Immune System Flashcards
The immune system recognizes —— and responds with the production of —— and —
- Foreign Bodies
- Immune Cells
- Proteins
Recognition of self from non-self occurs by —— that bind specifically to molecules from —— and —
- receptor molecules
- Foreign cells
- Viruses
Are immune system can fight(5):
- Viruses
- Bacteria
- Protozoans
- Fungi
- Parasitic Animals
Only a small percentage of microbes are —, but are very good at invading our tissues when getting past initial barries
Pathogenic
What are the 2 types of immune defense?
- Innate Immunity
2. Adaptive Immunity
Innate Immunity is found in — animals and plants
All
Innate Immunity is present before any exposure to — and is effecive from the time of birth
Pathogens
Nonspecific Innate Immunity:
- Consists of — barriers plus — cellular and chemical defenses
- Relies on a ———— that bind structures common to a group of viruses, bacteria or other microbes
- External
- Internal
- Small set of receptors
Adaptive(aquired) Immunity:
- Only in —
- Activated after the ——— and develops more slowly
- Highly specific:
* Recognition relies on a vast arsenal of —, each of which is very — for a particular pathogen - Has memory to provide enhanced — when exposed again to the same pathogen
- Vertebrates
- Innate Immune response
- Receptors
- Specific
- Protection
Innate Immunity of Vertebrates:
- Some innate defenses are similar to those of invertebrates
1.—2.—3.—
- Other innate defenses are unique to vertebrates:
Eg. ———,— and the ——
- Barrier defenses, Phagocytosis, Antimicrobial peptides
2. Natural killer cells, interferons, and the complement system
Barrier Innate Defense:
- Include —, its normal ——, and —— of the —,—, & — tracts
- Skin
- Microbial Flora
- Mucous Membranes
- Respiratory
- Urinary
- Reproductive
Barrier Innate Defenses:
- Mucus, Saliva, & Tears
- Inhibit — through washing action
- Contain — that destroys —— of —
- Colonization
- Lysozyme
- Cell walls
- Bacteria
Barrier Innate Defenses:
- Low pH of — and —— prevents growth of many bacteria
Skin & Digestive System
Cellular Innate Defenses:
What are the 4 phagocytic cell types?
- Neutrophils
- Marcophages
- Dendritic Cells
- Eosinophils
Phagocytic Cells:
— circulates through the blood to infected tissues
Neutrophils
Phagocytic Cells:
— is found throughout the body; some migrate, some reside permanently in tissues
Macrophages
Phagocytic Cells:
—— mainly populate tissues that contact the environment (eg. Skin)
Dendritic Cells
Phagocytic Cells:
— often found beneath an epithelium and are important against multicellular invaders (eg. Parasitic worms)
Eosinophils
Natural Killer Cells:
- Circulate through the body and detect ——, such as virally infected or cancerous cells
- Do not —; instead release chemicals leading to cell death, inhibiting their spread
- Abnormal Cells
2. Engulf
Mast Cells:
- Involved in local — & ——
- Recruit — & —
- Inflamation & wound healing
2. Macrophages & neutrophils
Basophils:
- Involved in local —
- Defense against —
- Inflammation
2. Parasites
Both mast cells & basophils release — and can play a role in ——
- Histamines
2. Allergic Reactions
- Microbes have different cell surface markers than vertebrates
- Common to a wide range of — (i.e., non-specific)
- Contain ————
- Recognized by — immune cells
- Microbes
- Pathogen Associated Molecular Patterns(PAMPs)
- Phagocytic
-Binding of — triggers release of —: chemical that signals the presence of a pathogen to immune cells and to induce a response
* ~40 types, including:
—: mediate interactions between leukocytes
—: interfere with viral replication and help activate macrophages
—: is comprised of about 30 proteins which cause lysis of invading cells and help trigger inflammation
- PAMP
- Cytokines
- Interleukins
- Interferons
- Complement System
Inflammatory Response:
-Brought about upon — or —
Involves:
- ——
- —
- —
- ——
- Histamines
- Cytokines
Injury or Infection
- Mast Cells
- Macrophages
- Neutrophils
- Signaling Molecule
Step 1
——, found in connective tissue release —, which triggers blood vessels to dialte and become more permeable
- Mast Cells
2. Histamine
Step 2
Activated — release — that recruit —
- Macrophages
- Cytokines
- Neutrophils
Step 3
— digest — and ——. — heals
- Neutrophils
- Pathogens
- Cell debris
- Tissue
Inflammation can be either — or —
- Local
2. Systemic(throughout body)
—: a systemic inflamatory response triggered by — released by macrophages and include toxins from pathogens
- Fever
2. Pyrogens
Certain bacterial infections can lead to ——, a life threatening condition caused by an overwhelming systemic inflammatory response
Septic Shock
The adaptive response relies on 2 types of lymphocytes:
—— & ——
B cells & T cells
——: humoral response
Bcells
——: cell-mediated response
Tcells
All blood cells originate from stem cells in bone marrow:
- B cells: remain and mature in ——
- T cells: migrate to and mature in the —
- Bone Marrow
2. thymus
- B cells make —
- Secreted in the — component of blood
- Also serve as ——— for B cells
- Antibodies
- Liquid (humoral)
- Membrane-bound receptors
What are the 3 populations of T cells?
