1.2.0 Natural Killer Cells NK cells are one of the most sophisticated weapons in the innate immune systems arsenal however, they a short lived. Cytotoxic effector cell which resemble NK cells have been a part of the innate immune system for approximately 500 million years, long before the arrival of T and B cells of the adaptive immune system (Caligiuri, 2008). NK cells are best known for their role in the innate defense against viral infection and potential tumour cells. However, more recently they are being recognized with roles in the coordination of immunity, immunoregulation and the modulation of autoreactivity. NK cells got their name ‘natural killer’ due to the nature of being able to cause cell death instantly without priming, effector …show more content…
Although presence of CD56 can alter between NK cells and leads to subsets. In the peripheral blood, mature NK cells express low levels of CD56 including CD16 an IgG Fc receptor FcγRIIIA. These are given the name CD56 dim, this means that fluorescent intensity is slightly higher then then cell which are CD56 negative. A small amount approximately 10% in blood and 100% in secondary lymphoid tissue of peripheral blood NK cells express high levels of CD56 without CD16 present of the cell surface and these are considered immature however, functionally enabled NK cell subset or CD56 bright (Orange, 2013). CD56 bright NK cells can produce and high levels of cytokines and chemokines within a few minutes of their activation. Although, they show little or no ability to spontaneously kill tumour or virally infected cell targets. Contrary CD56 dim show lesser ability to produce cytokines in response to activation, however the majority can instantly lyse susceptible targets. The population of human NK cells are phenotypically and functionally heterogenous. Although, CD56 bright mature into CD56 dim as they develop they both have key roles within the human immune system (Caligiuri, …show more content…
IFN-γ is a prototypic NK cell cytokine and its production within the cell influences the T helper 1 cells response, up regulates MHC class 1 expression on antigen presenting cells and activates macrophages while having antiproliferative effects on viral and transformed tumour cells (Caligiuri, 2008). Mature NK cells specialize against T cell elusive pathogens, this is mostly viruses. Most viruses evade cytotoxic T lymphocytes by downregulating the class I MHC in infected cells also seen in tumours, this prevents the presenting of derived viral proteins by the cell. However, by doing this it becomes susceptible to NK cell defenses. NK cells can become activated by many activation receptors however, they are inhibited by killer cell immunoglobulin-like receptors (KIRs). These are ligated by class I MHC. Activation receptors can directly recognize viral antigens which include natural cytotoxicity receptors which binds to viral hemagglutinin. Some viruses and tumours induce specific cell stress molecules that serve as ligands to NK activation receptors (Orange, 2013). This relationship between KIRs and activating receptors can be seen below in figure
I am playing the Anti Hunter Activist role in animal rights. I am going to be fighting against people who do hunting, fur trapping, pigeon shooting and Alaskan Wolf hunts. I will be dressing up in camo and have a big red line through it to show that I am against Anti- hunting activist. The props I will use to show how hunters use animal props. I will use an intimal letter made out animal antlers, Uggs that are made out of sheep skin. I will also use a handout out that better explains fur trapping and pigeon shooting.
