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Biomedical subjects

A E Chang

Publications and source records attributed to A E Chang.

At least 55 records · Page 3Linked to original sources
PubMed1997

Adoptive immunotherapy with vaccine-primed lymph node cells secondarily activated with anti-CD3 and interleukin-2.

PURPOSE: In preclinical studies, we have reported the ability to induce immune T cells in lymph nodes (LN) primed by in vivo vaccination with tumor cells admixed with a bacterial adjuvant. These LN cells can be activated and expanded ex vivo for the successful immunotherapy of established tumors. We have applied these methods to generate vaccine-primed LN in patients with advanced melanoma and renal cell cancer (RCC) for therapy. MATERIALS AND METHODS: Irradiated autologous tumor cells admixed with bacille Calmette-Guérin (BCG) were used to vaccinate patients. Seven days later, draining LN were removed for activation with anti-CD3 monoclonal antibody (mAb) followed by expansion in interleukin-2 (IL-2). Activated LN cells were administered intravenously (IV) with the concomitant administration of IL-2. RESULTS: A total of 23 patients were evaluated (11 melanoma and 12 RCC). Vaccine-primed LN were expanded ex vivo with a mean of 8.4 x 10(10) cells administered per patient. Among 20 patients assessed, 15 demonstrated minimal cytotoxicity of autologous tumor cells by the activated LN cells, with the remaining mediating nonspecific cytotoxicity. By contrast, a majority of the activated LN cells showed highly specific release of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon gamma (IFN-gamma) to autologous but not allogeneic tumor stimulation. This tumor-specific cytokine release was found to be major histocompatibility complex (MHC) class I-restricted, which indicates the involvement of CD8+ cells. Among 11 melanoma patients, one had a partial tumor response. Among 12 RCC patients, two had complete and two partial responses. A trend (P = .066) between the enhancement of delayed-type hypersensitivity (DTH) reactivity to autologous tumor after therapy and tumor regression was observed. CONCLUSION: Tumor vaccines can be used to induce immunologically specific T-cell responses against melanoma and RCC in draining LN. Anti-CD3/IL-2 activation of primed LN cells can be reliably performed for clinical therapy and appears to have activity in patients with metastatic RCC.

Adult↗
PubMed1996

Immune response in human melanoma after transfer of an allogeneic class I major histocompatibility complex gene with DNA-liposome complexes.

Analysis of the antitumor immune response after gene transfer of a foreign major histocompatibility complex class I protein, HLA-B7, was performed. Ten HLA-B7-negative patients with stage IV melanoma were treated in an effort to stimulate local tumor immunity. Plasmid DNA was detected within treated tumor nodules, and RNA encoding recombinant HLA-B7 or HLA-B7 protein was demonstrated in 9 of 10 patients. T cell migration into treated lesions was observed and tumor-infiltrating lymphocyte reactivity was enhanced in six of seven and two of two patients analyzed, respectively. In contrast, the frequency of cytotoxic T lymphocyte against autologous tumor in circulating peripheral blood lymphocytes was not altered significantly, suggesting that peripheral blood lymphocyte reactivity is not indicative of local tumor responsiveness. Local inhibition of tumor growth was detected after gene transfer in two patients, one of whom showed a partial remission. This patient subsequently received treatment with tumor-infiltrating lymphocytes derived from gene-modified tumor, with a complete regression of residual disease. Thus, gene transfer with DNA-liposome complexes encoding an allogeneic major histocompatibility complex protein stimulated local antitumor immune responses that facilitated the generation of effector cells for immunotherapy of cancer.

Adult↗
PubMed1996

Injection of complementary DNA encoding interleukin-12 inhibits tumor establishment at a distant site in a murine renal carcinoma model.