- Produce various cell-mediated responses after a pathogen binds to a specific T cell receptor
- Helper T cells
- Cytotoxic T cells
- Regulatory T cells
—: substance that elicits a response from a B or T cell
* Usually — and are typically —— that protrude from the surface of a pathogen
- Antigen
- Foreign
- Large Molecules
- Recognition occurs through specific —— activating the cell
- Millions of different receptors, but each cell expresses many copies of only — antigen receptor
- Antigen Receptors
2. One
- —: accessible part of an antigen that binds to an antigen receptor
- Represents only a small region of the — (e.g., range of ~5 – 20 amino acids of a protein)
- Epitope
2. Antigen
Antigen receptors of B cells and T cells have ——, but they encounter — in different ways
- Similar components
2. Antigens
Each B cell antigen receptor is a —— molecule with two identical —— and two identical ——
- Y-shaped
- Heavy chains
- Light chains
- Both are comprised of — and — regions
- Constant regions vary —, whereas the variable regions differ —
- The — regions provide antigen specificity
- Constant (c)
- Variable (v)
- Little
- Greatly
- Variable
Heavy and light chain variable regions are —, generating unique binding sites
Asymmetrical
Both antigen binding site are —
Identical
- Binding of a B cell antigen receptor to an antigen is an early step in ———
- Gives rise to cells that secrete a soluble form of the receptor called an — or —
- B cell activation
- Antibody
- Immunoglobulin (Ig)
Each T cell receptor consists of two different —— (called a and B)
Polypeptide chain
The tips of the chain form a — region; the rest is a — region
- Variable (V)
2. Constant (C)
T cell and B cell antigen receptors are ——
Functionally different
- T cells bind to —— presented on a host cell surface by —molecules
- ——: can display many different antigen fragments
- Antigen Fragments
- MHC ( major histocompatibility complex)
- Not specific
MHC Class 1 is found on all host ——
Nucleated cells
- Display — antigens to — T cells
- — = hosts normal microbial flora and virally infected or mutated host cells
- Presentation of foreign or over-abundant antigens targets cell for —
- Endogenous
- Cytoxic
- Endogenous
- Destruction
MHC Class 2:
- FOund on antigen presenting cells (APCs):
1. ——
2. ——
3. —
- B cells
- Dendritic Cells
- Macrophage
In infected cells, host MHC molecules bind and transport —— to the ——
- Antigen fragments
2. Cell Surface
- T cell then binds both the — and the — molecule
* This interaction is necessary for the T cell to participate in the ———
- Antigen Fragement
- MHC
- Adaptive Immune Response
Step 1. Pathogen — or is taken in by a host cell
Step 2. Enzymes — the antigen into smaller fragements
Step 3. MHC — the fragments and presents them on the ——
Step 4. T-cell binding requires — & ——
- Infects
- Cleave
- Binds
- Cell surface
- Antigen & MHC Recognition
- The adaptive immune system has 4 major characteristics:
- Diversity of — & —
- —— (i.e., lack of reactivity against an animal’s own molecules)
- B and T cells — after activation
- — memory
- Lymphocytes & receptors
- Self-Tolerance
- Proliferate
- Immunological
By combining variable elements, the immune system assembles a diverse variety of ——
Antigen Receptors
Diversity is provided by the — gene structure
Immunoglobulin (Ig)
-Many different chains that make up the receptor can be produced from the same gene by — of the —
E.g., the B cell light chain Ig is comprised of 3 segments:
- —
- —
- —
- Rearrangment
- DNA
- Variable (v)
- Joining (j)
- Constant (C)
— different variable regions and — different joining regions
- 40
2. 5
By combining the light chain & heavy chain variations and chain combinations results in ——— antigen-binding specificities
> 1 million
As lymphocytes mature in —— or the —, they are tested for ——
- Bone marrow
- thymus
- Self-reactivity
- Some B and T cells with receptors specific for the body’s own molecules are destroyed by —, or programmed ——
- The remainder are rendered —
- Apoptosis
- Cell death
- Nonfunctional
There are few lymphocytes with antigen receptors for any particular —
Epitope
- In the lymph nodes, an antigen is exposed to a steady stream of lymphocytes until ————
- Initiates events that activate the —
- A match is made
2. Lymphocyte
Once activated, a B cell or T cell undergoes — cell divisions to produce — of ——
- Multiple
- Clones
- Identical Cells
What are the two types of cloned cells produced?
