Phase I Trial Using Human DCDerived Exosomes

These data were the rationale for launching vaccination with DC-derived exosomes in metastatic tumor-bearing patients. A GMP has been set up to harvest large amounts of MD-DC-derived exosomes (ultrafiltration followed by ultracentrifugation on a high-density sucrose D2O cushion) and load exosomal MHC class I molecules with synthetic tumor peptides. Phenotypical analysis of clinical-grade exosomes is allowed by FACS-beads-assay, i.e., DC-derived exosomes, are fixed onto 4.5-micron beads stained...

Nuclear Localization of Plasmid DNA

Once released from endosomes into the cytoplasm, plasmids are facing another barrier the nuclear membrane. Generally, higher levels of transgene expression are observed in actively dividing cells where the nuclear membrane disappears during mitosis (34). However, unless tumor or bone marrow cells are being targeted for transfection most cells, including muscle and dendritic cells, are nondividing. To overcome this barrier plasmids should contain specific nuclear localization sequences. The...

In Vitro Measures of Functional Antigen Specific Immune Responses

In addition to phenotypic assays, in vitro assays of T-cell function play an important role in detecting and quantitating antigen-specific immune responses. Functional assays measure a T-cell activity in response to a specific antigenic stimulus, include proliferation, cytokine secretion, and cytolytic function. These assays can be performed on specimens stimulated in vitro with antigen and cytokines, or on PBMC samples, without any preceding in vitro stimulation. The capacity of T cells to...

Peptide vaccine strategies

Over the last decade, at least 20 HLA class I-restricted peptide epitopes have been defined from multiple melanoma differentiation and cancer-testis antigens. They are reviewed in ref. 15. Peptide vaccine trials have been conducted with individual or multiple peptides in patients with stage IV disease in aqueous solution or using different adjuvants, with different cytokines, or via DNA plasmid delivery. Some trials have already been conducted in high-risk resected patients, which would appear...

Pcr

Reverse transcriptase real-time quantitative cytokine mRNA, 535-536 PCR-based cDNA subtraction. See Subtractive hybridization (SSH) PCTA-1, 453 PEL, 571 Penicillin, 279 Peptide(s) binding site modification, 131 improving immunogenicity, 129-132 Peptide-based vaccines, 121-132 Peptide immunization human clinical trials, 129-131 Peptide vaccine, 382-384 gastrointestinal cancer vaccines, 499-500 Peptide vaccine adjuvants dendritic cells (DC), 387-388 Peripheral blood lymphocytes (PBL), 367,...

Including the Exogenous Pathway

The presentation of vaccine antigens on MHC class I is needed to activate CD8+ CTLs, which are critical for protective antitumor immunity. The classical, endogenous pathway for presenting peptides on MHC class I products begins when endogenously synthesized proteins are clipped by the proteasome, and peptide fragments are transported via transporters associated with antigen presentation (TAPs) into the rough endoplasmic reticulum (13). There, the resulting peptides bind the peptide-binding...

TF Tn and sTn Vaccines

Patients with various epithelial cancers have been immunized with unclustered TF-KLH and sTn-KLH vaccines plus various adjuvants (84,85). High-titer IgM and IgG antibodies against TF and sTn antigens resulted. In our hands the majority of the reactivity was against antigenic epitopes present in the vaccine that were not present on naturally expressed mucins (porcine or ovine submaxillary mucins PSM or OSM ) or tumor cells (84,86). Based on previous studies with Tn antigen (87), Kurosaka and...

Malcolm S Mitchell MD

Allogeneic Melanoma Lysates for the Treatment of Disseminated Melanoma Adjunctive Therapy With Lysates in Resected Stage II and III Disease Melacine vs Observation for Resected Stage II Intermediate Thickness (1.5-4.0 mm) Melanoma Southwest Oncology Group Trial Melacine Followed by Interferons (IFN-a) in Disseminated Melanoma Immunological and Immunohistochemical Observations Other Clinical Trials With Allogeneic Lysates Conclusions and Future References

Discovery of haptens

Haptens are tiny lights that illuminate the dark recesses of the immune system. They were discovered by Karl Landsteiner, who used haptens to explore the breadth and fine sensitivity of antibody responses. Landsteiner (1) worked with a variety of simple chemicals, including nitrophenyls and phenyl arsonates, that were incapable of inducing an immune response by themselves, but became immunogenic when they were attached covalently to a protein carrier. He coined the term hapten from the Greek...

