Chapter 28&29 The Immune System

Antigens are best described as a. molecules that are recognized by specific antibodies b. highly conserved structures found on many microbes c. anything that prevents phagocytosis d. toxins

A

Which of these immune cells do NOT participate in antigen presentation? a. neutrophils b. T cells c. macrophages d. dendritic cells

A

What is the inflammatory response and what is its function?

A non-specific reaction to damage or an infection. It is the normal outcome of the immune response as it limits the growth of pathogens, limits damages to the host and can also repair the damage done.

Complement

A set of proteins in blood. Circulate in the precursor state. Can be activated in different ways: Classical Pathway- antibodies activate Alternative Pathways- by microbe features Lectin Pathways- by mannose Several functions- Kill microbes directly, attract immune cells, promote an very efficient form of phagocytosis

Adaptive Immunity

A subsystem of the overall immune system that is composed of highly specialized, systemic cells and processes that eliminate pathogens or prevent their growth.

Opsonization

An improved phagocytosis • Pore formation results in cell lysis • Can increase it up to 50 folds

What are the MHCI and MHCII molecules and which cell types have which? Which T cell proteins are involved in MHCI versus MHCII interactions?

Antigen Presenting Cells use MHC proteins to display antigens. Cytotoxic T-Cell Receptor recognize MHC1 and signals T cells to attack if necessary (Dendritic cells present forging antigen on MHC1 to CD8 T Cell. CD8 Cell is activated to cytotoxic T Cell) Antigen Presentation cells and B cells use MHC11 proteins

Antigen

Any molecule that elicits a specific immune response

Cytokines are best defined as a. small molecule inflammation inhibitors b. secreted proteins that are signaling molecules c. cell surface receptors that bind antigen d. host proteins that recognize MHCI and MHCII complexes e. blood proteins that can recognize pathogens

B

What is one purpose of MHCII antigen presentation? a. It alerts the immune system that a host cell contains intracellular foreign antigens b. It activates B cells to produce antibody c. It regulates neutrophil function d. it potentiates the action of cytokines

B

Which of these immune cells are NOT phagocytes? a. neutrophils b. mast cells c. macrophages d. dendritic cells

B

Identify the main tissues and organs of the immune system.

Bone Marrow and Thymus- where immune cells develop and mature Lymphatic System-Lymph vessels drain tissues to the lymph nodes. Lymph nodes are where immune cells interact Spleen-Filters blood and immune cells interact here

Recognition of pathogens by the innate immune system is mediated by ___________ and _________. a. antigens, antibodies b. MHC proteins, antigens c. pathogen associated molecular patterns (PAMPS), PRR d. complement, complement receptors

C

CD4 & CD8 Proteins

CD4's main role is to send signals to other types of immune cells, including CD8 killer cells, which then destroy the infectious particle.

What types of signals (be specific) can initiate the innate immune response?

Cells respond to damage in the body.

Which is NOT a primary role for macrophages? a. phagocytosis b. antigen presentation c. cytokine secretion d. antibody production

D

Which of the following is NOT considered a PAMP? a. lipopolysaccharide (LPS) b. bacterial flagella c. peptidoglycan d. all of the above are considered PAMPs

D

White blood cells (leukocytes) can be found in a. the blood b. the lymph nodes c. bone marrow d. the thymus e. all of these places

E

True/False. Dendritic cells are important for innate immunity but not for adaptive immunity. a. True b. False

FALSE

True/False. Although neutrophils are phagocytic cells, their main purpose is in antigen presentation. a. True b. False

False

Adaptive immunity: what is the basic sequence of events for B cell activation?

Helper T Cell is activated by the Class MHC11 molecule being presented on a antigen. The b cell then comes into play and either differentiates into plasma cells or memory cells to help kill the bacterium.

What are the major functions of the complement system?

Kill Microbes Directly- Membrane attack complex (MAC) proteins that assemble directly to the surface Attract Immune Cells- Chemo attractive peptides Promote Phagocytosis - helps improve phagocytosis

What is meant by specificity, tolerance, and memory in the adaptive immune response?

Memory- can hang out for years or decades and can quickly be called into action Tolerance to self- don't react to your self

Innate Immunity

Natural Response that can trigger an adaptive immune response

Know the following cell types and their main roles in the immune response: Neutrophils, Macrophages, Dendritic cells, B cells, T cells (both helper T and cytotoxic T).

