Project Grant R21AI202536

The National Institute of Allergy and Infectious Diseases awarded Emory University $234,750 on August 19, 2026, under the Allergy and Infectious Diseases Research program (CFDA 93.855) to support molecular engineering research on immunoglobulin G3 (IgG3) therapeutic potential.

The research addresses the underdevelopment of IgG3 as a clinical therapeutic agent despite its superior effector mechanism potency and flexible antigen-binding properties compared to other immunoglobulin subclasses. While IgG1, IgG2, and IgG4 have found widespread use in monoclonal antibody therapeutics—IgG1 for cell-killing applications such as trastuzumab and rituximab, IgG2 for receptor blocking or neutralizing antibodies such as panitumumab, and IgG4 for chronic diseases and immune checkpoint inhibitors such as nivolumab—IgG3 has seen minimal clinical development. The project employs protein engineering to optimize IgG3's FcRn interaction to extend its in vivo half-life and define its full range of achievable effector mechanism activation through Fcγ receptor interactions. Technical obstacles to IgG3 development include its short in vivo half-life, multiple allotypes, purification challenges, and pH stability issues.

Performance occurs in Atlanta, Georgia. The award runs through July 31, 2028. This is a Project Grant, the standard assistance type for research project support under NIAID's infectious disease research program.