HuKSIL2 Immunocytokine

Besides hu14.18-IL-2, one other immunocytokine huKS-IL-2 (EMD273066 Fig. 3) is currently being studied in patients. Immunocytokine huKS-IL-2 is composed of two molecules of IL-2 genetically fused to a humanized antibody directed against human adenocarcinoma-associated antigen (KSA, also known as EpCAM, or epithelial cell adhesion molecule), which is highly expressed on many epithelial cancers including prostate, colon, breast, and lung (34,35). Each immunocytokine molecule comprises two IL-2...

Antibody Responses in Vaccinated Cancer Patients

Table 3 summarizes humoral immune responses in vaccinated cancer patients including only those studies in which the binding of vaccine-induced antibodies to the surfaces of tumor cells was demonstrated. Antibodies binding to the tumor cell surface may destroy the cells via ADCC or CDC mechanisms or induce apoptosis, whereas antibodies binding to intracytoplasmic structures are most likely of no benefit to the patient. Thus, there are numerous reports on the induction of antibodies to isolated...

TCell Anergy Tolerance

T-Cell Anergy in Cancer Patients Selective T-cell nonresponsiveness to a particular antigen, as shown by defective antigen-specific IFN-y production and proliferation, has been repeatedly reported using murine tumor models. T-cell anergy has been shown to be an early event in tumor progression (30). Naive CD4+ T cells specific for a tumor-associated antigen, transferred into tumor-bearing mice, had a significantly diminished response to the peptide antigen (30). In clinical settings, the...

Alphavirus replicons and related vector systems general characteristics

Some efforts have been made to generate vaccine vectors from fully replication-competent alphaviruses. In these cases, attenuated strains are used, and the subgenomic 26S promoter is duplicated to allow expression of both the viral structural proteins and a heterologous gene (74). However, such vectors are limited with respect to both the size and stability of the heterologous gene, and in addition, efficiently induce antivector immune responses. Thus, replicon vectors have proven to be more...

Alphavirus characteristics applicable to vector development

Alphaviruses have several characteristics that are potentially advantageous for the derivation of vaccine vector systems. Within the general population, preexisting anti-alphavirus immunity is not widespread. Alphaviruses generally exhibit diverse cellular tropism within a given host, allowing for a broad range of administration routes for antitumor immunotherapeutics, although some alphaviruses such as Venezuelan equine encephalitis (VEE) show a natural and pronounced initial tropism for...

Info

Carcinoma tumor cells tumor cells ADCC Antibody-dependent cellular cytoxicity ELISA Enzyme-linked immunosorbent assay FACS Fluorescence-activated cell sorter Gp100 Glycoprotein 100 HMW-MAA High-mol wt melanoma-associated antigen TRP Tyrosinase-related protein VSV Vessicular stomatitis virus or carcinoembryonic antigen (CEA) (62,63). The Ab2 induced anti-anti-idiotypic antibodies (Ab3), which bound to CRC cells (59-63) and mediated ADCC with human effector cells (62,63). Interestingly, the...

DC Dose Frequency Route and Schedule of Injections

In most studies thus far, the DCs were usually given at 2- to 4-wk intervals, and at doses between 4 and 40 million without striking differences in results. In vitro studies on human T-cell activation by DCs would predict that higher doses of DCs given more frequently should provide more intense and durable TCR triggering and thus promote T-cell priming and polarization. However, frequent stimulation might also cause activation-induced death of T cells. Also, the induced CTLs may kill booster...

Introduction

The success of cancer immunotherapy is dependent on the discovery of tumor-associated antigens (TAAs) for vaccine targets, but equally important is the need for effective delivery strategies and potent adjuvants to induce an appropriate immune response. Although there is evidence that many cancer patients do mount an immune response against their tumor, the affinity and frequency of responding T cells appears to be low. Additionally, the natural immune response to some cancers is a T helper 2...

