Patho Ch8

A bacterial toxin that has been chemically inactivated but still remains its immunogenicity is referred to as what

A toxoid, and is used in some immunizations to help stimulate antibodies without making the host sick

A large majority of cytokines are secreted by what

APC's and lymphocytes

Antigen is processed and presented to the immunity cells by what

APC's, these are antigen presenting cells, and they are necessary because immunity cells can not sense the antigens presence without them

A substance recognized as foreign or nonself by the body is considered what

An antigen

What is an APC

An antigen presenting cell

When an antigen is capable of triggering an immune response the antigen is referred to as what

An immunogenic Antigen

When an APC or a lymphocyte secretes a cytokine, what are the most common responses

An increase in the production of protein, and cause lymphocytes to proliferate and differentiate. The precise combination of cytokines influences the ultimate response of a given cell.

What are the main characteristics of Passive-Aquired-Immunity

Antibodies and T cells are transferred from a donor to a recipient, either naturally, or artificially and provides short term immunity with no memory involvement to protect against future exposure

What are the main characteristics of Active-Aquired Immunity

Antibodies or T cells are produced after an exposure to an antigen or immunization, producing memory and long lasting immunity

A molecule that can react with antibodies or receptors on T and B cells is referred to as what

Antigen

What Results from the recognition of soluble antigen by BCRs, processing of antigen, and presentation by MHC class II antigens to Th2 cells

B cell activation

Which cell serves as an APC by presenting antigen to Th cells that facilitate humoral immune response

B-lymphocytes

How to immunocompetent lymphocytes make it from their site of production to the secondary lymphoid tissue

By way of specialized small veins, called high endothelial venules, or HEV's

One of the biggest differences between MHC's and CD1s is what

CD1's present lipid antigens as oppose to protein antigens, and are very important factors in infections with bacteria of mycobacterium tuberculosis and mycobacterium leprae that causes leprosy, due to these cells having large amounts of lipid in their cell membranes.

TC Lymphocites are involved in destroying what cells

Cancer cells or cells infected with a virus

Cell-Mediated immunity involves which cells

Cell- Mediated immunity involves T cells and are most protective against viruses and cancer

What makes transplantation of tissues so difficult

Cells in transplanted tissue from one individual have a different set of MHC surface antigens than those of the recipient, meaning The recipient can mount an immune response against foreign MHC molecules, causing rejection of the transplanted tissue

What two types of tolerance prevent the destruction of self

Central tolerance is the process by which all lymphocytes containing self antigen receptors are eliminated. Peripheral tolerance protects self-antigens by eliminating lymphocyte and antibodys capability of recognizing them.

What are the 3 molecules that recognize antigens

Circulating antibodies, Antigen receptors on B cells referred to as B cell receptors of BCR, and antigen receptors on T cells referred to as T cell receptors of TCR

Low-molecular-weight proteins, or glycoproteins, that function as chemical signals between cells are

Cytokines

What are the aging effects on the immune system

Decreased T-cell activity, in part because the Thymic size is 15% of its maximum size, Decreased production of specific antibodies, Decreased circulating memory B cells, Increased circulating immune complexes, and Increased circulating autoantibodies

How do tregs or T regulatory cells suppress the immune response

Decreases Th1 and Th2 activity, suppresses antigen recognition and Th cell proliferation, and Provides peripheral tolerance, which Controls or limits the immune response to help protect the host's own tissues against autoimmune reactions.

The 4 major characteristics that determine an antigens immunogenic capabilities are

Degree of foreignness to the host is most important, size, chemical complexity, and amount

Which cell serves as an APC by processing antigen from a site of inflammation to T-cell rich areas of lymph nodes

Dendritic Cells

List the 3 most efficient antigen processing and presentation cells

Dendritic cells, macrophages, and B lymphocytes

What are the main functions of the activated T cell

Direct killing of foreign or abnormal cells, via T cells or cytotoxic T lymphocytes, CTLs, assistance or activation of other cells such as macrophages, as well as differentiation into Tregs to prevent massive immune response, and differentiation into T memory cells to help induce secondary cell mediated response

Natural killer cells are different from T cells in that

Do not undergo maturation in the thymus, lack atigen specific receptors, and are capable of killing cells that do not express MHC class 1. Also if a pathogen expresses foreign antigen that elicits IgG antibody which binds to the antigen, the NK cell can attack through the FC receptors and activate its normal killing mechanisms, this is referred to as antibody-dependent cell-mediated cytotoxicity.

