BIO 207 Exam 3

Skin & Mucosal System Defenses

tight junctions in epithelial tissue, mucus

Diet and drugs

Can alter normal flora

Antimicrobial secretions

lysozyme, defensin proteins, blood proteins, fatty acids

bacteria, saliva, tears

Lysozyme and other enzymes kill ___ in ____ and _____

insert, membranes

Defensin proteins ______ in microbial ________

sequester

Blood proteins _______ nutrients

lower

Fatty acids on skin ____ pH

cilia/mucus movement and urine flushing

Physical removal (general defense)

closed

Blood is a ______ loop powered by the heart

drainage system

Lymph is a _________ returning tissue fluid to blood

one-way, chest

______ valves keep lymph moving to ______

Extravasation

white blood cells move in and out of lymph

thymus, bone marrow, develop

The ______ and ______ are primary organs/tissues, where lymphocytes ______

spleen, lymph nodes, tonsils, adenoids, appendix, collect

The ______, ______, ________, ________, ______ are secondary organs/tissues, where lymphocytes ______

SALT, MALT, GALT

skin, mucus, gut-associated lymphoid tissue

M cells

monitor flora

skin, tonsils, adenoids, intestines

Organs/tissues with M cells

Erythrocytes, enucleated

______ are red blood cells. They are not a part of the immune system. They are _______ and carry oxygen

Platelets

involved in clotting

Leukocytes

White blood cells

Monocytes, dendritic cells, macrophages- phagocytic, antigen-presenting cells (APCs)

Types of white blood cells (there are 4 listed)

engulf, display, peptides

White blood cells _____ foreign cells, viruses, proteins

Break these down & ______ foreign ______ on their surface

Monocytes

WBC that circulate blood

Dendritic cells and macrophages

WBC that attach to different tissues

neutrophils, eosinophils, basophils

types of polymorphonuclear leukocytes (PMNs or granulocytes, in blood)

phagocytic, migrate

neutrophils are _______ cells that ______ to the site of infection

Neutrophil Extracellular Trap (NET)

used by neutrophils to kill cells

Eosinophils

anti-protozoan secretions

Basophils

inflammation mediator

Mast cells

mediate inflammation throughout body, not in blood

Lymphocytes, cancerous, spleen, T, B

_______ are natural killer cells- kill infected or ______ cells

mostly in ____ and lymph nodes

includes ___ cells and ____ cells

T cells

central to adaptive immunity

B cells

part of adaptive immunity, produce antibodies

Plasma proteins, fibrinogen, sequestration

________ are soluble in fluid portion of blood

Consist of: ______ for clotting and antibodies

Iron ______ and other antibacterial proteins

Inflammatory response

a non-specific response to wounds and infection

macrophages, cytokines,

Inflammatory response process:

Resident _______ engulf pathogens and release ______ (chemical alarm signals)

Vasoactive factors and [blank #2] help deliver additional phagocytes

Some [blank #2] initiate healing as pathogens are destroyed

signals, toll, nod, transcription, cytokines

Detection:

Triggered by unique _____ of invader (MAMPs, microbe-associated molecular patterns)

bind to ____-like receptors (in membrane) or _____-like receptors (in cytoplasm)

cause _____ and release of _____

platelets, contain

Clotting factors released by _____ and attempt to ______ infection

phagocyte, self-antigen, leukocytes, cytokines

Phagocytosis:

_______ (macrophage) engulfs microbe

invader is recognized because it does not have ________ (CD47)

microbe is killed/digested in phagolysozome

peptides from invader may be displayed on phagocyte surface

peptide release can stimulate/attract other ________

macrophages also release (and are activated by) ________

capsule

Some pathogens can avoid being engulfed because of _____

increase, opsonization

Antibodies can ______ phagocytosis (________)

antigen presentation

displaying of peptides from invader on phagocyte surface

Extravasation

brings neutrophils from nearby capillaries

endothelial, selectins, integrin, bradykinin, histamines, vasodilation, permeability, edema, prostaglandin

Extravasation:

Cytokines cause local _____ cells to make _____

[blank #2]/_____/ICAM-1 retain passing neutrophils from circulating blood

_____ from damaged host cells loosens connections between [blank #1] cells

allows neutrophils to squeeze out

triggers mast cells to release ________

causes ______ (blood volume increases), bringing more cells

vessel wall _______ increases, leading to ______ (fluid buildup)

triggers _____ release —> pain

blood, temperature, isolate

Benefits of inflammation:

increased ______ volume brings in more antimicrobial agents

increased ______ makes phagocytes more efficient, may inhibit bacteria

clot may ______ area of infection

nutrients, bacterial, blood vessels, host

Downside of inflammation:

may release ______ & promote ______ growth

microbe can gain access to further tissue via ________

high fever can harm ______

chronic inflammation damages host tissue

serum, antibodies, cascade, active, inactive

Complement system:
_____ proteins that can work with or independent of ______ to kill bacteria (cytoplasm leaks out and proton gradient cannot be maintained)

______ of protein interactions leads to pores forming in bacterial membrane

Presence of bacteria converts these proteins into their _____ form (exist in blood as _____)

Activated by binding to bacterial cells (LPS) directly or by antibodies sticking to complement cells 

Antibodies

secreted proteins that bind antigen

light, heavy, constant (C), variable (V), antigen

Antibody structure:

four polypeptide chains, 2 ____ & 2 ____, held together by disulfide bonds

each chain has ______ and _____ regions

on a given antibody, all binding domains bind the same _____

C regions

the same for that individual/chain (allotype) and class (isotype)

V regions

unique to each antibody (idiotype)

antigen binding domains

formed by V regions of 1 H and 1 L chain

antigen

whatever antibody binds to, usually protein (carbohydrate, lipid, DNA)

epitope

the specific part of the antigen being bound

bivalent, blood serum

IgG:

_____ antibody (will bind 2 of the exact same antigen)

found in _______

classic Y-shape

longer, first, bind, presentation

IgM:

five antibody proteins held together

_____ constant domain

generally the ____ Ig made in immune response

IgM monomers in B cell membrane ____ antigen, help bring it in for _______

body secretions

IgA:

two antibodies held together

common in __________ (tears, breast milk, mucus, etc.)

longer, mast, allergic

IgE:

______ constant domain (has CH4)

binds to ____ cells

important in _____ reactions

IgD

helps antigen bind to B cells

Major Histocompatibility Complex (MHC) proteins

exist in plasma membrane of host cells

unique to individual, help determine "self" (HLA type)

two types, both will bind and display antigens

nucleated, alerts, infected cell

MHC I cells:

present in all _____ cells in the body

_____ immune system that the cell is infected

tells immune system to kill _________

takes proteins in the cell and puts them on the surface (holds them there)

B, APCs, activate

MHC II cells:
unique to ___ cells and _____

tells other immune cells that [blank #2] has found a foreign antigen

tells immune system that it found something and to _____ against it

T cell receptor (TCR)

structurally similar to MHC but only found on T-cells

each type will bind only one antigen (with limited cross-reactivity to others)

variable region is different in each cell, ensuring a range of binding specificities

B cell receptor (BCR)

classic antibody sitting in membrane of a B cell

antibodies are secreted by activated B cells

has extra domain in tail to insert into membrane

antigen presentation

I- viruses, cancer; II- proc. antigen

N/A

N/A

N/A

Macrophages dendritic cells receptor interactions:

cell function:

MHC displays:

receptor:

co-receptor:

binds to:

activate other immune cells

I- viruses, cancer

TCR

CD4

MHC II/antigen

helper T cells (T H) receptor interactions:

cell function:

MHC displays:

receptor:

co-receptor:

binds to:

kill infected host cells

I- viruses, cancer

TCR

CD8

MHC I/antigen

Cytotoxic T cells (T C) receptor interactions:

cell function:

MHC displays:

receptor:

co-receptor:

binds to:

antibody production

I- viruses, cancer; II- proc. antigen

BCR

N/A

intact antigen

B cells receptor interactions:

cell function:

MHC displays:

receptor:

co-receptor:

binds to:

N/A

I- viruses, cancer

N/A

N/A

N/A

Body cells receptor interactions:

cell function:

MHC displays:

receptor:

co-receptor:

binds to:

internal, MHC I

All cells display _______ antigens in ______

foreign, T C

if antigens are ______ (viral or cancerous) → activate ______ (cell-mediated immunity)

external, MHC II

only "true" APCs (dendritic cells, macrophages, B cells) process ______ antigens

take in, break down, and display antigens on surface of APC in ______

size, complexity, dosage

Immunogenicity of antigen depends on:

exceeding minimum ____ (5-100 a.a.?)

molecular _______ (proteins > carbohydrates > lipids & nucleic acids)

form (soluble or insoluble)

