Chapter 14 micro- Innate Immunity

phagosome maturation and phagolysosome formation

-membrane-bound bodies within phagocyte come in contact with and then fuse with phagosome: neutrophils have granules, macrophages have lysosomes, regardless of cell type resulting structure termed *phagolysosome*

B cells

type of lymphocyte programmed to make antibodies

natural killer cells

type of lymphocyte that induces apoptosis in cells to which antibody has bound or that lack MHC class 1 molecules on the surface and are stressed

macrophage

type of phagocytic cell that resides in tissues and has multiple roles, including scavenging debris and producing pro-inflammatory cytokines

pyroptosis

type of programmed cell death that elicits an inflammatory response

The complement system components react

In a cascade

Which role does histamine play during inflammation?

It leads to vasodilation

NOD-like receptors (NLRs)

Large family of proteins containing a nucleotide-oligomerization domain (NOD) associated with various other domains, and whose general function is the detection of microbes and of cellular stress.

A ______ contains hydrolytic enzymes to digest foreign bacteria

Lysosome

The microbe is digested within the phagocyte by enzymes delivered by a _______.

Lysosome

giant cells

very large cells with many nucleic, formed by the fusion of many macrophages during a chronic inflammatory response; found in granulomas

PAMPs (pathogen-associated molecular patterns)

Molecules associated with groups of pathogens that are recognized by cells of the innate immune system. not exclusive to pathogens

______ are the precursors to macrophages.

Monocytes

Which cell type is capable of phagocytosis?

Neutrophils and macrophages

granulocytes

wbc characterized by the presence of prominent granules; types include basophils, eosinophils, and neutrophils

After being engulfed, a microbe is found within a _______.

Phagosome

Activated complement proteins play a part in eliminating microbial invaders from a host. They belong to the group of non-specific immune responses. Which of these is NOT part of that group?

Plasma cells

The complement system comprises a group of ______ found in the bloodstream.

Proteins

cytokines

Proteins that function as chemical messengers, allowing cells to communicate

leukocytes

white blood cells

Complement proteins are found in

Serum

What is the function of selectins?

They promote sticking of neutrophils to the inner vessel wall

Complement factor C3b coats a bacterium and binds to C3b receptors on phagocytes, making the bacterium more susceptible to being phagocytized.

True

If a bacterium could escape from a phagosome, it would be able to resist digestion by that phagocyte.

True

It is possible for one host to be resistant to infection by a pathogen that can normally cause disease in a different host.

True

Margination occurs when neutrophils stick to the lining of the endothelium.

True

Phagocytosis is part of the body's innate immune defenses

True

The symptoms of inflammation are mostly due to ______.

Vasodilation

antibodies

Y-shaped glycoproteins made by B cells of the immune system in response to the presence of an antigen.

Innate lymphoid cells

a group of lymphocytes that lack specificity in their mechanism of antigen recognition; includes natural killer cells

Toll-like receptors (TLRs)

a group of pattern recognition receptors located on the surface of cells and within endosomes

lymphocytes

a group of wbc involved in adaptive immunity; B cells and T cells are examples

adhesion molecules

a molecule on one cell surface that interacts with a counter molecule on another cell causing cells to adhere together

fever

an increase in internal body temp to 37.8 degrees C

dendritic cells

antigen-presenting cells that play an essential role in the activation of naive T cells

Pro-inflammatory cytokines

any of a group of cytokines that contribute to the inflammatory response

recognition and attachment

bind directly or indirectly

C3b

binds to the surfaces of microorganisms and phagocyte receptors.

hematopoietic

bone marrow cells that give rise to all blood cells

phagocytes

cell type that specializes in engulfing and digesting microbes and cell debris

Damage-associated molecular patterns (DAMPs)

characterize damaged tissues

inflammatory mediators

chemicals such as histamine that trigger an inflammatory response when released from cells, inducers are microbes and tissue damage

granulomas

collection of lymphocytes and macrophages that accumulate in certain chronic infections; an attempt by the body to wall off and contain persistent organisms and antigens

membrane attack complex (MAC)

complement system components assembled to form pores in membranes of invading cells

inflammatory response

coordinated response with the purpose of containing a site of damage, localizing the response, eliminating the invader, restoring tissue function

The membrane attack complex kills cells by

creating holes in cell membranes

chemokine

cytokine important in chemotaxis of cells of the immune system

interleukins (ILs)

cytokines produce by leukocytes; they have diverse overlapping functions

interferons (IFNs)

cytokines that induce cells resist viral replication they also help regulate the immune response

interferons (IFNs)

cytokines that induce cells to resist viral replication, they also help regulate the immune response

antimicrobial peptides (AMPs)

defensins and other short chains of amino acids that have antimicrobial properties

destruction and digestion

destroy an invador

The three primary functions of complement activation are

enhancing phagocytosis, causing inflammation, and killing target cells

peroxidases

enzymes found in neutrophil granules, saliva, and milk that react q/ hydrogen peroxide to form antimicrobial compounds

Phagocytes are attracted by all of the following EXCEPT

enzymes released by lysosomes.

