Production of a dendritic cell-based vaccine containing inactivated autologous virus for therapy of patients with chronic human immunodeficiency virus type 1 infection

Apoptotic bodies: bioactive treasure left behind by the dying cells with robust diagnostic and therapeutic application potentials

Apoptosis, a form of programmed cell death, is essential for growth and tissue homeostasis. Apoptotic bodies (ApoBDs) are a form of extracellular vesicles (EVs) released by dying cells in the last stage of apoptosis and were previously regarded as debris of dead cells. Recent studies unraveled that ApoBDs are not cell debris but the bioactive treasure left behind by the dying cells with an important role in intercellular communications related to human health and various diseases. Defective clearance of ApoBDs and infected-cells-derived ApoBDs are possible etiology of some diseases. Therefore, it is necessary to explore the function and mechanism of the action of ApoBDs in different physiological and pathological conditions. Recent advances in ApoBDs have elucidated the immunomodulatory, virus removal, vascular protection, tissue regenerative, and disease diagnostic potential of ApoBDs. Moreover, ApoBDs can be used as drug carriers enhancing drug stability, cellular uptake, and targeted therapy efficacy. These reports from the literature indicate that ApoBDs hold promising potential for diagnosis, prognosis, and treatment of various diseases, including cancer, systemic inflammatory diseases, cardiovascular diseases, and tissue regeneration. This review summarizes the recent advances in ApoBDs-related research and discusses the role of ApoBDs in health and diseases as well as the challenges and prospects of ApoBDs-based diagnostic and therapeutic applications.

Highly Efficient Autologous HIV-1 Isolation by Coculturing Macrophage With Enriched CD4+ T Cells From HIV-1 Patients

We described a novel HIV autologous isolation method based in coculturing macrophages and CD4+T-cell-enriched fractions from peripheral blood collected from antiretroviral-treated (ART) HIV patients. This method allows the isolation of high viral titers of autologous viruses, over 1010HIV RNA copies/ml, and reduces the time required to produce necessary amounts for virus for use as antigens presented by monocyte-derived myeloid cells in HIV therapeutic vaccine approaches. By applying these high titer and autologous virus produced in the patient-derived cells, we intended to elicit a boost of the immunological system response in HIV therapeutic vaccines in clinical trials.

The Evolution of Dendritic Cell Immunotherapy against HIV-1 Infection: Improvements and Outlook

Dendritic cells (DC) are key phagocytic cells that play crucial roles in both the innate and adaptive immune responses against the human immunodeficiency virus type 1 (HIV-1). By processing and presenting pathogen-derived antigens, dendritic cells initiate a directed response against infected cells. They activate the adaptive immune system upon recognition of pathogen-associated molecular patterns (PAMPs) on infected cells. During the course of HIV-1 infection, a successful adaptive (cytotoxic CD8⁺ T-cell) response is necessary for preventing the progression and spread of infection in a variety of cells. Dendritic cells have thus been recognized as a valuable tool in the development of immunotherapeutic approaches and vaccines effective against HIV-1. The advancements in dendritic cell vaccines in cancers have paved the way for applications of this form of immunotherapy to HIV-1 infection. Clinical trials with patients infected with HIV-1 who are well-suppressed by antiretroviral therapy (ART) were recently performed to assess the efficacy of DC vaccines, with the goal of mounting an HIV-1 antigen-specific T-cell response, ideally to clear infection and eliminate the need for long-term ART. This review summarizes and compares methods and efficacies of a number of DC vaccine trials utilizing autologous dendritic cells loaded with HIV-1 antigens. The potential for advancement and novel strategies of improving efficacy of this type of immunotherapy is also discussed.

