Supplementary MaterialsSupplementary Info. the median Lox-1+ PMN-MDSC percentage showed the opposite trend. NK cell frequencies significantly increased in responders but not in non-responders. NK cell frequency inversely correlated with that of Lox-1+ PMN-MDSCs after the first treatment cycle. The NK cell-to-Lox-1+ PMN-MDSC ratio (NMR) was significantly higher in responders than in non-responders. Patients with NMRs 5.75 after the first cycle had significantly higher objective response rates and longer progression-free and overall survival than those with NMRs 5.75. NMR shows promise as an early predictor of response to further anti-PD-1 therapy. (%)mutation7 (11.3)or rearrangement1 (1.6)Wild type54 (87.1)Previous treatmentChemotherapy35 (56.4)Targeted therapy9 (14.5)Immunotherapy0 (0)Surgery4 (6.4)Radiotherapy7 (11.2)No. of prior therapies129 (46.8)212 (19.4) 221 (33.8) Open in a separate window Immune-cell frequencies differ between Nivolumab responders and non-responders after treatment To determine the effect of anti-PD-1 therapy on immune cells, we SCH 442416 monitored T cells, B cells, NK cells, monocytes, and MDSCs in the peripheral blood of patients with advanced NSCLC both before and after the first round of nivolumab therapy. We also monitored the proportions of the M-MDSC and PMN-MDSC subsets as well as the expression of lectin-type oxidised low-density lipoprotein receptor 1 (Lox-1), which distinguishes between PMN-MDSCs and neutrophils (Fig.?1)12. Open in a separate window Figure 1 Gating strategies for peripheral blood immune cells. (A) Strategies for lymphocytes: CD19+ B cells, CD56+NK cells, CD3+CD56+NKT cells, CD3+ total T cells, CD3+CD4+ T cells, and CD3+CD8+ T cells. (B) Strategies for MDSCs: HLA-DR-/lowCD11b+Compact disc14+ M-MDSCs, Compact disc14-Compact disc11b+Compact disc33+Compact disc15+ PMN-MDSCs, and Lox-1+ PMN-MDSCs. Singlet cells were deceased and selected cells were removed in line with the scatter story. At baseline, there have been no significant distinctions in the frequencies from the examined immune system cells between responders and nonresponders (Supplementary Fig.?1). Following the initial treatment, the median percentage of NK cells was higher in responders, whereas the median percentage of Lox-1+ PMN-MDSCs within the responders was greater than that within the nonresponders (Fig.?2A). There is a significant upsurge in the NK cell regularity after the initial treatment within the responders however, not within the nonresponders (Fig.?2B). Nevertheless, there have been no significant distinctions in frequencies of Compact disc4+ SCH 442416 T, Compact disc8+ T, Compact disc19+ B, NKT cells, Compact disc14+ monocytes or NLR (Supplementary Fig.?1). Open up in another window Body 2 (A) Percentages of NK cells and Lox-1+ PMN-MDSCs among CD45+ T cells in non-responders and responders at 2 weeks SCH 442416 after the first round of nivolumab. Dot plots represent frequencies of immune cells, and small horizontal lines indicate means (SD). (B) Changes in NK frequencies between baseline and after the first nivolumab treatment in non-responders and responders. Each dot indicates a single patient. *mutation, and PD-L1 expression, the adjusted hazard ratios (AHRs) for the risk of progression and OS after anti-PD-1 therapy were significant in patients with an NMR??5.75 (Table?2). Taken together, these data suggest that NMR after the first cycle of anti-PD-1 therapy strongly correlated with treatment outcomes, including ORR, PFS, and OS, in NSCLC patients. Table 2 Factors affecting the progression-free survival and overall survival in patients after anti-PD-1 therapy based on multivariate analysis. engagement of death receptors, secreting granzymes/perforins, and antibody-dependent cell-mediated cytotoxicity15. Recent studies have exhibited that NK cells also play pivotal roles in cancer immunotherapy. When NK cells were depleted in mice, PD-1/PD-L1 blockade was completely ineffective14. In addition, the anti-tumour activity of NK cells was inhibited by PD-1/PD-L1 interactions and was restored by PD-1/PD-L1 blockade. Another immune-checkpoint molecule, the T Rabbit polyclonal to ACBD6 cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain name (TIGIT), was shown to mediate NK cell exhaustion in cancer, with the blockade of TIGIT restoring the anti-tumour activity of NK cells16. Moreover, TIGIT inhibition promoted tumour-specific T cell immunity and enhanced the survival of tumour-bearing mice, depending on the presence of NK cells. An increased frequency of NK cells has generally been correlated with an improvement in the OS of patients17. Recent clinical studies SCH 442416 have exhibited the contribution of NK cells in cancer patients treated with ICI. In patients with NSCLC treated with ICI, an allelic variant of the NK-cell receptor was associated with the NK-cell antitumor activity18. In metastatic melanoma, the frequencies of both intratumoral stimulatory dendritic cells and NK cells correlated with responsiveness to anti-PD-1 therapy19. MDSCs are one of the main factors in creating an.