In the paper by Fung-Lung and colleagues, it was discovered that CD8 is a molecule crucial for the development of cytotoxic T-cells. They skillfully presented the implications of their results and convincingly concluded the importance of CD8 in immune response. Through the use of knockout mice, Fung-Lung et al. were able to demonstrate that disruption of the CD8α gene impairs the cytotoxic functions of T-cells and does not affect helper T-cell functions. CD8 has been and still is being widely studied in immunologic diseases, particularly leukemia. Various studies show that CD8 plays an important role in the affects and development of specific types of leukemia. Background CD8 is a co-receptor molecule important for the activation of T-cells, found on many cells in the lymphoid system and exists in 2 forms; the αα homodimer and αβ heterodimer form. The αα homodimer is found on natural killer cells, γδ T cells, intestinal lymphocytes and some dendritic subsets. The function of the αα homodimer has not yet been clearly identified. The αβ heterodimer form is found on about 90% of killer T-cells and plays a major role in enhancing T-cell activation by increasing their sensitivity to antigens. It also stabilizes the interaction between TCR and MHC class I molecule. (Cole et al., 2012) CD8 has two subunits; α and β, both of which contain an NH2-terminal domain and a “hinge” region, which connects the NH2-terminal to the membrane-spanning region. The NH2-terminal is similar to the immunoglobulin variable domains and contains 9 beta-strands divided into 2 beta-sheets. A disulfide bridge connects the B-strand and F-stand of the CD8α subunit. There also is an intersheet connection between the B and the C strand, which suggests that eith... ... middle of paper ... ...ritish Journal of Haematology. (Early View). National Center for Biotechnology Information. (2014). CD8A molecule. National Center for Biotechnology Information. (2014). CD8B molecule. Shore, D. A., Issafras, H., Landais, E., Teyton, L., Wilson, I. A. (2008). The crystal structure of CD8 in complex with YTS156.7.7 Fab and interaction with other CD8 antibodies define binding mode of CD8αβ to MHC class I. Journal of Molecular Biology, 384(5), 1190-1202. te Raa, G. D., Pascutti, M. F., Garcia-Vallejo, J. J., Reinen, E., Remmerswaal, E. B. M., ten Berge, I. J. M., van Lier, R. A. W., Eldering, E., van Oers, M. H. J., Tonino, S. H., Kater, A. P. (2013). CMV-specific CD8+ T-cell function is not impaired in chronic lymphocytic leukemia. Blood, 123(5), 717-724. Zhang, N. & Bevan, M. J. (2011). CD8+ T cells: Foot soldiers of the immune system. Immunity, 35(2), 161-168.
Lymphoid tissue is made up of cells called lymphocytes, a type of white blood cell that fights infection. There are 2 major types of lymphocytes: B lymphocytes (B cells) and T lymphocytes (T cells). Normal T cells and B cells have different jobs. But because all the importance of these cells they can travel around the body spreading the cancerous cells. There are four stages for Hodgkin’s lymphoma when testing is completed the doctors can determine what stage the cancer is at and what treatment will be best suited to fighting the disease.
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.
McCabe Jr., M. and Lawrence, D. Lead, A Major Environmental Pollutant, Is Immunomodulatory by Its Differential Effects on CD4+ T Cell Subsets. Toxicology and Applied Pharmacology, Vol. 111, 1991, pp. 13-23.
“Cells Involved In Immune Responses and Antigen Recognition.” Microbiology and Immunology. Web. 18 Dec. 2011. .
The World Health Organization (WHO) classifies Hodgkin’s lymphoma into two different groups: nodular lymphocyte predominant (NLPHL) and classical HL (cHL). NLPHL develops slowly, is found predominantly in males, and accounts for about 5% of all HL cases. It is characterized by L&H cells and a different antigenic profile (Roddle, Peggs, 2009, p. 208). In contrast, cHL, the most common subtype, comprises nearly 80% of diagnosed cases. Classical HL is divided into four subtypes. “The diagnosis is dependent on the pathological finding of H...
The immune system, which is composed of cells, proteins, tissues, and organs, is the body’s innate defense against foreign particles that may show to be harmful or infectious to us. Through a series of steps called the immune response, the immune system attacks potentially dangerous organisms and substances that invade our systems. (Durani, Y., 2012) The immune system’s key players include leukocytes, the lymphoid organs, and the lymphatic vessels. Leukocytes are white blood cells that recognize and destroy the harmful invaders. Lymphoid organs (lymph nodes, bone marrow, thymus, and spleen) make and/or store the leukocytes, and lymphatic vessels are a network of tissues that allow for the leukocytes to circulate through blood or the various lymphoid organs. (Durani, Y., 2012)
Cell cycle is a complex mechanism that governs the cell growth and proliferation. Cell proliferation contributes to the continuity of life by producing cells, replenishing cells which undergone to cellular differentiation to acquired specialized phenotypes (function and morphology) to carry out living mechanism and towards the end-point-cell-death. Cell proliferation is determined by both extracellular signals such as cytokines and mitogen, and intrinsic cellular factors. Interactions of extracellular signals with intrinsic cellular factors trigger the biochemical events of cell proliferation. In the case of acquired immunity, proliferation is the important state after lymphocytes encountered to antigen presentation, and then leads to their effectors functions. Cell cycle regulators control the appropriate entry and progression throughout the cell cycle event. Thus, any cell cycle deregulation will potentially lead to tumourigenesis. (Malumbres and Carnero 2003)
This can trigger cytotoxic T cells to kill cancer cells with the same antigen – often HPV viral proteins in cervical cancer. T cells may not be activated to their full potential – recall that the inhibitory receptor CTLA-4 in T cells sends a stronger signal than CD28, the activating receptor.
“This knowledge will help us design drugs that mimic the viral effects on these proteins to either activate a host’s immune response or shut it down,” said Dr. Michael Gale, associate ...
People infected with Human Immunodeficiency Virus (HIV) have a sequential destruction of CD4 T cells which always lead to a weakening of the immune system. Despite the reduction of CD4 T cells, the macrophages and dendritic cells are also affected by HIV. Moreover, HIV causes a dysfunctionality in B cells, CD8 T cells, and innate immune system cells (Shipley, 2013). For instance, the reduction of perforin production and IFN-γ secretion in CD8 T cells cannot help effector T cells to destruct virus-infected cells (Kuerten et al., 2008). The reduc...
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.
Seattle Education Project. (2013, November). STEP: The Immune System - An Overview, [Online]. Available: http://www.thebody.com/step/immune.html [11/12/14].
Bacteria exist everywhere in the environment and have continuous access to the body through the mouth, nose and pores of skin. Further more, many cells age and die daily and their remains must be removed, this is where the white blood cell plays its role.
Adaptive immune system happens much quicker to the presence of an “infection creating potent mechanisms for neutralizing or eliminating the microbes. There are two types of adaptive immune responses: humeral immunity, mediated by antibodies produced by B lymphocytes, and cell-mediated immunity, mediated by T lymphocytes.”