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H Kim Lyerly

Publications and source records attributed to H Kim Lyerly.

At least 19 recordsLinked to original sources
PubMed2006

Gene therapy for lung cancer.

Lung cancer patients suffer a 15% overall survival despite advances in chemotherapy, radiation therapy, and surgery. This unacceptably low survival rate is due to the usual finding of advanced disease at diagnosis. However, multimodality strategies using conventional therapies only minimally improve survival rates even in early stages of lung cancer. Attempts to improve survival in advanced disease using various combinations of platinum-based chemotherapy have demonstrated that no regimen is superior, suggesting a therapeutic plateau and the need for novel, more specific, and less toxic therapeutic strategies. Over the past three decades, the genetic etiology of cancer has been gradually delineated, albeit not yet completely. Understanding the molecular events that occur during the multistep process of bronchogenic carcinogenesis may make these tasks more surmountable. During these same three decades, techniques have been developed which allow transfer of functional genes into mammalian cells. For example, blockade of activated tumor-promoting oncogenes or replacement of inactivated tumor-suppressing or apoptosis-promoting genes can be achieved by gene therapy. This article will discuss the therapeutic implications of these molecular changes associated with bronchogenic carcinomas and will then review the status of gene therapies for treatment of lung cancer.

Animals↗
PubMed2006

Recent clinical progress in virus-based therapies for cancer.

As our knowledge of the molecular basis of cancer expands, viral vectors have been increasingly studied as potential antitumour therapeutic agents. With their ability to invade and replicate within target cells, viruses have been utilised as oncolytic agents to directly lyse tumour cells. Viruses can also deliver their genetic payload into infected cells, allowing for the repair of defective tumour suppressor genes, disruption of oncogenic pathways, and production of cytokines that activate the immune system. Finally, viruses encoding tumour-associated antigens can infect dendritic cells, triggering the development of a tumour-specific immune response. The ability to engineer viruses with high levels of tumour specificity and efficient rates of infection has enhanced the safety profile of these agents, allowing for the development of viable therapeutic options that have been examined in the clinic, either alone or in conjunction with more conventional therapies. This review highlights the principles underlying virus-based therapies for cancer, with an emphasis on recent developments from the clinic.

Cancer Vaccines↗
PubMed2006

Role of natural killer cell function in dendritic cell-based vaccines.

Recent studies have elucidated the functional links between natural killer (NK) cells and, demonstrating the reciprocal activation of these cell types through NK-DC interactions. The subsets of cells and molecular pathways involved in such interactions have been defined, and the possible anatomical sites of these interactions have also been reported. Murine experiments have demonstrated that injection of mature DCs induces rapid recruitment of NK cells to lymph nodes and that these NK cells provide interferon-gamma for Type 1 priming. Thus, there is an increasing body of in vivo evidence indicating that NK-DC interactions during the early phase of innate immunity can impact the quality and magnitude of the subsequent adaptive immune response. Importantly, these studies imply that NK cells might not serve merely as cytotoxic lymphocytes combating viral pathogens and malignant tumors, but must also be considered as important immunoregulatory cells with a significant influence on adaptive immunity. In contrast to the large volume of knowledge obtained through basic research, there is a relative paucity of information regarding NK cell function in adaptive immunity from clinical trials, as few DC vaccine studies have attempted to evaluate the nonspecific, yet potentially clinically relevant, NK response to immunization. In this article, the authors will review studies focusing on NK-DC interactions and highlight the most recent clinical findings relating to the potential role of NK cells in DC-based vaccine therapy.

Adoptive Transfer↗
PubMed2005

NK cell activation by dendritic cell vaccine: a mechanism of action for clinical activity.

