Once inside the body, hiv's surface glycoproteins can mutate to recognize a new type of cell receptor. how does this mutation aid the virus in its life cyle

To kill a foreign object, the white blood cells need to recognize the object by looking at their cell receptor. If the virus changes its receptor, it won't be recognized by the white blood cells. The immune system cant fight the infection if they don't learn to recognize the new form of the virus. This makes the virus hard to fight