Chapter 24

descrie the tc(cell) response that causes cell death

This is considered a direct immune response. PRR interacts with PAMPS to activate the phagocyte ( antigen presenting cells) the MHC I found on the cells surface and the antigen are recognized by the TCR of the T-cytotoxic cells which then produce perforins and grnymes that cause trageted cell death

natural passive immunity ?

Through antibody transfer across the placenta or in breast milk ?

How do T-lymphocytes recognize the peptide antigens?

Through t-cell receptors

What are TLR's

Toll-like receptors, recognize PAMP's

B cells are precurosrs to what ?

antibody-producing plasma cells (a.k.a antibodies

what are b-cells

b cells are specialized lymphocytes that have antibodies on their surface

Where do B-Cells originate ?

bone marrow

what is natural active immunity ?

by acquiring an infection that initates an adaptive immune response.

what are the granulocytes ?

granulocytes, and they are leukocytes of the innate immune system that have granules in their cytoplasm. (neutrophils, basophils, eosinophils)

Where are IgM's and IgG's found

in blood

Antibody-mediated immunity

is effective against extracellular pathogens such as bacteria and soluble pathogen products (think B-cells)

What does the first exposure of an antigen generate ?

it generates a primary adaptive immune response

Name the three important phagocytes

macrophages, monocytes and dendritic cells

What is the rapid increase in adapative immunity after a second antigen exposure

memory

Where is IgA mostly found ?

mostly in the blood and in high concentrations in mucous membrane secretions, such as in the lungs and gut.

what is the precursors for APC's

myeloid cells

What IgE involved in ?

parasite immunity and allergies

What are PAMPS

pathogen-associated molecular patterns--> macromolecules inside and on the surface of pathogens display pamps ex. lipopolysaccharide common to all gram negative bacterial outer membrane

cell-mediated immunity

pathogen-infected host cells are killed after they are recognized via pathogen antigens found on their surface

What are PRR's ?

pattern recognition receptors, specialized molecules, it interacts with specific PAMP to activate the phagocyte.

opsonization

phagocytes have general antibody receptors called Fc receptors that bind to

What are the usual the first modes of defense

phagocytes such as macrophages and neutrophils are the first line of defense against pathogens

Memory

subsequent exposures to the same antigen result in rapid production of large quantities of antigen-reactive T cells or antibodies

What are leukocytes ?

-->A.K.A white blood cells --> Cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. --> There are two types of lymphocytes (B and T cells) -->Include phagocytes and lymphocytes --> 0.1% of blood cells are leukocytes

what are Lymphocytes

-->Part of the immune system ( specialized leukocytes--> Leukocytes are nucleated white blood cells) -->There are three types, T cells, B cells and Natural Killer cells. -->Natural killer cells are able to recognize and destroy altered cells as in tumor cells or cells that have been infected by viruses. -->B cells manufacture antibodies which neutralize bacteria and viruses. -->T cells are of two kinds. -->Helper T cells produce cytokines that direct the immune response. --> And other T cells produce granules that cause infected cells to die. (Both B and T cells are involved in the production of memory cells. These provide long lasting immunity to the specific pathogen or germ)

What are the T-lymphocyte subsets ?

-->T-cytotoxic (Tc) cells -->T-helper (Th) cells -->Th1 cells -->Th2 cells

What is Adaptive immunity ?

->The acquired ability to recognize and destroy a particular pathogen or its products ->Dependent on previous exposure to the pathogen or its products ->Directed toward an individual molecular component of the pathogen (antigen)

about how many cells are leukocytes

0.1%

Name the two type of myeloid cells ?

1. Antigen-presenting cells (APCs) engulf, process, and present antibodies to lymphocytes Monocytes, macrophages, and dendritic cells 2. Granulocytes contain toxins or enzymes that are released to kill target cells Neutrophils, basophils, eosinophils

what occurs during primary and secondary adaptive immune response

1. primary adaptive response --> it induces both immune and antibody response 2.Secondary response --> activates the clones of antigen-reactive cells and generates a faster and stronger secondary adaptive response that peaks within several days --> the rapid increase is called memory --> the finally the adaptive immunity is directed to outside agents that pose genuine threats

what occurs during antibody immune response ?

1. they antibodies must first bind to the antigen. 2. that reaction triggers, producing a battery of pathogen-derived peptide antigens 3. these peptides are then are complexed and presented to MHC II on the B cell to Th2-( TCR) 4. then cytokines send signals that stimulate antigen reactive B cells, which in turn respond by growing and dividing. establishing clones of the original antigen reactive B cell. 5. these B cells then differentate into plasma cells, which produce antibodies 6. Some of the activated B cells remain in the blood system as memory cells

What is Innate immunity ?

A.K.A. -> (nonspecific immunity) -->The noninducible ability to recognize and destroy an individual pathogen or its products -->Does not require previous exposure to a pathogen or its products -->Involves recognition of common pathogen-associated molecular patterns (PAMPs) on pathogens Mediated by phagocytes (Figure 24.3)

What are antibodies ?

Antibodies (immunoglobulins) are soluble proteins made by B cells in response to exposure to nonself antigens

what occurs in the primary adaptive immune response

Antigen contact stimulates growth and multiplication of antigen-reactive cells, creating clones, large numbers of identical antigen-reactive cells. These clones persist for years and confer long-ter, specific immunity

describe t-cell immunity/adaptive immnue response that causes inflammation

Antigen presenting cells (ex. phagocytes) ingest degrade and process antigens. ( which they recognize the antigen through (PAMPs) --> they then present the antigens to the T-cells who use their TCR to recognize the MHC II (protein found on the host cell) --> the Th1 helper cell will release cytokines ( which activates other cells --> This causes inflammation ( this is considered a indirect immune response

what are the functions of B-cells ?