- Effector Cells
2. Memory Cells
Effector cells: these are —— and act — against the antigen
- Effector B cells: —— (secrete antibodies)
- Effector T cells: — T cells and — T cells
- Short-lived
- Immediately
- Plasma Cells
- Helper
- Cytoxic
Immunlogical memory is responsible for —— protections against diseases, due to either a prior — or —
- Long-term
- Infection
- Vaccination
First exposure elicits the ———:
- Selected B and T cells give rise to their ——
- Memory cells produced for — immune response
- Primary Immune Response
- Effector Forms
- Secondary
In the secondary immune response, a reservoir of T and B memory cells facilitate a —, — and —— response
- Faster
- Stronger
- Longer-lasting
Helper T cells trigger both the ——— & ————
- Humoral Immune Response
2. Cell-mediated Immune Response
Humoral Immune Response:
* Production of — by B cells that ——
- Antibodies
2. Neutralize Pathogens
Cell-Mediated Immune Response:
* Activation of — T cells that kill ——
- Cytotoxic
2. Infected Cells
The antigen must be displayed on the surface of an ———by an ——— molecule
*MHC II provides the ——by which antigen-presenting cells are —
- Antigen Presenting Cell (APC)
- MHC Class 2
- Molecular Signature
- Recognized
Antigen receptors on the surface of helper T cells bind to the — and the ——— molecule; then — signals are exchanged between the two cells
- Antigen
- Class 2 MHC
- Cytokine
The helper T cell is —, —, and — a clone of helper T cells, which then activate the appropriate — cells and cytotoxic —cells
- Activated
- Proliferates
- Forms
- B
- T
———are the effector cells in the cell-mediated immune response
Cytotoxic T Cells
The activated cytotoxic T cell secretes — that disrupt the membranes of —— and trigger —
- Proteins
- Target Cells
- Apoptosis
Recognize fragments of foreign proteins produced by infected cells and possess an accessory protein that binds to ——— molecules
Class 1 MHC
The activated cytotoxic T cell secretes — and —. Perforin disrupts the membranes of target cells
- Perforin
2. Granzymes
Granzymes trigger —, leading to — and — of the cytotoxic T cell
- Apoptosis
- Fragmentation
- Release
The humoral response is characterized by secretion of antibodies by ——
B cells
Activation of B cells requires 2 things:
- ——
- —————
- An antigen
2. Cytokines from Helper T cells
In response, a B cell proliferates and differentiates into 2 cells types:
- ——:antibody secreting effector cells
- ———: quickly convert into plasma cells upon a future exposure to the same antigen
- Plasma Cells
2. Memory B cells
An antigen presenting cell engulfs a — and presents a —— on the cell surface via MHC II
- Pathogen
2. Small Fragment
Helper T cell with corresponding antigen receptor binds and gets — (with aid of cytokines from presenting cell)
Activated
B cell takes in a few foreign molecules by ——— and presents a small fragment on the cell surface via MHC II
Receptor-mediated endocytosis
Activated Helper T cell with corresponding antigen receptor binds to and activates the —— (with aid of cytokines)
B cell
Activated B cell proliferates and differentiates into ———and —— that secrete antibodies specific for the same antigen
Memory B cells & Plasma Cells
A variety of B cells activated by one antigen will give rise to —— producing — directed against different epitopes of the common antigen.
- Plasma Cells
2. Antibodies
Antibodies ——— pathogens
Do Not Kill
Act by:
- —: interfering with pathogen activity
- —: marking them for destruction
- Working with the —— to generate a ——— to lyse the pathogen
- Neutralization
- Opsonization
- Complement System
- Membrane Attack Complex
Antibodies bind to viral surface proteins preventing — of a host cell
*Can also bind to — in body fluids and prevent them from — body cells
- Infection
- Toxins
- Entering
Antibodies bind to antigens on bacteria creating a target for — or —, triggering —
- Macrophages
- Neutrophils
- Phagocytosis
Both the — and —— responses can include primary and secondary immune responses
- Humoral
2. Cell-Mediated
Memory cells enable the ——
Secondary response
