Who does the polarizing? Page 1 SUSAN L. SWAIN T-CELL SUBSETS Who does the
polarizing? T cells can 'polarize' into T1 and T2 effector cell types in response to distinct
cytokines. T cells and cells presenting antigen to the T cells are themselves candidate sources
of these polarizing cytokines. As they develop, T cells can become 'polarized' and restricted to
producing either T1 or T2 patterns of cytokines: interleukin (IL)-12 and interferon y on the one
hand (T1), and IL-4 on the other (T2). The T1 and T2 T-cell subsets mediate largely …