Resumen:
lycans are a class of molecules with high structural variability,
frequently found in the plasma membrane facing the extracellular space.
Because of these characteristics, glycans are often considered as
recognition molecules involved in cell social functions, and as targets
of pathogenic factors. Induction of anti-glycan antibodies is one of
the early events in immunological defense against bacteria that
colonize the body. Because of this natural infection, antibodies
recognizing a variety of bacterial glycans are found in sera of adult
humans and animals. The immune response to glycans is restricted by
self-tolerance, and no antibodies to self-glycans should exist in
normal subjects. However, antibodies recognizing structures closely
related to self-glycans do exist, and can lead to production of harmful
anti-self antibodies. Normal human sera contain low-affinity anti-GM1
IgM-antibodies. Similar antibodies with higher affinity or different
isotype are found in some ne