Exam 1 Flashcards
(INTRACELLULAR/EXTRACELLULAR) microbes are able to survive in animals by growing extracellular being simply immersed in nutrients.
Extracellular
(INTRACELLULAR/EXTRACELLULAR) microbes invade and live and replicate within animal cells where they utilize host-cell energy sources.
Intracellular
This is the term for a set of cooperative defense mechanisms which provide protection from various infectious diseases.
Immunity
An immune response against microbes can cause tissues injury (immunopathology), let’s call it “______ ______”.
Collateral damage
Noninfectious foreign substances called _______ can also elicit an immune response.
Antigens (Ags)
In some pathological conditions, self Ags in the body can elicit an _________ response.
Autoimmune
Antigens (Ags) are defined as substances (either microbial or nonmicrobial) that induce an immune response. Ags can include…
Proteins
Carbohydrates
Lipids
Nucleic acids
Each ______ has many microbial Ags which can be recognized by the immune system.
Microbe
An _______ is a protein induced by the immune system when it detects antigens.
Antibody (Ab)
An _______ (also called an antigenic determinant) is a portion of an Ag molecule to which an antibody binds.
Epitope
The (SMALLEST/LARGEST) epitope (antigenic determinant) to which an antibody can be made is about 3-6 amino acids or about 5-6 sugar residues.
Smallest
An Ag may contain a number of different epitopes to which individual responses (_______ or ______) are made.
Antibodies
T cells
All large molecules have (ONE/MULTIPLE) epitopes.
Multiple
Abs bind to conformational antigenic epitopes which are dependent on the ________ of the molecule.
Folding
T cell receptors recognize _______ amino acid sequences.
Linear
Ags which can stimulate an immune response are also called…
Immunogens
All (IMMUNOGENS/AGS) are (IMMUNOGENS/AGS), but not all (IMMUNOGENS/AGS) are (IMMUNOGENS/AGS).
Immunogens; Ags
Ags; Immunogens
Some very small Ags called ______ can bind to Abs but they cannot initiate an immune response.
Haptens
(ADAPTIVE/INNATE) immunity is the first line of defense against infection that:
- Works rapidly
- Gives rise to an acute inflammation
- Has some specificity for Ag
- Has no memory
Innate
(ADAPTIVE/INNATE) immunity:
- Takes longer to develop
- Is highly specific (ensures that the immune response to a microbe or nonmicroblal Ags is selective to that microbe or Ag
- Shows memory (remembers Ag it has encountered previously)
Adaptive
This type of immunity develops within hours and includes phagocytes, natural killer cells, and blood components.
Innate
This type of immunity develops within days or weeks and includes the generation of specific receptors.
Adaptive
This component of innate immunity are small peptides which target pathogenic microorganisms ranging from viruses to parasites.
Antimicrobial peptides
This component of innate immunity is a system of plasma proteins that enhances the ability of Abs and phagocytic cells to clear pathogens from an organism.
Complement
This component of innate immunity are a large group of blood proteins whose plasma concentrations change in response to tissue injury, acute infections, burns, or inflammation.
Acute phase proteins (APPs)
This component of innate immunity are cell signaling molecules that aid cell to cell communication in immune responses.
Cytokines
This component of innate immunity are a subfamily of cytokines secreted by immune cells to induce chemotaxis (movement) in nearby cells.
Chemokines
This component of innate immunity are immune cells that have the ability to ingest and digest microbes.
Phagocytes
Blood proteins including complement, acute phase proteins, cytokines, chemokines, and others are all part of innate immunity. Specifically, they are _______ innate immunity.
Humoral
Cells contain components such as phagocytes (macrophages, neutrophils), dendritic cells, natural killer cells, and innate lymphoid cells that are part of innate immunity. Specifically, they are _______ innate immunity.
Cellular
What are the cellular and chemical barriers for innate immunity?
Skin
Mucosal epithelia
Antimicrobial peptides
What are the cellular and chemical barriers for adaptive immunity?
