TY - JOUR T1 - Characterization of T-Cell Memory Phenotype after <em>In Vitro</em> Expansion of Tumor-infiltrating Lymphocytes from Melanoma Patients JF - Anticancer Research JO - Anticancer Res SP - 4099 LP - 4109 VL - 31 IS - 12 AU - JUHUA ZHOU AU - PRAKASH NAGARKATTI AU - YIN ZHONG AU - MITZI NAGARKATTI Y1 - 2011/12/01 UR - http://ar.iiarjournals.org/content/31/12/4099.abstract N2 - Memory T-cell populations in human antitumor tumor-infiltrating lymphocytes (TILs) for adoptive cell transfer have not been fully characterized. Our studies demonstrated that CD62L, CD27 and CD28 positive effector memory T-cells were present in the TIL samples from the tumor tissues of melanoma patients and T-cell expansion led to the significant loss of memory T-cells. CD27- and CD28-positive T-cells had high levels of CD44 expression. T-Cell expansion resulted in significant down-regulation of CD44 expression. Interleukin-2 (IL-2) and anti-CD3 antibody stimulation may be responsible for CD44 down-regulation on CD8+ T-cells during expansion. Furthermore, CD44 down-regulation using small interfering RNA (siRNA) on TILs dramatically reduced interferon-gamma and IL-2 release upon tumor stimulation. These results suggest that the regulation of CD44 expression in TILs may play an important role in memory T-cell maintenance and antitumor immune response. ER -