_____ (not too high, not too low)

route of introduction (injection better than ingestion)

self/non-self (self should not provoke immune response)

antigenic determinant

response is only to small part of immunogen (4-6 a.a.)

called ________ or epitope

a single protein has hundreds of potential epitopes

T-helper cells, T-cytotoxic cells, and B-cells

3 types of cells activated by antigen-presenting cells (APCs)

MHC II, proliferating, differentiating

T-helper cell (TH0) activation:

Signal 1.) TCR fits this particular antigen held in an _____

Signal 2.) TCR CD28 binds to APC’s B7 (serves as confirmation signal)

Signal 3.) Once it is activated, it will start ________ and ___________ (going from TH0 to a different type of TH) and move out into the body looking for infected cells

Cell-Mediated Immunity

effective against virally infected cells or cancerous host cells

operates via activated cytotoxic T-cells (TC)

MHC I, cytokines, T-helper

Cytotoxic T-cell (TC) activation:

Signal 1.) TCR fits this particular antigen held in an _____

Signal 2.) TCR CD28 binds to APC’s B7 (serves as confirmation signal)

Signal 3.) _______ release by an activated ______ cell

activated TC kills infected host cells

capping, free-floating, T-helper cells, plasma

B-cell activation:

can be activated in two ways

• ______ 

  • antigen binds to more than one BCR on its surface

  • they start clustering together

  • binding lots of antigen on their surface

  • change from ______ to clusters is the signal that causes it to activate

• interaction with _________

  • BCR detects something in macrophage’s MHC II that matches the T-cell receptor 

  • confirmatory signal

  • causes B-cells to differentiate into ______ cells (secrete antibodies) and memory cells

antibody/receptor diversity, clonal, deletion

What the immune system can do:

 respond to anything, even if never encountered before (__________)

 strengthen its response upon encountering something (______ proliferation and memory)

 discriminate between self and non-self (clonal _______)

TCR and CD8

how does TC cell bind to virally infected cell to kill it?

TH2 cell

induces differentiation of B-cell

Virus/toxin neutralization

bind to viral surface or toxin

 prevent intended interaction of virus or toxin with host

clump, precipitate

Agglutination/Precipitation:

_____ antigens together

will ______ soluble antigen and agglutinate (clump) cells

allows rapid detection of some infectious agents

cleavage, inflammation, positive

Activate complement system of proteins:

antibody bound to bacterial cell surface triggers binding/_______ of complement proteins

cleaved complement proteins cause _______

other fragments of complement proteins insert into membrane

pores form, cell dies

doesn't work for Gram ________

Opsonization

antibodies and complement on cell surface "flag" cell for phagocytosis

works for all bacteria

can also clump cells or toxin molecules leading to easier phagocytosis

DNA segments

Antibody diversity is created by uniquely splicing ___________ in each B cell

(even more variation because of imprecise joining of segments + high mutation rate during B cell proliferation)

Natural active immunity

disease exposure

infection leads to immune response, boost in memory cells (takes weeks)

second exposure results in stronger, faster response

Artificial active immunity

vaccination

vaccination leads to immune response (takes weeks)

whole organism- killed or attenuated

subunit- natural, modified or recombinant

hapten + carrier molecule- when antigen is too small on its own

second exposure (or booster) results in stronger, faster response

Natural passive immunity

maternal immunity

antibodies are received from mother through placenta, breast milk (instant protection)

no host immune response, no boost for later exposure

Artificial passive immunity

antitoxins

injection of antibodies from another individual or animal (instant protection)

used against toxins

no host immune response, no boost for later exposure

Allergies

an overreaction of the immune system

Autoimmune diseases

the immune system attacks self-antigens

Superantigens

can activate T cells indiscriminately and destabilize the system

deleted

During embryonic/neonatal development, B & T cells that bind antigen (presumed to be self) are _______

bone marrow, thymus

B cells mature in _______

T cells mature in _______

MHC, antigen

if maturing cell does not react with _____, it dies

if maturing cell does react with ______, it dies

macrophages, dendritic cells, and TH cells (immune system cells)

HIV attacks CD4+ cells, which include: ________, ________, ________

Without [blank #3], cannot amplify TC cells or B-cells and entire immune response collapses

detection, identification

Quick _______ and _______ of pathogens is critical to effective treatment

site, contamination, normal flora, oxygen

Proper sampling & handling of samples:

must take sample from ____ of infection

may be swab, blood, fluid or stool collection

include precautions to prevent ________

must not contaminate with _________ (if possible)

must be mindful of _______ tolerance of suspected pathogens