Antigenic liposomes displaying CD22 ligands induce antigen-specific B cell apoptosis

Area of Science:

• Immunology
• Nanotechnology
• Biotechnology

Background:

• Antibodies are crucial for immunity but can cause harm when targeting self, foreign, or therapeutic antigens.
• Current strategies for suppressing unwanted antibody responses, especially to T cell-dependent antigens, are limited.
• Inhibitory antibodies to Factor VIII (FVIII) pose a significant challenge in hemophilia A treatment.

Purpose of the Study:

• To develop novel antigen-specific strategies for suppressing undesired antibody responses.
• To investigate the potential of SIGLEC-engaging tolerance-inducing antigenic liposomes (STALs) for inducing B cell tolerance.
• To evaluate the efficacy of STALs in preventing inhibitory antibody formation against FVIII in a hemophilia mouse model.

Main Methods:

• Liposomal nanoparticles were engineered to display both antigen and glycan ligands for the inhibitory coreceptor CD22.
• These STALs were administered to mice to assess their ability to induce antigen-specific tolerance.
• The efficacy of STALs in preventing anti-FVIII antibody formation and enabling FVIII therapy was tested in a hemophilia mouse model.

Main Results:

• STALs induced a tolerogenic program, selectively causing apoptosis in mouse and human B cells.
• STALs generated robust antigen-specific tolerance to protein antigens in mice, preventing subsequent immune responses.
• In a hemophilia mouse model, STALs successfully prevented the formation of inhibitory FVIII antibodies, allowing effective FVIII treatment.

Conclusions:

• STALs represent a novel approach for inducing antigen-specific tolerance by targeting B cells via CD22.
• This technology effectively prevents harmful antibody responses to protein antigens, including therapeutic proteins like FVIII.
• STALs hold potential for eliminating or preventing detrimental B cell-mediated immune responses in various clinical settings.