Our immune system is essential for the protection against and destruction of pathogens, but also has an important role in cancer and tumor control. Therapy that is committed to use the immune system as anti-cancer strategy is called immunotherapy. Effective immunotherapy depends on the induction and activation of both innate (non-specific) and adaptive (specific and memory) immunity simultaneously combined with inhibition of tumor induced immune suppression. Vaccination, widely applied in the field of virology, can also be exploited in cancer to provide activation signals to the innate and adaptive immune players. Central players of innate and adaptive immunity that need to be instructed by vaccines are antigen presenting cells (APCs) such as dendritic cells (DCs) or Langerhans cells, which are both located in the skin, the prime vaccination site. APCs can be seen as messengers of the immune system that take up antigens, either tumor or pathogen derived, process and present them to T-cells that belong to the adaptive immunity and create specifity and memory. Stimulation of APCs facilitates their migration to lymph nodes where they can establish activation of innate immune cells, such as invariant natural killer T-cells (iNKT) in addition to activation of the adaptive immune response trough cross-presentation of antigens to CD8+ and CD4+ T-cells. These CD8+ and CD4+ T-cells can be respectively seen as effector cells that can kill tumor cells and helper cells that support CD8+ T-cells. iNKT can be described as immune boosters that aid in activation of both CD8+ and CD4+ T-cells, but also DCs and natural killer cells (which can kill tumor cells) but above all iNKT also exert killing capacities themselves. Since APCs play such a central role in the activation of antigen specific T-cell responses and iNKT, it is an attractive strategy to develop vaccines that are specifically delivered to APCs.
The most efficient way to mount a sustained immune response is to target antigens to antigen presenting cells that trigger both innate and adaptive immune responses. A comprehensive view of the current approaches to the design of new antigenic formulations will enhance our understanding and perspective of targeted immunotherapy. The aim of this Research Topic is to provide an overview of the currently adopted targeting strategies by a collection of articles on: 1.Novel approaches of antigen targeting for immunotherapeutic strategies against cancer and/or infectious diseases. 2. Diversity and biology of dendritic cell subsets in human and mouse. 3. Combined strategies for the delivery of antigens and adjuvant molecules that stimulate innate immune responses and their influence on the quality of immune responses. 4. Impact of the receptor mediate intracellular trafficking on antigen presentation.
This comprehensive, authoritative treatise covers all aspects of mucosal vaccines including their development, mechanisms of action, molecular/cellular aspects, and practical applications. The contributing authors and editors of this one-of-a-kind book are very well known in their respective fields. Mucosal Vaccines is organized in a unique format in which basic, clinical, and practical aspects of the mucosal immune system for vaccine development are described and discussed. This project is endorsed by the Society for Mucosal Immunology. Provides the latest views on mucosal vaccines Applies basic principles to the development of new vaccines Links basic, clinical, and practical aspects of mucosal vaccines to different infectious diseases Unique and user-friendly organization
Particle-based delivery of antigen has great potential for generating improved vaccines. During the course of an immune response, a pathogen may trigger multiple pattern-recognition receptors, instilling a strong proinflammatory immune response. Highly successful vaccines, such yellow fever vaccine and Dryvax® (smallpox), also induce immune responses by utilizing multiple pathogen-sensing signaling pathways, yielding long-lasting B and T cell responses. Subunit vaccines generally require an external adjuvant to boost immune responses; however, recent data has shown that targeting multiple immune activation pathways generates a more potent immune response, similar to native infection or immunization with live vaccines (Kasturi et al., 2011; Ahonen et al., 2004, 2008). To determine the effects of presenting targeting and/or activating moieties in a multivalent form, we generated two different particle-based vaccines. The first, an antigen-loaded, pH-sensitive hydrogel microparticle, was found to be taken up and presented by bone marrow-derived dendritic cells (BMDCs) in vitro and targeted to dendritic cells (DCs) and monocytes in vivo. Addition of targeting antibodies to the particle surface did not influence its uptake. DCs also upregulated activation markers when treated with microparticles, even when no agonistic anti-CD40 was conjugated to the microparticles. Furthermore, these particles induced increased percentages of interferon-[gamma]-producing CD8 T cells in response to challenge with a pathogen expressing the same antigen, in both an accelerated vaccination strategy using pre-loaded BMDCs and a traditional mouse immunization setting. The second particle, a luminescent porous silicon nanoparticle, displayed the same targeting and/or activating antibodies. This particle used antigen that was encoded in the 3' end of the targeting antibody instead of encapsulating it in the particle. Nanoparticles displaying agonistic anti-CD40 (with no antigen), produced a multivalent effect in B cells in vitro, in which the stimulatory effects of the CD40 nanoparticle were observed at 30-40-fold lower dose of antibody versus free anti-CD40. In vitro and in vivo, nanoparticles displaying targeting antibodies induced CD8 T cell proliferation better than those displaying control antibodies; however, this effect could not be consistently observed long-term in vivo, even with both targeting antibody and anti-CD40. In fact antigen-specific cells were most often deleted at memory time points.