Automated generation of immature dendritic cells in a single-use system

Dendritic cells (DCs) are an indispensable part of studying human responses that are important for protective immunity against cancer and infectious diseases as well as prevention of autoimmunity and transplant rejection. These cells are also key elements of personalized vaccines for cancer and infectious diseases. Despite the vital role of DCs in both clinical and basic research contexts, methods for obtaining these cells from individuals remains a comparatively under-developed and inefficient process. DCs are present in very low concentrations (<1%) in blood, thus they must be generated from monocytes and the current methodology in DC generation involves a laborious process of static culture and stimulation with cytokines contained in culture medium. Herein, we describe an automated fluidic system, MicroDEN, that allows for differentiation of monocytes into immature-DCs (iDCs) utilizing continuous perfusion of differentiation media. Manual steps associated with current ex vivo monocyte differentiation are vastly reduced and an aseptic environment is ensured by the use of an enclosed cartridge and tubing network. Benchmark phenotyping was performed on the generated iDCs along with allogeneic T-cell proliferation and syngeneic antigen-specific functional assays. MicroDEN generated iDCs were phenotypically and functionally similar to well plate generated iDCs, thereby demonstrating the feasibility of utilizing MicroDEN in the broad range of applications requiring DCs.

Therapeutic Vaccination With Dendritic Cells Loaded With Autologous HIV Type 1-Infected Apoptotic Cells

BACKGROUND

We report the results of a phase I/II, open-label, single-arm clinical trial to evaluate the safety and anti-human immunodeficiency virus type 1 (HIV-1) efficacy of an autologous dendritic cell (DC)-based HIV-1 vaccine loaded with autologous HIV-1-infected apoptotic cells.

METHODS

Antiretroviral therapy (ART)-naive individuals were enrolled, and viremia was suppressed by ART prior to delivery of 4 doses of DC-based vaccine. Participants underwent treatment interruption 6 weeks after the third vaccine dose. The plasma HIV-1 RNA level 12 weeks after treatment interruption was compared to the pre-ART (ie, baseline) level.

RESULTS

The vaccine was safe and well tolerated but did not prevent viral rebound during treatment interruption. Vaccination resulted in a modest but significant decrease in plasma viremia from the baseline level (from 4.53 log10 copies/mL to 4.27 log10 copies/mL;P= .05). Four of 10 participants had a >0.70 log10 increase in the HIV-1 RNA load in plasma following vaccination, despite continuous ART. Single-molecule sequencing of HIV-1 RNA in plasma before and after vaccination revealed increases in G>A hypermutants in gag and pol after vaccination, which suggests cytolysis of infected cells.

CONCLUSIONS

A therapeutic HIV-1 vaccine based on DCs loaded with apoptotic bodies was safe and induced T-cell activation and cytolysis, including HIV-1-infected cells, in a subset of study participants.

CLINICAL TRIALS REGISTRATION

NCT00510497.

Current Advances in Virus-Like Particles as a Vaccination Approach against HIV Infection

HIV-1 virus-like particles (VLPs) are promising vaccine candidates against HIV-1 infection. They are capable of preserving the native conformation of HIV-1 antigens and priming CD4+ and CD8+ T cell responses efficiently via cross presentation by both major histocompatibility complex (MHC) class I and II molecules. Progress has been achieved in the preclinical research of HIV-1 VLPs as prophylactic vaccines that induce broadly neutralizing antibodies and potent T cell responses. Moreover, the progress in HIV-1 dendritic cells (DC)-based immunotherapy provides us with a new vision for HIV-1 vaccine development. In this review, we describe updates from the past 5 years on the development of HIV-1 VLPs as a vaccine candidate and on the combined use of HIV particles with HIV-1 DC-based immunotherapy as efficient prophylactic and therapeutic vaccination strategies.

Dendritic cells transfected with adenoviral vectors as vaccines

Dendritic cells (DCs) are critical to the initiation of a T-cell response. They constitute the most potent antigen-presenting cell (APC) endowed with the unique capacity to stimulate an antigen-specific T-cell responses by naïve T cells. Adenoviruses (Ad) have high transduction efficiency for many cell types including cells of hematopoietic origin independent of their mitotic status, and replication-defective Ad have demonstrated a safety profile clinically. Further, Ad vectors provide a high level of transgene expression, and Ad-transduced DCs can effectively present antigenic proteins. In this chapter, we outline a functionally closed, good manufacturing protocol for the differentiation of monocytes into DCs and transduction by Ad vectors. Basic functional and phenotypic release assays are provided, as well as contrasting research approaches for Ad-transduced DC-based vaccines.

