When HIV invades the human body, it must contend with the considerable forces that are at the disposal of the immune system. * A defense network composed of white blood cells is produced in the bone marrow.
हेल्पर टी सेल नावाच्या पेशी प्रतिकार यंत्रणेत महत्त्वाची भूमिका बजावतात.