Gerald Pier, Harvard Medical School

Molecular Factors Mediating Immunity Targeting the Conserved Microbial Surface Polysaccharide, Poly-N-Acetyl Glucosamine

Poly-N-acetyl glucosamine (PNAG) is a broadly expressed surface or capsular polysaccharide detected on major bacterial and eukaryotic pathogens. Natural antibody to PNAG is generally poorly effective at mediating protection against infection, but by using modified glycoforms of the antigen antibodies can be elicited or selected from libraries that have the ability to kill target organisms facilitated by activation of the classical pathway of complement. Protective efficacy has been validated in a broad range of mouse systems of infection with different organisms and in pigs challenged with Actinobacillus pleuropneumoniae. The unexpected discovery by multiple investigators of a highly conserved surface antigen on most major pathogens, and means to engender effective immunity, opens up the potential for a single vaccine to provide partial or perhaps complete protection against many of the major infectious agents relevant to animal and human health.