Najjar Yana G, Ding Fei, Lin Yan, VanderWeele Robert, Butterfield Lisa H, Tarhini Ahmad A
University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
Biostatistics Facility, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA.
J Transl Med. 2017 Feb 21;15(1):39. doi: 10.1186/s12967-017-1140-9.
In a previously reported study, patients with regionally advanced melanoma were treated with neoadjuvant ipilimumab (ipi) (Tarhini in PLoS ONE 9(2): e87705, 3). Significant changes in circulating myeloid derived suppressor cells (MDSC), regulatory T cells (Treg) and peptide specific type I CD4 and CD8 T cells were noted at week 6 that correlated with clinical outcome. Characterization of antigen-specific effector T cell secreted cytokines may shed insights into ipi associated T cell activation and function.
Patients were treated with neoadjuvant ipi (10 mg/kg every 3 weeks ×2) administered intravenously before and after surgery. Peripheral blood mononuclear cells (PBMC) that were collected at baseline and week 6 (after ipi) were tested here. Each sample was divided into 5 groups and stimulated with controls or shared melanoma antigen overlapping peptide pools (NY-ESO 1, gp-100, MART-1). Secreted cytokines, chemokines and growth factors were assessed using Luminex. Cytokine expression levels between the 3 antigen groups were compared using the Wilcox rank-sum test.
Seventeen cytokines were differentially expressed with stimulation by each antigen at baseline (p value <0.05): IL1β, MIP1β, IL1RA, VEGF, IL13, IL17, MIP1α, GM-CSF, MCP1, IL5, IL2R, IL4, IL10, IFNγ, TNFα, IL8 and IL2. At week 6, 15 cytokines were differentially expressed (p < 0.05): IL1β, VEGF, G-CSF, HGF, IL13, IL17, GM-CSF, MCP1, IL5, IL7, IL4, IL10, IFNγ, IL8 and IL2. Patients were later clustered based on cytokine expression levels at baseline and at week 6, and recurrence free survival (RFS) was compared. Clear differences in RFS were noted based on cytokine level clustering both at baseline and at week 6: Patients whose PBMCs secreted more cytokines in response to NY-ESO-1 showed a trend towards better RFS.
PBMCs of patients treated with ipi secreted significantly more cytokines, chemokines and growth factors in response to NY-ESO-1 than to gp-100 or MART-1. These cytokines belonged to different functional groups, including inflammatory, type 1, type 2 and regulatory, that warrant further study. Patients whose PBMCs secreted more cytokines (particularly in response to NY-ESO-1) tended to have better RFS, supporting further exploration in terms of therapeutic predictive value.
在一项先前报道的研究中，局部晚期黑色素瘤患者接受了新辅助伊匹单抗（ipi）治疗（Tarhini发表于《公共科学图书馆·综合》9(2): e87705, 2014年）。在第6周时，循环髓源性抑制细胞（MDSC）、调节性T细胞（Treg）以及肽特异性I型CD4和CD8 T细胞出现显著变化，且这些变化与临床结局相关。对抗原特异性效应T细胞分泌的细胞因子进行表征，可能有助于深入了解ipi相关的T细胞激活和功能。
患者在手术前后接受静脉注射新辅助ipi治疗（每3周10mg/kg，共2次）。对在基线和第6周（ipi治疗后）采集的外周血单个核细胞（PBMC）进行检测。每个样本分为5组，分别用对照或共享的黑色素瘤抗原重叠肽库（NY-ESO 1、gp-100、MART-1）进行刺激。使用Luminex技术评估分泌的细胞因子、趋化因子和生长因子。采用Wilcox秩和检验比较3个抗原组之间的细胞因子表达水平。
在基线时，每种抗原刺激后有17种细胞因子差异表达（p值<0.05）：IL1β、MIP1β、IL1RA、VEGF、IL13、IL17、MIP1α、GM-CSF、MCP1、IL5、IL2R、IL4、IL10、IFNγ、TNFα、IL8和IL2。在第6周时，有15种细胞因子差异表达（p<0.05）：IL1β、VEGF、G-CSF、HGF、IL13、IL17、GM-CSF、MCP1、IL5、IL7、IL4、IL10、IFNγ、IL8和IL2。随后根据基线和第6周时的细胞因子表达水平对患者进行聚类，并比较无复发生存期（RFS）。基于基线和第6周时的细胞因子水平聚类，RFS存在明显差异：PBMC对NY-ESO-1刺激分泌更多细胞因子的患者，其RFS有更好的趋势。
接受ipi治疗的患者的PBMC对NY-ESO-1刺激分泌的细胞因子、趋化因子和生长因子明显多于对gp-100或MART-1的刺激。这些细胞因子属于不同的功能组，包括炎症性、1型、2型和调节性，值得进一步研究。PBMC分泌更多细胞因子（特别是对NY-ESO-1的反应）的患者往往有更好的RFS，这支持在治疗预测价值方面进行进一步探索。