Recent reports revealed that dendritic cell (DC)-natural killer (NK) cell interaction plays an important role in tumor immunity, but few DC vaccine studies have attempted to evaluate the non-specific, yet potentially clinically relevant, NK response to immunization. In this study, we first analyzed in vitro activation of NK cells by DCs similar to those used in clinical trials. Subsequently, NK cell responses were analyzed in a phase I clinical trial of a vaccine consisting of autologous DCs loaded with a fowlpox vector encoding CEA. The data were compared with the clinical outcome of the patients. DC enhances NK activity in vitro, partly by sustaining NK cell survival and by enhancing the expression of NK-activating receptors, including NKp46 and NKG2D. Among nine patients in our clinical trial, NK cytolytic activity increased in four (range 2.5-5 times greater lytic activity) including three who had increased NK cell frequency, was stable in two and decreased in three. NKp46 and NKG2D expression showed a good correlation with the patients' NK activity. When patients were grouped by clinical activity (stable disease/no evidence of disease (stable/NE, n=5) vs progressive disease (N=4) at 3 months), the majority in the stable/NE group had increases in NK activity (P=0.016). Anti-CEA T cell response was enhanced in all the nine patients analyzed, but was not significantly different between the two groups (P=0.14). Thus, NK responses following DC vaccination may correlate more closely with clinical outcome than do T cell responses. Monitoring of NK response during vaccine studies should be routinely performed.

Adenocarcinoma↗
PubMed2005

Maximizing the retention of antigen specific lymphocyte function after cryopreservation.

The ability to cryopreserve lymphocytes in peripheral blood mononuclear cells (PBMC) to retain their function after thawing is critical to the analysis of cancer immunotherapy studies. We evaluated a variety of cryopreservation strategies with the aim of developing an optimized protocol for freezing and thawing PBMC to retain viability and function. We determined several factors which do not affect cell viability after cryopreservation such as shipping frozen samples on dry ice, the length of time and speed at which samples are washed and centrifuged after thawing, and the number of cells frozen per container. Different media additives, however, did impact the viability of the cells after thawing. There was a significant reduction in the viability of the cells after freezing when using human AB serum compared to all other additives tested (p<0.000). A second critical parameter was the temperature of the media used to wash the cells after removal from the cryotubes. When the media was cooled to 4 degrees C prior to washing, the mean viability was 69.7+/-12.5%, at 25 degrees C 92.55+/-3.1%, and at 37 degrees C 95.11+/-2.5%. Finally, we used an optimized cryopreservation protocol with different media additives to determine if functional T cell responses to tetanus toxoid could be preserved. There was a statistically significant correlation between the tetanus specific stimulation index (S.I.) of the non-cryopreserved PBMC and SI obtained from cells frozen with media containing human serum albumin as compared to other additives such as dextran or fetal bovine serum.

Antigens↗
PubMed2005

Release of endogenous danger signals from HIFU-treated tumor cells and their stimulatory effects on APCs.

The effects of high-intensity focused ultrasound (HIFU) on the release of endogenous danger signals from tumor cells and subsequent activation of antigen-presenting cells (APCs) were evaluated in vitro. MC-38 mouse tumor cells were treated using a 1.1 MHz HIFU transducer under two different protocols (P-=6.7 MPa, 30% duty cycle, 5 s vs. P-=10.7 MPa, 3% duty cycle, 30 s) to produce either thermal necrosis or mechanical lysis of the tumor cells. Here, we report that HIFU treatment can cause the release of endogenous danger signals (ATP and hsp60) and exposure of dendritic cells (DCs) and macrophages to the supernatants of HIFU-treated tumor cells leads to an increased expression of co-stimulatory molecules (CD80 and CD86) with enhanced secretion of IL-12 by the DCs and elevated secretion of TNF-alpha by the macrophages. The potency in APC activation produced by mechanical lysis is much stronger than thermal necrosis of the tumor cells. These findings suggest that optimization of treatment strategy may help to enhance HIFU-elicited anti-tumor immunity.

Adenosine Triphosphate↗
PubMed2005

Ex vivo expanded human CD4+ regulatory NKT cells suppress expansion of tumor antigen-specific CTLs.