Immunopotentiators in Modern Vaccines provides an in-depth insight and overview of a number of most promising immunopotentiators in modern vaccines. In contrast to existing books on the subject it provides recent data on the critical mechanisms governing the activity of vaccine adjuvants and delivery systems. Knowledge of immunological pathways and scenarios of the cells and molecules involved is described and depicted in comprehensive illustrations. Contributions from leading international authorities in the field Well-illustrated, informative figures present the interactions between immunopotentiators and the host immune system Each chapter lists advantages and potential hurdles for achieving a practical application for the specific immunopentiator
Cancer remains a major challenge for modern society. Not only does cancer rank among the first three causes of mortality in most population groups but also the therapeutic options available for most tumor types are limited. The existing ones have limited efficacy, lack specificity and their administration carry major side effects. Hence the urgent need for novel cancer therapies. One of the most promising avenues in research is the use of specific immunotherapy. The notion that the immune system may have important anti-tumor effects has been around for more than a century now. Every major progress in microbiology and immunology has been immediately followed by attempts to apply the new knowledge to the treatment of cancer. Progress has reached a point where it is well established that most cancer patients mount specific T cell responses against their tumors. The molecular identity of the antigens recognized by anti-tumor T cells has been elucidated and several hundreds of tumor-derived antigenic peptides have been discovered. Upon recognition of such peptides presented by self MHC molecules, both CD8 and CD4 T cells are activated, expand to high numbers and differentiate into effective anti-tumor agents. CD8 T cells directly destroy tumor cells and can cause even large tumors to completely regress in experimental mouse models. These observations have spurred intense research activity aimed at designing and testing cancer vaccines. Over 100 years ago Coley successfully used intratumoral injection of killed bacteria to treat sarcomas. The important anti-tumor effects observed in a fraction of these patients fueled major research efforts. These led to major discoveries in the 80s and the 90s. It turns out that bacterial lipopolysaccharides stimulate the production of massive amounts of a cytokine still known today as tumor necrosis factor (TNF-a). They do so by engagement of a rather complex set of interactions culminating in the ligation of a Toll-like receptor, TLR -4. Ensuing signaling through this receptor initiates potent innate immune responses. Unfortunately the clinical use of both TNF-a and LPS can not be generalized due to their very narrow therapeutic margin. Importantly, synthetic Lipid A analogs have been identified that retain useful bioactivity and yet possess only mild toxicity. The relatively large body of information accumulated thus far on the molecular and cellular interactions set in motion by administration of LPS as well as by the synthetic lipid A analogs allow to place this family of bacterially-derived molecules at the crossroads between innate and adaptive immunity. By virtue of this key position, the therapeutic applications being pursued aim at using these compounds either as direct anti-tumor agents or as vaccine adjuvants. The clinical experience acquired so far on these two avenues is asymmetric. Few clinical trials using Lipid A analogs as single anti-cancer agents involving less than 100 patients with advanced cancer have been reported. In contrast, lipid A has been tested in over 300,000 individuals in various vaccines trials, including therapeutic cancer vaccines. Clearly most of the work needed to develop lipid A as effective anti-cancer agents and/or as vaccine adjuvant lies ahead in the near future. This book is a timely contribution and provides a much needed up-to-date overview of the chemical, biological and physiological aspects of lipid A. It should be a beacon to all those involved in this field of research.