Autologous and allogenic systems of HIV expansion: what is the better choice for clinical application in therapeutic vaccine?

AIMS

HIV-1 expanded in an allogenic system (Al-HIV) represents a cheaper and faster alternative to the autologous virus (Au-HIV) as an antigen in anti-HIV immunotherapy. In this study, chemically inactivated HIV-1 obtained through autologous or allogenic systems were compared.

PATIENTS & METHODS

Au-HIV and Al-HIV obtained from cultures of peripheral blood mononuclear cells from 11 HIV(+) individuals were tested for virus production, yield and time of culture, and their ability to elicit a specific immune response in vitro.

RESULTS

The allogenic system was more efficient than the autologous system. Dendritic cells pulsed with Au-HIV and Al-HIV presented a similar phenotypic profile, but only Al-HIV induced a significant increase in IFN-γ(+) lymphocytes.

CONCLUSION

The use of an allogenic system displays several advantages in terms of cell manipulation, time and cost of culture, and immunogenicity.

Improvement of HBsAg gene-modified dendritic cell-based vaccine efficacy by optimizing immunization method or the application of β-glucosylceramide

Hepatocellular carcinoma (HCC) in China is mostly Hepatitis B virus infection related. The antitumor efficacy of HBsAg gene-modified dendritic cells (DC) has been widely tested both in vitro and in vivo. In this study, we analyzed whether adenoviral vector mediated HBsAg expression would alter cell surface phenotype or autologous T cell stimulating function of mature DCs. Further, the anti-tumor efficacy of pAd-HBsAg-DC-based vaccine was evaluated in mice bearing HBsAg expressing HCC. We also tested whether β-glucosylceramide (β-GC) would enhance the anti-tumor activity of pAd-HBsAg-DC. Results revealed that pAd-HBsAg-DC expressed and secreted HBsAg, while maintaining phenotypic characteristics of mature DCs. Vaccination with pAd-HBsAg-DC conferred specific therapeutic antitumor immunity to animal model bearing HBsAg expressing HCC. The application of β-GC activated mice hepatic NKT cells and enhanced the antitumor activity of pAd-HBsAg-DC. Most importantly, in vivo results showed that the inhibiting effect of pAd-HBsAg-DC vaccination on tumor growth was more significant when applied before tumor inoculation, suggesting that genetically modified DC based therapeutic cancer vaccine may achieve the most optimized antitumor effect when applied before tumor onset, and β-GC may serve as a potent innate immune enhancer for augmenting the antitumor effect of pAd-HBsAg-DC vaccine.

Enhancing immunogenicity and cross-reactivity of HIV-1 antigens by in vivo targeting to dendritic cells

Current retroviral treatments have reduced AIDS to a chronic disease for most patients. However, given drug-related side effects, the emergence of drug-resistant strains and the persistence of viral replication, the development of alternative treatments is a pressing need. This review focuses on recent developments in HIV immunotherapy treatments, with particular emphasis on current vaccination strategies for optimizing the induction of an effective immune response by the recruitment of dendritic cells. In addition to cell-based therapies, targeted strategies aiming to deliver synthetic HIV peptides to dendritic cell-specific receptors in vivo will be discussed.

