Spatio-Temporal Patterns of Demyelination and Remyelination in the Cuprizone Mouse Model.

Cuprizone administration in mice provides a reproducible model of demyelination and spontaneous remyelination, and has been useful in understanding important aspects of human disease, including multiple sclerosis. In this study, we apply high spatial resolution quantitative MRI techniques to establish the spatio-temporal patterns of acute demyelination in C57BL/6 mice after 6 weeks of cuprizone administration, and subsequent remyelination after 6 weeks of post-cuprizone recovery. MRI measurements were complemented with Black Gold II stain for myelin and immunohistochemical stains for associated tissue changes. Gene expression was evaluated using the Allen Gene Expression Atlas. Twenty-five C57BL/6 male mice were split into control and cuprizone groups; MRI data were obtained at baseline, after 6 weeks of cuprizone, and 6 weeks post-cuprizone. High-resolution (100 µm isotropic) whole-brain coverage magnetization transfer ratio (MTR) parametric maps demonstrated concurrent caudal-to-rostral and medial-to-lateral gradients of MTR decrease within corpus callosum (CC) that correlated well with demyelination assessed histologically. Our results show that demyelination was not limited to the midsagittal line of the corpus callosum, and also that opposing gradients of demyelination occur in the lateral and medial CC. T2-weighted MRI gray/white matter contrast was strong at baseline, weak after 6 weeks of cuprizone treatment, and returned to a limited extent after recovery. MTR decreases during demyelination were observed throughout the brain, most clearly in callosal white matter. Myelin damage and repair appear to be influenced by proximity to oligodendrocyte progenitor cell populations and exhibit an inverse correlation with myelin basic protein gene expression. These findings suggest that susceptibility to injury and ability to repair vary across the brain, and whole-brain analysis is necessary to accurately characterize this model. Whole-brain parametric mapping across time is essential for gaining a real understanding of disease processes in-vivo. MTR increases in healthy mice throughout adolescence and adulthood were observed, illustrating the need for appropriate age-matched controls. Elucidating the unique and site-specific demyelination in the cuprizone model may offer new insights into in mechanisms of both damage and repair in human demyelinating diseases.

Tumor-infiltrating lymphocytes and interleukin-2: dose and schedules of administration in the treatment of metastatic cancer.

PURPOSE: The potential for therapeutic use of tumor-infiltrating lymphocytes (TIL), as adoptive cellular therapy has been touted for many years with some encouraging reports in patients with metastatic melanoma. MATERIALS AND METHODS: We previously described methodologies for TIL production and phenotypic characterization of TIL generated in our laboratory between 1991 and 1995 in semipermeable bags and between 1996 and 2000 in bioreactors. Patients treated in the earlier era were to have received a hybrid bolus and a 12-hour continuous infusion of interleukin (IL)-2 (total, 48 MIU), while in the latter era 4 days of interferon- alpha preceded the TIL and IL-2; which was given by a hybrid schedule that included bolus and 72- hour continuous IL-2 (total, 96 MIU). There were 55 patients, including 23 patients with melanoma, 9 patients with renal cell carcinoma, and 8 patients with colorectal cancer. There was only 1 objective tumor response, which was noted in a patient with renal cell carcinoma. The 55 patients who received these products were grouped in cohorts by treatment era, quantity of TIL received, amount of IL-2 intended, and different combinations of TIL and IL-2. RESULTS: There was no difference in survival by production method (treatment era), or amount of IL-2 given with TIL, but 33 patients who received an intermediate or higher dose of TIL (mean = 54.4 x 10(9)) had a median survival of 11.8 months, compared to 6.4 months for 22 patients who received 1 low-dose TIL (mean = 6.48 x 10(9)) (p = 0.059, log rank test). The objective response rate in this heterogeneous group of patients was not encouraging. The data suggest there may be a dose/benefit relationship between the total number of TIL infused and survival.

Treatment of human solid malignancies with autologous activated lymphocytes and cimetidine: a phase II trial of the cancer biotherapy research group.