Immunization plays a key role in maintaining human health and each year, saves millions of lives from lethal pathogens and other fatal diseases in the most economical way, thanks to the advanced development of model vaccines. Subunit vaccines are regarded as a safer product than the whole microbe based-conventional vaccines and can be entrapped in various nanocarriers to form a vaccine adjuvant-delivery system (VADS) able to further boost their immunostimulatory activity. In this book, six groups of authors introduce immunization advances in VADSs designed for infection prophylaxis and cancer immunotherapy, problems and their resolution in both human and poultry immunization, and also, the mathematical model for assay of the basic immunization problem (BIP) understood from a finance point of view.
This volume presents detailed laboratory protocols for in vitro synthesis of mRNA with favorable properties, its introduction into cells by a variety of techniques, and the measurement of physiological and clinical consequences such as protein replacement and cancer immunotherapy. Synthetic techniques are described for structural features in mRNA that provide investigational tools such as fluorescence emission, click chemistry, photo-chemical crosslinking, and that produce mRNA with increased stability in the cell, increased translational efficiency, and reduced activation of the innate immune response. Protocols are described for clinical applications such as large-scale transfection of dendritic cells, production of GMP-grade mRNA, redirecting T cell specificity, and use of molecular adjuvants for RNA vaccines. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Synthetic mRNA: Production, Introduction into Cells, and Physiological Consequences is a valuable and cutting-edge resource for both laboratory investigators and clinicians interested in this powerful and rapidly evolving technology.
The field of pharmaceutical biotechnology is evolving rapidly. A whole new arsenal of protein pharmaceuticals is being produced by recombinant techniques for cancer, viral infections, cardiovascular and hereditary disorders, and other diseases. In addition, scientists are confronted with new technologies such as polymerase chain reactions, combinatorial chemistry and gene therapy. This introductory textbook provides extensive coverage of both the basic science and the applications of biotechnology-produced pharmaceuticals, with special emphasis on their clinical use. Pharmaceutical Biotechnology serves as a complete one-stop source for undergraduate pharmacists, and it is valuable for researchers and professionals in the pharmaceutical industry as well.
Vaccines against infectious diseases are one of the most critical accomplishments in modern medicine. Despite significant progress in vaccinology, there is still a dire need for developing vaccines against various acute and chronic infections and cancer. In general, vaccines are categorized as prophylactic, given to healthy individuals to prevent disease, and therapeutic, administered to people who already have disease. As such, the nature, quality, and quantity of immune responses required for the efficacy of these two types vaccines are different. Prophylactic vaccines against infectious diseases primarily rely on the generation of neutralizing high titers of antibody for their efficacy. These vaccines are generally effective because they target a host with an unaltered and competent immune system. In marked contrast, the efficacy of therapeutic vaccines has been a major challenge since they are administered into a host with a compromised immune system. Therapeutic vaccines need not only to generate effective adaptive cellular, particularly CD8+ T cell, immune responses to chronic infection and cancer, but they also need to overcome various immune evasion mechanisms employed by infection and progressing tumor. For both types of vaccines, the generation of a long-lasting adaptive immunity is the key. Historically, prophylactic vaccines against infections were made from live-attenuated or inactivated forms of the microbes, but there were concerns about stability, side effects and safety of such vaccines. Advancements in molecular biology and DNA technologies led to the development of recombinant subunit vaccine with well-defined antigens. In particular, vaccines based on recombinant proteins present an attractive approach because of their ease of production, storage, distribution, and safety profiles. However, recombinant protein based subunit vaccines are poorly immunogenic and require adjuvants for efficacy. Most of the adjuvants that have been approved for clinical use, and those under development primarily target innate arm of the immune system for the generation of subsequent adaptive immunity. Key to the initiation of adaptive immune responses is the interactions between an APC and T cells and acquisition of 3 distinct singles by T cells. Signal 1 is delivered by the interaction of TCR on T cells with an MHC/peptide complex on APC. This signal is then qualified by costimulatory receptor ligand interaction on the APC and T cells, providing signal 2. Signal 3 is provided by various cytokines elaborated by activated APCs and T cells and critical for the expansion of the immune response. The lack of costimulation