The novel HLA-B*15:644 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-B*15:644 differs from HLA-B*15:17:01:02 by one nucleotide in exon 4.

[Effects of blocking inhibitory KIR receptors on cytotoxic activity of human NK cells in vitro].

OBJECTIVE: To investigate the effect of blocking the inhibitory receptors KIR2DL1 and KIR2DL2/2DL3 with monoclonal antibody on cytotoxic activity of human NK cells. METHODS: Human peripheral blood NK cells were isolated by Rosettesep NK sorting kit. The cytotoxic activity of NK cells against human leukemia NB4, K-562, Raji cells and allogeneic mature or dendritic cells (DCs) was detected before or after KIR2DL1 and KIR2DL2/2DL3 were blocked. The effect of NK cells on T lymphocyte proliferation was detected by mixed lymphocyte reaction and TGF-ß1 concentration in culture supernatant was measured. RESULTS: The cytotoxicity of NK cells to NB4 cells was augmented with increasing concentration of the antibody. Combination of both antibodies enhanced killing activity of NK cells. NK cells had strong cytotoxicity to K-562 cells, but were not enhanced by the blockade of inhibitory receptors. The cytotoxicity to Raji cells was not evidently augmented. The cytotoxicity of NK cells to mature DC was enhanced remarkably with the increase of concentration of the antibodies (2.20% ±1.10% compared with 37.59% ±5.06%, P<0.05). In mixed lymphocyte reaction, the blockade of two antibodies enhanced the inhibition effect of NK cells on T cell proliferation (77.85% ± 8.31% compared with 43.05% ± 5.95%, P<0.05) and the content of TGF-ß1 in the supernatant was increased. CONCLUSION: The cytotoxic effects of human NK cells against target cells were significantly enhanced with the blockade of inhibitory KIR receptor; and the cytokine TGF-ß1 secreted by NK cells further inhibits T cells proliferation.

[Synergistic cytotoxic effects of rapamycin and idarubicin on human acute T-cell lymphoblastic leukemia Jurkat cells].

OBJECTIVE: To investigate the cytotoxic effects of mTOR inhibitor rapamycin (Rapa) and idarubicin (IDA) on human T-cell acute lymphoblastic leukemia Jurkat cell line. METHODS: The proliferation of Jurkat cells was observed by CCK-8 assay. The combined index was analyzed by Isobologram method. Apoptosis was detected by electron microscopy and flow cytometry with Annexin V/PI staining. Protein expressions of Caspase 3, PARP, Caspase 8, Caspase 9, Akt, p-Akt, P85S6K, p-P85S6K, P70S6K, p-P70S6K, ERK1/2 and p-ERK1/2 were determined by Western blotting. RESULTS: The IC(50) of IDA for Jurkat cells was significantly reduced when combined with 10 nmol/L rapamycin. The combined index was <1. Both electron microscopy and Annexin V/PI staining flow cytometry revealed that rapamycin significantly increased apoptotic sensitivity to IDA. The combination of IDA with rapamycin enhanced the expressions of Caspase 3, PARP, Caspase 8 and Caspase 9. Rapamycin significantly inhibited mTOR signaling upstream Akt and downstream S6K activation triggered by IDA, and the combination of the two agents led to synergistic inhibition of ERK phosphorylation. CONCLUSION: Combination of IDA with rapamycin exerted a synergistic anti-proliferative effect and promoted apoptosis by both extrinsic and intrinsic apoptotic pathways in Jurkat cells. Inhibition of ERK phosphorylation and mTOR signaling by rapamycin may play a certain role in this synergistic effect.

Early Death and Survival of Patients With Acute Promyelocytic Leukemia in ATRA Plus Arsenic Era: A Population-Based Study.

Most randomized trials for acute promyelocytic leukemia (APL) have investigated highly selected patients under idealized conditions, and the findings need to be validated in the real world. We conducted a population-based study of all APL patients in Zhejiang Province, China, with a total population of 82 million people, to assess the generalization of all-trans retinoic acid (ATRA) and arsenic as front-line treatment. The outcomes of APL patients were also analyzed. Between January 2015 and December 2019, 1,233 eligible patients were included in the final analysis. The rate of ATRA and arsenic as front-line treatment increased steadily from 66.2% in 2015 to 83.3% in 2019, with no difference among the size of the center (≥5 or <5 patients per year, p = 0.12) or age (≥60 or <60 years, p = 0.35). The early death (ED) rate, defined as death within 30 days after diagnosis, was 8.2%, and the 3-year overall survival (OS) was 87.9% in the whole patient population. Age (≥60 years) and white blood cell count (>10 × 109/L) were independent risk factors for ED and OS in the multivariate analysis. This population-based study showed that ATRA and arsenic as front-line treatment are widely used under real-world conditions and yield a low ED rate and a high survival rate, which mimic the results from clinical trials, thereby supporting the wider application of APL guidelines in the future.

[Relationship of tumor necrosis factor gene polymorphism and acute graft-versus-host disease after unrelated allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To explore the relationship between tumor necrosis factor (TNF) gene polymorphisms in donors and recipients and the incidence and severity of acute graft-versus-host diseases (aGVHD) after unrelated allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: Single nucleotide polymorphisms (SNPs) of TNFalpha-238 (G/A), TNFalpha-857 (C/T), TNFalpha-863 (C/A), TNFalpha-1031 (T/C), TNFbeta + 252(A/G) were analyzed by Multiplex SNaPshot analysis in 76 pairs of donors and recipients. RESULTS: Transplantation involving donors with TNFalpha-857 CC genotype resulted in a higher incidence of grade II-IV aGVHD than donors with CT genotype (91.3% vs 8.7%, P = 0.039). In the 23 patients with grade II-IV aGVHD, no patients had TNFbeta + 252 AA genotype, 19 (82.6%) had GA genotype and 4 (17.4%) had GG genotype. There was a significant difference in the distribution pattern of the TNFbeta + 252 (AA, GA and GG) genotypes in these patients (P = 0.03). There was no significant association of TNFalpha-238 (G/A), TNFalpha-863 (C/A) and TNFalpha-1031(T/C) polymorphisms with the risk of aGVHD. CONCLUSION: These results suggest donor TNFalpha-857 CC genotype is related to a higher incidence of grade II-IV aGVHD, and patients with TNFbeta + 252 AA genotype have protection against the risk of grade II-IV aGVHD.