Which binding fragment on an immunoglobulin contains the recognition site (receptors) for antigenic determinants and confer the molecules specificity towards a particular antigen

Fab, also referred to as an antigen binding fragment, to which 2 identical strands are present

Which binding fragment is responsible for most of the biological functions of antibodies, including the activation of the complement cascade and opsonization by binding to the Fc receptors on the surface of the cells of the innate immune system

Fc, or crystalline fragment,

Where is IgA2 predominantly found

Found in normal body secretions. This Subclass of IGA are dimers anchored by the J chain and secretory piece which may function to protect it from enzyme degredation

What is another name for Major Histocompatibility Complexes MHC

Human Leukocyte Antigens HLA, which are configured by the MHC class I and MHC class II loci, receiving one from each parent with millions of possibilities makes finding a transplant match very difficult

Humoral immunity involves which cells

Humoral immunity involves B cells and circulating antibodies. They Causes direct inactivation of a microorganism or the activation of inflammatory mediators and are most protective against viruses and bacteria

What are Ig alpha and Ig beta's primary role as members of the Beta Cell Receptor Complex

Ig alpha and Ig beta are responsible for delivering the message into the B cell activating it to mature and produce antibodies

Which immunoglobulin is most important in the secretory immune response

IgA, very small numbers of IgG and IgM may be present

Which class of immunoglobulins lacks functional information, but, Concentration is low in the blood, Is located primarily on the surface of developing B lymphocytes, and Functions as one type of B-cell antigen receptor

IgD

Which class of immunoglobulin Is the least concentrated of the immunoglobulin classes in the circulation, Acts as a mediator of many common allergic responses, and Defends against parasites.

IgE

Which immunoglobulin is the primary cause of asthma

IgE

Explain the relationship between IgE and Eosinophils

IgE is a specialized class of antibodies that protect against large parasitic worms, and eosinophils are the primary cell for granuloma formation around the parasite causing degranulation

What are the 5 classes of immunoglobulins also referred to as antibodies

IgG, IgA, IgM, IgE, and IgD

Which antibodies contain 2 binding sites

IgG, IgD, circulating IgA or IgA1, and IgE

Which antibodies are transported by trophoblastic cells through the mothers placenta allowing the child to be born with near adult levels at birth

IgG, however infants immune system is deficient, they are capable of a primary IgM response but are unable to produce an IgG challenge

Which immunoglobulin class is the most abundant class 80% to 85%, Is transported across the placenta, and, Accounts for most of the protective activity against infections

IgG, which breaks into 4 categories of IgG 1-4

Which class of immunoglobulin as the largest of the immunoglobulins, Consists of a Pentamer stabilized by a J-chain, Is the first antibody produced during the primary response to an antigen, and Is synthesized during fetal life

IgM

Which antibody contains 10 binding sites

IgM contians 10 binding sites, however, due to structure it is likely that not more than 5 binding sites could be accessed at one time.

Describe the secondary immune response

Is more rapid than the primary response, Larger amounts of antibody are produced, Rapidity is due to the presence of memory cells that do not have to differentiate, IgM is produced in similar quantities to the primary response, but IgG is produced in considerably greater numbers

How does size effect the degree of an antigens immunogenic capabilities

Large antigens are extremely immunogenic, smaller angitens called haptens cannot trigger an immune response alone, however, with the help of a carrier protein an immune response is still possible

Which cell serves as an APC by presenting antigen to memory Th cells to initiate a rapid response to antigen (secondary immune response)

Macrophages

Two antigen presenting molecules are

Major Histocompatibility complexes and CD1

Antibody function protects against infection both directly and indirectly. In what ways does it directly protect

Neutralization, by inactivating or blocking the binding or an antigen to a receptor, agglutination, by clumping insoluble particles that are in suspension, and preciptation, by converting a soluble antigen into an insoluble precipitate

Describe the primary immune response

Occurs during the initial exposure, During the latent period or lag phase, B-cell differentiation occurs, After 5 to 7 days, an IgM antibody for a specific antigen is detected, An IgG response equal to or slightly less follows the IgM response, The immune system is now primed

What is the process for B-cell Maturation

Occurs in the bone marrow. As stem cell matures it develops surface markers CD45R and IL7 Receptor, Interleukin 7 produced by stromal cells is critical in the further differentiation and proliferation of the B cell. The last step is the development of the B-Cell Receptors, using light and heavy chains and V, D, and J genes.

