Unit 4 - Adaptive Immunity

Here is Chapter 15 in the same rapid-recall format, with no extra blank lines:

Adaptive immunity targets pathogens how?

Specific antigen receptors

What does each lymphocyte recognize?

One specific epitope

What activates a matching lymphocyte?

Clonal selection

What happens after clonal selection?

Clonal expansion

Activated lymphocytes become what?

Effector and memory cells

What are self molecules?

Normal body molecules

What are non-self molecules?

Foreign antigens

What abnormal self cells may be attacked?

Cancerous or infected cells

What prevents attacks against self?

Immune tolerance

Failure to tolerate self causes what?

Autoimmune disease

Overreaction to harmless antigens causes what?

Allergies

What is an antigen?

Molecule recognized by immune receptors

What is the recognized part of an antigen?

Epitope

Which receptors recognize antigens?

Antibodies, BCRs, and TCRs

Which cells connect innate and adaptive immunity?

Dendritic cells

What do dendritic cells collect?

Antigens

Where do dendritic cells travel?

Lymph nodes

How do dendritic cells display antigens?

On MHC molecules

Which cells recognize presented antigens?

T cells

What additional signal helps activate T cells?

Costimulation

When do dendritic cells provide costimulation?

When danger is detected

Which immunity uses T cells?

Cell-mediated immunity

Which immunity uses B cells and antibodies?

Humoral immunity

Cell-mediated immunity targets what?

Infected or abnormal body cells

Humoral immunity targets what?

Extracellular microbes and toxins

What do both adaptive branches provide?

Specificity and memory

What receptor activates a B cell?

B-cell receptor

What does a BCR bind?

Free intact antigen

What second signal usually activates B cells?

Helper T-cell cytokines

Activated B cells undergo what?

Clonal expansion

Antibody-secreting B cells are called?

Plasma cells

Long-lived B cells are called?

Memory B cells

What are BCRs structurally?

Membrane-bound antibodies

Do BCRs bind free antigens directly?

Yes

What do TCRs bind?

Presented antigen fragments

What presents antigen fragments to TCRs?

MHC molecules

Can TCRs bind free antigen?

No

What helps T cells bind the correct MHC?

CD markers

What do BCRs and TCRs share?

Epitope specificity

Do BCRs and TCRs remain cell-bound?

Yes

What shape is an antibody?

Y-shaped

How many heavy chains does an antibody have?

Two

How many light chains does an antibody have?

Two

Are the two heavy chains identical?

Yes

Are the two light chains identical?

Yes

Which antibody region binds antigen?

Fab region

How many Fab regions does an antibody have?

Two

What does each Fab bind?

Specific epitope

Which antibody region is the stem?

Fc region

What does the Fc region signal?

Target destruction

What can the Fc region attract?

Immune cells

What system can Fc activate?

Complement

How do antibodies neutralize toxins?

Block receptor-binding sites

How do antibodies neutralize viruses?

Prevent attachment and entry

What does neutralization prevent?

Cell damage

What is opsonization?

Coating a target for phagocytosis

Which molecules can opsonize microbes?

Antibodies or complement

What recognizes an opsonized target?

Phagocytes

How does opsonization help phagocytes?

Improves attachment and engulfment

How do antibodies activate complement?

Neighboring Fc regions bind complement

What must antibodies do before complement activation?

Bind close together

What follows complement binding?

Complement cascade

How can antibodies block bacterial attachment?

Cover pili

How can antibodies block bacterial movement?

Cover flagella

What is bacterial clumping called?

Agglutination

How does agglutination help immunity?

Limits spread and aids removal

What is ADCC?

Antibody-dependent cellular cytotoxicity

What does ADCC target?

Antibody-coated body cells

Which cells perform ADCC?

Natural killer cells

What antibody region do NK cells bind?

Fc region

What happens after NK cells bind Fc?

Target cell is killed

Another name for an epitope?

Antigenic determinant

What does an epitope bind?

Specific immune receptor

How can known epitopes be used in labs?

Detect antibodies or antigens

How can epitopes help measure samples?

Quantification

How can epitopes help identify proteins?

Specific antibody binding

How can epitopes help purify proteins?

Affinity purification

What fluid does the lymphatic system collect?

Excess tissue fluid

What is tissue fluid called after entering lymphatics?

Lymph

What does lymph transport?

Fluid and antigens

Where does lymph carry antigens?

Lymph nodes

Where is lymph eventually returned?

Bloodstream

Why is lymph transport important?

Brings antigens to immune cells

Which cells are lymphocytes?

B cells, T cells, and NK cells

Which lymphocytes are adaptive?

B and T cells

Which lymphocytes are innate?

Natural killer cells

How does inflammation affect tissue fluid?

Increases it

How does inflammation affect antigen drainage?

Increases lymphatic transport

Where do antigens meet lymphocytes?

Lymph nodes

Which cells may present antigens there?

Antigen-presenting cells

What produces all lymphocytes?

Bone marrow

What cells give rise to lymphocytes?

Hematopoietic stem cells

Where do B cells mature?

Bone marrow

Where do immature T cells mature?

Thymus

Why is the thymus called “murder university”?

Most developing T cells die

What are developing T cells tested for?

Proper MHC recognition

What must surviving T cells avoid?

Strong self-reactivity

What does thymic testing help prevent?

Autoimmunity