Chevalier de Lamarck

Different organisms originated separately by spontaneous generation from nonliving matter.

We now see a hierarchy of species because they differ in age

Species differ from one another because they have different needs.

TLS Online TPP Program

#Id: 10300

#XL - Q Biochemistry

T-Cell Activation and Differentiation

TLS Online TPP Program

#Id: 10301

#XL - Q Biochemistry

Three signals are required for activation of a naïve T cell

TLS Online TPP Program

#Id: 10302

#XL - Q Biochemistry

Positive Costimulatory Receptors: ICOS

ICOS binds to another member of the growing B7 family, ICOS-ligand (ICOS-L), which is also expressed on a subset of activated APCs.

ICOS plays a key role in maintaining the activity of already differentiated effector and memory T cells.

TLS Online TPP Program

#Id: 10303

#XL - Q Biochemistry

T-cell costimulatory

TLS Online TPP Program

#Id: 10304

#XL - Q Biochemistry

Negative costimulation

TLS Online TPP Program

#Id: 10305

#XL - Q Biochemistry

Anergy versus clonal expansion