4 - Immunologic Flashcards by Joanna Brown

B cells have the job of ________ and are therefore part of _______ immunity

Making Antibodies

Humoral

How well did you know this?

Not at all

Perfectly

Cytotoxic (CD8) T cells have the job of ______ and are therefore responsible for ______ immunity

attacking and killing cells directly

cellular immunity

How well did you know this?

Not at all

Perfectly

What does the T in T cells stand for?

Thymus, where T cells mature

How well did you know this?

Not at all

Perfectly

Helper T (CD4) Cells have three jobs:

Augment antibody production by B cells
Responsible for delayed hypersensitivity
Activation of cytotoxic T cells

How well did you know this?

Not at all

Perfectly

Which immune cells does HIV attack?

Helper T cells (CD4)

How well did you know this?

Not at all

Perfectly

Macrophages have three roles in acquired immunity:

Required for activation of BOTH T cells
Final mediators of delayed hypersensitivity
Phagocytize cells tagged with antibodies

T CELLS IS MOST CRITICAL ROLE

How well did you know this?

Not at all

Perfectly

What are Antigen-Presenting Cells?

APCs

What macrophages are called when they are activating T cells/ presenting antigens

How well did you know this?

Not at all

Perfectly

What’s are the similarities and differences between dendritic cells and macrophages?

Both of them are antigen-presenting

But dendritic cells are not scavengers

How well did you know this?

Not at all

Perfectly

Which cells mediate immediate hypersensitivity reactions?

Mast cells and basophils

How well did you know this?

Not at all

Perfectly

Mast cells are derived from ______ and are primarily found in the _______

Basophils

skin and soft tissues

How well did you know this?

Not at all

Perfectly

Mast cells are derived from ______ and are primarily found in the _______

Basophils

skin and soft tissues

How well did you know this?

Not at all

Perfectly

Basophils are found in the _______

blood

How well did you know this?

Not at all

Perfectly

What triggers a basophils and mast cells to degranulate?

Binding on an antigen to the antibodies on the cell’s surface

How well did you know this?

Not at all

Perfectly

What is the role of neutrophils?

Phagocytes

Think IgG and inflammation

How well did you know this?

Not at all

Perfectly

What is the role of Eosinophils?

Attack and destroy foreign particles coated with IgE antibodies (usually helminths)

Also involved in immediate hypersensitivity reactions

How well did you know this?

Not at all

Perfectly

Antibodies mediate _____ immunity

humoral

How well did you know this?

Not at all

Perfectly

What are alternative names for antibodies?

Immunoglobulins

Globulins

How well did you know this?

Not at all

Perfectly

ALL antibodies are produced by _______

B lymphocytes

How well did you know this?

Not at all

Perfectly

What happens to most of the antibodies that are created by B lymphocytes?

They are secreted from the B cell and bind to antigens

How well did you know this?

Not at all

Perfectly

What are Major Histocompatibility Complexes?

MHCs

The MHC is a group of genes that codes for MHC molecules, which are expressed on the surface of all endogenous cell

What is a cytokine?

any mediator molecule released by any immune system cell

Cytokine is the generic term anything other than an antibody that is released by immune cells

What is a lymphokine?

a cytokine released by a lymphocyte

What is a monokine?

a cytokine released by a mononuclear phagocyte

Antibody production requires three types of cells:

APCs, which activate CD4 cells (because CD4 cells can’t recognize antigen that is free in solution. It has to be bound to an MHCII molecule)

CD4 cells, which stimulate B cells

B cells, which actually make the antibody

How does antibody production begin?

With the binding of an antigen to either a virgin B cells or an APC

When a CD4 cells binds with the processed antigen on a C cell, what happens?

The B cell proliferates and differentiates into Plasma Cells (which produce antibodies) and Memory B Cells (which lie in wait)

What happens after an antigen binds with an antibody on a B cell?

The receptor-antigen complex is internalized The antigen is broken down into small peptide fragments Each fragment is combined with a class II MHC The antigen-MHCII complex is transported to the cell surface A CD4 cell recognizes and binds with the antigen-MHCII complex on the B cell The CD4 cell secretes cytokines, some of which stimulate the B cell to proliferate and differentiate

How do antibodies destroy molecules attached to antigens?

They don't Antibodies just bind with antigens. They don't have any other powers Antibodies work in conjunction with phagocytes and the complement system to kill x, y, and z

The only antigens that antibodies can neutralize without help are:

bacterial toxins and viruses That's because with these, if you block the binding site (the antigen), you take away the complete effect of the toxin/virus No action is needed other than just binding

What are opsonins?

Antibodies that have bound to bacteria The opsonin give the phagocytes essentially a handle to grab in bacteria that would otherwise be too slippery to grab and phagocytize

What is the classical pathway for complement activation?

C1 encounters an antigen-antibody complex and binds with it C1 cannot bind with antigens that are free in the serum, so it can't activate an immune response. The antigen has to be bound as a complex

What is the end result of complement activation?

Lysis by Membrane Attack Complexes (formed by the complement cascade, literally poke a big hole in the target membrane and cause lysis)

There are two branches of cell-mediated immunity:

1. CD4 cells and lymphocytes/macrophages (responsible for delayed hypersensitivity AKA Type IV Hypersensitivity) 2. CD8 cells, which result in target cell destruction

What is the purpose of Type IV hypersensitivity?

To rid the body of bacteria that replicate INSIDE OF macrophages (listeria, mycobacterium tuberculosis)

How is activation of CD8 cells different from activation of CD4 cells?

CD4 cells are activated by Antigen-MHCII complexes on APCS CD8 cells are activated by Antigen-MHCI complexes on APCs

The principal job of CD8 cells is:

to kill self cells that are infected with viruses, halting viral replication AND transplant rejection

Which cells have MHC II molecules? Which cells have MHC I molecules?

Type II: B cells and and APCs Type I: Literally all other cells in the body

Should you give a child tylenol before vaccines?

No. It reduces immune response and it also just doesn't work

Which forms of hepatitis have a vaccine?

A and B

In the periphery, Histamine is synthesized and stored in two types of cells:

Basophils Mast Cells

The allergic release of histamine requires:

prior exposure to the allergn

The initial requirement for allergic release of histamine is production of _______ antibodies

IgE

What are the effects of H1 stimulation?

Vasodilation Bronchoconstriction Increased Capillary Permeability Itching and Pain Wakefulness and seizure prevention

Why aren't histamines helpful in asthma?

Histamines cause bronchoconstriction if administered exogenously, but histamine doesn't cause the level of bronchoconstriction that causes an asthma attack

The symptoms of mild allergies are usually caused by \_\_\_\_\_

Histamine Severe reactions are usually NOT due to histamine

Low doses of antihistamine can cause CNS: Overdose with antihistamines can cause CNS:

Low dose: Sedation High: seizures (histamine has a seizure-prevention role

Why do antihistamines have anticholinergic effects

They possess weak atropine-like properties

What is the other name for fexofenadine?

Allegra

Promethazine carries a black box warning for:

Causing fatal respiratory depression in children \< 2 years