MPLContaining Adjuvants

Ribi et al. (36,40-43) carried out systematic studies on the antitumor activities of cell wall components from both mycobacteria and Gram-negative Salmonella species. The findings from these studies led to the development of two adjuvants currently in advanced clinical studies with cancer vaccines Corixa Corporation's monophosphoryl lipid A (MPL adjuvant) and Enhanzyn immunostimulant. LPS is the major component of Gram-negative bacterial cell walls. Evaluation of different LPS preparations for...

Carbohydrate Cell Surface Cancer Antigens The Mskcc Experience

We have screened a variety of malignancies and normal tissues with a series of 40 monoclonal antibodies against 25 antigens that were potential target antigens for immunotherapy (18-21). Results for the 12 defined antigens expressed strongly in 50 or more of biopsy specimens of breast, ovary, prostate cancer, melanoma, sarcoma, and small-cell lung cancer (SCLC) are shown as examples in Table 2. The 13 excluded antigens (including CEA carcinoembryonic antigen and HER2 neu) were expressed in 0-2...

John Fikes PhD

The Challenge of Overcoming Immunological Tolerance 1. the challenge of overcoming immunological tolerance For all cancer vaccine strategies, a major challenge facing efforts to induce a clinically effective T-cell response is the necessity to break tolerance to normal, self antigens. To control auto-reactivity, some T cells with high avidity for tumor-associated antigen TAA epitope-major histocompatibility MHCs complexes are deleted in the thymus and the remaining T cells are controlled by...

Patients With Cancer Can Be Immunized With Class II Peptide Based Vaccines

A potential pitfall of the use of single class I binding peptides is illustrated in two similar studies vaccinating patients with an HLA-A2-binding peptide, p369-377, derived from the protein sequence of HER-2 neu, a well-defined tumor antigen. In an initial clinical study, HLA-A2-positive patients with metastatic HER-2 neu-overexpressing breast, ovarian, or colorectal carcinomas were immunized with 1 mg of p369-377 admixed in incomplete Freund's adjuvant IFA every 3 wk 38 . Peptide-specific...

Humana Press

2004 Humana Press Inc. 999 Riverview Drive, Suite 208 Totowa, New Jersey 07512 All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise without written permission from the Publisher. All articles, comments, opinions, conclusions, or recommendations are those of the author s , and do not necessarily reflect the views of the publisher. Due...

References

Studies on the immunological response to foreign tumor transplants in the mouse. I. The role of lymph node cells in conferring immunity by adoptive transfer. J Exp Med 1955 102 157-177. 2. Rosenberg SA. Progress in human tumour immunology and immunotherapy. Nature 2001 411 380384. 3. Billingham RE, Brent L, Medawar PW. Quantitative studies on tissue transplantation immunity II the origin, strength and duration of actively and adoptively acquired immunity. Proc Roy Soc Biol 1954...

Paul F Robbins PhD

Antigens Recognized by HLA Class I-Restricted T Cells Antigens Recognized by Tumor-Reactive, Class II-Restricted T Cells Clinical Applications References Studies first carried out in the early 1980s demonstrated that incubation of tumor-infiltrating lymphocytes TILs with high doses of interleukin-2 IL-2 resulted in the generation of CD8 cytotoxic T cells CTL that recognized tumor cells in a major histocompatibility complex MHC -restricted manner. This procedure resulted in the generation of...

James L Gulley MD PhD Philip M Arlen MD and Jeffrey Schlom PhD

Vaccinia Vector

Dendritic Cell Vaccines With Pox Vectors Cytokine Expression Driven by Pox Vectors Future Development of Recombinant Pox Virus Vaccines Tumor-associated antigens TAAs are by definition either weakly immunogenic or functionally nonimmunogenic. Vaccine strategies must be developed in which the presentation of these TAAs to the immune system results in far greater activation of T cells than is being achieved naturally in the host. One approach to create an inflammatory milieu designed to trigger a...

