Bharat Ankit, Benshoff Nicholas, Fleming Timothy P, Dietz Jill R, Gillanders William E, Mohanakumar T
Department of Surgery, Washington University School of Medicine, 660 South Euclid Avenue, 3328 CSRB, P.O. Box 8109-3328, St. Louis, MO 63110, USA.
Breast Cancer Res Treat. 2008 Aug;110(3):453-63. doi: 10.1007/s10549-007-9741-2. Epub 2007 Sep 15.
Mammaglobin-A(mam-A) is expressed in over 80% of human breast tumors. We recently reported that mam-A DNA vaccination resulted in breast cancer immunity in a preclinical model. Here we investigated whether mam-A HLA-class-I tetramers could be used to monitor and define the role of CD8(+)cytotoxic T-lymphocytes(CTL) in mediating breast cancer immunity following mam-A DNA vaccination.
Mam-A DNA vaccination was performed in HLA-A2(+)huCD8(+ )transgenic mice. HLA-A2 tetramers carrying the immunodominant mamA2.1 peptide were used to monitor CD8(+)CTL. Human breast cancer colonies were developed in immunodeficient SCID-beige mice. ELISPOT was used to correlate frequency of mamA2.1 tetramer(+)CD8(+)T cells and IFN-gamma production [spots per million cells (spm)] in human subjects.
Vaccination of HLA-A2(+)huCD8(+) mice with mam-A DNA vaccine, but not empty vector, led to the expansion of mamA2.1 tetramer(+)CD8(+)T-cells in peripheral blood (<0.5% pre-vaccination compared to >2.0% post-vaccination). CD8(+)T cells from vaccinated mice specifically lysed UACC-812(HLA-A2(+)/mam-A(+), 25% lysis) but not MDA-MB-415(HLA-A2(-)/mam-A(+)) or MCF-7(HLA-A2(+)/mam-A(-)) breast cancer cells. Adoptive transfer of purified CD8(+)T cells from vaccinated mice into immunodeficient SCID-beige mice with established human breast cancer colonies led to tetramer(+)CD8(+ )T-cell infiltration with regression of UACC-812 but not MCF-7 tumors. HLA-A2(+) breast cancer patients revealed increased frequency of mamA2.1 tetramer(+)CD8(+ )T-cells compared to normal controls (2.86 +/- 0.8% vs. 0.71 +/- 0.1%, P = 0.01) that correlated with the IFN-gamma response to mamA2.1 peptide (48.1 +/- 20.9 vs. 2.9 +/- 0.8 spm, P = 0.03).
CD8(+ )T-cells are crucial in mediating breast cancer immunity following mam-A DNA vaccination. Mam-A HLA-class-I tetramers can be effectively used to monitor development of CD8(+ )T-cells following mam-A vaccination.
乳腺珠蛋白-A（mam-A）在超过80%的人类乳腺肿瘤中表达。我们最近报道，在临床前模型中，mam-A DNA疫苗接种可产生乳腺癌免疫。在此，我们研究了mam-A HLA-I类四聚体是否可用于监测和确定CD8(+)细胞毒性T淋巴细胞（CTL）在mam-A DNA疫苗接种后介导乳腺癌免疫中的作用。
在HLA-A2(+)huCD8(+)转基因小鼠中进行mam-A DNA疫苗接种。携带免疫显性mamA2.1肽的HLA-A2四聚体用于监测CD8(+)CTL。在免疫缺陷的SCID-米色小鼠中培养人乳腺癌集落。采用酶联免疫斑点法（ELISPOT）关联人类受试者中mamA2.1四聚体(+)CD8(+)T细胞的频率与干扰素-γ产生[每百万细胞中的斑点数（spm）]。
用mam-A DNA疫苗而非空载体对HLA-A2(+)huCD8(+)小鼠进行疫苗接种，导致外周血中mamA2.1四聚体(+)CD8(+)T细胞扩增（接种前<0.5%，接种后>2.0%）。接种疫苗小鼠的CD8(+)T细胞特异性裂解UACC-812（HLA-A2(+)/mam-A(+)，25%裂解），但不裂解MDA-MB-415（HLA-A2(-)/mam-A(+)）或MCF-7（HLA-A2(+)/mam-A(-)）乳腺癌细胞。将接种疫苗小鼠纯化的CD8(+)T细胞过继转移到已建立人乳腺癌集落的免疫缺陷SCID-米色小鼠中，导致四聚体(+)CD8(+)T细胞浸润，UACC-812肿瘤消退，但MCF-7肿瘤未消退。与正常对照相比，HLA-A2(+)乳腺癌患者的mamA2.1四聚体(+)CD8(+)T细胞频率增加（2.86±0.8%对vs.0.71±0.1%，P = 0.01），这与对mamA2.1肽的干扰素-γ反应相关（48.1±20.9对vs.2.9±0.8 spm，P = 0.03）。
CD8(+)T细胞在mam-A DNA疫苗接种后介导乳腺癌免疫中起关键作用。Mam-A HLA-I类四聚体可有效用于监测mam-A疫苗接种后CD8(+)T细胞的发育。