during these interactions results in T cell anergy or apoptosis. Costimulation is not only important for the generation of adaptive immunity, but also is involved in the regulation of the various immune evasion mechanisms employed by cancer and chronic infections. Therefore, we hypothesized that costimulatory ligands may serve as the preferred adjuvants for generating effective and long-lasting adaptive immunity. We particularly focused on the natural costimulatory ligands of tumor necrosis factor (TNF) family given their pleiotropic function on cells of innate, adaptive, and regulatory immunity. The TNF family represents a critical group of costimulatory molecules since their receptors (TNFR) are inducibly expressed on activated cells and may serve as preferred targets for antigen specific responses through induction of expansion, survival of T cells and establishment of long term memory. Among these family members, 4-1BB/4-1BBL interaction has received the most attention as signaling through 4-1BB provides essential signals for CD8+ T cell expansion, effector function, and survival. Importantly, this signaling also endows effector CD8+ T cells resistant to suppression by regulatory T cells that are the predominant mechanism of immune evasion used by cancer and chronic infections. Since 4-1BBL has costimulatory function as a cell surface membrane-bound protein and has no function in soluble form, our laboratory has previously generated a novel form of this molecule chimeric with streptavidin, SA-4-1BBL. This molecule was demonstrated to have robust costimulatory activity with a Th1 bias as a soluble protein. The main premise of this PhD thesis is to use SA-4-1BBL as an adjuvant platform to develop adjuvant systems for subunit vaccines with desired immune activities for targeted indications. We particularly focused on subunit vaccines against two indications; Y. pestis and breast cancer for the development of prophylactic and therapeutic vaccines, respectively. First, we tested if SA-4-1BBL can improve the immune efficacy of a lead subunit vaccine, rF1-V (a recombinant Y. pestis fusion protein), adjuvanted with alum with a Th2 bias against plague. Inasmuch as the lead candidate vaccine generates a Th2 response, and Th1 cellular responses have been shown to be important in protection against Y. pestis infection, we hypothesize that SA-4-1BBL as a Th1 adjuvant will improve the immune efficacy of the lead candidate vaccine. Single immunization with a vaccine formulation containing rF1-V as antigen and SA-4-1BBL as single adjuvant generated increased TNFa and IFN signature cytokines for Th1 responses in both CD4+ and CD8+ T cells without detectable antibody titers against rF1-V. This vaccine formulation protected 20% of mice against bubonic plague. However, in a prime-boost setting, SA-4-1BBL and rF1-V generated long lasting high titers of antibodies and protected all mice from bubonic Y. pestis infection. Alum adjuvanted rF1-V vaccine generated high titers of antibodies against rF1-V without a significant Th1 response, and protected 80% of mice against bubonic plague. A combination of SA-4-1BBL and alum as an adjuvant system generated at balanced Th1 cellular and humoral responses that resulted in 100% protection in bubonic plague model. Next, we tested if SA-4-1BBL has efficacy as adjuvant component of a Her-2/neu protein-based subunit vaccine against breast cancer and if the therapeutic efficacy of this subunit vaccine can further be improved by using toll-like receptor 4 (TLR4) agonist monophosphoryl lipid A (MPL) as adjuvant system. We hypothesize that MPL will work in synergy with SA-4-1BBL by targeting antigen presenting cell for activation, antigen presentation to T cells, leading to T cell activation and up regulation of 4-1BB receptor. Activated T cells will then serve as a direct target of SA-4-1BBL for expansion, acquisition of effector function, and establishment of long-term memory. A prime-boost immunization with extracellular domain of the rat Her-2/neu protein and SA-4-1BBL resulted in eradication of established Her-2/neu expressing A2L2 tumors in 10% of BALB/c mice. In contrast, MPL monotherapy did not have a therapeutic effect. However, vaccination with combined adjuvants resulted in eradication of established tumors in 30% of BALB/c mice, and showed better therapeutic efficacy over individual therapies. Furthermore, immunization with combined adjuvants resulted in eradication A2L2 tumors in 20% of tolerogenic BALB/neuT mice. Depletion of Tregs prior to tumor challenge increased the efficacy of combined adjuvants to 40%. The therapeutic efficacy of combined adjuvant platform correlated with increased tumor specific killing response and pro-inflammatory cytokine IFN production. The combination of SA-4-1BBL and MPL achieved therapeutic efficacy in the absence of detectable toxicity as assessed by various indicators of toxicity, including liver enzymes, total number of various lymphocyte populations in several lymphoid tissues, vaccine-induced organ damage, and histological analysis of the liver. Taken together, these data provide scientific rationale for using SA-4-1BBL as a novel adjuvant platform with other adjuvants having synergistic immune activities for the development of subunit vaccines against intracellular infections and cancer.