Adenovirus use in cancer vaccine strategies

With so much known about Ad biology, it was a natural step to use recombinant Ad for vaccination purposes. As a first example, E1- Ad vectors have been engineered that express genes encoding epitopes or whole proteins derived from a number of pathogens, including but not limited to malaria, bovine herpesvirus type 1 , foot-and-mouth disease virus FMDV , measles virus, and HIV human immunodeficiency virus 5-7 . Vaccination with these Ad vectors has shown positive efficacy in preventing viral...

Practical Issues of Peptide Immunization Assessed in Early Human Clinical Trials

One of the first considerations addressed in initial clinical trials of peptide-based vaccines was the route of administration. The primary routes of administration that have been used are the intramuscular, subcutaneous, and intradermal routes. The dose and volume of the vaccine itself, the choice of adjuvant, and the desired immune response have largely determined immunization route. There have been few human clinical peptide vaccine studies comparing the routes of administration. For...

Endosome Escape Sequences

The acidic environment of endosomes is detrimental to DNA, thus it is imperative for the plasmid to exit the endosome as quickly as possible. Unlike several viral peptides that facilitate escape of the virus from the endosome, such sequences are probably missing in most plasmids. Apart from providing a component of cellular targeting, cationic polymers can also protect naked DNA from degradation in the endosome. This might be another reason why transfection with cationic lipid-plasmid DNA...

Production and purification of exosomes

Since exosomes mediate MHC class I- and class II-restricted T-cell stimulatory capacity 29-31 and efficiently substitute for whole DC cultures 5 , good manufacturing process GMP laboratory procedures for exosome harvesting and purification have been set up for clinical implementations 32 . Exosomes derived from DC and tumor cell culture supernatants can be readily purified within 4-5 h starting from 2-3 liters of culture supernatant based on their physical properties. Exosomes float on sucrose...

Systemic and Local Suppression of T Cells

Immunosuppressive mechanisms that promote tumor growth include suppressive factors directly produced by tumor cells and those that are produced by other cells, although induced by the tumor. The most studied suppressive factor that can be produced by both the tumor and immunocompetent cells is the transforming growth factor-P TGF-P . TGF-P inhibits differentiation of both CD4 and CD8 naive T cells via different transcriptional activators 16 . Blocking of TGF-P signals in T cells in mice leads...

Biological effects of exosomes

The primary aim of exosomal release for a cell might be to discard membrane proteins. This role was suggested for reticulocyte-derived exosomes that carry transferring receptors TfRs useless in erythrocytes 36 . Thus, exosomes could be an alternative to lysosomal degradation, for example, to eliminate proteins that resist degradation by lysosomal proteases. However, based on their protein composition, i.e., enrichment for MHC complexes, hsp, and some targeting molecules, it is conceivable that...

Bacterial Extracts in Cancer Vaccines

Over a century ago, a New York physician, William B. Coley, noted that some cancer patients experienced tumor regression following episodes of acute bacterial illness. Dr. Coley hypothesized that the two events were linked and treated an inoperable cancer patient with a viable bacterial culture to induce a commotion in the blood. Remarkably, the patient recovered from both the bacterial infection and the tumor. From 1900 to 1936, Coley went on to successfully treat many tumor-bearing patients...

Contributors

Andrea Amalfitano, do, phd Departments of Pediatrics, Molecular Genetics and Microbiology, and Pathology, Duke University Medical Center, Durham, NC Fabrice Andre, md Department of Clinical Biology, Institut Gustave Roussy IGR , Villejuif, France Philip M. Arlen, md Laboratory of Tumor Immunology and Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD Jory R. Baldridge, phd Corixa Corporation, Hamilton, MT David Berd, md Division of Medical Oncology, Department of...

Mlmaqealafl

Peptide, appeared to only weakly stimulate these T cells. Thus, it appears that NY-ESO-1157-165 may represent the peptide that is naturally processed and presented on the surface of tumor cells. The NY-ESO-1157-165 peptide contains a cysteine residue at the carboxy terminus, and substitution of amino acids such as alanine or valine for this residue appeared to further enhance recognition by CD8 T cells, presumably by inhibiting the formation of peptide dimers that are linked through a disulfide...