pyrogens

fever-inducing substances

Hematopoiesis

formation and development of blood cells

RIG-like receptors (RLRs)

found in cytoplasm, detect viral RNA indicating infection, produce interferons

sentinel cells

help the immune system detect signs of invasion by providing cytokines when their pattern recognition receptors recognize an invading microbe

innate immunity

host defenses involving anatomical barriers, sensor systems that recognize patterns associated with microbes or tissue damage, phagocytic cells, and the inflammatory response

host cell

in immunology one of the body's own cells; self cells

iAVPS

inactive antiviral proteins can be activated by viral dsRNA

transferrin

iron-binding protein found in blood and tissues

lactoferrin

iron-binding protein found in milk, saliva, and mucus

basophils

leukocyte with large dark-staining granules that contain histamine and other inflammatory mediators; bind to IgE

chronic inflammation

long-term inflammatory response, marked by prevalence of macrophages, giant cells and granulomas

activated macrophages

macrophages stimulated by ingesting Ag or by cytokines, greatly increased capability to kill and degrade intracellular

opsonin

molecule such as the complement system component C3b and certain antibody classes that binds to invading particles, making it easier for phagocytes to engulf them

microbe-associated molecular patterns (MAMPs)

molecules that characterizes invading microbes

mononuclear phagocytes

monocytes and macrophages

monocytes

mononuclear phagocytes of the blood; part of the mononuclear phagocyte system of professional phagocytes

Extravasation, also known as diapedesis or transmigration, occurs when

neutrophils squeeze through the blood vessel wall.

alternative pathway

pathway of complement activation initiated by the binding of a complement protein (C3b) to cell surfaces

classical pathway

pathway of complement system activation initiated by antibodies binding to antigens to form immune complexes, requires antibodies

lectin pathways

pathway of complement system activation initiated by binding of mannose-binding lectins to microbial cell walls

Phagocytosis

process in which extensions of cytoplasm surround and engulf large particles and take them into the cell

adaptive immunity

protection provided by host defenses that develop throughout life, involves B cells and T cells

inflammasome

protein complex in macrophages that activates a potent pro-inflammatory cytokine, thereby initiating an inflammatory response

pattern recognition receptors (PRR)

protein on or in cells that recognize specific compounds unique to microbes or tissue damage

surface receptors

proteins in the membrane of a cell to which certain signal molecules bind; they allow the cell to sense and respond to external signals, eyes and ears

engulfment

pseudopods surround, form phagosome

Chemotaxis

recruited to site of infection or tissue damage

erythrocytes

red blood cells

exocytosis

releases debris with cytoplasmic membrane

complement system

series of serum proteins involved with innate immunity they can be rapidly activated, contributing to protective outcomes including inflammation, lysis of foreign cells and opsonization

complement system

series of serum proteins involved with innate immunity; they can be rapidly activated, contributing to protective outcomes including inflammation, lysis of foreign cells, and opsonization

inflammation

set of signs and symptoms (swelling, redness, heat, and pain) that characterizes an innate immune response to infection or injury

actue inflammation

short-term inflammatory response, characterized by an abundance of neutrophils

tumor necrosis factor (TNF)

A cytokine that plays an important role in the inflammatory response and other aspects of immunity- cell suicide

colony-stimulating factors

A group of cytokines that direct development of various types of blood cell from hematopoietic stem cells

ligand

A molecule that binds specifically to another molecule, usually a larger one.

Antigen

A molecule that the immune system recognizes either as part of the body or as coming from outside the body. reacts specifically within an antibody or lymphocyte

T cells

A type of lymphocyte responsible for cell-mediated immunity that differentiates under the influence of the thymus.

Eosinophils

A type of white blood cell with low phagocytic activity that is thought to play a role in defense against parasitic worms by releasing enzymes toxic to these invaders.

Which of the following is NOT a function of inflammation?

Activate the complement system

Phagocytosis can be enhanced by immunological mediators such as ______.

Activated complemented proteins

Which of the following antimicrobial substances are not part of our body's first line defenses?

Antibodies

first-line defenses

the barriers that separate and shield the interior of the body from the surrounding environment

Which of the following is part of the body's adaptive defense?

B cells

How are microbes killed and digested in the phagolysosome?

By hydrolytic enzymes

The classical complement pathway is activated when

C1 binds to the antibody in an antigen-antibody complex

Both the classical and alternative complement pathways create

C3 convertase.

C3 convertase cleaves C3 into

C3a and C3b

The membrane attack complex is made from

C5b, C6, C7, C8, and C9.

Tissue injury leading to inflammation can be due to

Chemical injury, Infection, Mechanical injury

Which event occurs in the early stages of inflammation?

Chemical mediators and cytokines are released from injured cells.

What is the name of the process by which phagocytes move towards microbial products?

Chemotaxis

The four classic signs and symptoms of inflammation include all the following EXCEPT

Chills

Which of the following is part of the body's sensor systems?

Complement proteins

phagocytosis

the process by which certain cells inject particulate matter by surrounding and enveloping those materials, bringing them into the cell in phagosome

opsonization

Enhanced phagocytosis caused by coating of a particle with an opsonin

In phagocytosis, the digested contents are eliminated by ______.

Exocytosis

Mitochondria contain hydrolytic enzymes.

False

The complement system is part of the specific immune response.

False

mast cells

tissue cells similar in appearance and function to basophils of the blood, with receptors for IgE, inflammatory