The green river killer is a man known by the name of Gary Ridgeway on the surface he lead a seemingly normal life, head down a regular job and was married. Ridgeway began his murders in 1982 by murdering young prostitute who were runaways.Many of these girls were minorities. He dumped the bodies of his victims in the Green River which ultimately gave him the name the Green River killer because he dumped all of his bodies in the same river. From the beginning of his crime spree there were many dead bodies but no good leads on who the murderer was. It wasn't until 2001 when more technology became available that the case was reopened. The specific technology that they used to solve this cold case was DNA. In 2003 he pleaded guilty to 48 counts
It has targeted cells that work to kill and defend any pathogen or impurity that enters one’s body. In the case of cancers, a person’s cells grow abnormally forming a tumor. Unlike normal cells, cancer cells lose the ability to undergo apoptosis, cell death. Thus, one’s body harvests a tumor that most likely has a chance to spread and become deadly. Luckily, the biotech industry concocted innovative research that called for a new method of cancer treatment. Immunotherapy is designed to program one’s immune system to destroy and fight off the cancer. Originally, it has been mainly used for allergies. Dosages of medication or vaccinations are given to a patient to ensure that the immune system will not overreact to certain types of foreign substances. The therapy requires a drug that delivers an anticancer immune cell, specifically designed to attach on to the specific antigen that the tumor contains. According to scientist, immunotherapy gives patients “long term protection with reduced side effects against the cancer” (McGinley). The purpose of this treatment is to strengthen the immune system and specifically targets cancerous cells. Due to scientific research and the use of biotechnological methods, immunotherapy is able to prevent the threat of killing cells necessary to one’s body. Providing patients with a treatment that does not take a toll on their bodies, nor threaten to kill healthy cells is one relief the person
Lymphocytes are vital to the human body to protect us against disease and initiate an immune response. Each person possesses billions of lymphocytes which collectively provide an individual with the ability to respond to a huge variety of antigens. The wide
The research presented in Jedd D. Wolchok “Cancer’s Off Switch” examines two different forms of immunotherapy used to treat cancer cells by boosting the patient's own immune system defenses. The article provides a comprehensive history of the scientific discoveries and previous research that lead to the immunotherapy treatments, specifically the different levels of the immune system. In addition, the article addresses two different methods of immunotherapy currently in testing in clinical use. The research is educationally significant because it focuses on the body's internal defense system and attempts to disable the brakes cancer cells enforce on the immune system, which has shown progress in both tumor size regression and improvements in
Cancer immunotheraphy is a concept that has been around for centuries. Back in the 1800s, a bone surgeon named William Coley injected his patients with a vaccine consisting of killed bacteria hoping it would stimulate the body's defense system. During the 1990s, physicians treated people with cancer with a cytokine treatment. This treatment involved high amounts of interleuken-2 (IL-2) and interferon-γ (IFNγ), also known as inflammatory cytokines. These inflammatory cytokines were released by white blood cells that fight infection (T cells). However, this treatment can have very dangerous side effects such as vascular leakage and kidney damage, but some people that received the cytokine treatment have lived for decades. In the year of 1996,
The key role of NK cells in various aspects of immune response are now being recognized and have been attracting increased attention for their potential clinical efficacy via immune-based therapies. As their name implies, this unique member of the innate immune system can recognize targets without being previously sensitized and thus kill cells that are deemed dangerous to the host. This is particularly important when evaluating biologic studies of NK cells and factors that influence NK-cell effect in cancer immune-surveillance, viral immunity, and transplantation alloreactivity. In this chapter, we will review NK cell biology, discuss their role in the alloHSCT setting, and review new advances in incorporating NK cells as therapeutic options for malignancies. Large granular lymphocytes (LGL) can be divided broadly into two major lineages mainly T cells and natural killer (NK) cells. While mature cells NK cells are morphologically identified as LGL, nearly a decade after their initial discovery, NK cells were characterized as lymphocytes having an immuno-phenotype that lacked expression of CD3- but expressed CD56+. This characterization thereby differentiated them from T-cells having CD3+ expression and thus NK cells do not express the CD3/T-cell receptor (TCR) complex or experience TCR gene rearrangement. NK cells can be further divided into two distinct
Now I wish to share with you three of the ways I evade the immune system efficiently. I have learned to be really sneaky and evasive over the years of fighting with the pesky immune system. One of my favorite ways I evade the immune system is by tricking your Natural Killer (NK) cells into thinking the cells around them are healthy, even when I have actually already infected them. NK cells typically induce apoptosis in cells that are stressed. Cells indicate that they are stressed by displaying a decreased amount of Major Histocompatibility Complex I (MHCI) on their surface. So I had to think of a way to prevent NK cells from binding to the cells that I infected and keep a normal level of MHCI displayed on the infected cell surface. I did this simply by producing fake MHCI that will be displayed on the infected cell surface. My fake MHCI resembles the real MHCI so closely that the NK cells are tricked into not inducing apoptosis in the infected cell. If that does not convince you of how much smarter I am than your immune system, just wait. I will share with you two more ways in which I evade my
Background: Innate immunity is the first line defense against invading microbes pathogens. Human blood is full of cells that express immune system such as Neutrophils. The most important operation that Neutrophils do in this lab is phagocytosis. Phagocytosis is normal reaction white blood cells doing when human body is under attack from bacterial pathogens.
