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Biomedical subjects

Mark E Dudley

Publications and source records attributed to Mark E Dudley.

9 recordsLinked to original sources
PubMed2003

High efficiency TCR gene transfer into primary human lymphocytes affords avid recognition of melanoma tumor antigen glycoprotein 100 and does not alter the recognition of autologous melanoma antigens.

The alpha- and beta-chains of the TCR from a highly avid anti-gp100 CTL clone were isolated and used to construct retroviral vectors that can mediate high efficiency gene transfer into primary human lymphocytes. Expression of this TCR gene was confirmed by Western blot analysis, immunocytometric analysis, and HLA Ag tetramer staining. Gene transfer efficiencies of >50% into primary lymphocytes were obtained without selection for transduced cells using a method of prebinding retroviral vectors to cell culture vessels before the addition of lymphocytes. The biological activity of transduced cells was confirmed by cytokine production following coculture with stimulator cells pulsed with gp100 peptides, but not with unrelated peptides. The ability of this anti-gp100 TCR gene to transfer high avidity Ag recognition to engineered lymphocytes was confirmed in comparison with highly avid antimelanoma lymphocytes by the high levels of cytokine production (>200,000 pg/ml IFN-gamma), by recognition of low levels of peptide (<200 pM), and by HLA class I-restricted recognition and lysis of melanoma tumor cell lines. CD4(+) T cells engineered with this anti-gp100 TCR gene were Ag reactive, suggesting CD8-independent activity of the expressed TCR. Finally, nonmelanoma-reactive tumor-infiltrating lymphocyte cultures developed antimelanoma activity following anti-gp100 TCR gene transfer. In addition, tumor-infiltrating lymphocytes with reactivity against non-gp100 melanoma Ags acquired gp100 reactivity and did not lose the recognition of autologous melanoma Ags following gp100 TCR gene transfer. These results suggest that lymphocytes genetically engineered to express anti-gp100 TCR may be of value in the adoptive immunotherapy of patients with melanoma.

Animals↗
PubMed2003

Adoptive-cell-transfer therapy for the treatment of patients with cancer.

Adoptive immunotherapy--the isolation of antigen-specific cells, their ex vivo expansion and activation, and subsequent autologous administration--is a promising approach to inducing antitumour immune responses. The molecular identification of tumour antigens and the ability to monitor the persistence and transport of transferred cells has provided new insights into the mechanisms of tumour immunotherapy. Recent studies have shown the effectiveness of cell-transfer therapies for the treatment of patients with selected metastatic cancers. These studies provide a blueprint for the wider application of adoptive-cell-transfer therapy, and emphasize the requirement for in vivo persistence of the cells for therapeutic efficacy.

Animals↗
PubMed2002

Cancer regression and autoimmunity in patients after clonal repopulation with antitumor lymphocytes.

We report here the adoptive transfer, to patients with metastatic melanoma, of highly selected tumor-reactive T cells directed against overexpressed self-derived differentiation antigens after a nonmyeloablative conditioning regimen. This approach resulted in the persistent clonal repopulation of T cells in those cancer patients, with the transferred cells proliferating in vivo, displaying functional activity, and trafficking to tumor sites. This led to regression of the patients' metastatic melanoma as well as to the onset of autoimmune melanocyte destruction. This approach presents new possibilities for the treatment of patients with cancer as well as patients with human immunodeficiency virus-related acquired immunodeficiency syndrome and other infectious diseases.

Adolescent↗
PubMed2002

Functional heterogeneity of vaccine-induced CD8(+) T cells.

The functional status of circulating vaccine-induced, tumor-specific T cells has been questioned to explain their paradoxical inability to inhibit tumor growth. We enumerated with HLA-A*0201/peptide tetramers (tHLA) vaccine-elicited CD8(+) T cell precursor frequency among PBMC in 13 patients with melanoma undergoing vaccination with the HLA-A*0201-associated gp100:209-217(210 M) epitope. T cell precursor frequency increased from undetectable to 12,400 +/- 3,600 x 10(6) CD8(+) T cells after vaccination and appeared heterogeneous according to previously described functional subtypes: CD45RA(+)CD27(+) (14 +/- 2.6% of tHLA-staining T cells), naive; CD45RA(-)CD27(+) (14 +/- 3.2%), memory; CD45RA(+)CD27(-) (43 +/- 6%), effector; and CD45RA(-)CD27(-) (30 +/- 4.1%), memory/effector. The majority of tHLA(+)CD8(+) T cells displayed an effector, CD27(-) phenotype (73%). However, few expressed perforin (17%). Epitope-specific in vitro stimulation (IVS) followed by 10-day expansion in IL-2 reversed this phenotype by increasing the number of perforin(+) (84 +/- 3.6%; by paired t test, p < 0.001) and CD27(+) (from 28 to 67%; by paired t test, p = 0.01) tHLA(+) T cells. This conversion probably represented a change in the functional status of tHLA(+) T cells rather than a preferential expansion of a CD27(+) (naive and/or memory) PBMC, because it was reproduced after IVS of a T cell clone bearing a classic effector phenotype (CD45RA(+)CD27(-)). These findings suggest that circulating vaccine-elicited T cells are not as functionally active as inferred by characterization of IVS-induced CTL. In addition, CD45RA/CD27 expression may be more informative about the status of activation of circulating T cells than their status of differentiation.