Immunoregulatory properties of rapamycin-conditioned monocyte-derived dendritic cells and their role in transplantation

In efforts to minimize the chronic administration of immunosuppression (IS) drugs in transplantation and autoimmune disease, various cell-based tolerogenic therapies, including the use of regulatory or tolerogenic dendritic cells (tolDC) have been developed. These DC-based therapies aim to harness the inherent immunoregulatory potential of these professional antigen-presenting cells. In this short review, we describe both the demonstrated tolerogenic properties, and current limitations of rapamycin-conditioned DC (RAPA-DC). RAPA-DC are generated through inhibition of the integrative kinase mammalian target of rapamycin (mTOR) by the immunosuppressive macrolide rapamycin during propagation of monocyte-derived DC. Consistent with the characteristics of tolDC, murine RAPA-DC display resistance to phenotypic maturation induced by pro-inflammatory stimuli; exhibit the ability to migrate to secondary lymphoid tissue (important for 'cross-presentation' of antigen to T cells), and enrich for naturally-occurring CD4+ regulatory T cells. In rodent models, delivery of recipient-derived RAPA-DC pulsed with donor antigen prior to organ transplantation can prolong allogeneic heart-graft survival indefinitely, especially when combined with a short course of IS. These encouraging data support ongoing efforts to develop RAPA-DC for clinical testing. When compared to murine RAPA-DC however, human RAPA-DC have proven only partially resistant to maturation triggered by pro-inflammatory cytokines, and display heterogeneity in their impact on effector T-cell expansion and function. In total, the evidence suggests the need for more in-depth studies to better understand the mechanisms by which mTOR controls human DC function. These studies may facilitate the development of RAPA-DC therapy alone or together with agents that preserve/enhance their tolerogenic properties as clinical immunoregulatory vectors.

An old enzyme for current needs: adenosine deaminase and a dendritic cell vaccine for HIV

After nearly three decades of searching for a vaccine against HIV, a cure for this pandemic disease still remains elusive. The low immunogenicity of the surface proteins and the huge variability of the virus, together with the immunocompromised status of the host, have made developing an HIV vaccine an uphill battle. Over the past few years, both immunogen design and immunization strategies have improved, providing hope for future, although the anti-HIV responses achieved still remain modest. As developing a prophylactic vaccine seems unlikely nowadays, efforts have focused on alternative therapeutic immunization approaches, although these still need to be further optimized. Using an immunomodulator capable of restoring immune function in the context of infection, thereby boosting cell-mediated and humoral responses, could be critical in effectively improving current therapeutic approaches. Adenosine deaminase, a protein with a pivotal role in T-cell co-stimulation, has been shown to robustly enhance specific T-cell responses against HIV in vitro. Although its role in humoral responses has not yet been assessed, genetic defects in this enzyme are associated with impaired cellular and humoral responses. Importantly, this molecule is already commercially available pharmaceutically and, therefore, it fulfils all the requirements to be assayed as an anti-HIV vaccine adjuvant.

Challenges in dendritic cells-based therapeutic vaccination in HIV-1 infection Workshop in dendritic cell-based vaccine clinical trials in HIV-1

Therapeutic immunization has been proposed as an approach that might help limit the need for lifelong combined antiretroviral therapy (cART). One approach for therapeutic vaccination which has been explored during the last few years is the administration of autologous monocyte-derived DCs (MD-DCs) loaded ex vivo with a variety of antigens. It has been shown in experimental murine models as well as in cancer patients and in patients with chronic infections that this approach can induce and potentiate antigen-specific T-cell response (and to induce a potent protective immunity). Contrary to the wide experience with this strategy in cancer, in HIV-1 infection the experience is limited and the design of the clinical trials varies greatly between groups. This variability affects all the steps of the process, from preparation of immunogen and DCs to clinical trial design and immune monitoring. Although both the study designs and the DC preparation (the maturation stimuli and the identity and source of HIV-1 antigens used to pulse DCs) varied in most of the studies that were published so far, overall the results indicate that DC immunotherapy elicits some degree of immunological response. To address this situation and to allow comparison between trials a panel of experts working in DC-based clinical trials in HIV-1 infection met in Barcelona at the end of 2010. During this meeting, the participants shared the data of their current research activities in this field in order to unify criteria for the future. This report summarizes the present situation of the field and the discussions and conclusions of this meeting.