NKT cells can produce large amounts of both Th1- and Th2-type cytokines and are an important regulatory cell type. To elucidate their role in acquired immunity, we examined the effect of human Valpha24+Vbeta11+ NKT cells or CD1d-specific ligand alpha-galactosylceramide (alphaGalCer) on the in vitro generation of antigen-specific CTLs from PBMCs using autologous MART-1(26-35) peptide-pulsed dendritic cells as stimulators. Flow cytometry using tetramer for MART-1(26-35) peptide revealed that NKT cells have inhibitory effects on CTL generation. Cytokine analysis using cytometric bead array assay and ELISA showed higher IL-4 and IL-10 secretion in the alphaGalCer(+) and/or NKT cell(+) culture setting, whereas IL-13 secretion in the culture was not affected by the presence of alphaGalCer. The CD4+ NKT cell subset seemed to play a major role in this inhibitory effect by secreting large amounts of Th2-type cytokines. Interestingly however, unlike recent reports utilizing mouse models, IL-13 was not a main effector molecule in our human system. Culture with alphaGalCer in the presence of cytokine-neutralizing antibodies for the Th2 cytokines, IL-4, IL-5 and IL-10, resulted in enhanced CTL generation, suggesting the dominant role of Th2 cytokines over Th1 cytokines. Thus, CD4+ NKT cells can work as immunoregulatory T cells that suppress anti-tumor immune response and, therefore, NKT cells or alphaGalCer could be used as therapeutic modalities to modulate systemic immune responses, such as autoimmune diseases. Conversely, the use of NKT cells along with anti-Th2 cytokine-neutralizing antibodies or CD4-negative NKT cell subset could enhance the generation of antigen-specific CTLs for adoptive immunotherapy.

Antigens, Neoplasm↗
PubMed2005

Impact of cryopreservation on tetramer, cytokine flow cytometry, and ELISPOT.

BACKGROUND: Cryopreservation of PBMC and/or overnight shipping of samples are required for many clinical trials, despite their potentially adverse effects upon immune monitoring assays such as MHC-peptide tetramer staining, cytokine flow cytometry (CFC), and ELISPOT. In this study, we compared the performance of these assays on leukapheresed PBMC shipped overnight in medium versus cryopreserved PBMC from matched donors. RESULTS: Using CMV pp65 peptide pool stimulation or pp65 HLA-A2 tetramer staining, there was significant correlation between shipped and cryopreserved samples for each assay (p <or= 0.001). The differences in response magnitude between cryopreserved and shipped PBMC specimens were not significant for most antigens and assays. There was significant correlation between CFC and ELISPOT assay using pp65 peptide pool stimulation, in both shipped and cryopreserved samples (p <or= 0.001). Strong correlation was observed between CFC (using HLA-A2-restricted pp65 peptide stimulation) and tetramer staining (p < 0.001). Roughly similar sensitivity and specificity were observed between the three assays and between shipped and cryopreserved samples for each assay. CONCLUSION: We conclude that all three assays show concordant results on shipped versus cryopreserved specimens, when using a peptide-based readout. The assays are also concordant with each other in pair wise comparisons using equivalent antigen systems.

Antigen Presentation↗
PubMed2005

Phase I study of immunization with dendritic cells modified with fowlpox encoding carcinoembryonic antigen and costimulatory molecules.

