adaptive immune system Flashcards
the two types of response produced by the adaptive immune system
humoral and cell mediated response
the two main characteristics of the adaptive immune system
specificity
memory
the main cells of the adaptive immune system
lymphocytes
the two main types of lymphocytes in the adaptive immune system
B and T cells
functions of the B cells
Production of antibodies
Antigen presentation Cytokine secretion
where are B cells produced
where do they mature
what type of immune response do they produce
in the bone marrow
bone marrow
humoral response
functions of an antibody
agglutination
opsonisation
immunological memory
activation of immune cells
neutralisation
killing pathogens
state as many features of antibodies that you know(including the basic structure)
Y-shaped proteins
consist of 4 polypeptide chains held together by disulphide bonds
the polypeptides are grouped into two heavy and light chains
both chains are made up of a variable site and a constant site (domain)
what feature of antibodies allows the immune system to recognize an equally wide variety of antigens
Enormous diversity of antibody paratopeson the antigen-binding fragments of the antibodies
the major blood immunoglobin
IgG antibody
the IgG antibody is an opsonin, true or false
true
name one of the unique functions of IgG that differentiates it from other Immunoglobins
its ability to cross the placenta during maternal-foetal transfer.
the earliest Ig to be produced after contact with a new antigen
IgM antibody
on which cells are IgM antibodies expressed
B cells
other functions of the IgG
opsonisation
complement fixation
other functions of the IgM
agglutination
complement fixation
the IgM antibody is pentameric, true or false
true
is IgA a dimer or a monomer
dimer
monomer units of IgA
Serum IgA
second most prevalent immunoglobin in the serum
IgA
unique function of the IgA antibody
protects external or mucosal surfaces
which immunoglobin has an unknown function
IgD
which antibody is THOUGHT to be the B cell receptor for antigens
IgD
IgD is thought to be expressed on which types of cells
B cells
clonal selection
a process in immunology where the immune system responds to specific threats by selecting and multiplying immune cells with receptors that recognize the encountered antigens (foreign substances)
clonal expansion
refers to the rapid proliferation or multiplication of a specific type of immune cell, forming a population of identical cells, known as a clone
the T in T cells stands for
Thymus
where do t-cells originate from, and mature
the bone marrow
in the thymus
can the T cells bind to free antigens in the body
no
the two main types of T cells
Killer T cells (CD8)
Helper T cells(CD4)
the structural variation between CD8 and CD4
CD8 is a glycoprotein composed of two chains, an alpha chain, and a beta chain, which are linked together. It forms a heterodimer
while
CD4 is a glycoprotein composed of four immunoglobulin-like domains and is associated with a single transmembrane chain. It forms a monomer.
functions of CD4
Secrete small proteins called cytokines
Activate immune response by activating other immune cell
functions of CD8
Destroy virally infected cells and tumour cells
Implicated in transplant rejection and autoimmune disease
the MHC meaning
MAJOR HISTOCOMPATIBILITY COMPLEX (MHC)
the five classes of antibodies
IgG
IgM
IgD
IgA
IgE
main function of IgE
provide immunity against parasites such as Helminths
other functions of IgE
plays an essential role in type 1 hypersensitivity
in humans, MHC is also known as
human leucocyte antigen (HLA)
how does the binding of antibodies to antigens inactivate the antigens
by blocking the viral binding sites or bacterial antigens
Agglutination of particulate antigens
precipitation of soluble antigens
activation of complement system
Most abundant immunoglobulin in serum
IgG
FAB region of antibody
Region that binds to an antigen
Epitope
Part of antigen bound by the antibody
Immunoglobulins present at lowest concentration of all antibody classes in the blood
IgE
Immunoglobulin involved in asthma and allergy prevention
IgE
complement fixation
Complement fixation is a process by which antibodies, specifically immunoglobulins of the IgM and IgG classes, activate the complement system
which type of T cells cells are implicated in transplant rejection and autoimmune diseases
CD8
briefly describe how the complement system works(just the main points will be enough)
The complement system is a part of the immune system that enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism. It consists of a group of proteins that, when activated, work together in a cascade of events. The process begins when antibodies, particularly IgM or IgG, bind to antigens on the surface of pathogens. This binding triggers a conformational change in the antibodies, exposing a site for complement proteins. The initial complement protein, C1q, recognizes the altered antibodies and initiates the complement cascade. This cascade involves a series of enzymatic reactions that result in the formation of the membrane attack complex (MAC). The MAC creates pores in the membranes of target cells, leading to their lysis. Additionally, complement activation promotes opsonization, enhancing the recognition and engulfment of pathogens by phagocytic cells. The complement system also contributes to inflammation, attracting immune cells to the site of infection. Overall, complement activation plays a crucial role in the immune response, providing a coordinated and effective defense against pathogens
can T cells recognise free antigens
no
for antigens to be recognised by T cells, what should they be associated with
MHC protein
on which chromosome in humans can we MHC
what about in mouse
chromosome 6
chromosome 17
in humans the MHC is also known as
the HLA( human leucocyte antigen)
what are the two classes of the MHC
class I
class II
what is a similarity between the class I and class II MHC genes
they are both polymorphic
they both code for cell surface proteins
differences between the MHC coded proteins by class I and class II MHCs (respectively)
Class I is expressed on all nucleated cells while class II has restricted expression, found on cells in immune system
Involved in antigen recognition of CD8 cells while class II Involved in antigen recognition of CD4 cells
examples of cells that act as APCs
Dendritic cells, B cells, macrophages, Langerhans Cells, monocytes, microglial cells
after a pathogen has been recognised by the cytotoxic T cells, how are the pathogens killed(outline the process)
Clonal Expansion of cytotoxic T cells
Effector cytotoxic T cells approach the infected cell and release cytotoxic granules.
Perforin, a protein present in the granules, forms pores in the membrane of the infected cell
Through the pores created by perforin, granzymes enter the target cell.
Induction of Apoptosis
Macrophages or other phagocytic cells recognize and engulf the apoptotic cell debris for clearance
functions of caspases in apoptosis
they cleave key cellular components in the target cell, leading to DNA fragmentation.
which type of enzymes activate caspases
granzymes
vaccination
a way of stimulating the immune system to provide protection from disease caused by a pathogen without subjecting the host to disease
pioneer of modern vaccination
Edward jenner
types of vaccines
Live attenuated vaccines
Inactivated vaccines (killed antigen)
Subunit vaccines(purified antigens)
Toxoid vaccines(inactivated toxins)
what are some properties of an ideal vaccine
safety
price
stability
ease of administration
all nucleated cells should have which class of MHC molecule?
MHC I
