Zwitterionic polysaccharides (ZPSs)

Zwitterionic polysaccharides (ZPSs), a newly described class of bacterial polysaccharides, elicit T cell-derived chemokines and cytokines that influence the immune response governing at least one classic host response to bacterial infection: abscess formation.
Tzianabos et al. 2003

They are structurally diverse, but all share a zwitterionic charge motif that allows them to directly interact with T cells and antigen-presenting cells to initiate an immunomodulatory T cell response.
Tzianabos et al. 2003

see also:
Capsular Polysaccharides (CPSs)