PURPOSE: To determine the safety and immunologic and clinical efficacy of a dendritic cell vaccine modified to hyperexpress costimulatory molecules and tumor antigen. EXPERIMENTAL DESIGN: In this phase I study, we administered one or two cycles of four triweekly s.c./intradermal injections of ex vivo generated dendritic cells modified with a recombinant fowlpox vector encoding carcinoembryonic antigen (CEA) and a triad of costimulatory molecules [rF-CEA(6D)-TRICOM]. Controls consisted of immature dendritic cells loaded with tetanus toxoid and a HLA A2-restricted peptide derived from cytomegalovirus pp65 protein. RESULTS: Fourteen patients (11 with colorectal cancer and 3 with non-small cell lung cancer) were enrolled and 12 completed at least one cycle of immunization. There were no grade 3/4 toxicities directly referable to the immunizations. One patient had a decrease in the CEA level from 46 to 6.8 and a minor regression in adenopathy that occurred several months after completion of the immunizations. Five other patients were stable through at least one cycle of immunization (3 months). Direct analysis of peripheral blood mononuclear cells using the ELISpot assay showed an increase in the frequency of CEA-specific T cells in 10 patients (range, 10-541 CEA-specific cells/10(5) peripheral blood mononuclear cells). There was a trend for a greater peak frequency of CEA-specific T cells among those with either a minor response or a stable disease following at least one cycle of therapy. A second cycle was not associated with higher T-cell frequencies. Cytokine flow cytometry showed CEA-specific immune response among both CD4(+) and CD8(+) T cells in all immune responders. CONCLUSION: This immunization strategy is safe and activates potent CEA-specific immune responses.

B7-1 Antigen↗
PubMed2005

A phase I study of dexosome immunotherapy in patients with advanced non-small cell lung cancer.

BACKGROUND: There is a continued need to develop more effective cancer immunotherapy strategies. Exosomes, cell-derived lipid vesicles that express high levels of a narrow spectrum of cell proteins represent a novel platform for delivering high levels of antigen in conjunction with costimulatory molecules. We performed this study to test the safety, feasibility and efficacy of autologous dendritic cell (DC)-derived exosomes (DEX) loaded with the MAGE tumor antigens in patients with non-small cell lung cancer (NSCLC). METHODS: This Phase I study enrolled HLA A2+ patients with pre-treated Stage IIIb (N = 4) and IV (N = 9) NSCLC with tumor expression of MAGE-A3 or A4. Patients underwent leukapheresis to generate DC from which DEX were produced and loaded with MAGE-A3, -A4, -A10, and MAGE-3DPO4 peptides. Patients received 4 doses of DEX at weekly intervals. RESULTS: Thirteen patients were enrolled and 9 completed therapy. Three formulations of DEX were evaluated; all were well tolerated with only grade 1-2 adverse events related to the use of DEX (injection site reactions (N = 8), flu like illness (N = 1), and peripheral arm pain (N = 1)). The time from the first dose of DEX until disease progression was 30 to 429+ days. Three patients had disease progression before the first DEX dose. Survival of patients after the first DEX dose was 52-665+ days. DTH reactivity against MAGE peptides was detected in 3/9 patients. Immune responses were detected in patients as follows: MAGE-specific T cell responses in 1/3, increased NK lytic activity in 2/4. CONCLUSION: Production of the DEX vaccine was feasible and DEX therapy was well tolerated in patients with advanced NSCLC. Some patients experienced long term stability of disease and activation of immune effectors.

Journal Article↗
PubMed2005

Immune monitoring.

A wide array of immunologic tests are available for immune monitoring in cancer vaccine trials, and the number of novel assays and technical modifications continues to burgeon. Because only a small fraction of all proposed vaccine trials tested in phase I-II trials, for practical reasons, will ultimately move forward to be tested in phase III trials, there must be a system of establishing the most promising immunization strategies. This evaluation of cancer vaccine will require standardization of the immune assays and statistical methods used in immunologic monitoring. Furthermore, the use of a systematic approach to evaluating and adopting novel technologies for immunologic assessment would likely lead to timely implementation of more reliable, practical and cost-effective methods of immune. It should be the goal and expectation that this rational approach to immune monitoring will allow the critical appraisal of the most promising vaccine candidates in the context of pivotal, multi-center trials.

Biomarkers↗
PubMed2005

Recent developments in therapeutic cancer vaccines.