Interleukin (IL-12) protein has been shown to elicit diverse immunological responses and potent antitumor activity. We demonstrate here that intradermal injection of IL-12 cDNA induces systemic biological effects characteristic of the cytokine in vivo. Intradermal injection of IL-12 cDNA resulted in local expression of IL-12 mRNA, which correlated with a 10-fold increase in natural killer activity and a 3-4-fold increase in anti-CD3-induced IFN-gamma production in cultured splenocytes. Furthermore, when challenged with Renca tumor cells at a distant site, the day of tumor emergence was significantly delayed, and tumor growth was reduced in mice that received IL-12 cDNA, compared to mice given injections of plasmid vector alone. A number of the mice receiving IL-12 cDNA injections remained tumor free months after tumor challenge. In contrast to mice receiving recombinant IL-12 protein, no splenomegaly was detected when natural killer activity was significantly induced in mice receiving injections of IL-12 cDNA. Because purified plasmid DNA is more economical to prepare and has a longer shelf-life than recombinant proteins, and intradermal administration of cDNA encoding IL-12 did not cause splenomegaly, our findings suggest that the in vivo injection of cDNA encoding IL-12 may be a less toxic and more cost-effective alternative to IL-12 protein therapy in some clinical or experimental therapeutic applications.

Animals↗
PubMed1996

Diverse manifestations of tumorigenicity and immunogenicity displayed by the poorly immunogenic B16-BL6 melanoma transduced with cytokine genes.

We evaluated the in vivo response to the poorly immunogenic B16-BL6 (BL6) murine melanoma genetically altered to secrete interleukin-2 (IL-2), IL-4, interferon gamma (IFN gamma) and granulocyte/macrophage-colony-stimulating factor (GM-CSF). Three parameters were evaluated: (1) tumorigenicity, (2) vaccination of naive animals, and (3) assessment of antitumor reactivity of T cells derived from tumor-draining lymph nodes (TDLN). Secretion of IL-2 abrogated the tumorigenicity of BL6, while IFN gamma and IL-4 partially reduced tumorigenicity, and GM-CSF had no effect. Protective immunity to wild-type tumor challenge could not be achieved by vaccination with irradiated cytokine-secreting tumors, although IL-2 and IL-4 secretion appeared to retard the growth of the challenge inoculum significantly. An alternative method to evaluate the immunogenicity of the cytokine-secreting tumors was to measure the ability of T cells obtained from TDLN to mediate regression of wild-type tumor in adoptive immunotherapy. Neither IL-2 nor IFN gamma secretion resulted in the induction of immune T cells. By contrast, GM-CSF and IL-4 secretion were found to induce immune T cells in the TDLN with GM-CSF being superior to IL-4. The combined secretion of GM-CSF and IL-4 did not lead to enhanced induction of immune T cells. GM-CSF secretion was found to upregulate B7-1 expression in TDLN, consistent with an increase in the population of antigen-presenting cells. These studies demonstrated that reduced tumorigenicity by cytokine secretion did not correlate with increased immunogenicity. With the cytokines examined, there was limited capability of developing protective immunity against the BL6 tumor. Nevertheless, GM-CSF and IL-4 secretion significantly enhanced T cell immune reactivity to the poorly immunogenic BL6 tumor.

Animals↗
PubMed1996

Direct transfer of a foreign MHC gene into human melanoma alters T cell receptor V beta usage by tumor-infiltrating lymphocytes.