OBJECTIVE: The Cancer Biotherapy Research Group conducted a clinical trial to verify encouraging reports of antitumor activity of autolymphocyte therapy. PATIENTS AND METHODS: Patients with a variety of advanced solid malignancies underwent an initial leukapheresis procedure to collect about 5 x 10(9) autologous lymphocytes that were stimulated in vitro for 3 days with anti-CD3 monoclonal antibody in the presence of indomethicin and cis-retinoic acid to obtain media that was frozen in aliquots. This media contained significant amounts of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, interferon-gamma, and IL6, but no IL-2. Subsequently patients underwent up to 6 monthly leukaphereses to collect 2-5 x 10(9) autologous lymphocytes that were incubated in vitro for 6 days in the cryopreserved media containing autologous lymphokines, resulting in a cell population enriched for noncytotoxic T-helper lymphocytes. These were administered intravenously monthly for up to 6 months with daily oral cimetidine at a dose of 600 mg po qid, which was given throughout the treatment period. Tumor response was assessed every 2 months. RESULTS: There were 47 patients (25 women and 22 men) with a median age of 55 years (range 31-79). One hundred seventy four treatments were delivered and were well tolerated. A mean of 2.05 +/- 1.46 (range 0.82-12.8 x 10(9)) cells were infused. Eighty-five percent received two or more doses; 19% received six doses. Objective tumor responses were observed in 1/15 renal cell, 1/13 colorectal, 0/6 breast, 0/5 lung, 0/2 gastric, 0/2 sarcoma, 0/1 pancreas, 0/1 prostate, 0/1 melanoma, and 0/1 eccrine. Forty-three patients have died. Median survival was 8.8 months, 1-year survival 35%, and 2-year survival 15%. CONCLUSION: This complex treatment program was feasible. Infusion of these cells was well tolerated. Some antitumor activity was seen in patients with renal cell cancer and colorectal cancer.

Does continuous-infusion interleukin-2 increase survival in metastatic melanoma?

Pharmacy logbooks and clinical trial records were used to identify all 60 patients with metastatic melanoma who were treated as inpatients with intermediate-dose, continuous-infusion interleukin-2 (IL-2) in Hoag Hospital during 1987 to 1998. The hospital tumor registry was used to identify contemporary controls who had not received inpatient IL-2, matched for having distant metastatic melanoma, and by year and stage at original diagnosis, gender, and age. The mean time from original diagnosis to the documentation of distant metastatic disease was similar in both groups, 24 to 26 months. From the date of starting IL-2 therapy, patients had a median survival of 8.8 months, 38% 1-year survival, and 20% 5-year survival, with 8 patients alive beyond 5 years. However, there was no difference in survival from the first date of distant metastatic disease (median 25.8 months for IL-2 versus 31.5 months for controls, with survival rates 5 years after metastatic disease of 26% versus 31%). There was also no difference in overall survival from the date of original diagnosis (60.1 months for the IL-2 group versus 86.3 months for controls, with 5-year survival rates of 51% versus 64%, and 10-year survival rates of 29% versus 33%). This single-institution study failed to establish a survival advantage for patients with metastatic melanoma who received intermediate-dose, continuous-infusion IL-2 administered in the inpatient setting, compared to contemporary, matched-control patients who never received inpatient IL-2 therapy. However, the 5-year survival rates after a diagnosis of distant metastatic disease were a surprisingly high 26% to 31% in both groups. In the absence of a control group, the survival impact of IL-2 has probably been overestimated from single-arm phase II and III trials.

Irradiated cells from autologous tumor cell lines as patient-specific vaccine therapy in 125 patients with metastatic cancer: induction of delayed-type hypersensitivity to autologous tumor is associated with improved survival.

OBJECTIVE: We established short-term cultures of pure tumor cells for use as autologous tumor cell vaccines in an effort to study the effects of patients-specific immunotherapy. PATIENTS AND METHODS: Surgically resected fresh tumor was obtained from patients with metastatic cancer. Successful tumor cell lines (5 x 10(7)) were expanded to 10(8) cells, irradiated, and cryopreserved for clinical use. Following a baseline test of delayed-type hypersensitivity (DTH) to an i.d. injection of 10(6) irradiated autologous tumor cells, patients received 3 weekly s.c. injections of 10(7) cells, had a repeat DTH test at week-4, then received monthly vaccinations for 5 months. A positive DTH test was defined as > or = 10 mm induration; survival was determined from the first DTH test. RESULTS: Short-term cell lines were successfully established for 299/695 patients (43%). Vaccines were prepared for 231 patients, 142 of whom were treated, and 125 had a baseline DTH test recorded. Median follow up at the time of analysis was greater than 5 years. There was no difference in survival for any of the following: gender, age > 50 years, melanoma histology, anergy to common recall antigens or baseline DTH test result. Only 17 patients had a positive DTH at baseline (14%), but DTH converted from negative to positive in 31/80 (39%) of those who were tested, and in 31/108 (29%) of all patients (intent-to-convert analysis). For the 48 patients who were DTH-positive at entry, or converted to DTH-positive, the median survival was 30.5 months and 5-year survival 41% compared to 11.4 months and 9% 5-year survival for 77 patients whose DTH was never positive (P2 = 0.003). However, survival was even better for patients whose DTH test converted to positive compared to patients who were DTH-positive at baseline (median 37.5 vs 11.9 mos, P2 = 0.066). CONCLUSION: This patient-specific, cell culture-derived, autologous tumor cell vaccine induced anti-tumor immune reactivity that was associated with improved survival in patients with advanced cancer.