Natural Killer (NK) cells are immune cells which are kenned to exhibit cytotoxicity towards various types of cancer cells during metastasis (spread to other organs) [53, 54]. Natural Killer (NK) cells cytotoxicity has been found to be enhanced by G. lucidum towards a variety of tumors [55].
In immunocompetent hosts, viral titers in the lung increase 1-2 days post-infection, reach a maximum at 3-5 days, start to decline at day 7, and are cleared between day 9 and day 14 (19). Early (day 2) p.i., the viral titers in the lungs of WT and NK-depleted mice were identical (not shown). As viral replication reached more significant levels at day 4 p.i., there was a trend toward increased viral load in NK-depleted animals, but these did not reach statistical significance (Fig. 5D). At day 6 p.i., a time point at which peak numbers of IFN-γ+ NK cells occur in the lung, a significant increase in VACV titer was observed in anti-NK1.1-treated mice, and this high titer continued in some animals through to day 9. Despite this, both NK-depleted and untreated NK-sufficient WT controls cleared VACV between day 9 and day 14, directly correlating with the kinetics of weight loss recovery. To further assess the anti-viral activities of NK cells, we investigated the dissemination of VACV from the lung to peripheral tissues. At day 4 p.i., there was a 10-fold increase in VACV titers in ovaries from NK-depleted mice (not shown). Again, VACV titers continued to increase over the next two to five days but were minimally detectable by day 14 (not shown). Notably, NK-depletion did not affect all organs, because an increase in infectious virus was not found in the liver, spleen, heart, and kidneys (not shown). These data suggest that NK cells provide a temporary barrier limiting VACV replication and dissemination during the acute phase of
B cells are a third class of important immune system cells. They do not kill the invaders, but they do tell the killers who to kill. B cells produce specific protein called Antibodies. Each B cell watches out for a particular pathogen and when that pathogen arrives, e B cell begins to produce specific antibodies. Antibodies attach themselves to the specific pathogen so that the killers can recognise that these pathogens need to be destroyed.
Immunoglobulins that are vital to the host immunity are absorbed through specific receptors (called as Fc receptors)
Immunology basically involves understanding the immune system and how it responds to various disease conditions. the immune system consists of a number of components. Traditionally, it is divided into humoral and cellular immune responses. It can also be distinguished into innate and adaptive immunity. The innate immunity can discriminate between normal tissues , self and newly encountered non-self-proteins while the adaptive immunity is the more complex system aimed at the eradication of intracellular pathogens. To do this, antigen derived from such pathogens that are often new to the host organism, need to be recognised by receptor-bearing specialised immune cells which respond to a complex system of stimulatory and costimulatory signals. Better understanding of the human immune system has led to the identification of a number of tumor-associated antigens in the 1980s and the development of various immunotherapeutic approaches. In recent years, identification of the specific antigenic MHC class I epitopes, advancements in genetic engineering, gene delivery, and cell-based therapeutic approaches allowed development of the novel immunotherapeutics.
The adaptive immune response is antigen-specific and requires the recognition of specific “non-self” antigens during a process called antigen presentation. Antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells. The ability to mount these tailored responses is maintained in the body by "memory cells". Should a pathogen infect the body more than once, these specific memory cells are used to quickly eliminate it. so basically killer T cells will identify antigens present on foreign cells. These antigens are not found in any of the cells inside our body. So T cells will identify them and kill them.