The direct introduction of foreign genes into tumors shows promise as a therapeutic modality to enhance tumor immunogenicity. Hence, melanoma nodules were directly injected with a vector encoding an allogeneic MHC class I molecule, HLA-B7. Tumor-infiltrating lymphocytes (TIL) were isolated from cutaneous melanoma biopsies before and after HLA-B7 gene transfer. TIL were expanded in interleukin-2 (IL-2) by standard techniques for approximately 4 weeks, then analyzed for T cell receptor V beta usage by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Prior to gene transfer. TIL V beta usage was found to be highly restricted, the only one to four V beta families being expressed and one or two of these families representing more than 90% of the repertoire. As anticipated, TIL V beta usage varied among patients expressing different HLA types. However, V beta 13 was over-represented in that six of eight patients utilized V beta 13 as a dominant family, regardless of HLA type. Following HLA-B7 gene transfer, TIL V beta usage was markedly altered: (1) V beta families that dominated following gene transfer differed from the V beta families utilized by TIL prior to treatment, and (2) introduction of the HLA-B7 gene resulted in a more diverse repertoire with an increase in the number of V beta families represented. In two patients, TIL were evaluated before treatment and from multiple, distinct melanoma nodules following gene transfer. In these two patients, a comparison was made between TIL V beta profiles obtained after treatment from nodules that had been injected with the HLA-B7 gene or left untreated. Interestingly, the V beta repertoires of TIL from uninjected nodules following gene transfer were similar to that of TIL from injected nodules, rather than pretreatment TIL. These data demonstrate a direct immunological effect of foreign MHC gene transfer into human melanoma, and suggest that local expression of an allogeneic MHC molecule generates systemic alterations in the antitumor immune response.

CD4 Antigens↗
PubMed1996

Current status of adoptive immunotherapy of cancer.

The sentinel observations made by William B. Coley. M.D. in the 1890s that patients with malignancics can respond to the intratumoral inoculation of live bacterial organisms or bacterial toxins became the cornerstone for the development of immunotherapy for cancers. It has been repeatedly demonstrated that tumors express unique proteins which can trigger an immune response. The adoptive transfer of immune cells to the host with established malignancy can mediate complete eradication of local or disseminated tumors and result in systemic immunity. This review summarizes the current experimental as well as clinical status of adoptive immunotherapy of cancer. There are a number of different methods to isolate tumor-reactive T cells from the tumor-bearing host and allow for their ex vivo expansion. A new direction in this field includes attempts to up-regulate the immunogenicity of tumors by genetically modifying tumor cells to express immunoregulatory peptides (i.e. cytokines, co-stimulatory molecules, etc.) in order to exploit endogenously weak immune responses to autochthonous tumors. Other new directions involve developing methods to generate or isolate tumor-reactive T cells subsets by selective in vitro stimulation (i.e. bacterial superantigens) or genetic engineering of activated T cells to enhance their ability to mediate tumor destruction. Although adoptive immunotherapy has thus far added little to the routine treatment of human cancer, it is likely that continued efforts at defining the elements involved in T cell recognition and destruction of tumor cells will broaden the applicability of T cells as important therapeutic reagents.

Clinical Trials as Topic↗
PubMed1996

Secretion of both IL-2 and IL-4 by tumor cells results in rejection and immunity.

The generation of a therapeutic immune response to malignancy is critically dependent on the inherent immunogenicity of the tumor. Our study demonstrates that secretion of both interleukin-2 (IL-2) and IL-4 by a seemingly nonimmunogenic tumor abrogates tumorigenicity, and mice that have rejected the genetically modified tumor are immune to challenges with the parental tumor. The induction of immunity by the IL-2/IL-4-secreting tumor was significantly better than that achieved with the admixture of tumor cells and the classic adjuvant, Corynebacterium parvum. To elicit a primary immune response, the majority of cells needed to secrete both cytokines. Ad-mixture of IL-2-secreting cells with IL-4-secreting cells did not result in tumor cell rejection. The IL-2/IL-4-secreting tumor cells were efficiently rejected in animals immunosuppressed by total body irradiation. Depletion of CD4+ or CD8+ T cells did not abrogate rejection of the tumor cells, but the animals depleted of CD4 cells failed to generate protective immunity. Our study demonstrates that secretion of the combination of IL-2 and IL-4 significantly enhances tumor immunogenicity. The requirement of cells secreting both cytokines suggests an intricate mechanism different from the mere presence of both cytokines at the tumor-inoculation site.

Animals↗
PubMed1996

Genetic approaches to adoptive cellular therapy of malignancy.

