Identification and characterization of the T lymphocyte adhesion receptor for an alternative cell attachment domain (CS-1) in plasma fibronectin | JoVE Visualize

Identification and characterization of the T lymphocyte adhesion receptor for an alternative cell attachment domain (CS-1) in plasma fibronectin

E A Wayner¹, A Garcia-Pardo, M J Humphries

¹Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.

The Journal of Cell Biology|September 1, 1989

View abstract on PubMed

Summary

This study identifies alpha 4 beta 1 as a new fibronectin receptor on T lymphocytes, distinct from alpha 5 beta 1. It clarifies their specific roles in cell adhesion to fibronectin domains.

Area of Science:

Cell Biology
Immunology
Molecular Biology

Background:

Fibronectin is a key extracellular matrix protein involved in cell adhesion.
Integrin receptors mediate cell adhesion to fibronectin, but specific receptors for different fibronectin domains were not fully elucidated.
T lymphocytes utilize specific adhesion mechanisms for migration and function.

Purpose of the Study:

To identify and characterize the fibronectin receptors involved in T lymphocyte adhesion.
To determine the specific fibronectin domains recognized by different integrin receptors on T lymphocytes.
To elucidate the roles of alpha 4 beta 1 and alpha 5 beta 1 integrins in T cell adhesion.

Main Methods:

Monoclonal antibody (mAb) technology was used to identify and characterize fibronectin receptors.
T lymphocyte adhesion assays were performed using various fibronectin fragments.
Immunofluorescence microscopy localized integrin receptors to focal adhesions.

Main Results:

Monoclonal antibodies identified alpha 4 beta 1 as a novel fibronectin receptor on T lymphocytes.
Alpha 4 beta 1 specifically binds to the Heparin II and IIICS domains of fibronectin, including the CS-1 region.
Alpha 5 beta 1 binds to the RGD-containing domain of fibronectin.
Both alpha 4 beta 1 and alpha 5 beta 1 were localized to focal adhesions.

Conclusions:

Cultured T lymphocytes use two independent fibronectin receptors: alpha 5 beta 1 for the RGD domain and alpha 4 beta 1 for the carboxy-terminal Heparin II/IIICS domains.
Alpha 4 beta 1 is the primary receptor for the CS-1 adhesion site within the IIICS domain.
These findings clarify the distinct roles of integrin receptors in T lymphocyte adhesion to specific fibronectin regions.