- Lymphocytes in epithelia
- Antibodies secreted at epithelial surfaces
For ________ immunity, there are blood protein components such as antibodies and cytokines.
Adaptive
For ________ immunity, there are cell components such as B and T lymphocytes.
Adaptive
In (INNATE/ADAPTIVE) immunity there is specificity for molecules (Ags) shared by groups of related microbes and molecules produced by damaged host cells.
Innate
In (INNATE/ADAPTIVE) immunity there is specificity for microbial and nonmicrobial agents.
Adaptive
In (INNATE/ADAPTIVE) immunity there is limited diversity, the germline is encoded.
Innate
In (INNATE/ADAPTIVE) immunity the diversity is very large. Receptors are produced by somatic recombination of gene segments.
Adaptive
Which type of immunity has memory?
Adaptive
T/F. Both innate and adaptive immunity are reactive to themselves.
False. They have no reactivity to self.
The innate and adaptive immune systems work (TOGETHER/SEPARATELY).
Together
T/F. Many cells and molecules of the innate immune system are also used by the adaptive immune system and vice versa.
True
In addition to inflammation, the innate immune system is a “______-______ ______” of an immune response.
Decision-making stage
Innate immunity “evaluates” the invader in the context of _______ vs. ______ microbes and then provides the instructions to adaptive immunity.
Extracellular
Intracellular
The immune system “sees” pathogens as intracellular or extracellular by the components present. What components are these?
Intracellular – Neutrophils (polymorphonuclear cells)
Antibodies
Extracellular – Cytotoxic T cells (CTLs)
Natural Killer cells (NK cells)
Macrophages
Cells communicate through direct cell-to-cell contacts and through interactions involving _______ and _______.
Cytokines
Chemokines
_______ are a large group of small secreted proteins with diverse structures and functions, which regulate and coordinate many activities of the cells of innate and adaptive immunity.
Cytokines
Functions of cytokines include –
- Regulate _______ and _______ of all immune cells
- Activate the _______ functions of lymphocytes and phagocytes.
Growth; Differentiation
Effector
Each cytokine acts via a specific ________ receptor expressed on target cells.
Signaling
________ are a large subset of structurally related cytokines that regulate cell migration and movement.
Chemokines
The primary function of these is to ingest and destroy microbes and get rid of damaged tissues (scavenger function).
Phagocytes
Phagocytes include _______ and _______.
Neutrophils
Macrophages
The steps in functional responses of phagocytes include:
1) _______ of the cells to the sites of infection
2) _______ recognition of and activation by microbes
3) _______ of the microbes by the process of phagocytosis
4) _______ of ingested microbes
Recruitment
Recognition
Ingestion
Destruction
This type of cell is called polymorphonuclear leukocytes because their nucleus is segmented into 3-5 connected lobules.
Neutrophils
These are the most abundant population of circulating spherical white blood cells of 12-15 um in diameter.
Neutrophils
These cells mediate the earliest phases of inflammatory reactions.
Neutrophils
Neutrophils are produced in the ______ ______ and arise form precursors that also give rise to mononuclear phagocytes.
Bone marrow
Production of neutrophils is stimulated by cytokine called…
Granulocyte colony-stimulating factor (G-CSF)
An adult human produces more than ______ neutrophils per day, and circulate in the blood for hours or a few days. After entering the tissues, neutrophils function only for 1-2 days and then die.
1x10(11)
The mononuclear phagocyte system includes circulating ________ and resident tissue ________ (play central roles in innate and adaptive immunity).
Monocyte
Macrophages
Many tissues are populated with long-lived resident ________, which assume specialized phenotypes depending on the organ.
Macrophages
Cells of the macrophage lineage arise from committed precursor cells in the ______ ______, driven by monocyte/macrophage colony-stimulating factor (M-CSF).
Bone marrow
Mature monocytes enter the blood circulation and then migrate into tissues, where they further mature into macrophages, especially during _________.
