Clonal Upregulation of Effector Cytotoxic T Lymphocytes in a Patient with Multiple Tyrosine Kinase Inhibitor-Refractory Chronic Myeloid Leukemia with Long-Term Survival.

We present the case of a patient with multiple tyrosine kinase inhibitor (TKI)-refractory chronic phase chronic myeloid leukemia (CP-CML) with a T315I mutation of abl1. Dasatinib, a second-generation TKI, was administered as the initial treatment but achieved neither a cytogenetic nor molecular response. A mutational analysis of abl1 revealed that the patient had a T315I mutation. The patient was then administered ponatinib, a third-generation TKI, which is thought to be effective against T315I; however, the complete blood counts became within normal limits, and neither a cytogenetic nor molecular response was achieved. However, the patient has maintained a healthy chronic phase (with no blast crises) for more than 5½ years since the diagnosis of CP-CML. T-cell receptor (TCR) repertoire analyses using peripheral blood revealed a remarkable clonal expansion of effector cytotoxic T lymphocytes (CTLs) that contained TCR V beta 13.6. We observed the clonal expansion of naïve CTLs with TCR V beta 13.6; however, no clonality was observed in the memory CTLs. The naïve and effector CTLs persisted at very high percentages since the seventh month after starting dasatinib. The CTLs could not have led to the molecular response; therefore, there might be plenty of CML stem cells remaining in the bone marrow. Therefore, although the CTLs might have prevented the disease from developing blast crises over more than 5 years, the CTLs might not have been able to become memory CTLs.

Induction of Effector and Memory Cellular Immunity in a Patient with Long-Term Complete Molecular Response to Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia.

This case report is about a patient who suffered from Philadelphia chromosome (Ph1)-positive acute lymphoblastic leukemia. The blasts were positive for myeloid-lineage markers including CD13 and CD33, as well as B-cell-lineage markers. Minor bcr-abl1 mRNA was detected by real-time quantitative polymerase chain reaction. Chromosomal abnormality monosomy 7 was also observed, in addition to Ph1. Despite treatment difficulties that were anticipated based on these findings, the patient had long-time complete molecular response (CMR) for approximately 5 years using chemotherapy and two tyrosine kinase inhibitors, imatinib and dasatinib. Lymphocytes were elevated after the patient switched from imatinib to dasatinib, and a T-cell receptor (TCR) V beta gene repertoire analysis revealed oligoclonal expansion of effector and memory cytotoxic T lymphocytes (CTLs), including Wilms tumor 1-specific CTLs. More specifically, the two memory CTLs expressing TCR V beta 3 and V beta 7.1 gradually increased after dasatinib administration. The activation and maintenance of anti-leukemia immunity may have allowed the patient to obtain long-time CMR. These results highlight that obtaining memory CTLs for leukemia cells may lead to safe withdrawal from dasatinib in the patient.

Elevation of Memory Cytotoxic T Lymphocytes, Including Human T Lymphotropic Virus Type 1 Tax-Specific and Hepatitis Virus Type C-Specific Cytotoxic T Lymphocytes, in a Patient with Adult T-Cell Leukemia/Lymphoma and Hepatocellular Carcinoma.

Herein, we present the case of a patient who suffered from adult T-cell leukemia/lymphoma (ATLL) and hepatocellular carcinoma (HCC) after obtaining a sustained virological response following treatment with a direct-acting antiviral (DAA) at different points in time. The patient went into complete remission (CR) for ATLL. Unfortunately, subsequent relapse of ATLL was observed. This situation was overcome using chemotherapy with pegylated interferon alpha-2b. Human T lymphotropic virus type 1 Tax-specific cytotoxic T lymphocytes (CTLs) were recognized after obtaining second CR, and those CTLs have been maintained for many years. After 4 years from the second CR, chronic hepatitis type C was treated with a DAA, and sustained virological response was attained. However, the occurrence of HCC was detected. Surprisingly, the tumor disappeared spontaneously. Hepatitis virus type C-specific CTLs were also detected in the patient. T-cell receptor (TCR) V beta gene repertoire analyses revealed oligoclonal expansion of effector and memory CTLs. The number of CTLs expressing the TCR V beta 13.1 has increased over the years since HCC occurrence. The activation and maintenance of anticancer cellular immunity may have allowed the patient to obtain long-term survival and overcome two lethal neoplasms.

Mogamulizumab Plus EPOCH Therapy for Patients With Newly Diagnosed Aggressive Adult T-cell Leukemia/lymphoma.

BACKGROUND/AIM: Adult T-cell leukemia/lymphoma (ATLL) is a relatively refractory CD4-positive peripheral T-cell lymphoma. VCAP-AMP-VECP (mLSG15) is one of the standard chemotherapeutic regimens for patients with aggressive ATLL. Mogamulizumab (moga), a monoclonal antibody for C-C chemokine receptor 4 antigen expressed on the cell surface, has recently been poised for use as monotherapy and in combination with chemotherapy. However, to date, a significant survival benefit has not been obtained with the combination of moga + mLSG15 therapy. PATIENTS AND METHODS: We retrospectively analyzed 77 patients diagnosed with aggressive ATLL. Of them, 22 were treated with moga + a chemotherapy regimen comprised of etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisolone (EPOCH), 16 with moga + mLSG15, and 39 with chemotherapy alone. RESULTS: A risk reduction of approximately 30% was obtained with moga + EPOCH compared with moga + mLSG15. CONCLUSION: The addition of moga to chemotherapy did not result in a survival benefit compared with chemotherapy alone. However, a statistically significant overall survival benefit was observed in patients with moga-induced skin disorders.