The basic structure of an antibody molecule consists of two light chains and two heavy chains held together by disulfide bonds, what is the name of this chain

Polypeptide chain, which determines the name of the particular immunoglobulin depending upon which heavy chain it uses

The biggest differences between Innate and Adaptive Immunity is that Adaptive immunity what

Provides long term protection, is slower to develop, and has memory

Major histocompatibility complexes are glycoproteins found on the surface of every human cell except

Red Blood Cells

The spleen, lymph nodes, adenoids, tonsils, peyer patches of the intestines, and the appendix are all what

Secondary lymphoid organs where immunocompetent lymphocytes travel to await antigen

Which antibodies contain 4 binding sites

Secretory IgA or IgA2

Under conditions of chronic inflammation T cells produce cytokines that activate macrophages, what does this do

Stimulates a macrophage to become a more efficient phagocyte, Increases production of proteolytic enzymes and other antimicrobial substances, Retains macrophages at the inflammatory site,and Increases adhesion between Th1 and macrophages

When molecules are not digested and processed by APC's and result in the activation of large populations of T lymphocytes, regardless of antigen specificity, producing excessive amounts of cytokines, it is termed

Superantigens that result in systemic inflammatory reaction including fever, low blood pressure and potentially fatal shock. Staph aureus and strep pyrogenes are examples

What are the end products of adaptive immunity

T and B lymphocytes and immunoglobulins

What is the difference in cellular reaction between TCRs and BCR's

T cell receptors can only see what has been processed and presented to them limiting their ability to forge an attack, B cell receptors can react with soluble antigens and with the help of a Th2 cell, antibody and memory cells are made eliminating the need for further differentiation on secondary exposure

Which T helper cell subset provides help in developing cell mediated immunity by activating macrophages and Tc cells

T helper 1 cells

Which T helper cell subset provides help in developing humoral immunity by activating B cells

T helper 2 cells

What is the primary role of T helper cells

T helper cells help the antigen driven maturation of B and T cells, and facilitate and magnify interaction between APC's and immunocompetent lymphocytes

The 2 Tcells are products of T-cell Activation

Tc cells or cytotoxic T lymphocytes and Tmemory cells

Where is a B Cell Receptor (BCR) complex located, what does it consist of and what is its function

The B cell receptor complex (BCR) is located on the surface of the immunocompetent B cell, BCRs act as IgM and IgD to recognize and bind to an antigen, and then use its accessory molecules Ig alpha and Ig beta heterodimers to convey the message to the cell, which activates the cell to complete maturation and produce of antibodies.

Where is the T Cell Rectptor (TCR) complex located, what does it consist of and what is its function

The T Cell Receptor Complex consists of a Antibody-like Transmembrane protein TCR, which is located on the surface of the immunocompetent T cell, which is responsible for recognizing and binding to an antigen, and then use it's accessory receptor proteins CD3 to convey the message to the cell, which activates the cell to differentiate T cells

The part of the antibody or lymphocyte receptor that attaches to an antigen is referred to as

The antigen binding site, also referred to as the paratope

The part of the antigen that is configured for recognition and bindingby an antibody or lymphocyte is called what

The antigenic determinent also referred to as the epitope

Where is IgA1 predominantly found

The blood

The primary lymphoid organ where a lymphocyte will differentiate into a B cell is

The bone marrow

APC's interact with Thelper cells to facilitate an immune response and they interact with immunocompetent T and B cells which do what

The interaction of APC's with immunocompetent B and T cells, resutls in the differentiation of B cells into active antibody producing cells (plasma cells) and T cells into effector cells, such as T-cytotoxic cells. These cells being immunocompetent means that they have differentiated and are capable of interacting with an antigens

The primary lymphoid organ where a lymphocyte will differentiate into a T cell is

The thymus

What is the purpose of a T-regulatory Cell

These cell are developed by additional T cells to regulate the immune response and avoid inadvertently attacking self-antigens and avoid overactivation of the immune response.

A specific combination of alleles at the six major HLA loci on one chromosome make up what

This makes up a haplotype, each person has 2 HLA haplotypes, one from each parent.

How do TC lymphocites destroy cells

Through direct apoptosis, or stimulation of Perforin and Granzymes, where perforin forms pores in the target cells membrane and granzymes enter through the pores and activate cellular enzymes that produce apoptosis. T cells may also interact directly by means of their Fas receptor located on their cell surface which after activation signals the target cell to undergo apoptosis

What is the process of T-cell maturation

Thymus is the central lymphoid organ of T-cell development. T cells move from the thymic cortex to the medulla, and the Changes include the development of the TCRs and the expression of surface molecules, T cells are then released into the blood and take up residence in the secondary lymph organs to await antigens

What happens when a B cell encounters an antigen

When an immunocompetent B cell encounters an antigen for the first time, B cells with specific BCRs are stimulated to differentiate and proliferate, A differentiated B cell becomes a plasma cell, A the plasma cell is a factory for antibody production

Indirect antibody functions include

activation of the complement cascade, and phagocytes

Small molecular weight antigens that cannot trigger an immune response without being bound to a carrier protein are called

haptens

Describe the indirect effects of antibody function

it Is mediated by the Fc portion of the antibody molecule, and Includes opsonic activity, leading to enhanced phagocytosis, Activates the complement system, which may lead to complement-mediated destruction of the pathogen, and Increases opsonic activity through the deposition of C3b

Where are CD1 cells found

on APCs and thymus cells