Non-Protein Antigens

T cell–independent (TI) B cell responses to Non-Protein Antigens involve multiple cues from the innate immune system
Cumpelik et al. 2023 J Immunol 210(1): 19-23

Neutrophils express Complement receptors, and activated neutrophils can release BAFF
Cumpelik et al. 2023 J Immunol 210(1): 19-23

Sequential activation of complement on neutrophils crucially supports humoral TI and mucosal IgA responses through upregulating neutrophil production of B cell-activating factor (BAFF)
Cumpelik et al. 2023 J Immunol 210(1): 19-23

There aB cells / B Lymphocytesre antibodies to non-protein antigens such as nucleic acids, polysaccharides, and glycolipids. They play essential roles against microbes and the development of autoimmune diseases.
Tsubata 2022 Immunological Reviews 307: 53-65

Non-protein antigens are not recognized by T cells.
Tsubata 2022 Immunological Reviews 307: 53-65

B cell response to non-protein self-antigens such as nucleic acids and gangliosides, sialic acid-containing glycolipids are suppressed by inhibitory B cell co-receptors CD72 and Siglec-G, respectively.
Tsubata 2022 Immunological Reviews 307: 53-65

How carbohydrates and glycopeptides are recognized by T cells: Pure carbohydrates do not interact with MHC molecules in a significant manner. T cells don't recognize glycopeptides removed from the core MHC-binding region. Some glycosylation of proteins destroys MHC binding and T cell recognition. Some glycosylation of proteins doesn't ablate MHC binding or T cell recognition.
Ishioka et al., 1992 J. Immunol. 148: 2446–2451

However, even the carbohydate moiety is an important part of the antigenic determinant recognized by T cells.
Ishioka et al., 1992

see also:
Acquired Immune System / Adaptive Immune System
Antigen recognition / Antigen presentation