Live attenuated VZV vaccination induces antitumor immunity in ATLL patients.

Adult T cell leukemia/lymphoma (ATLL) is a CD4-positive peripheral T cell lymphoma caused by human T cell lymphotropic virus type 1 (HTLV-1). Although ATLL is quite difficult to be cured, up-regulation of cellular immunity such as HTLV-1 Tax-specific cytotoxic T lymphocytes (CTLs) has been proved to be important to obtain long-term survival. At present, no efficacious method to activate ATLL-specific cellular immunity is available. This study aimed to investigate whether live attenuated varicella-zoster virus (VZV) vaccination to ATLL can activate HTLV-1 Tax-specific cellular immune response. A total of 3 indolent- and 3 aggressive-type ATLL patients were enrolled. All aggressive-type patients had the VZV vaccination after completing anti-ATLL treatment including mogamulizumab, which is a monoclonal antibody for C-C chemokine receptor 4 antigen, plus combination chemotherapy, whereas all indolent-type patients had the VZV vaccination without any antitumor treatment. Cellular immune responses including Tax-specific CTLs were analyzed at several time points of pre- and post-VZV vaccination. After the VZV vaccination, a moderate increase in 1 of 3 indolent-type patients and obvious increase in all 3 aggressive-type patients in Tax-specific CTLs percentage were observed. The increase in the cell-mediated immunity against VZV was observed in all indolent- and aggressive-type patients after VZV vaccination. To conclude, VZV vaccination to aggressive-type ATLL patients after mogamulizumab plus chemotherapy led to the up-regulation of HTLV-1 Tax-specific CTLs without any adverse event. Suppression of regulatory T lymphocytes by mogamulizumab may have contributed to increase tumor immunity in aggressive-type ATLL patients. Japan Registry of Clinical Trials number, jRCTs051180107.

HTLV-1 Tax-specific memory cytotoxic T lymphocytes in long-term survivors of aggressive-type adult T-cell leukemia/lymphoma.

PURPOSE: Adult T-cell leukemia/lymphoma (ATLL) is a relatively refractory peripheral T-cell lymphoma caused by human T-cell lymphotropic virus type 1 (HTLV-1). The objective of this study was to investigate the characteristics of long-term survivors with ATLL. METHODS: We conducted an observational study of 75 aggressive-type ATLL patients. Flow cytometry was conducted to analyze HTLV-1 Tax-specific cytotoxic T-lymphocytes (CTLs) and T-cell receptor Vß gene repertoire. RESULTS: We first evaluated six long-term survivors among 37 patients who were newly diagnosed with ATLL and then treated with intensive chemotherapy without mogamulizumab, a monoclonal antibody for C-C chemokine receptor four antigen. Reversal of the CD4-to-CD8 ratio (CD4/CD8) in peripheral mononuclear cells was observed in all six patients. Three of these six patients showed reversed CD4/CD8 immediately after herpes virus infection. Four of these six patients who could be examined demonstrated long-term maintenance of HTLV-1 Tax-specific CTLs. We subsequently identified four long-term survivors among 38 patients who were newly diagnosed with ATLL and then treated with intensive chemotherapy plus mogamulizumab. All four patients showed reversed CD4/CD8, and three of the four patients contracted herpes virus infection during immunochemotherapy. Six of the total 10 patients were subjected to CTL analyses. Tax-specific CTLs were observed, and the CTLs that were almost entirely composed of memory CTLs in all patients were recorded. HTLV-1 provirus was also detected in all six patients. CONCLUSIONS: These data suggest that Tax-specific memory CTLs probably, together with anticancer agents, eradicate ATLL cells and exhibit long-term preventive effects from relapse ATLL. Thus, the strong activation of cellular immunity, such as herpes virus infection, seems to be necessary to induce such a potent number of Tax-specific CTLs.

Long-lasting memory of cellular immunity in a chronic myeloid leukemia patient maintains molecular response 5 after cessation of dasatinib.

Tyrosine kinase inhibitors (TKIs), including imatinib, dasatinib and nilotinib are primarily used in the initial treatment of chronic phase (CP)-chronic myeloid leukemia (CML), as CMLs harbor the BCR-ABL fusion product. An increased number of lymphocytes and large granular lymphocytes (LGLs) have been observed in patients treated with dasatinib, but not other TKIs. The LGLs have been reported to be primarily natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). In the present study, a CP-CML patient who has maintained molecular response 5 for >2.4 years after stopping dasatinib was reported. Memory and effector CTLs and NK cells, were observed after 2.4 years of treatment-free remission, despite the fact that lymphocyte counts are not elevated in the patient. These results suggest that dasatinib may induce cellular immunity, including NK cells and CTLs and this cellular immunity may be maintained for a long period following cessation of dasatinib. The results suggest that this cellular immunity may provide a long-term cure without the need for continued TKI treatment.

Therapeutic index of methotrexate depends on circadian cycling of tumour necrosis factor-alpha in collagen-induced arthritic rats and mice.

OBJECTIVES: Rheumatoid arthritis is an autoimmune disorder of unknown aetiology. Morning stiffness, a characteristic feature of rheumatoid arthritis, shows a 24-h rhythm. Noticing this rhythm, we hypothesized the presence of a similar rhythm for a rheumatoid arthritis indicator, in addition to dosing-time dependency of the anti-rheumatic effect of methotrexate in arthritis induced by collagen in rats and mice, which reflect the symptomatology of rheumatoid arthritis patients. METHODS: To measure tumour necrosis factor (TNF)-alpha concentration, blood was taken at different times (2, 6, 10, 14, 18 or 22 h after the light was turned on (HALO)) in collagen-induced arthritic mice. Methotrexate was administered at two different dosing times based on these findings to estimate arthritis. KEY FINDINGS: The arthritis score was significantly lower in the 22 HALO-treated group than in the control and 10 HALO-treated groups in collagen-induced arthritic rats and mice. Plasma TNF-alpha concentrations showed obvious 24-h rhythms, with higher levels at light phase and lower levels at dark phase after rheumatoid arthritis crisis. Arthritis was relieved after administration of methotrexate during the dark phase in synchronization with the 24-h rhythm. CONCLUSIONS: Our findings suggest that choosing an optimal dosing time associated with the 24-h cycling of TNF-alpha could lead to effective treatment of rheumatoid arthritis by methotrexate.