Structure/functions | Normal immune cells | Cancer cells |
Expression of antigen receptors | I. Immunoglobulins are expressed by B cells II. T cell receptors are expressed by T cells | Both antigen receptors are expressed by cancer cells and are of a single clone |
Class switching of immunoglobulins | Yes. In B cells | No |
Hypermutation of variable regions of immunoglobulins | High frequency | Low frequency |
Glycosylation patterns (unique) | No O-linked glycosylation and only one N-linked glycosylation at N297 position of IgG heavy chains; terminal NeuAc only (not
| Both O-linked and N-linked glycans are detected in cancerous IgG heavy chains with terminal NewAc and NuGc (O-linked glycan recognized by RP215 Mab |
Interactions with TLRs (based on gene expression studies) | No known interactions with TLRs | Strong interaction with TLRs within cancer cells |
Relative immunoactivity | Normal immunoactivity | Weak immunoactivity (less than 1% - 5%) due to aberrant glycosylations |
Function assays (apoptosis and CDC reactions) | No known effect | Induced apoptosis and CDC reactions by RP215 and anti-antigen receptors (in vivo nude mouse models) |