Neutrophils- Circulate in the blood until recruited to the site of infection. Function: Phagocytosis Abundant and Short Lived. Macrophages- Circulation of blood as monocytes or migrate to tissues and mature to macrophages Function: Phagocytosis, Cytokine Secretion, Antigen Presentation Dendritic Cells- Located in the tissue Function: Antigen Presentation to initiate adaptive immune response T Cells found in the lymph nodes Helper T- Activate other immune cells Cytotoxic T Cells -Kill infected host cells B Cells- lymph nodes Function: when activated by antigen and T cell, they differentiate to plasma cells and produce antibodies Some can be activated as memory cells for later use.

13. Be able to describe the main structural features of antibodies, and understand F(ab) and F(c) regions, variable and constant regions.

Proteins that recognize and bind to antigens Immunoglobulins 4 polypeptides- 2 light and 2 heavy chains F(ab) is highly variable between antibodies F(c) consistently binds to Fc receptors on phagocytes Various cells of the immune system produce specific binding sites for each molecule. High level of specificity.

What are the main functions of antibodies?

Proteins that recognize and bind to antigens. Neutralization Opsonization Complement Activation Agglutination

What is the basic sequence of events in the innate immune response? How does this work to control the pathogen?

Recognition- Damage is indicated Response- Phagocytes recognize pathogens Result- Inflammation controls the pathogen and has potential to damage host

How do TC cells recognize host cells for killing?

Recognize infected host cells via MHC1 display on the cells and then kills the infected cell

Adaptive immunity: what is the basic sequence of events for cytotoxic T cell activation?

Recognize infected host cells via MHC1 displayed on a cell. Then goes on to kill infected cells.

Cytokine

Secreted Immune Communication Proteins

Give examples of preformed "barrier" defenses.

Skin and mucosal surfaces are physical barriers and produce antimicrobial substances Mucus is able to trap microbes and remove them Normal Microbiota prevent colonization Blood proteins kill microbes

Be able to explain herd immunity and why it is important.

The number needed to protect a population from experiencing an outbreak of the virus. There is no magic number it is different for every pathogen.

Epitope

The part of an antigen molecule to which an antibody attaches itself. An antigen can contain multiple

What is antigen presentation? What is its purpose?

The process by which immune cells capture antigens and then enable their recognition by T cells.

True or False. The Fab region of an antibody protein is the variable region. a. True b. False

True

Antibody

Used by the immune system to neutralize pathogens.

Lymph Node

Where the immune cells interact

During inflammation, increase in vascular permeability is thought to a. facilitate entry of neutrophils to the infection site b. promote the interferon response c. remove pathogen cells by dilution d. promote macrophage activation

a

The molecules that define a host cell as "self" are a. major histocompatibility type I (MHCI) proteins b. major histocompatibility type II (MHCII) proteins c. pattern recognition receptors (PRRs) d. cytokine profiles

a

Lymphocyte

a form of small leukocyte (white blood cell) with a single round nucleus, occurring especially in the lymphatic system.

Plasma Cell

a fully differentiated B cell that produces a single type of antibody.

Microbe Associated Molecular Pattern

are molecules associated with groups of pathogens, that are recognized by cells of the innate immune system.

Neutrophils are leukocytes that ____________________ but do NOT _______________________. a. produce cytokines, phagocytose pathogens b. develop from monocytes, circulate in the bloodstream c. phagocytose pathogens, present antigen to T cells d. present antigen to T cells, produce cytokines

c

Which is considered to be the link between the innate and adaptive immune systems? a. antibody production b. complement c. antigen presentation d. inflammation

c

Which of the following is a role for the complement system (any of its parts)? a. direct microbial killing b. opsonization of pathogens c. immune cell chemoattraction d. all of the above

d

Be able to describe how a vaccine works.

mimicking disease agents and stimulating the immune system to build up defenses against them

Pattern Recognition Receptor

play a key role in the innate immune response by recognizing conserved pathogen associated molecular patterns (PAMPs) which are unique to each pathogen, and are essential molecular structures required for the pathogens survival.

What is the overall process of phagocytosis?

process by which a cell engulfs a particle or other cell by surrounding it with its cell membrane