chapter 16 pt. 1

when does the adaptive immune system respond?

days after being exposed to a microbe

what shows antigens to the cells of the adaptive immune system?

antigen presenting cells of the innate immune system

Two forms of an adaptive immune response: ??

humoral immune response and the cell-mediated immune response

Humoral → _ ____ activation → antibody production

B cell

Cell-mediated → ______ __ __________ activation → infected host cell
destruction

Cytotoxic T lymphocyte

Proteins that are found on the surfaces of cells that help immune system cells
recognize foreign substance

MHC proteins

All human cells (except red blood cells) have ______ on their cell surfaces

MHC l

Immune cells like macrophages, dendritic cells, and lymphocytes (B and T cells) have both _____ and ______

MHC-I and MHC-II

Antigens loaded onto MHC-I have an _________ (endogenous) origin

intracellular

_________ antigens are made by viruses and intracellular bacteria that grow
within the cytoplasm of the host cell and become attached to MHC-I
molecules on the ER surface

Endogenous

MHC-I only binds to what?

CD8+ receptors on cytotoxic T cells

what triggers a cell-mediated response?

MHC-l binding to CD8+ receptors on cytotoxic T cells

Antigens loaded onto MHC-II have an _______ (exogenous) origin

extracellular

_______ antigens are made from phagocytotic cells breaking down
microbial cells that are causing infection outside of human cells

Exogenous

When Antigen Presenting Cells (APCs) phagocytose and ________
microbes and produce antigens, those antigens get loaded onto MHC-II
proteins

break down

MHC-II of APCs present antigen to naïve ….

CD4+ helper T cells

What triggers those helper T cells differentiate into Type 1 or Type 2

helper T cells, which will go aid in activating Cytotoxic T Lymphocytes or B

cells, respectively?

MHC-II of APCs present antigen to naïve CD4+ helper T cells

_____ _ _____ aid in activating the side of the adaptive immune system (Humoral or Cell- mediated) will predominate in response to a particular antigen

Helper T cells

APCs will show naïve helper T cells their antigens and will release chemicals in the form of ______ to trigger the helper T cells to differentiate into either TH1 Cells or TH2 Cells

cytokines

This class of helper T cells aid in activation of cytotoxic T lymphocytes for a cell mediated response

th1 cells

TH1 Cells release cytokines in the form of IL-2 to stimulate the _____ _____ necessary for Cytotoxic T lymphocyte activation

third signal

what activates the Cytotoxic T cell into an Activated Cytotoxic T
lymphocyte to go and find the human cells that have that infection to
destroy them?

th1 cells releasing cytokines in the form of IL-2 to stimulate the third signal

This class of helper T cells aid in activation of B cells for a humoral
response

th2 cells

TH2 cells will bind to the______ on B cells

MHC-II

B cell MHC-II will be presenting the _____ antigen match that the
APC cell showed to the naïve helper T cell to trigger differentiation in to a TH2 T cell

same

what will allow for the th2 cell to bind to the MHC-ll?

the B cell MHC-ll presenting the same antigen on the B cell

presentation of antigen on the B cell will allow for the TH2 cell to bind to the MHC-Il

signal 1 of activation

_____ on the B cell binds to CD40L on the TH2 cell (signal 2 of activation)

CD40

what activates the B cell to undergo antibody class switching and produce plasma cells and memory cells?

CD40 on the B cell binds to CD40L on the TH2 cell

when does cell-mediated immunity begin?

when an APC presents an antigen on its MHC-I to an inactive cytotoxic T cell

Histocompatibility Complex Interaction – MHC 1 on APC binds and shows
antigen to the matching CD8 T cell receptor of the CTL

signal 1 activation

Co-Stimulation – molecular interaction between CD28 on the T cell and the B7 molecule on the APC

signal 2 activation

Chemical Cytokine Signaling – the activated CD4 TH1 Helper T cell releases the cytokine IL-2 to finish the CTL activation

signal 3 activation

the cytotoxic T cell will proliferate and become an Activated Cytotoxic T Lymphocyte (CTL)

final step

The ____ will leave the lymph node and will travel to the infection site and kill any cell bearing the same peptide-MHC-I complex that triggered the activation

CTL

Human Cell Death by CTL

• A CTL binds to an infected human cell via ____

MHC-l

Human Cell Death by CTL

The CTL makes a _______ ____ into the human cell so it can push granzymes
into the target human cell

perforin pore

Human Cell Death by CTL

The _________ trigger cell damage in the form of mitochondrial, DNA, etc. and
eventually triggers the human cell into apoptosis

granzymes

Antibodies belong to the family of proteins called __________

immunoglobulins

Antibodies consist of 4 polypeptide chains – two heavy chains and 2 light chains – this forms a _ shape structure

Y

This Y shape allows for ____ antigen binding sites, but only one type of antigen
can bind in either binding site – an antibody is specific to one type of antigen, and will not bind to antigens that don’t match its binding site

two