Some new views of the cell surface

Area of Science:

• Cell Biology
• Immunology
• Biochemistry

Background:

• Mammalian cell surfaces, including normal and tumor cells, are investigated using novel methods.
• Histocompatibility antigens are ubiquitous on mammalian cells and may act as adaptors for T cell receptor recognition of foreign antigens like viruses.
• Cell surface molecules, including histocompatibility antigens, are not static but move freely within the lipid bilayer of the cell membrane.

Purpose of the Study:

• To explore the dynamic nature of cell surface molecules and their interactions.
• To investigate the hypothesis that histocompatibility molecules function as adaptors for foreign antigen recognition.
• To elucidate the intracellular mechanisms controlling the motion and distribution of cell surface molecules.

Main Methods:

• Observation of cell surface protein clustering (capping) following cross-linking by antibodies or lectins.
• Investigation of the role of intracellular protein networks in regulating cell surface molecule dynamics.
• Analysis of the involvement of microfilaments and microtubules in anchoring cell surface receptors.

Main Results:

• Cross-linking of cell surface receptors leads to their aggregation into patches and subsequent capping.
• Mitogenic lectins, such as concanavalin A, bind to carbohydrate portions of receptors and induce cross-linking.
• Cross-linking of specific receptors can inhibit the motion of other cell surface receptors, indicating a general anchoring network.

Conclusions:

• Cell surface molecule mobility is regulated by an intracellular protein network.
• This network, potentially composed of microfilaments and microtubules, anchors cell surface receptors.
• Understanding these dynamics is crucial for cell-cell interactions and signaling.