試題詳解

42. Which of the following is not true about helper T cells?
(A) They function in both cell-mediated and humoral immune responses.
(B) They bear surface CD4 molecules.
(C) They recognize polysaccharide fragments presented by infected cells.
(D) They are subject to infection by HIV.
(E) When activated, they secrete cytokines that stimulate other lymphocytes.