B cells display antibodies on their cell surfaces that directly interact with antigens to cause B cells to ingest pathogen via phagocytosis. B cells then produce many pathogen-derived peptide antigens that are presented to antigen-specific Th2 cells (Figure 24.7)

What are the two types of lymphocytes ?

B cells originate and mature in bone marrow T cells originate in bone marrow, but mature in thymus

Where do B cell orginate from ?

B cells originiate and mature in the bone marrow

basophils

Basophils are chiefly responsible for allergic and antigen response by releasing the chemical histamine, which causes dilation of the blood vessels.

What activates the phagocyte to kill ?

Binding by phagocyte PRR activates the phagocyte to kill pathogen

What are Dendritic cells?

Dendritic cells function in phagocytosis and antigen presentation When they ingest antigen, they move to the lymph node to present antigen to T cells

In indirect immune response how are the cytokines produced?

Differentiated antigen-specific thQ cells interact with peptide-MCH II complexes on the surface of the macrophages. This interaction caues the Th1 cells to produce cytokines that actiavate the macrophages

Eosinophils

Eosinophils primarily deal with parasitic infections. They are also the predominant inflammatory cells in allergic reactions.

What happens wfollowing first antigen exposure ?

Following first antigen exposure, a primary immune response occurs Stimulation of specialized antigen-reactive immune leukocytes (lymphocytes: T and B cells) Each lymphocyte produces a unique protein that interacts with a single antigen T cells: T cell receptors (TCRs) B cells: antibodies or immunoglobulins (Igs)

IgA where?

IgA is found in secretions from mucous membranes

Where is IgD, found ?

IgD is found on surface of B cell

Where is IgD antibodies mostly found

IgD is found primarily as a surface immunoglobulin on B cells

This antibody is found in mast cells involved in parasite immunity and allergies

IgE

Secondary antibody response consists mostly of what antibody ?

IgG

Which antibodies are found in the blood ?

IgM and IgG

What are the different classes of antibodies ?

IgM and IgG are found in blood IgA is found in secretions from mucous membranes IgE is involved in parasite immunity and allergies IgD is found on surface of B cell

Primary antibody response consists mostly of which antibody

IgM antibodies

Th1 cells

Initiate inflammation and immunity by activating macrophages (Figure 24.6)

T-helper (Th) cells

Interact with peptide-MHC II complexes on the surface of antigen-presenting cells Act through cytokines to promote immune reactions

Describe inflammation

It is a nonspecific reaction to noxious stimuli. Redness, swelling, pain, and heat localized at site of infection. Effective inflammatory response isolates and limits tissue damage, destroying damaged cells and pathogens. Inflammation can result in considerable damage to healthy tissue

All cells display what protein that displays peptides from viruses

MHC1

molecular mediator

Molecular mediators of inflammation are proteins called cytokines and chemokines

what are monocytes ?

Monocytes are precursors of macrophages Large cells found in tissues such as lymph nodes and spleen

What do differented Th2 cells use cytokines for

they use it to stimulate antigen-reactive B cellsto produce antibodies

What are neutrophils ?

Neutrophils are the first to arrive at an infection --> they are attracted by interleukins Activated neutrophils release chemokines to recruit macrophages by guiding them along a chemokine gradient. Usually causing inflammation ( rapid localization and destruction of pathogen) --> Neutrophils are actively mobile granulocytes

does innate immunity require pervious exposure ?

No it doesn't

Are all antigens , immunogens

No they are not, Haptens are not immunogens, although they are antigens Complex proteins and carbohydrates are immunogens Large, complex macromolecules in insoluble or aggregate form are usually excellent immunogens

When can T-cells recognize antigens ?

Only when presented on self proteins called major histocompatibility complex (MHC) proteins

What do membrane bound phagocytes recognize?

PAMP's pathogen associated molecular patterns

What is a phagocytes ?

Phagocytes are cells found in the bloodstream and protect the body by ingesting and destroying foreign cells. These include, bacteria, dead or dying cells and other invading cells. They are part of the immune system. Chemical signals from invading cells are released and receptors on phagocytes detect these cells which are not "self" and they then proceed to engulf and destroy those cells.

who do phagocytes recognize pathogens ?

Phagocytes recognize a pathogen using pattern recognition receptors (PRRs)

What occurs in secondary adaptive immune response ?

Products of this secondary immune response quickly target the pathogen for destruction

T-cytotoxic (Tc) cells

Recognize antigen presented by MHC I protein on an infected cell Kill antigen-bearing target cells directly

Th2 cells

Stimulate antigen-reactive B cells to produce antibodies

What is the importance of Th2 cells in antibody immune response ?

Th2 cells stimulate the antigen-reactive B-cells.Those activated b-cells then differntite into plasma cells that produce soluble antibody response (primary antibody response) --Subsequent exposure to the same antigen induces memory (secondary antibody response)

Which white blood cells are phagocytes?

The professional phagocytes include many types of white blood cells (such as neutrophils, monocytes, macrophages, and mast cells) and dendritic cells.

What are myeloid cells

They are located in the red bone marrow. Myleoid cells include: monocytes,macrophages,neutrophils, basophils, eosinophils, erythocytes, dendritic cells (etc.)

Cytokines

They are soluble proteins that activate other cell types

How do T cells come about

They begin to develop in the bone marrow but travel to the thymus