Novel Human Tenascin-C Function-Blocking Camel Single Domain Nanobodies

Area of Science:

• Biochemistry
• Immunology
• Oncology

Background:

• Tenascin-C (TNC) is an extracellular matrix molecule known to promote tumor progression.
• Current methods for detecting TNC in clinical tissue samples are limited.
• TNC plays a role in immune suppression within the tumor microenvironment.

Purpose of the Study:

• To generate and characterize novel single-domain nanobodies specific for human TNC (hTNC).
• To evaluate the potential of these nanobodies for detecting hTNC in human tissues.
• To assess the functional impact of these nanobodies on TNC-mediated effects, including cell adhesion and immune cell tethering.

Main Methods:

• Generation of dromedary single-domain nanobodies (Nb3 and Nb4).
• Biochemical characterization using ELISA, western blot, and isothermal fluorescence titration.
• Microscopic analysis including negative electron microscopy, immunofluorescence, and immunohistochemistry.
• Functional assays assessing cell adhesion and dendritic cell immobilization.

Main Results:

• Nb3 and Nb4 were highly specific for hTNC, binding to distinct sequences within fibronectin type III repeats.
• Both nanobodies successfully detected hTNC in various human tissues, including tumors and ulcerative colitis samples.
• Nb3 and Nb4 restored tumor and mesangial cell adhesion to fibronectin/TNC substrata.
• The nanobodies blocked TNC-mediated tethering of dendritic cells.

Conclusions:

• Novel hTNC-specific nanobodies (Nb3 and Nb4) have been developed.
• These nanobodies are valuable tools for detecting TNC in clinical settings.
• The nanobodies can inhibit TNC's pro-tumorigenic functions, including immune suppression and impaired cell adhesion, offering therapeutic potential.