The rapid strides made in recombinant gene technology have been the impetus for equally dramatic developments in our understanding of various aspects of cancer biology. These areas include genetic events leading to carcinogenesis, growth factors, cellular proliferation, differentiation, apoptosis, and metastasis. Novel therapeutic approaches that take advantage of this new knowledge involve biological alteration of the host target cell at a genetic level. Many of these approaches are discussed in greater detail in other sections of this issue. This article focuses on genetic approaches to the adoptive immunotherapy of malignancy. This form of cellular therapy refers to the infusion of tumor reactive immune cells to mediate regression of established tumor. This review is divided into several areas, each one involving different methods of genetic manipulation to generate immune cells for subsequent adoptive transfer and include: (1) the use of gene-modified tumors to serve as immunogens to generate antitumor T cells, (2) genetic manipulation of effector cells to enhance antitumor reactivity; and (3) genetic construction of immunocompetent effector cells from naive cells.

Animals↗
PubMed1995

Direct gene transfer for treatment of human cancer.

Genetic instability within malignant cells gives rise to mutant proteins which can be recognized by the immune system. Recognition of tumor-associated antigens by T lymphocytes could thus contribute to the elimination of neoplastic cells. We have developed a molecular genetic intervention for the treatment of malignancies based upon the knowledge that foreign major histocompatibility complex (MHC) proteins expressed on the cell surface are efficient at stimulating an immune response. Expression of this foreign MHC gene within tumors induced a cytotoxic T cell response to the introduced gene. More importantly, the immune system recognized tumor-specific antigens on unmodified tumor cells as foreign. Growth of the tumors diminished, and in many cases, there was complete regression. This research provides evidence that direct gene transfer in vivo can induce cell-mediated immunity against specific gene products, and offers the potential for effective immunotherapy for the treatment of cancer and infectious diseases in man. Our laboratory conducted a phase I clinical trial to determine the safety and efficacy of this treatment in humans. These studies suggest that direct gene transfer provides a safe and feasible approach for the treatment of human cancer. More recent developments using combination gene therapy and the initiation of a second human trial with improvements on this technology have been implemented. Finally, we have begun to define mechanisms of resistance to immune recognition by established malignancies.

Animals↗
PubMed1995

Efficient transduction of early passage human melanoma to secrete IL-4.

Augmentation of tumor immunogenicity has been increasingly studied as a strategy to develop host immunity against established malignancies. Genetic modification of tumors to secrete immunoregulatory peptides such as IL-4 has been demonstrated to augment tumor immunogenicity and enhance the induction of tumor reactive lymphoid cells in animal models. To explore the ability of IL-4 to augment the immunogenicity of melanoma cells, we constructed a recombinant retrovirus vector encoding for human IL-4 and used it to transduce human melanomas. After optimizing retrovirus transduction conditions using a reporter virus, an IL-4 encoding retrovirus vector was used to transduce early and late passage melanoma cells. IL-4 production rates of up to 2000 pg/ml per 24 h per 10(6) cells were achieved, and provirus could be detected by Southern blot of the transduced cells at 0.1 copies per cell. The IL-4 produced by the melanoma cells was biologically active. Irradiated transduced melanoma cells continued to produce IL-4 for at least two weeks of observation. Thus melanoma cells can be efficiently modified to secrete biologically active IL-4, and may be suitable substrates for autologous tumor cell vaccines.

Cryopreservation↗
PubMed1995

Preoperative radiation therapy and iododeoxyuridine for large retroperitoneal sarcomas.

