family, which also include Muromegalovirus and Roseolovirus. The Alphaherpesvirinae subfamily includes Simplexvirus, Varicellovirus, Mardivirus and Iltovirus genera. The Gammaherpesvirinae subfamily contains Lymphocryptovirus and Rhadinovirus genera. The diameter size of the virus is based on each specific family; however, the core remains the same throughout the species, which contains single layer of double stranded DNA tightly condensed in the capsid. In the tegument component, there are 30 or more viral proteins that are shapeless that encompass the capsid. Out of the four major components, the tegument has the most poorly defined structure. On the other hand, the capsid is a well-defined structure that is an icosahedron, which is composed of 162 capsomeres, 12 of which are pentons and 150 are hexons (1). Last but not least, the liquid envelope surrounds the tegument with approximately 10 glycoprotein and cellular proteins. Each subfamily under the herpesviriade has its own arrangement between the liquid envelop and the tegument layer.
HSV-1 is spread through saliva and direct contact, such as kissing, sharing eating utensils, sharing drinks or sharing personal items. Children often contract the virus from kissing their parents and coming in contact with other children. HSV-2 is spread through sexual intercourse. HSV must be transported through bodily fluids (saliva, pus, semen, vaginal fluid) to infect cells.3 The virus is transmitted through the mucosal linings of the body or through an open wound and has an incubation period of 2-12 days.4
Hepatitis B Virus (HBV) is a virus that attacks the liver. The virus is transmitted through blood and bodily fluids. This can occur through direct blood-to-blood contact, unprotected sex, use of contaminated needles, and from an effected mother to her newborn during the delivery process. The majority of people do not have noticeable symptoms when they are first infected with the HBV. People who do not know they are infected with the HBV, their body can respond in different ways. I learned that some of the common symptoms of Hepatitis B infection include fever, fatigue, muscle or joint pain, loss of appetite, mild nausea, vomiting, and dark-colored urine. Some of the serious symptoms that require immediate medical attention and maybe even hospitalization are: severe nausea and vomiting, yellow eyes and skin (jaundice), bloated or swollen stomach.
The virus is primarily spherical shaped and roughly 200nm in size, surrounded by a host-cell derived membrane. Its genome is minus-sense single-stranded RNA 16-18 kb in length. It contains matrix protein inside the envelope, hemagglutinin and neuraminidase, fusion protein, nucleocapsid protein, and L and P proteins to form the RNA polymerase. The host-cell receptors on the outside are hemagglutinin and neuraminidase. The virus is allowed to enter the cell when the hemagglutinin/ neuraminidase glycoproteins fuse with the sialic acid on the surface of the host cell, and the capsid enters the cytoplasm. The infected cells express the fusion protein from the virus, and this links the host cells together to create syncitia.
Hepatitis B virus (HBV) is a severe and common virus that has infected ‘more than two billion people alive today at some point in their life.’1 It is a hepadanavirus that interferes with the liver functions as it replicates in the hepatocytes (liver cells) and induces a immune response that is responsible for the inflammation of liver.2 Viruses are not motile, which means that HBV is also sessile and does not form spores. The spherical virion, is called a Dane Particle3 that is 42nm in diameter binds to the surface of hepatocyte.1 The virion itself contains an inner protein core, 27nm thick filled with circular partially double stranded DNA, DNA polymerase and reverse transcriptase.1 It is an enveloped virus, so it also holds an outer lipoprotein envelope4 that is 7nm thick and is comprised of many embedded surface proteins such as surface antigen for viral binding and entry.1 HBV has an average incubation period of three months, which means that it does not start showing symptoms for the first three months that the person is infected and that person can unknowingly infect others.2 ...
Pathogens are a type of microorganism that spreads viral and bacterial diseases. These diseases when present in human blood and body fluids are known as blood borne pathogens, and can spread from one person to another. (Worcester polytechnic institute) The most serious types of blood borne diseases are the hepatitis B virus (HBV) and hepatitis C virus (HCV), which can cause liver damage; and HIV (human immunodeficiency virus), which is responsible for causing AIDS (acquired immune deficiency syndrome). The blood borne pathogens can be spread when the blood or body fluids (semen, vaginal fluid, breast milk, and amniotic fluid) of an infected individual comes into contact with mucous membranes or an open sore or cut on the skin of another person. Mucus membranes are located in the eyes, nose, mouth, and other areas as well. ("Bloodborne pathogens: MedlinePlus Medical Encyclopedia") Two of the most common ways that pathogens are transmitted is through the exchange of fluids during sexual intercourse or by sharing infected IV needles. (Worcester polytechnic institute)
Chronic HBV is developed when HBV infection dose not result in immunization and is defined as existence of HbsAG in the body for more than six months [1]. Progression from acute HBV to chronic HBV is highly influenced by the age at infection and is a common state for those infected at...
There is a disease spreading out in the world called Hepatitis C. It affects the liver and may cause the liver to fail. This disease is caused by a virus called Hepatitis C virus which is also known as HCV. About 32,000 people are affected with this disease per year only in the United States area. Some It’s a disease with many symptoms and many causes. of these symptoms are easy bruising, upset stomach and fever. These are just some of the many symptoms that come from the virus. Hepatitis Cs nature of the causative agent is determined by many things. The biological data of this disease is filled so much information. It is estimated that over 180 million people have gotten Hepatitis C and it is growing.
Hepatitis B results from cellular injury to the liver, subsequently affecting its metabolic functions. However, the HBV is not cytopathic by itself. The pathogenesis of Hepatitis B occurs as a result of the interactions between the host’s immune system and the virus. The host immune system targets HBV in liver cells (hepatocytes), inadvertently causing damage to the liver. HBV derived proteins (...
In the 1960s the HeLa cells were everywhere. In the 1960s the scientist wondered since the cells grew so fast and lived on earth so well if they would live in space. They got the idea to send the Hela cells to space. They sent several vials into space by the Discoverer XVII when it went. They discovered that when the HeLa cells went to space they became more powerful and divided faster every time they went to space. Several years later in 1965 they took equal amounts from the HeLa cells and cells from a mouse. The scientists done this to study to see what the genes would do. Harris also took HeLa cells and chicken cells, but they discovered they couldn’t reproduce.
Ghosh MK, Borca MV, Roy P. Virus-derived tubular structure displaying foreign sequences on the surface elicit CD4+ Th cell and protective humoral responses. Virology 2002; 302: 383-92.
The nucleus is often the largest organelle found in a Eukaryotic cell with a size of 10-20 un. It is surrounded by two membrane layers which can be identified on the diagram below. Within the nucleus structure are small pores with a size of 100un in diameter. These pores together make up around one third of the nuclear membrane surface area.