chapter 16 pt.2

There are 5 classes of antibodies and these classes are determined based on the _____ _____– IgM, IgG, IgA, IgD, and IgE

heavy chain

Make up the majority of antibody-based immunity against microbes
Can opsonize
Can cross the placenta

IgG

Secretory antibody found in mucosal surfaces like tears, breast milk, and saliva
Typically found in the form of a dimer molecule (two IgA molecules bound
together

IgA

o Can be found as a monomer or as a pentamer (5 IgM molecules bound together) molecule
In its monomer form, it can be found attached to B cells serving as a B cell
receptor
o The first type of antibody produced and detected in an immune response

IgM

Rarely found in circulation
Predominately found bound to B cells to serve as a B cell receptor with IgM

IgD

Found bound to mast cells and basophils and control a mast cell’s degranulation events

IgE

Antibody activation WITHOUT helper T cells

This process is called _______

Capping

Antibody activation WITHOUT helper T cells

____ and ____ make up the B cell receptors on a B cell – when identical repeating epitopes of an antigen bind to the B cell receptors (IgM and IgD), it can cause the B cell receptors to cross-link and cluster together

IgM and IgD

Antibody activation WITHOUT helper T cells

When multiple _______ repeating epitopes bind and cause the cross-linking of
the B cell receptors, this can trigger B cell activation into clonal selection, where
the B cell makes multiple copies of itself to produce plasma cells and memory
cells

identical

Antibody activation WITHOUT helper T cells

ONLY IgM IS SECRETED WHEN A B CELL IS ACTIVATED VIA
_____ – there is no antibody class switching

CAPPING

Antibody activation WITH helper T cells
Antigens that do not contain identical repeating epitopes will bind to the B cell
receptors will not cause capping, but will trigger _______ – the B cell brings
the antigen into the cell and will then present the antigen on its MHC-II proteins

endocytosis

Antibody activation WITH helper T cells
An APC will communicate with a naïve helper T cell – the APC will present its
antigen to the naïve helper T cell and will trigger the helper T cell to differentiate
into a ___cell

TH2

Antibody activation WITH helper T cells
The TH2 Cell will go find the ______ _ ____that is presenting the same antigen
that the TH2 cell was shown by the APC

inactive B cell

Antibody activation WITH helper T cells

The TH2 cell will bind to the B cell’s _______ protein (activation signal 1)

MHC-II

Antibody activation WITH helper T cells

The _____ on the T cell will bind to the CD40 molecule on the B cell (activation
signal 2

CD40L

What triggers the B cell to become active, and it will start
differentiating and producing both plasma cells and memory cells?

CD40L on the T cell will binding to the CD40 molecule on the B cell

Activation with the help of a TH2 cell allows for what?

antibody class switching