Ex vivo production of autologous whole inactivated HIV-1 for clinical use in therapeutic vaccines

This study provides a detailed description and characterization of the preparation of individualized lots of autologous heat inactivated HIV-1 virions used as immunogen in a clinical trial designed to test an autologous dendritic-cell-based therapeutic HIV-1 vaccine (Clinical Trial DCV-2, NCT00402142). For each participant, ex vivo isolation and expansion of primary virus were performed by co-culturing CD4-enriched PBMCs from the HIV-1-infected patient with PBMC from HIV-seronegative unrelated healthy volunteer donors. The viral supernatants were heat-inactivated and concentrated to obtain 1 mL of autologous immunogen, which was used to load autologous dendritic cells of each patient. High sequence homology was found between the inactivated virus immunogen and the HIV-1 circulating in plasma at the time of HIV-1 isolation. Immunogens contained up to 10⁹ HIV-1 RNA copies/mL showed considerably reduced infectivity after heat inactivation (median of 5.6 log₁₀), and were free of specified adventitious agents. The production of individualized lots of immunogen based on autologous inactivated HIV-1 virus fulfilling clinical-grade good manufacturing practice proved to be feasible, consistent with predetermined specifications, and safe for use in a clinical trial designed to test autologous dendritic cell-based therapeutic HIV-1 vaccine.

In vivo trafficking and immunostimulatory potential of an intranasally-administered primary dendritic cell-based vaccine

BACKGROUND

Coccidioidomycosis or Valley fever is caused by a highly virulent fungal pathogen: Coccidioides posadasii or immitis. Vaccine development against Coccidioides is of contemporary interest because a large number of relapses and clinical failures are reported with antifungal agents. An efficient Th1 response engenders protection. Thus, we have focused on developing a dendritic cell (DC)-based vaccine for coccidioidomycosis. In this study, we investigated the immunostimulatory characteristics of an intranasal primary DC-vaccine in BALB/c mouse strain that is most susceptible to coccidioidomycosis. The DCs were transfected nonvirally with Coccidioides-Ag2/PRA-cDNA. Expression of DC-markers, Ag2/PRA and cytokines were studied by flow cytometry, dot-immunoblotting and cytometric bead array methods, respectively. The T cell activation was studied by assessing the upregulation of activation markers in a DC-T cell co-culture assay. For trafficking, the DCs were co-transfected with a plasmid DNA encoding HSV1 thymidine kinase (TK) and administered intranasally into syngeneic mice. The trafficking and homing of TK-expressing DCs were monitored with positron emission tomography (PET) using 18F-FIAU probe. Based on the PET-probe accumulation in vaccinated mice, selected tissues were studied for antigen-specific response and T cell phenotypes using ELISPOT and flow cytometry, respectively.

RESULTS

We found that the primary DCs transfected with Coccidioides-Ag2/PRA-cDNA were of immature immunophenotype, expressed Ag2/PRA and activated naïve T cells. In PET images and subsequent biodistribution, intranasally-administered DCs were found to migrate in blood, lung and thymus; lymphocytes showed generation of T effector memory cell population (T(EM)) and IFN-γ release.

CONCLUSIONS

In conclusion, our results demonstrate that the intranasally-administered primary DC vaccine is capable of inducing Ag2/PRA-specific T cell response. Unique approaches utilized in our study represent an attractive and novel means of producing and evaluating an autologous DC-based vaccine.

Dendritic cells infected by recombinant rabies virus vaccine vector expressing HIV-1 Gag are immunogenic even in the presence of vector-specific immunity

Dendritic cells (DC) are the most potent antigen presenting cells whose ability to interact with T cells, B cells and NK cells has led to their extensive use in vaccine design. Here, we designed a DC-based HIV-1 vaccine using an attenuated rabies virus vector expressing HIV-1 Gag (RIDC-Gag). To test this, BALB/c mice were immunized with RIDC-Gag, and the primary, secondary as well as humoral immune responses were monitored. Our results indicate that RIDC-Gag stimulated HIV-1 Gag-specific immune responses in mice. When challenged with vaccinia virus (VV) expressing HIV-1 Gag, they elicited a potent Gag-specific recall response characterized by CD8+ T cells expressing multiple cytokines that were capable of specifically lysing Gag-pulsed target cells. Moreover, RIDC-Gag also enhanced CD8+ T cell responses via a homologous prime-boost regimen. These results show that a DC-based vaccine using live RV is immunogenic and a potential candidate for a therapeutic HIV-1 vaccine.

