Specific Responses - antibodies

What is the key responses in specific reponse

Anything, Immunoglobins, lymphocytes

Antibody mediated immunity

Humoral

Plasma cells secrete

antibodies that circulate in the blood, bind to antigens, clear antigens from body

Cell mediated immunity

Specific T cells are activated that attack and kill spraying pathogens and infected cells

Antigen

A molecule or molecular structure, such as may be present at the outside of a pathogen that can be bound to an antigen-specific antibody or an antigen receptor and is capable of triggering immune reactions

Epitope

the precise molecular group of an antigen that defines it specificity and triggers the immune response

The immune system wont usually react to… under normal homeostatic conditions due to… of T cells in the…

self-antigens under normal homeostatic conditions due to negative selection of T cells in the thymus

Gene segments

encode for receptors on the surface of T and B cells and variable region on antibodies

Gene segments are… leads to…

rearranged extensively which leads to huge assortment of receptors on T and B cells and antibodies

What do each T and B lymphocyte have in combine?

They contain a protein receptor of a unique configuration. It’s specific and reactor to a specific antigen

What occurs during the development of B cells

A complete coding sequence for each of the two antibody Charmaine to be synthesized and assembled by the site specific genetic recombination

V(D)J recombination

is the unique mechanism of genetic recombination that occurs one in developing lymphocytes during the early stages of T and B cells maturation. Resulting in highly diverse repertoire of antibodies/immunoglobulins (IGs) and T cell receptors (TCRs) found on B cells and T cells

Clone

each genetically unique line of lymphocytes arising from the gene segment rearrangement

Each T and B cells that are generating will respond to how many specific antigens?

one

Where do T and B cells migrate

lymphoid tissues

Thymus

Location of T lymphocyte maturation, this specialized organ has T cells attack the body’s own proteins and eliminate them

Thymosin

polypeptide hormone secreted by the thymus that controls the T cell maturation

Each T cell …. Substance which it identifies with its receptor

attacks a specific foreign substance

How are T cell receptors generated

via random shuffling of gene segments

What is the first step of clonal selection theory?

A hematopoietic stem cell undergoes differentiation and genetic rearrangement to produce immature lymphocytes

What is the second step of clonal selection theory?

The immature lymphocytes are bonded to different antigens receptors

What is the third step of clonal selection theory?

Those that bind to styling from red board own tissues ARE DESTROYED

What is the fourth step of clonal selection theory?

Those that bond with different tissues become mature into inactive lymphocytes

What is the fifth step of clonal selection theory?

Foreign antigens are presented and some may bind

What is the sixth step of clonal selection theory?

Those that bind with the antigens are activated and produce many clones of themselves

Hematopoietic stem cell can give rise to…

all the other blood cells through teh process of haematopoiesis in the red bone marrow

Immunoglobulin

Contains large glycoprotein molecules that serve as a antibodies and a specific receptor to B cells

Immunoglobin is secreted by… which reside in the..

plasma cells which reside in the blood plasma

IgD

Membrane receptor for mature B cells

Allergy to IgE

A hypersensitivity disorder of the immune system → red eyes and itchiness wtvH

Hives

Also known as urticaria, its an outbreak of swollen and pale red bumps on the skin as a result of the body’s reaction to certain allergens

Allergic reactions are

distinctive because of excessive activation of certain white blood cells by a type of antibody - IgE →inflammatory response which can range from uncomfortable to danergous

Which white blood cells are over activated during an allergic reaction

mast cells and basophils → histamine

The body is able to produce milling of different antibodies because…

it combines different segments of the same gene and removing different introns for different antibodies

Genetic rearrangements in developing B cells… into genes encoding light and heavy chains

combine gene segments

What are light and heavy chain genes transcribed to?

precursor mRNA → processed into finished mRNAs or translated into antibody polypeptides

What generates the capability needed to respond to numerous antigens?

The differentiation of B cells and the random C and J DNA segments joining with C to form light chain genes and the assembly of heavy chains for T cell receptor formation

Dendritic Cells

A type of Antigen presenting cell (APC) that is located in tissues which are in contact with the external environment - i.e skin, lining of nose, lungs, stomach, intestines

When dendritic cells are activated, where do they migrate?

lymph nodes

When the dendritic cells aer in the lymph nodes they interact with…

T cells and B cells to initiate adaptive immune response

What is the role of a helper T cell?

They trigger a humoral and cell mediated response (CMI)

Cytokines from help T cells..

initiate antibody production and fabricate T cells to kill infected cells

What two conditions must be met before the T cell can activate the adaptive immune response

1. An antigen fragment must be displayed in the APC

2. The antigen must bind to the T cell receptor on the helper T cell

Antigen presenting cell (APC) examples

Dendritic cells, macrophages, or B cells

What makes APCs so special ?

They contain both the MHC class I and MHC class II proteins where as other cells only have MHC I protein

What can activate a helper T cell?

macrophage or dendritic cell

When B cells are activated by the T cell, they give rise to?

antibody secreting cells - plasma cells

Antibodies can unite with the antigen via

opsonization where the virus or pathogen is coated

Antibodies can immobilize with the antigen via

aggutinate where antibodies can cross-link

Antibodies can call attention to the antigen via

binding of Ab enhancing phagocytotic recognition so wbc can engulf the pathogen

Antibodies can neutralize the antigen via

Ab filling receptor site on the virus to prevent attachment to the host cell

Antibodies can destroy the antigen via

interaction of Ab with complement fixation to rupture some viruses

What are the ways Antibodies can kill invading bacteria?

agglutination of bacteria into a clump preventing potential infections

stimulations of complement

enhancing phagocytosis

initiate membrane response complexes via innate immune responses

Whats the main distinction between B and T cells?

Antigen receptors of T cells will only bind to antigens that are displayed and antigen receptors of B cells bind to epitopes of intact antigens on pathogens or circulating free in body fluids

What occurs at 1?

The bacterium is taken up by phagocytosis and degraded in a lyosome

What occurs at 2?

Bacterial antigens are displayed on the APC cell surface bound to class II MHC proteins and presented to CD4+ T cells with TCRs that recognize the antigen

What occurs 3?

The APC secretes an interleukin which activates the T cell

What occurs 4?

Activated T cell secretes cytokines, which stimulate the T cell to proliferate to produce a clone of cells

What occurs at 5?

The cloned cells differentiate into helper T cells

What occurs at 6?

BCR binds to antigen on the bacterium. The bacterium is engulfed and its macromolecules degraded. The antigens produced are displayed on cell surface bound to class II MHC proteins

What occurs at 7

The TCR of a helper T cell recognizes the specific antigen on the B cells bind and link the two cells together

What occurs at 8?

Interleukins stimulate B-cells proliferation to produce a clone of cells

What occurs at 9?

Some cloned B cells differentiate into plasma cells, which secrete antibodies specific for the antigen while a few differentiate into memory B cells