Inflammation
Tissue-resident ________ are a heterogenous population of immune cells that fulfill tissue-specific and niche-specific functions.
Macrophages
Macrophage functions include –
- Dedicated _______ functions, such as clearance of cellular debris and iron processing
- Central roles in tissue immune _______
- Response to ________
- Resolution of ________
Homeostatic
Surveillance
Infection
Inflammation
These are cells of innate immunity that comprise a diverse group of professional antigen presenting cells (APCs).
Dendritic cells (DCs)
DCs share a particular morphology - long surface membrane extensions called _______.
Dendrites
DCs are potent stimulators of ______ to induce the adaptive immunity.
T cells
DCs can be broadly divided to _______ and ________ DCs.
Myeloid (mDCs)
Plasmacytoid (pDCs)
mDCs (myeloid dendritic cells) are derived from monocytes and differentiated from ______ ______ _______ cells.
Peripheral blood mononuclear cells (PBMCs)
Other DC subpopulations include _______ cells residing in the epidermis of the skin.
Langerhan’s (LCs)
These cells play roles in innate and adaptive immune responses and protect against helminthes and reactions that cause allergic diseases.
Mast cells
Basophils
Eosinophils
These cells share the common feature of having cytoplasmic granules filled with various inflammatory and antimicrobial mediators.
Mast cells
Basophils
Eosinophils
These cells are common at sites in the body that are exposed to the external environment, such as the skin.
Mast cells
Mast cells are found in close proximity to ______ ______, where they can regulate vascular permeability and effector-cell recruitment.
Blood vessels
Although mast cells do not have direct cell-to-cell contact with local populations, mast cells can modulate the behavior of these and other neighboring effector cells through the release of _______.
Mediators
There are two major types of lymphocytes, ______ and ______.
B cells
T cells
Interaction between T cells and B cells, as well as between T cells and ______-______ cells, are critical to the development of specific immunity.
Antigen-presenting (APCs)
The development and maturation of T cells occurs in the ______. When mature T cell is Ag-stimulated it gives rise to _______ immunity.
Thymus
Cellular
The development and maturation of B cells mature mainly in the _____ _____ and give rise to ______ immunity, immunity that involves production of soluble molecules, _________.
Bone marrow
Humoral
Immunoglobulins
Humoral adaptive immunity is mediated by _____ in the blood and mucosal secretions which are produced by B lymphocytes (B cells).
Abs
Abs recognize microbial ____, neutralize the infectivity of the microbes, and target microbes for elimination by various effector mechanisms.
Ags
Humoral adaptive immunity is the principal defense mechanism against (INTRACELLULAR/EXTRACELLULAR) microbes and their toxins because secreted Abs can bind to these microbes and toxins and assist in their elimination.
Extracellular
There are several classes of _____ which may activate different mechanisms to combat microbes (effector mechanisms).
Abs
Cell-Mediated (or Cellular) immunity is controlled by responses of ________ which often function in concert with Ag-presenting cells and phagocytes to eliminate microbes.
T lymphocytes (T cells)
Cell-mediated immunity mediates host defense against (INTRACELLULAR/EXTRACELLULAR) microbes, such as viruses and some bacteria, where they are inaccessible to circulating Abs.
Intracellular
Cell-mediated immunity function is the killing of infected _____ cells to eliminate reservoirs of infection.
Host
Some T lymphocytes, called _______ _______ also help B cells to make effective Abs thus contributing to eradication of extracellular microbes.
T helper lymphocytes
In (HUMORAL/CELL-MEDIATED) adaptive immunity, T helper cells activate macrophages to kill phagocytize microbes, or cytotoxic T lymphocytes to directly destroy infected cells.
Cell-mediated
This is the father of humoral immunity. He postulated that immune cells can secrete receptors (he called side chains) which recognize microbial toxins (we now call them Ags) and combat invading microbes. He also coined the term antibodies (Abs) for the serum proteins that bind toxins.