CD8-Positive T-Lymphocytes↗
PubMedDate not supplied

To bead or not to bead.

To bead or not to bead, that is the question posed by Ito et al. in this issue of the Journal of Immunotherapy. The generation of tumor-reactive T cells remains a major impediment to the wider application of adoptive cell transfer (ACT) therapy for the treatment of patients with cancer. Ito et al. used lymph nodes of mice draining implanted sarcomas as an enriched source of tumor antigen-specific cells. They investigated the ex vivo activation of the lymph node cells by artificial antigen presenting cells (aAPCs) for the production of therapeutic T cell cultures. The optimal aAPC consisted of magnetic beads coated with anti-CD3 and anti-CD28 antibodies. Short-term ex vivo culture with the aAPCs led to a selective expansion and/or activation of tumor antigen specific CD4+ cells. These results lay a solid foundation for the clinical application of bead-based T cell activation, and promote efforts to develop the therapeutic strategy of in vivo immunization, ex vivo T cell activation, and adoptive cell transfer.

Animals↗
PubMedDate not supplied

Generation of tumor-infiltrating lymphocyte cultures for use in adoptive transfer therapy for melanoma patients.

The generation of T lymphocytes with specific reactivity against tumor antigens is a prerequisite for effective adoptive transfer therapies. Melanoma-specific lymphocyte cultures can be established from tumor infiltrating lymphocytes (TILs) by in vitro culture in high levels of IL-2. We have optimized methods for generating melanoma-reactive TIL cultures from small resected tumor specimens. We report a retrospective analysis of 860 attempted TIL cultures from 90 sequential melanoma biopsy specimens from 62 HLA-A2+ patients. Multiple independent TIL derived from a single tumor often exhibited substantial functional and phenotypic variation. Tumor specific activity was detected in TIL from 29 (81%) of 36 patients screened. TIL cultures selected for high activity were generally capable of large numerical expansion using a single round of a rapid expansion protocol. Limited clonal T-cell populations in an oligoclonal TIL culture could confer specific tumor recognition in these highly selected, highly expanded TIL cultures. These methods were efficient at generating TILs suitable for adoptive transfer therapy.

Antigens↗
PubMedDate not supplied

Cell transfer therapy for cancer: lessons from sequential treatments of a patient with metastatic melanoma.

The development of effective autologous cell transfer therapies for the treatment of patients with cancer has been difficult, in part because the cells used to treat each patient are different, as are the patient's tumor and immune status. Much can thus be learned by sequential treatments of the same patient with the same cells, making single modifications in the treatments to determine which factors are critical. The authors have treated a single patient with five sequential administrations of the same cells with minor modifications in the mode of administration and the immune status of the patient. The treatment of this patient strongly suggested that 1) the highly avid recognition of tumor antigens in vitro by a transferred lymphocyte population does not necessarily predict in vivo antitumor activity; 2) the administration of highly avid antitumor autologous lymphocyte populations can be far more active in mediating tumor regression in vivo when administered after nonmyeloablative chemotherapy than when administered without this prior chemotherapy; 3) intra-arterial administration of highly avid antitumor autologous lymphocytes into the blood supply of the tumor can be more effective in mediating tumor regression than the intravenous administration of these same tumor infiltrating lymphocytes; 4) one mechanism of tumor escape from immunotherapy is loss of class I MHC antigen expression by the tumor due to mutation of the beta-2 microglobulin gene.

Adult↗
PubMedDate not supplied

A phase I study of nonmyeloablative chemotherapy and adoptive transfer of autologous tumor antigen-specific T lymphocytes in patients with metastatic melanoma.

This report describes a phase I clinical trial using nonmyeloablative, lympho-depleting chemotherapy in combination with adoptive immunotherapy in patients with metastatic melanoma. The chemotherapy-conditioning schedule that induced transient lymphopenia consisted of cyclophosphamide (30 or 60 mg/kg per day for 2 days) followed by fludarabine (25 mg/m(2) per day for 5 days). Immunotherapy for all patients consisted of in vitro expanded, tumor-reactive, autologous T-cell clones selected for high avidity recognition of melanoma antigens. Cohorts of three to six patients each received either no interleukin (IL)-2, low-dose IL-2 (72,000 IU/kg intravenously three times a day to a maximum of 15 doses), or high-dose IL-2 (720,000 IU/kg intravenously three times a day for a maximum of 12 doses). The toxicities associated with this treatment were transient and included neutropenia and thrombocytopenia that resolved in all patients. High dose intravenous IL-2 was better tolerated by patients after chemotherapy than during previous immunotherapy cycles without chemotherapy. No patient exhibited an objective clinical response to treatment, although five patients demonstrated mixed responses or transient shrinkage of metastatic deposits. This study established a nonmyeloablative-conditioning regimen that could be safely administered in conjunction with adoptive T-cell transfer and IL-2 in patients with metastatic melanoma.

Adolescent↗