Question

under NORMAL circumstances, which of the following is NOT an antigen (or not likely to be an antigen)?

Group of answer choices

a-molecules bound by TCR

b-molecules bound by soluble antibodies and BCR

c-viral or bacterial components

d-host/self molecules

e-molecules that the immune system (T and B cells) can recognize, bind and respond to

Answer 1

Ans. Any foreign / non-self substance / chemical for our body / cells is known as antigen. If an antigen induce immune response (like induction of antibody production ) then it is called as immunogen. Like virus, bacteria, toxins etc. are antigens.

Antigens are bound to receptors present on immune cells (B and T cells). They bind to B cell receptors (BCR), free antibodies, T cell receptors (TCR) etc. B cells produce antibody against the antigen and an antigen binds to its specific antibody.

So, the option not correct for antigen is (d): self molecules. Our bodies don't consider chemicals / molecules present /synthesized in our body itself.