CIS deletion by CRISPR/Cas9 enhances human primary natural killer cell functions against allogeneic glioblastoma.

BACKGROUND: Glioblastoma (GBM) is the most common malignant brain tumor and has "immunologically cold" features. Changing GBM to an "immunologically hot" tumor requires a strong trigger that induces initial immune responses in GBM. Allogeneic natural killer cells (NKCs) have gained considerable attention as promising immunotherapeutic tools against cancer, where gene-edited NKCs would result in effective anti-cancer treatment. The present study focused on the immune checkpoint molecule cytokine-inducible SH2-containing protein (CISH, or CIS) as a critical negative regulator in NKCs. METHODS: The GBM tumor environment featured with immunological aspect was analyzed with Cancer immunogram and GlioVis. We generated human primary CIS-deleted NKCs (NK dCIS) using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) with single guide RNA targeting genome sites on CIS coding exons. The genome-edited NKCs underwent microarray with differential expression analysis and gene set enrichment analysis (GSEA). The anti-GBM activity of the genome-edited NKCs was evaluated by apoptosis induction effects against allogeneic GBM cells and spheroids. We further detected in vivo antitumor effects using xenograft brain tumor mice. RESULTS: We successfully induced human CIS-deleted NKCs (NK dCIS) by combining our specific human NKC expansion method available for clinical application and genome editing technology. CIS gene-specific guide RNA/Cas9 protein complex suppressed CIS expression in the expanded NKCs with high expansion efficacy. Comprehensive gene expression analysis demonstrated increased expression of 265 genes and decreased expression of 86 genes in the NK dCIS. Gene set enrichment analysis revealed that the enriched genes were involved in NKC effector functions. Functional analysis revealed that the NK dCIS had increased interferon (IFN)ɤ and tumor necrosis factor (TNF) production. CIS deletion enhanced NKC-mediated apoptosis induction against allogeneic GBM cells and spheroids. Intracranial administration of the allogeneic NKCs prolonged the overall survival of xenograft brain tumor mice. Furthermore, the NK dCIS extended the overall survival of the mice. CONCLUSION: The findings demonstrated the successful induction of human primary NK dCIS with CRISPR/Cas9 with efficient expansion. CIS deletion enhanced the NKC-mediated anti-tumor effects in allogeneic GBM and could be a promising immunotherapeutic alternative for patients with GBM.

Circulating tumor cells detected only after surgery for non-small cell lung cancer: is it a predictor of recurrence?

BACKGROUND: Surgical manipulation of a tumor can lead to shedding of tumor cells that can enter the circulation and lead to metastasis. The present study evaluated the clinical relevance of circulating tumor cells (CTCs) that were identified immediately after non-small cell lung cancer resection in patients without preoperative CTCs, and whether postoperative CTC detection was associated with recurrence. METHODS: Immediate preoperative testing for CTCs was performed for 147 patients with pulmonary nodules. This study included 81 lung cancer patients (55.1%) with negative preoperative results for CTCs and who completed postoperative testing for CTCs. The clinical relevance of postoperative CTC detection was evaluated based on the clinicopathological characteristics and recurrence patterns. RESULTS: Among the eligible patients, the postoperative CTC results were none detected in 58 patients (71.6%, "Group N"), only a single CTC detected in 6 patients (7.4%, "Group S"), and CTC clusters detected in 17 patients (21.0%, "Group C"). The presence of postoperative CTCs was associated with tumor vessel invasion, lymph duct invasion, and pleural invasion. Distant metastasis was very common in cases with postoperatively detected CTC clusters. The 2-year recurrence-free survival rates were 94.6% for Group N, 62.5% for Group S, and 52.9% for Group C (P<0.01). Multivariate analysis revealed that recurrence was independently related to the postoperative detection of single CTCs and CTC clusters. CONCLUSIONS: In cases without preoperative CTCs, we postoperatively detected CTCs and the postoperative CTC results were an independent predictor of recurrence.

Cytotoxic human peripheral blood-derived γδT cells kill glioblastoma cell lines: implications for cell-based immunotherapy for patients with glioblastoma.