Efficient clinical-scale enrichment of lymphocytes for use in adoptive immunotherapy using a modified counterflow centrifugal elutriation program

BACKGROUND AIMS

Clinical-scale lymphocyte enrichment from a leukapheresis product has been performed most routinely using costly magnetic bead separation systems that deplete monocytes, but this procedure may leave behind residual beads or antibodies in the enriched cell product. Counterflow centrifugal elutriation has been demonstrated previously to enrich monocytes efficiently for generation of dendritic cells. This study describes a modified elutriation procedure for efficient bead-free economical enrichment of lymphocytes from leukapheresis products from healthy donors and study subjects with human immunodeficiency virus (HIV) infection or malignancy.

METHODS

Modified program settings and conditions for the CaridianBCT Elutra device were investigated to optimize lymphocyte enrichment and recovery. Lymphocyte enrichment was measured using a novel approach utilizing cell sizing analysis on a Beckman Coulter Multisizer and confirmed by flow cytometry phenotypic analysis.

RESULTS

Efficient enrichment and recovery of lymphocytes from leukapheresis cell products was achieved using modified elutriation settings for flow rate and fraction volume. Elutriation allowed for enrichment of larger numbers of lymphocytes compared with depletion of monocytes by bead adherence, with a trend toward increased lymphocyte purity and yield via elutriation, resulting in a substantial reduction in the cost of enrichment per cell. Importantly, significant lymphocyte enrichment could be accomplished using leukapheresis samples from healthy donors (n=12) or from study subjects with HIV infection (n=15) or malignancy (n=12).

CONCLUSIONS

Clinical-scale closed-system elutriation can be performed efficiently for the selective enrichment of lymphocytes for immunotherapy protocols. This represents an improvement in cost, yield and purity over current methods that require the addition of monocyte-depleting beads.

Emerging nanotechnology approaches for HIV/AIDS treatment and prevention

Currently, there is no cure and no preventive vaccine for HIV/AIDS. Combination antiretroviral therapy has dramatically improved treatment, but it has to be taken for a lifetime, has major side effects and is ineffective in patients in whom the virus develops resistance. Nanotechnology is an emerging multidisciplinary field that is revolutionizing medicine in the 21st century. It has a vast potential to radically advance the treatment and prevention of HIV/AIDS. In this review, we discuss the challenges with the current treatment of the disease and shed light on the remarkable potential of nanotechnology to provide more effective treatment and prevention for HIV/AIDS by advancing antiretroviral therapy, gene therapy, immunotherapy, vaccinology and microbicides.

Developments in clinical cell therapy

Immunotherapy has become an important part of hematopoietic stem cell (HSC) transplantation and cancer therapy. Regenerative and reparative properties of somatic cell-based therapies hold tremendous promise for repairing injured tissue, preventing and reversing damage to organs, and restoring balance to compromised immune systems. The principles and practices of the diverse aspects of immune therapy for cancer, HSC transplantation and regenerative medicine have many commonalities. This meeting report summarizes a workshop sponsored by the National Heart, Lung and Blood Institute (NHLBI) and Production Assistance for Cellular Therapies (PACT), held on 23-24 April 2009 at the National Institutes of Health (NIH, USA). A series of scientific sessions and speakers highlighted key aspects of the latest scientific, clinical and technologic developments in cell therapy, involving a unique set of cell products with a special emphasis on converging concepts in these fields.

Clinical-scale elutriation as a means of enriching antigen-presenting cells and manipulating alloreactivity

BACKGROUND AIMS

Clinical-scale elutriation using the Elutra(c) has been shown to enrich monocytes reliably for immunotherapy protocols. Until now, a detailed assessment of the four (F1-F4) non-monocyte fractions derived from this process has not been performed.