Successful Treatment of a Patient with Brentuximab Vedotin-Refractory ALK-Negative Anaplastic Large Cell Lymphoma with Romidepsin.

We present the case of a 78-year-old male patient who was diagnosed with anaplastic lymphoma kinase (ALK)-negative, CC chemokine receptor 4 (CCR4)-negative, and CD30-positive anaplastic large cell lymphoma (ALCL). The patient had a past medical history of adult T-cell leukemia/lymphoma and colon cancers that had developed simultaneously approximately 2 years prior to the development of ALCL that were treated with immunochemotherapy and resection, respectively. Initial treatment for ALCL included brentuximab vedotin, an anti-CD30 monoclonal antibody-monomethyl auristatin E conjugate; however, we were unable to achieve a sufficient treatment effect. Romidepsin, an oral histone deacetylase inhibitor, was introduced as salvage chemotherapy; complete remission was attained. Interestingly, a reversal of the CD4/CD8 ratio and a reduction in human T-lymphotropic virus type 1 (HTLV-1) virus load was observed after 2 cycles of immunochemotherapy; the patient experienced upregulation of HTLV-1 Tax-specific cytotoxic T lymphocytes after a herpes zoster infection and the completion of immunotherapy. The immunologic status was maintained from the time of diagnosis through the completion of romidepsin therapy. Our findings indicate that romidepsin can be used safely and effectively to treat ALCL without impairing cellular immunity to HTLV-1.

Suppression of the pancreatic duodenal homeodomain transcription factor-1 (Pdx-1) promoter by sterol regulatory element-binding protein-1c (SREBP-1c).

Overexpression of sterol regulatory element-binding protein-1c (SREBP-1c) in ß cells causes impaired insulin secretion and ß cell dysfunction associated with diminished pancreatic duodenal homeodomain transcription factor-1 (PDX-1) expression in vitro and in vivo. To identify the molecular mechanism responsible for this effect, the mouse Pdx-1 gene promoter (2.7 kb) was analyzed in ß cell and non-ß cell lines. Despite no apparent sterol regulatory element-binding protein-binding sites, the Pdx-1 promoter was suppressed by SREBP-1c in ß cells in a dose-dependent manner. PDX-1 activated its own promoter. The E-box (-104/-99 bp) in the proximal region, occupied by ubiquitously expressed upstream stimulatory factors (USFs), was crucial for the PDX-1-positive autoregulatory loop through direct PDX-1·USF binding. This positive feedback activation was a prerequisite for SREBP-1c suppression of the promoter in non-ß cells. SREBP-1c and PDX-1 directly interact through basic helix-loop-helix and homeobox domains, respectively. This robust SREBP-1c·PDX-1 complex interferes with PDX-1·USF formation and inhibits the recruitment of PDX-1 coactivators. SREBP-1c also inhibits PDX-1 binding to the previously described PDX-1-binding site (-2721/-2646 bp) in the distal enhancer region of the Pdx-1 promoter. Endogenous up-regulation of SREBP-1c in INS-1 cells through the activation of liver X receptor and retinoid X receptor by 9-cis-retinoic acid and 22-hydroxycholesterol inhibited PDX-1 mRNA and protein expression. Conversely, SREBP-1c RNAi restored Pdx-1 mRNA and protein levels. Through these multiple mechanisms, SREBP-1c, when induced in a lipotoxic state, repressed PDX-1 expression contributing to the inhibition of insulin expression and ß cell dysfunction.

betaKlotho is required for fibroblast growth factor (FGF) 21 signaling through FGF receptor (FGFR) 1c and FGFR3c.

Fibroblast growth factor (FGF) 21, a structural relative of FGF23 that regulates phosphate homeostasis, is a regulator of insulin-independent glucose transport in adipocytes and plays a role in the regulation of body weight. It also regulates ketogenesis and adaptive responses to starvation. We report that in a reconstituted receptor activation assay system using BaF3 cells, which do not endogenously express any type of FGF receptor (FGFR) or heparan sulfate proteoglycan, FGF21 alone does not activate FGFRs and that betaKlotho is required for FGF21 to activate two specific FGFR subtypes: FGFR1c and FGFR3c. Coexpression of betaKlotho and FGFR1c on BaF3 cells enabled FGF21, but not FGF23, to activate receptor signaling. Conversely, coexpression of FGFR1c and Klotho, a protein related to betaKlotho, enabled FGF23 but not FGF21 to activate receptor signaling, indicating that expression of betaKlotho/Klotho confers target cell specificity on FGF21/FGF23. In all of these cases, heparin enhanced the activation but was not essential. In 3T3-L1 adipocytes, up-regulation of glucose transporter (GLUT) expression by FGF21 was associated with expression of betaKlotho, which was absent in undifferentiated 3T3-L1 fibroblasts. It is thus suggested that betaKlotho expression is a crucial determinant of the FGF21 specificity of the target cells upon which it acts in an endocrine fashion.