Glioblastoma (GBM) is a highly aggressive brain tumor for which novel therapeutic approaches, such as immunotherapy, are urgently needed. Zoledronate (ZOL), an inhibitor of osteoclastic activity, is known to stimulate peripheral blood-derived γδT cells and sensitize tumors to γδT cell-mediated killing. To investigate the feasibility of γδT cell-based immunotherapy for patients with GBM, we focused on the killing of GBM cell lines by γδT cells and the molecular mechanisms involved in these cell-cell interactions. Peripheral blood mononuclear cells were expanded in ZOL and interleukin (IL)-2 for 14 days, and γδT cells were enriched in the expanded cells by the immunomagnetic depletion of αßT cells. Gliomas are resistant to NK cells but susceptible to lymphokine-activated killer cells and some cytotoxic T lymphocytes. When the γδT cell-mediated killing of three GBM cell lines (U87MG, U138MG and A172 cells) and an NK-sensitive leukemia cell line (K562 cells) were tested, 32% U87MG, 15% U138MG, 1% A172, and 50% K562 cells were killed at an effector:target ratio of 5:1. The γδT cell-mediated killing of all three GBM cell lines was significantly enhanced by ZOL and this ZOL-enhanced killing was blocked by an anti-T cell receptor (TcR) antibody. These results indicated that TcR γδ is crucial for the recognition of ZOL-treated GBM cells by γδT cells. Since the low level killing of GBM cells by the γδT cells was enhanced by ZOL, γδT cell-targeting therapy in combination with ZOL treatment could be effective for patients with GBM.

Selective induction of antimicrobial peptides from keratinocytes by staphylococcal bacteria.

Staphylococcus aureus (S. aureus) is one of the most clinically important inflammation-inducing pathogens, while Staphylococcus epidermidis (S. epidermidis) is nonpathogenic and hardly causes inflammation on skin. ß-defensins, antimicrobial peptides, are secreted from keratinocytes constitutively or upon induction by various microorganisms. However, the difference between S. aureus and S. epidermidis is still unclear in terms of their influences on the production of ß-defensins. In this study, we focused on the influences of S. aureus and S. epidermidis on the keratinocyte innate immune response. Pathogenic S. aureus mainly induced human ß-defensin (hBD) 1 and hBD3, but not hBD2, and nonpathogenic S. epidermidis mainly induced hBD2 from human keratinocytes. Molecular weight fractions of >10 kDa prepared from S. aureus supernatants induced the production of hBD1 and hBD3. On the other hand, molecular weight fraction of >100 kDa prepared from S. epidermidis supernatants induced the production of hBD2.Furthermore, the secreted products of S. epidermidis used the toll-like receptor (TLR) 2 pathway in the induction of hBD2 production. The secreted products of S. aureus and S. epidermidis differentially induced subtypes of hBD through different receptors, which may be associated with the difference in virulence between these two bacteria.

Microbial exposure early in life regulates airway inflammation in mice after infection with Streptococcus pneumoniae with enhancement of local resistance.

The immunological explanation for the "hygiene hypothesis" has been proposed to be induction of T helper 1 (Th1) responses by microbial products. However, the protective results of hygiene hypothesis-linked microbial exposures are currently shown to be unlikely to result from a Th1-skewed response. Until now, effect of microbial exposure early in life on airway innate resistance remained unclear. We examined the role of early life exposure to microbes in airway innate resistance to a respiratory pathogen. Specific pathogen-free weanling mice were nasally exposed to the mixture of microbial extracts or PBS (control) every other day for 28 days and intratracheally infected with Streptococcus pneumoniae 10 days after the last exposure. Exposure to microbial extracts facilitated colonization of aerobic gram-positive bacteria, anaerobic microorganisms, and Lactobacillus in the airway, compared with control exposure. In pneumococcal pneumonia, the exposure prolonged mouse survival days by suppressing bacterial growth and by retarding pneumococcal blood invasion, despite significantly low levels of leukocyte recruitment in the lung. Enhancement of airway resistance was associated with a significant decrease in production of leukocyte chemokine (KC) and TNFalpha, and suppression of matrix metalloproteinase (MMP-9) expression/activation with enhancement of tissue inhibitor of MMP (TIMP-3) activation. The exposure increased production of IFN-gamma, IL-4, and monocyte chemoattractant-1 following infection. Furthermore, expression of Toll-like receptor 2, 4, and 9 was promoted by the exposure but no longer upregulated upon pneumococcal infection. Thus, we suggest that hygiene hypothesis is more important in regulating the PMN-dominant inflammatory response than in inducing a Th1-dominant response.