Immatology Assignment

The innate immune system is effective to a certain degree. That said, if the environment is regulated then the body is less likely to get ill. Innate immunity is effective as once the patient matures his immune system will mature due to the B and T memory cells. The memory cells will help the body prepare for the virus once it has arrived. The memory cells will send specialised lymph nodes to the invading pathogen. The B and T memory cells are key to immunity of a virus.

Adaptive immunity (p.446): The body’s ability to recognize and defend itself against distinct invaders and their products.

Innate immunity refers to nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body. Adaptive immunity refers to antigen-specific immune response.

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.

A primary response happens when an antigen is exposed, after a period of time which is normally a few days, particular antibodies start to show in the blood.

They go through negative selection after V(D)J recombination where the self-reacting cells are eliminated. Positive selection is in the periphery and where B cells become mature B-cells. Unlike T-cells, B-cells also go through hypermuation and class switching in the lymph nodes after they are activated. This helps them be more specific for antigens. B-cells either proliferate into memory B-cells or plasma cells that secrete antibodies. Antibodies opsonize, neutralize or fight by complement fixation against the virus. The memory cells are used if an infection of the same virus occurs

The immune system is made up of several types of cells that work together to fight infections. Lymph cells (called lymphocytes) are the main type of cell in the adaptive immune system. There are 2 types of lymph cells: T cells and B cells. When B cells respond to an infection, they change into plasma cells. The plasma cells are found mainly in the bone marrow—the soft, inner part of some bones. The plasma cells

Humans such as us alike cannot live in a world without a highly effective defense system that helps us to resist against infections and toxins caused by microorganisms. The immune system is a complex network of consorting cells, tissues and organs that defend the body from pathogens and other harmful substances. This essential complex consists of two subsections : the innate immune system and the adaptive immune system.

The effector cells of the cellular immunity are responses from T-cell-mediated cells. The humoral effect on the immune systems is that the B cells recognize the antigen in the blood or the lymph. Once it recognizes the antigen, it is able to produce antibodies that are specific to the antigen, thus removing the antigen from the body. The B cells also create memory cells that will provide immunity to the antigen in the future. The cellular immunity’s effect on the immune response is the T cells recognize antigens. T cells are not able to bind with the antigens directly, so they require the assistance from MHC-bound peptides. Once the T cell is activated, the T cells produce gene products and create memory cells. T cell activation activates B cells as

Adaptive, or acquired, immunity refers to antigen-specific defence mechanisms that take several days to become protective and are designed to react with and remove a specific antigen. This is immunity develops throughout life.

Lymphocytes are a type of white blood cell, which are an important part of the immune system. Lymphocytes can defend the body against infection because they can distinguish the body’s own cells from foreign ones. Once they recognize foreign material in the body, they produce chemicals to destroy that material. Two types of lymphocyte are produced in the bone marrow before birth.

Innate immune responses are known as the non-specific manner which composes the cells and defend the host from infection by other organism by mechanism. The adaptive immunity represents the antigen-specific immune response. Compare to innate immune response, adaptive response is more complex. In adaptive response the antigen needs to be recognised and processed. The adaptive immune system creates immune

It can then activate and rapidly reproduce the B cells, certain proteins that the virus releases allow the infected B cells to survive the germinal centre reaction and form resting memory B cells. Thereafter the virus slows its release of proteins to a rate where it’s still able to avoid any responses the hosts immune system may have.

The killer T cells detect the antigen located on the surface of the infected cells which then releases perforin that attaches to the infected cells. This makes pores within the infected cell and can let ions and water to diffuse inside the cell which therefore causes cell lysis.

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).