self

a self bow: one made from a single piece of wood

I owe you much, and, like a wilful youth

That which I owe is lost; but if you please

To shoot another arrow that self way

Which you did shoot the first, I do not doubt,

As I will watch the aim, or to find both,

Or bring your latter hazard back again,

And thankfully rest debtor for the first.

Similarity profiles between helper T cell epitopes (of self or microbial antigens and allergens) and human or microbial SWISSPROT collections were produced. For each antigen, both collections yielded largely overlapping profiles, demonstrating that self-nonself discrimination does not rely on qualitative features that distinguish human from microbial peptides. However, epitopes whose probability of mimicry with self or nonself prevails are, respectively, tolerated or immunodominant and coexist within the same (auto-)antigen regardless of its self/nonself nature. Epitopes (on self and nonself antigens) can cross-stimulate T cells at increasing potency as their similarity with nonself augments.