Therapeutic cancer vaccines are being developed with the intention of treating existing tumors or preventing tumor recurrence. While the results of clinical trials, predominantly in the metastatic setting have been sobering, the central hypothesis of active immunotherapy i.e. that the human immune system can be activated to recognize and destroy tumor cells, remains a viable one. We believe that a fundamental shift in how clinical trials are performed, and what concepts they test is required to make meaningful strides towards future clinical use of cancer vaccines. First, we must reappraise whether the metastatic setting is the appropriate arena to test these agents. Second, we must arrive at a consensus on the most important biologic endpoints and rapidly test vaccines for their ability to achieve these endpoints. Third, we need to expend more effort on understanding how to manipulate the immune system beyond the initial stimulation provided by a vaccine. Fourth, in order to permit comparison of results across different studies, it would be helpful to narrow down the large number of vaccine platforms. We will discuss the current state of development of cancer vaccines and the relevance for future clinical use of these agents to treat and prevent cancers.

Antigens, Neoplasm↗
PubMed2005

The development of therapeutic and preventive vaccines for gastric cancer and Helicobacter pylori.

Gastric cancer is one of the most important worldwide public health problems. Convincing epidemiologic and etiologic associations have been made between the development of gastric cancer and infection with Helicobacter pylori. H. pylori not only has adapted to survive within the harsh environment of the stomach but also is able to modulate and avoid endogenous immune responses. The design and creation of efficacious vaccine strategies against H. pylori requires an understanding of the complex interactions that make up mucosal immunity. An effective vaccine strategy against H. pylori has the potential to affect significantly on population health worldwide.

Adenocarcinoma↗
PubMed2004

Accelerated partial breast irradiation after conservative surgery for breast cancer.

OBJECTIVE: To critically review the theoretical and actual risks and benefits of accelerated partial breast irradiation (APBI) after breast-conserving surgery. SUMMARY BACKGROUND DATA: Because of rapid evolution of radiation therapy techniques related to brachytherapy and three-dimensional conformal radiation therapy, APBI has very recently come to the forefront as a potential local treatment option for women with breast cancer. This review aims to give an overview of the biologic rationale for APBI techniques, and benefits and limitations of APBI techniques. METHODS: The authors reviewed the currently available published world medical literature on breast-conserving surgery with and without postoperative irradiation; all studies involving partial breast irradiation, including brachytherapy, for breast cancer; and currently accruing and planned APBI trials. The focus of this review was the early results of treatment in terms of toxicity, complications, cosmesis, and local control. RESULTS: On average, approximately 3% of patients treated with breast-conserving surgery will have an in-breast local recurrence away from the original lumpectomy site with or without postoperative standard whole-breast irradiation. The results of phase I-II studies involving approximately 500 patients treated with APBI after breast-conserving surgery have been published. Although many of the studies have limited long-term follow-up and potential selection bias, early results suggest that toxicity, cosmesis, and local control are comparable to outcomes seen after breast-conserving surgery followed by standard whole-breast irradiation. CONCLUSIONS: Recent advances in radiation delivery and published series of partial breast irradiation support large randomized trials comparing APBI with standard whole-breast irradiation after breast-conserving surgery.

Brachytherapy↗
PubMed2003

Quantitating cellular immune responses to cancer vaccines.

While the future of immunotherapy in the treatment of cancer is promising, it is difficult to compare the various approaches because monitoring assays have not been standardized in approach or technique. Common assays for measuring the immune response need to be established so that these assays can one day serve as surrogate markers for clinical response. Assays that accurately detect and quantitate T-cell-mediated, antigen-specific immune responses are particularly desired. However, to date, increases in the number of cytotoxic T cells through immunization have not been correlated with clinical tumor regression. Ideally, then, a T-cell assay not only needs to be sensitive, specific, reliable, reproducible, simple, and quick to perform, it must also demonstrate close correlation with clinical outcome. Assays currently used to measure T-cell response are delayed-type hypersensitivity testing, flow cytometry using peptide major histocompatibility complex tetramers, lymphoproliferation assay, enzyme-linked immunosorbant assay, enzyme-linked immunospot assay, cytokine flow cytometry, direct cytotoxicity assay, measurement of cytokine mRNA by quantitative reverse transcriptase polymerase chain reaction, and limiting dilution analysis. The purpose of this review is to describe the attributes of each test and compare their advantages and disadvantages.

Cancer Vaccines↗