METHODS

Using fluorescence-activated cell sorting (FACS), we performed phenotypic analyses to investigate the possible enrichment of T, B, natural killer (NK) and dendritic cells (DC) or their subsets in one or more Elutra fractions.

RESULTS

Blood DC were enriched up to 10-fold in some fractions (F3 and F4) compared with the pre-elutriation apheresis product. This increased the number of DC that could be isolated from a given cell number by immunomagnetic separation. It was also found that CD62L(-) effector memory CD4(+) T cells were enriched in later fractions. In four of five cases tested, cells from F3 demonstrated decreased alloreactive proliferation in a mixed lymphocyte reaction compared with cells from the apheresis product. B cells were enriched in F1 compared with the apheresis product.

CONCLUSIONS

In addition to providing enrichment of monocytes for the generation of DC, the Elutra enriches cell subsets that may be incorporated into and enhance existing immunotherapy and stem cell transplantation protocols.

Immunologic activity and safety of autologous HIV RNA-electroporated dendritic cells in HIV-1 infected patients receiving antiretroviral therapy

Immunogenicity, manufacturing feasibility, and safety of a novel, autologous dendritic cell (DC)-based immunotherapy (AGS-004) was evaluated in ten human immunodeficiency virus type 1 (HIV-1)-infected adults successfully treated with antiretroviral therapy (ART). Personalized AGS-004 was produced from autologous monocyte-derived DCs electroporated with RNA encoding CD40L and HIV antigens (Gag, Vpr, Rev, and Nef) derived from each subjects' pre-ART plasma. Patients received monthly injections of AGS-004 in combination with ART. AGS-004 was produced within a mean of 6 weeks and yielded 4-12 doses/subject Full or partial HIV-specific proliferative immune responses occurred in 7 of 9 evaluable subjects. Responses were specific for the AGS-004 presented HIV antigens and preferentially targeted CD8(+) T cells. Mild adverse events included flu-like symptoms, fatigue, and injection site reactions. No evidence of autoimmunity, changes in viral load, or significant changes in absolute CD4(+) and CD8(+) T cell counts were observed. This pilot study supports the further clinical investigation of AGS-004.

Production Assistance for Cellular Therapies (PACT): four-year experience from the United States National Heart, Lung, and Blood Institute (NHLBI) contract research program in cell and tissue therapies

BACKGROUND

In 2002, the US National Heart, Lung, and Blood Institute (NHLBI) conducted a workshop to determine needs of the cell therapy community. A consensus emerged that improved access to cGMP facilities, regulatory assistance, and training would foster the advancement of cellular therapy.

STUDY DESIGN AND METHODS

A 2003 NHLBI request for proposals resulted in four contracts being awarded to three cell-manufacturing facilities (Baylor College of Medicine, University of Minnesota, and University of Pittsburgh) and one administrative center (The EMMES Corporation). As a result, Production Assistance for Cellular Therapies (PACT) was formed.

RESULTS

As of October 1, 2008, PACT has received 65 preliminary applications of which 45 have been approved for product manufacture. A variety of cell therapies are represented including T-regulatory cells, natural killer cells, adipose-derived stem cells, cardiac progenitor cells for cardiac disease, hematopoietic progenitor cells (HPCs) for central nervous system applications, cytotoxic T lymphocytes, and dendritic cells. A total of 169 products have been administered under 12 applications and 2 reagents were manufactured and delivered. Fourteen peer-reviewed publications and 15 abstracts have resulted from the PACT project to date. A cell therapy textbook is nearly complete. PACT technical projects have addressed assay development, rapid endotoxin testing, shipping of cell products, and CD34+ HPC isolation from low-volume marrow. Educational Web seminars and on-site training through workshops have been conducted.

CONCLUSIONS

PACT is an active and successful cell therapy manufacturing resource in the United States, addressing research and training while forging relationships among academia, industry, and participating institutions.