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Biomedical subjects

M Lotze

Publications and source records attributed to M Lotze.

5 recordsLinked to original sources

Lysis of autologous melanoma cells by tumor-infiltrating lymphocytes: association with clinical response.

Tumor-infiltrating lymphocytes (TILs) can be grown in vitro in medium containing interleukin-2 (IL-2). In clinical trials at the Surgery Branch of the National Cancer Institute, patients with metastatic malignant melanomas were treated with IL-2 plus the adoptive transfer of autologous TILs. At the time of treatment, TILs were assayed for in vitro lysis of fresh autologous and allogeneic melanoma cells and Daudi cells. Patients were evaluated for clinical response 4-8 weeks later. Lysis of autologous tumor cells by TILs was significantly higher for responding than for nonresponding patients. Tumor cells from responding and nonresponding patients were equally sensitive to lysis by allogeneic lymphokine-activated killer (LAK) cells. There was no difference between TILs from responding and nonresponding patients for lysis of LAK-sensitive Daudi cells, which was low in most cases and demonstrated that TIL lysis of autologous tumor cells was not due to LAK cells. The observed association of autologous tumor cell lysis by TILs with clinical response suggests that the development of culture methods to optimize lysis of autologous tumors may lead to increased response rates using this TIL treatment regimen.

Cell Division

Lymphocytes as cellular vehicles for gene therapy in mouse and man.

The application of bone marrow gene therapy has been stalled by the inability to achieve stable high-level gene transfer and expression in the totipotent stem cells. We show that retroviral vectors can stably introduce genes into antigen-specific murine and human T lymphocytes in culture. Murine helper T cells were transduced with the retroviral vector SAX to express both neomycin-resistance and human adenosine deaminase genes. These cells were expanded in culture and selected for expression of neomycin resistance with G418. The gene insertion, selection, and culture expansion did not alter antigen specificity or growth characteristics of the T cells in vitro. To determine if cultured T cells might be used for gene therapy, their persistence and continued expression of the introduced genes was evaluated in nude mice transplanted with the SAX-transduced T cells. G418-resistant cells could be readily recovered from the spleens of recipients of transduced T cells for several months. In addition, recovered cells continued to produce human adenosine deaminase. Based on these observations, we studied cultured human tumor-infiltrating lymphocytes as a candidate cell for a trial of gene transfer in man. Exponential cultures of interleukin-2-stimulated tumor-infiltrating lymphocytes were efficiently transduced with the neomycin-resistance gene using the retroviral vector N2. Gene insertion and subsequent G418 selection did not substantially alter the growth characteristics, interleukin 2 dependence, membrane phenotype, or cytotoxicity profile of the transduced T cells. These studies provided a portion of the experimental evidence supporting the feasibility of the presently ongoing clinical trials of lymphocyte gene therapy in cancer as well as in patients with adenosine deaminase deficiency.

Animals

Interleukin-2 administration causes reversible hemodynamic changes and left ventricular dysfunction similar to those seen in septic shock.

Interleukin-2, a lymphocyte product, has well demonstrated antitumor activity in humans. Early clinical studies showed hemodynamic alterations in patients receiving the drug as antitumor immunotherapy. We serially assessed interleukin-2-associated hemodynamic parameters and left ventricular ejection fractions in five patients with neoplastic diseases unresponsive to conventional therapies. By day 4 of therapy, compared with baseline (preinterleukin-2), all patients developed tachycardia (p less than 0.01), decreased mean arterial blood pressure (p less than 0.05), increased cardiac index (p less than 0.05), and decreased systemic vascular resistance (p less than 0.01). In addition, left ventricular ejection fraction fell from 58.0 +/- 4.7 to 36.4 +/- 4.0 percent (0.05 less than p less than 0.10), which was associated with a trend toward left ventricular dilatation manifested by an increase in left ventricular end-diastolic volume index. Transient renal dysfunction was noted in all five patients, and one developed transient respiratory failure; both types of organ dysfunction recovered to baseline values after cessation of immunotherapy. Thus, interleukin-2 induces multiple reversible cardiovascular abnormalities that are similar to the hemodynamic manifestations of human septic shock.

Adult