Paul Ehrlich
This is the father of cell-mediated immunity. In 1883, he discovered special immune cells and named them phagocytes which, he believed, are the principal effector mechanism of immunity. He was unable to prove that specific immunity to microbes could be mediated by cells.
Elie Metchnikoff
After Metchnikoff, the cellular theory of immunity became firmly re-established in the 1950s, when it was shown that resistance to an intracellular bacterium Listeria monocytogenes could be transferred with ______, but not with serum.
Cells
The immune system generates a very large number of ______ during the maturation of lymphocytes, thus maximizing the potential for recognizing diverse microbes. A ______ refers to a lymphocyte of one specificity and its progeny.
Clone
Clone
All immunocompetent individuals have many distinct lymphocytes, each of which is specific for a different Ag. When Ag is introduced into an individual, lymphocytes with receptors for this Ag seek out and bind Ag and are triggered to proliferate and _________ giving rise to clones of cells specific for the Ag. The cells from the clones or their products specifically react with the Ag to neutralize or eliminate Ag.
Differentiate
Some Ag-specific cells late in the immune response is responsible for the ‘______’ involved in the adaptive immunity.
Memory
An immune response eliminates the microbes that initiated the response. The expanded lymphocyte clones die in a ________ phase and homeostasis is restored.
Contraction
A few activated lymphocytes become Ag-specific ________ cells which may survive for years after the infection. These are more effective in combating microbes than are naive lymphocytes.
Memory
Memory cells are more numerous than naive cells specific for the Ag and respond (SLOWER/FASTER) and more effectively than do naive cells.
Faster
Generation of memory responses is an important goal of ________.
Vaccination
Ags X and Y induce the production of different Abs (specificity). The secondary response to Ag X is more rapid and larger than the primary response (memory). Abs levels (INCLINE/DECLINE) with time after each immunization (contraction of immune response).
Decline
The concept of ________ immunity dated to the ancient Chinese custom of making children resistant to smallpox by having them inhale powders made from the skin lesions of patients recovering from the disease.
Protective
An English physician ______ ______ was the first (not really) who successfully vaccinated against smallpox. He injected the material from a cowpox pustule into the arm of an 8-year-old boy. The disease did not develop when this boy was later intentionally inoculated with smallpox.
Edward Jenner
This is the father of immunology who developed the principle of vaccination and contributed to the foundation of immunology.
Dr. Pasteur
(ACTIVE/PASSIVE) immunity is conferred by a host response to a microbe or microbial Ags. (i.e., pathogen invasion or vaccination)
Active
(ACTIVE/PASSIVE) immunity is conferred by adoptive transfer of antibodies or T lymphocytes specific for the microbe. (i.e., Abs provided by injection, breast milk, across placenta)
Passive
Both active and passive immunity provide resistance to infection and are specific for microbial _____.
Ags
Only (ACTIVE/PASSIVE) immune responses generate immunologic memory.
Active
_____ lymphocytes recognize soluble Ags and develop into Ab-secreting cells.
B
_____ lymphocytes recognize Ags on the surfaces of Ag-presenting cells and secrete cytokines, which stimulate different mechanisms of immunity and inflammation.
T helper
_____ lymphocytes recognize Ags on infected cells and kill these cells.
Cytotoxic T
________ cells suppress and prevent immune responses (i.e., to self antigens).
Regulatory T cells
This is the term that indicates a defined subset of cellular surface receptors that identify cell type and stage of differentiation.
Cluster of differentiation (CD)
What are the two lineages that the pluripotent stem cell divides into?
Myeloid lineage
Lymphoid lineage
What the primary lymphoid organs?
Thymus
Bone marrow
What are secondary lymphoid organs?
Spleen
Lymph nodes
Mucosa-associated lymphoid tissue
All blood cells develop from common (MULTIPOTENT/PLURIPOTENT) stem cells.
Pluripotent
Starting from the _____ week of gestation, some stem cells migrate to the thymus and bone marrow which are referred to as the primary lymphoid organs.
13th
T lymphocytes are generated in the (BONE MARROW/THYMUS) where they proliferate, differentiate, and complete their maturation.