PURPOSE: Local failure is frequent after conventional therapy for patients with retroperitoneal sarcomas. A Phase I/II multimodality approach was used, combining iododeoxyuridine (IdUrd) and radiation therapy, followed by attempted surgical resection, with the goal of improving local control. METHODS AND MATERIALS: Patients with retroperitoneal sarcomas were treated with three to five consecutive cycles of treatment. Each 14-day cycle consisted of a continuous intravenous infusion of IdUrd on days 1-5, twice a day radiation therapy (1.25 Gy/fraction) on days 8-12, and a break on day 13 and 14. Surgical resection was attempted after three or five cycles. Patients resected after three cycles received an additional two cycles of treatment with radiation directed to the tumor bed. IdUrd dose was escalated in Phase I fashion (1000 mg/m2/day, 1333 mg/m2/day, and 1600 mg/m2/day). The median potential follow-up was 31 months. RESULTS: Sixteen patients (13 with high grade tumors) were treated. The median maximum tumor size was 17 cm. Resection margins were negative in four patients, microscopically positive in four patients, and grossly positive in three patients. Five patients were not resected. The only grade 4 acute toxicity observed was vomiting which occurred in three patients receiving upper abdominal radiation. Postsurgical and long-term complications were rare. Median survival overall and for resected patients were 18 and 32 months, respectively. Local control was observed in three out of four patients with negative margins (9, 40+, and 51+ months), two out of four patients with microscopically positive margins (4 and 22 months), and one out of three patients with grossly positive margins (46+ months). The overall freedom from local progression was 45% at 24 months. CONCLUSION: Retroperitoneal sarcomas can be resected after preoperative radiation therapy and IdUrd, with encouraging local control in patients resected with negative or microscopically positive margins. The recommended dose using this drug and radiation schedule appears to be 1600 mg/m2/day, which will form the basis for a Phase II trial.

Actuarial Analysis↗
PubMed1995

Tumor-specific granulocyte/macrophage colony-stimulating factor and interferon gamma secretion is associated with in vivo therapeutic efficacy of activated tumor-draining lymph node cells.

In this study, cytokine release by tumor-draining lymph node cells sensitized in vitro (IVS-TDLN) was examined and correlated with therapeutic efficacy in adoptive immunotherapy. Mice bearing immunologically distinct MCA 207 and MCA 205 sarcoma tumors were utilized in criss-cross experiments. IVS-TDLN obtained from mice bearing 10-day subcutaneous (s.c.) tumors mediated immunologically specific regression of established 3-day pulmonary metastases, but demonstrated non-specific cytolytic reactivity against both tumors in a 4-h 51Cr-release assay. By contrast, these IVS-TDLN cells were found specifically to secrete granulocyte/macrophage colony-stimulating factor (GM-CSF) and interferon gamma (IFN gamma) when restimulated in vitro with irradiated tumor cells. To determine the predictive value of tumor-specific cytokine release with in vivo therapeutic efficacy, a kinetic analysis of antitumor activities of TDLN obtained from animals bearing MCA 207 tumors for increasing lengths of time was performed. IVS-TDLN cells from mice bearing day-7, -10 and -14 s.c. tumors manifested tumor-specific release of GM-CSF and IFN gamma, and mediated significant antitumor reactivity in vivo. In contrast IVS-LN cells from day-0 and day-21 tumor-bearing animals did not release significant amounts of GM-CSF and IFN gamma, and were not therapeutically efficacious in vivo. Day-4 IVS-TDLN released high levels of GM-CSF and IFN gamma non-specifically, and were not therapeutic in adoptive immunotherapy at doses effective for day-7 and day-14 IVS-TDLN cells. In other experiments, IVS cells generated from different lymph node groups in animals bearing 10-day established s.c. tumors were examined and found to have unique profiles of cytokine release. In these studies, the ability of IVS cells to release specifically both cytokines as opposed to one was associated with greater therapeutic efficacy on a per cell basis. Our findings suggest that the tumor-specific releases of GM-CSF and IFN gamma are useful parameters to assess the in vivo therapeutic efficacy of immune lymphocytes.

Animals↗
PubMed1995

Basic principles associated with gene therapy of cancer.

