1 Several membrane molecules in addition to the Tcell recept

1. Several membrane molecules, in addition to the T-cell receptor, are involved in antigen recognition. Describe the properties and distinct functions of the following T-cell membrane molecules: a) CD3; b)CD3 and CD4, and c)Zeta chain.

2. Indicate whether each of the properties listed below applies to the T-cell receptor (TCR), B-cell immunoglobulin (Ig), or both (TCR/Ig).
a.   _______ Is associated with CD3
b.   _______ Is monovalent
c.   _______ Exists in membrane-bound and secreted form
d.   _______ Contains domains with immunoglobulin-fold structure
e.   _______ Is MHC restricted
f.   _______ Exhibits diversity generated by imprecise joining of gene segments
g.   _______ Exhibits diversity generated by somatic mutation.

Solution

1.

a) CD3 : (cluster of differeniation)

it activate Tc cells (cytotoxic)

b) CD3 and CD4:

It activate Th cells

zieta chain it is TCR

2.

a. TCR

b.B-cell

c.B-cell

d. Immunoglobulin

e.TCR

f.both (TCR/Ig)

g.TCR