Thymus
B cells proliferate, differentiate, and complete their maturation in the (BONE MARROW/THYMUS).
Bone marrow
T/F. Ag-specific receptors are localized on the inside of T and B cels.
False. They’re on the surface, not inside.
The structure of Ag-specific receptors varies from one cell to another but they are all _______ on a single cell.
Identical
Most of T cells are produced in (LATE/EARLY) life.
Early
The _______ is larger in infancy and during puberty, small in an adult, and replaced by fat and connective tissue in the elderly.
Thymus
T cells which are highly reactive with self-Ags are deleted by _______.
Apoptosis
T helper cells express _____ and provide help for B cell growth and differentiation.
CD4
Cytotoxic T lymphocytes (CTLs) express _____ and recognize and kill virus-infected cells.
CD8
At birth, all bone marrow is _____. During puberty, marrow increasingly converts to ______ marrow. In adults, around half of the bone marrow is ______ and half is ______.
Red
Yellow
Red; Yellow
Differentiation into B cells occurs within the fetal ______ and, after birth, in the bone marrow.
Liver
The development of B cells involves contact with _______ cells and cytokines.
Stromal
B cells which react with self-Ags are _________.
Eliminated
Ags are captured from a site of infection and the draining _____ ______ to which these antigens are transported and where the immune response is initiated.
Lymph node
Lymphocytes continuously circulate reaching various parts of the body except where?
Eye
Brain
Testicles
In search of foreign Ags, lymphocytes enter the secondary lymphoid organs via a specialized endothelium of post capillary venues called…
High endothelium venules (HEV)
Cells of HEV are much high than normal endothelial cells and they express high levels of adhesion molecules that serve as “______” receptors for lymphocytes.
Homing
Lymphocytes transmigrate by _______ from the blood into the tissue in response to chemokines.
Diapedesis
Lymphocytes reenter the circulation via _______ lymph vessel that merge into the thoracic duct.
Efferent
Ag-activated B cell proliferate and mature into _______ cells or into _______ cells. The latter being terminally differentiated B cells which produce and secrete large amounts of Abs.
Memory
Plasma
In the ______, Ag-activated B cells primarily produce Abs against microbial blood.
Spleen
In the spleen, what makes up the white pulp?
T cells and B cells
The function of a plasma cell is secretion of ______.
Abs
In the absence of Ag stimulation, lymphoid follicles (in lymph node) are (PRIMARY/SECONDARY) follicles, composed of small naive B cells or recirculating memory B cells.
Primary
With Ag stimulation, B cell proliferate and differentiate converting the primary follicle into a _______ follicle or ______ ______.
Secondary Germinal center (GC)
These are cells that capture, process, and display Ags to T lymphocytes and provide signals that stimulate the proliferation and differentiation of the lymphocytes.
Antigen-Presenting Cells (APCs)
T/F. Both T cells and B cells require APCs to display Ag to them.
False. Only T cells need them.
Only 3 cells can serve as APCs, which are…
Dendritic cells (DC)
Macrophages
Activated B cells
Only this type of cell is able to activate naive T cells in the lymph nodes.
Dendritic cells (DC)
Macrophages and activated B cells can present Ags only for (INACTIVATED/ACTIVATED) T cells.
Activated T cells
DCs and macrophages are cells of ______ immunity. Thus, they provide a link between innate and adaptive immunity.
Innate
DCs are part of the (MYELOID/LYMPHOID) lineage.
Myeloid
DCs can be broadly divided into ______ DCs, _______, and _________.
Classical
Myeloid (mDCs)
Plasmacytoid (pDCs)
mDCs are derived from…
Monocytes
Classical DCs, pDC, and Langerhan’s cells (LCs) in the epidermis of the skin, develop directly from ______ cells.
Stem
To acquire Ags, DCs use receptor-mediated ______ and ______.
Endocytosis
Pinocytosis
Activated DCs also secrete _______.
Cytokines