Advances in gene delivery systems have made possible the development of strategies to eradicate cancers via genetic manipulation. Although the strategy of 'gene therapy' remains in its infancy, experimental tumour models have produced encouraging results and have demonstrated that tumour growth or development can be altered by genetic manipulations. Investigators are hopeful that current and future human trials will confirm the role of these modalities in cancer treatment. This review focuses on several aspects of gene therapy that provide clinicians with a framework to understand the rationale and basic principles underlying current gene therapy protocols being conducted for cancer treatment. The relative merits of different gene delivery systems and the mechanisms underlying clinical gene therapy strategies are reviewed. In addition, we discuss the relevance of these new techniques to the oncologic surgeon.

Animals↗
PubMed1995

Generation of therapeutic T-lymphocytes after in vivo tumor transfection with an allogeneic class I major histocompatibility complex gene.

In an effort to enhance the generation of tumor-reactive T-lymphocytes for adoptive immunotherapy, we examined the effects of in vivo transfection of an allogeneic major histocompatibility complex (MHC) class I gene (H-2Ks) of the poorly immunogenic B16BL6 (BL6) melanoma of H-2b origin. Cells from lymph nodes (LNs) draining these tumors after transfection were assessed in adoptive immunotherapy experiments for tumor reactivity after sequential activation with anti-CD3 monoclonal antibody (mAb) followed by culture in interleukin (IL)-2. H-2Ks lipofection of progressively growing BL6 subcutaneous tumors did not reduce tumorigenicity. However, in vivo lipofection of BL6 by intratumor inoculation or admixture of H-2Ks cDNA/liposome complexes and tumor cells prior to inoculation resulted in enhanced development of sensitized T-lymphocytes in the draining LN, which mediated the reduction of the numbers of established 3-day parental lung metastases in six of six experiments. In subsequent studies, in vivo transfection of BL6 with naked H-2Ks cDNA was found to be more effective than lipofection in eliciting sensitized T-cells in the draining LN. Admixture of liposomes alone or control plasmid DNA did not have an adjuvant effect similar to H-2Ks cDNA. Relative tumor transfection efficiency was assessed by an indirect assay with the chloramphenicol acetyltransferase (CAT) reporter gene. BL6 tumors were more efficiently transfected by intratumor inoculation with naked cDNA compared with lipofection. In summary, in vivo allogenization of the poorly immunogenic BL6 tumor resulted in enhanced generation of therapeutic T-cells effective in the treatment of parental tumor.

Adjuvants, Immunologic↗
PubMed1995

A phase II trial of interleukin-2 and interferon-alpha in the treatment of metastatic colorectal carcinoma.

A total of 29 patients with stage IV colorectal cancer were entered into a phase II trial of bolus interleukin-2 (IL-2) and interferon-alpha (IFN alpha) (3 x 10(6) U/m2 of each cytokine given i.v. q8h x 15 doses and repeated in 2 weeks). Immunologic parameters measured on isolated peripheral blood lymphocytes revealed increased activated T cells with upregulated natural killer and lymphokine-activated killer activity. Among 24 evaluable patients, there were 4 partial responses (17%) of short duration ( < or = 6 months). Three of the responding patients had been refractory to prior chemotherapy. Overall median survival in the 24 evaluable patients was 18.5 months. Therapy necessitated an inpatient setting, with the most common toxicities being hypotension, hepatic insufficiency, fever, hypocalcemia, nausea/vomiting, and renal insufficiency. There were two treatment-related deaths. Because neither IL-2 nor IFN alpha alone has significant activity against colorectal cancer, the responses observed in this study suggest a potential synergistic effect between the two cytokines. However, the toxicity and short duration of response without survival benefit do not support the routine use of this regimen as a therapeutic modality for this tumor histology.

Adult↗
PubMed1995

Biopsy techniques for skin, soft-tissue, and bone neoplasms.

This article discusses important aspects of the biopsy of neoplasms in skin, soft tissues, and bone. There are a variety of clinical conditions in which specific biopsy techniques are indicated. Inappropriate biopsy of tumors in these sites may compromise subsequent definitive therapy.

Biopsy↗