Bio 308 Steiner Chapter 17

Front 1

Epitopes

Back 1

Where antibodies bind to specific chemical groups on a molecule. These can be on the body of the molecule or on structures such as cilia.

Front 2

Haptene

Back 2

Molecules which react with antibodies but cannot by themselves elicit a an antibody responce from the body. Ex is penicllin allergies

Front 3

B-Cells

Back 3

Come from the bone marrow and are found in all functional tissue in the body. Account for 1/4 of total antibodies.

Greatest concentration is found in the peyers patches in the body

Front 4

T- Cells

Back 4

Arise from the thymus and make up about 3/4 of the total lymphocytes which are in our body.

Later in life when thymus is less active they are thought to come from bone marrow or tissue under contoll of the thymus

Front 5

Humoral Immunity

Back 5

Arises from b-cells which circulate in the blood. Most effective in defending the body from antigens before they enter cells

Front 6

Cell-mediated immunity

Back 6

Is carried out by T-cells and is most effective in clear the body of cells after they have become infected.

Plays a role in virus infected cells, fungi, parasites, cancer, and transplanted organs.

Front 7

Recognition of Self vs Non-self

Back 7

Says that at birth there are antibodies made for pretty much everything, but the ones that attack the host are all killed during development so only the ones are left that are linked to substances outside of the body.

Front 8

Clonal selection hypothesis

Back 8

According to this theory, one of many B cells responds to a particular antigen and begins to divide, thereby producing a large population of identical B cells (a clone). All cells of such a clone produce the same antibody against the original epitope. B memory cells are also produced

Front 9

Helper T cells function in humoral immunitiy

Back 9

Facilitate the growth and differentiation of plasma cells. Process stops after about a week because by this time suppressor T cells are being produced

Front 10

Immunoglobulins (Ig)

Back 10

Y-shaped protein molecules which consist of 4 parts. 2 parts are the identical heavy chains and 2 parts are the identical light chains.

Chemical structure of constant region determines class and structure of variable region determines specificity

Front 11

IgG

Back 11

1) Only antibody which can cross the placenta
2) Activates complement
3) Binds to phagocytes
4) Binds to lymphocytes (acts as a receptor to antigen presenting cells)

Front 12

IgM

Back 12

1) Activates complement
2) Binds to lymphocytes (acts as a receptor to antigen presenting cells)
3) No memory cells are produced for IgM

Front 13

IgA

Back 13

2 forms, secretory and non-secretory. Unique ability of that antibody to traverse the epithelial layer and be in secretions (mucus) bc of secretory piece which confers solubility
1) Binds to lymphocytes (acts as a receptor to antigen presenting cells)

Front 14

IgE

Back 14

1) binds to lymphocytes (acts as a receptor to antigen presenting cells)
2) Binds to mast cells and basophils (plays a role in allergies)
3) Serves as a receptor on B cells to which antigen binds

Front 15

IgD

Back 15

Serves as a receptor on B cells to which antigen binds

Front 16

Antigen Presenting Cells

Back 16

Have MHCII on the surface of their cells. This activates Th cells to begin multiplying and dividing.

Front 17

MHCI presenting cells

Back 17

All cells have MHCI on them but the ones that present it activate Tc cells which kill the cell. These typically are infected with viruses or some other pathogen

Front 18

interleukin-1

Back 18

Presented by macrophages which have processed an antigen. This activates Th cells and they begin to divide into either Th1 or Th2 cells

Front 19

interleukin-2

Back 19

Secreted from activated T-helper cells. Stimulates the growth of gamma interfereon and the differentiation of Td cells and Tc cells. IL-1, IL-2, and gamma interfereon cause undifferentiated cells to become Nk cells.

Front 20

T-helper cells (Th)

Back 20

stimulate the growth and differentiation of b cells. Th2 cells interact with b cells. Th1 cells activate infected macrophages and help them destroy bacterial infections.

Front 21

Td Cells release various lymphokines including

Back 21

1. Macrophage chemotactic factor, which helps macrophage find microbes

2. Macrophage activating factor, which stimulates phagocytic activity and the production of anti-bacterial compounds, e.g., H2O2, O2-

3. Migration inhibiting factor, which prevents macrophage from leaving sites of infection

4. Macrophage aggregation factor, which causes macrophages to congregate at such sites
TD cells also participate in delayed hypersensitivity which will be discussed in chapter 18.

Front 22

How Tc cells and Nk cells kill other organisms

Back 22

Tc cells act mainly on virally infected cells. Bind to the antigens presented by the macrophage and attack these cells

Nk cells act mainly on tumors and cells infected with intracellular agents like rickettsias and chlamydias. These bind directly to the malignant cell without the help of macrophages

Both kill with perforin which tears a whole in membrane