Write An Essay On Influenza Virus

a. This function is mediated by T cells and B cells (memory cells) in our body via adaptive immunity. The adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory, where each pathogen is “remembered” by a signature antigen. 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. Therefore, T cells will identify them and kill them.

This essay will outline the mechanisms by which the body defends itself against the Influenza Virus, more commonly referred to as ‘Flu’.

The organs that make up the lymphatic and immune system are the tonsils, spleen, thymus gland, lymph nodes, and lymphatic vessels. White blood cells (leukocytes), red blood cells (erythrocytes), plasma, and platelets (thrombocytes) make up the blood. Lymphocytes are leukocytes (white blood cells) that help the body fight off diseases. Two types of lymphocytes are B cells and T cells. Lymphocytes recognize antigens, or foreign substances/matter, in the body. Lymphocytes are a classification of agranulocytes, or cells (-cytes) without (a-) granules (granul/o) in the cytoplasm. B cells are created from stem cells, which are located in the bone marrow. B cells respond to antigens by becoming plasma cells. These plasma cells then create antibodies. Memory B cells produce a stronger response with the next exposure to the antigen. B cells fight off infection and bacteria while T cells defend against viruses and cancer cells. A hormone created by the thymus gland called thymosin changes lymphocytes into T cells. The thymus gland is active when you are a child and slowly shrinks, as you get older. T cells bind to the antigens on the cells and directly attack them. T cells secrete lymphokines that increase T cell production and directly kill cells with antigens. There are three types of T cells: cytotoxic T cells, helper T cells, and memory T cells.

Every year, many people get influenza all over the world and sometime this disease causes death. Medical care has been improved, but it is difficult to prevent influenza. People get it easily. According to Mortada, during the ful season of 2012 to 2013, the disease has caused 111 deaths (Mortada, 16). We have to prevent ourselves from the disease as much as we can. Otherwise, it would be infect to other people 　including family, friends, classmates, coworkers, and more. To prevent influenza, we must have strong immune system and get vaccinations that are suited for each person.

There are two important proteins used in the determination of the type of influenza; haemagglutinin (HA) and neuraminidase (NA). There are 18 known variations of the haemagglutinin protein and 11 of the neuraminidase protein, giving hundreds of possible variations in the subtypes of the virus . These subtypes are further divided into different strains that have a divergent molecular makeup, giving rise to viruses that differ in virulence, ease of transmission and severity of symptoms. Not all strains of influenza can cause disease in humans; influenza D subtypes cannot infect humans and influenza C infections are rare and usually very minor. Influenza A and B are the subtypes that are responsible for the common infections and the epidemics and pandemics that occur periodically, with influenza A causing the majority of these infections. The virus is transmitted through the inhalation of droplets which are expelled when an infected person coughs or sneezes, through contact with a contaminated surface and through the exchange of saliva . The infected person becomes infectious to others around 12 hours after first contact with the virus and remains contagious for around the next five days; this can vary as the immunocompromised can take longer to subdue the virus and children tend to be more infectious than adults . The virus incubates in the respiratory tract by invading cells through the cleavage of the viral protein haemagglutinin by human proteases . The pathogenicity of a certain strain is determined by the spread of proteases in the respiratory tract that can cleave the proteins of the virus; a strain is typically milder if the proteases that reside in the lungs and throat are the only ones capable of cleaving the virus, causing an upper respiratory tract (URT)

function that selectively infects helper T cells” (545). My goal in this paper is to show the advances

Influenza, commonly called "the flu," is an illness caused by RNA viruses that infect the respiratory tract of many animals, birds, and humans. Influenza viruses are found in body fluids such as saliva and mucous and commonly transmitted via tiny, air-born droplets created through sneezing and coughing. Depending on the conditions and temperature of the environment, the Influenza virus can remain infectious for up to one month. Transmission occurs as a new host comes into contact with viruses dispersed into the air or onto surfaces of objects. The main targets of the influenza virus are the columnar epithelial cells of the trachea, bronchi and bronchioles. HA binds to galactose-bound sialic acid on the surface of host cells. The HA binding

Influenza is one of the most important human respiratory infections and its seasonal recurrence is a major contributor to human morbidity and mortality. Seasonal influenza has an estimated annual attack rate of 10-20%, leading to 3-5 million cases of severe illness and 250,000 to 500,000 deaths each year [1]. Throughout history, influenza A has also been the greatest contributor of human pandemics. During the last century, four influenza A pandemics (1918, 1957, 1968 and 2009) caused over 50 million deaths globally, created significant social and economic impact on the human society, and shaped future research and public health policies.

Hello Sherri, influenza was one of my clinical diagnoses based on the patient’s clinical symptoms of fever, fatigue and body ache. Influenza is an acute viral respiratory illness that impact the health of many individuals, families, and communities. Influenza viruses belong to the Orthomyxoviridae family and are enveloped, segmented, single-strand RNA viruses. They can be divided into three types, A, B, C and are varied by viral RNA segments. Types A and B are common and are more likely to cause severe symptoms and epidemics. Seasonal influenza results from circulating influenza A and B viruses. Influenza viruses enter human hosts through columnar epithelial cells of the trachea, bronchi and bronchioles through influenza hemagglutinin, which

Influenza, also known as ‘the flu’, is a viral infection that tends to extent through societies between November and April every year, with a highest number of cases occurring in January and February. It is a respiratory illness that causes chills, high fever, body aches, and cough, but sometimes, its complications can be deadly. “About 5% of the population will contract the flu each year” (Influenza and your Health, 2017). Considering this, the “flu” is a very significant infection to study, characterized by specific symptoms, affects diverse age groups, and needs a vaccine protocol of which we must have knowledge to be prepared

The influenza virus looks like a sphere covered with spike like proteins for grip ready to latch on to a healthy human cell. The virus holds RNA in the very center of the virus. The outside layer is called the envelope. “The H spike (hem agglutinin) and the N spike (neuraminidase) are called proteins and exist in the envelope and they are used for antigenic typing” (Pearson 2004). These proteins allow the virus to enter and exit the host (our cells). Once the virus is inside the cell, the virus can begin reproducing. Soon, each infected cell is filled with thousands of new viruses, each of them looking to leave the cell to find a new home in another cell and begin

The memory T cells can differentiate into Central memory T cells (TCM), effector memory T cells (TEM), or tissue-resident memory T cells (TRM). In addition, these memory T cells produce more IFN-gamma and other cytokines that recruit other effector cells. Also, CD4 T cell help is required for CD8 T-cell memory and involves CD40 and IL-2 signaling. The differentiation of Memory T cells into effector TH1 and CTLs cells can help eliminate this viral infection in the ways that I described in part (a).

The mucosa-associated lymphoid tissue (MALT) is the organized and compartmentalized tissue that makes up our mucosal immunity. MALT, which is almost fully independent from our systemic immunity, is further divided into the gut-associated lymphoid tissues (GALT) and the nasopharyngeal-associated lymphoid tissues (NALT). Within these tissues are B-cell zones, T-cell zones, and subepithelial regions where APCs initiate adaptive immune responses both locally and distally in mesenteric lymph nodes. The B-cell regions contain high concentrations of secretory IgA antibodies, which largely regulate the humoral immune response in MALT. The MALT also houses microfold cells (M cells) that sample antigens from the nasal and intestinal mucosa and transport them to APCs where they are processed within a Peyer’s patch or mesenteric lymph node. (1)

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.