Antigenic specificity of antibody-dependent cell-mediated cytotoxicity directed against human immunodeficiency virus in antibody-positive sera

Antibody-dependent cell-mediated cytotoxicity (ADCC) specific for human immunodeficiency virus (HIV) has been described for HIV-infected individuals. To determine the antigenic specificity of this immune response and to define its relationship to the disease state, an ADCC assay was developed using Epstein-Barr virus-transformed lymphoblastoid cell line targets infected with vaccinia virus vectors expressing HIV proteins. The vaccinia virus vectors induced appropriate HIV proteins (envelope glycoproteins gp160, gp120, and gp41 or gag proteins p55, p40, p24, and p17) in infected lymphoblastoid cell lines as demonstrated by radioimmunoprecipitation and syncytia formation with c8166 cells. Killer cell-mediated, HIV-specific ADCC was found in sera from HIV-seropositive but not HIV-seronegative hemophiliacs. This HIV-specific response was directed against envelope glycoprotein but was completely absent against target cells expressing the HIV gag proteins. The ADCC directed against gp160 was present at serum dilutions up to 1/316,000. There was no correlation between serum ADCC titer and the stage of HIV-related illness as determined by T-helper-cell numbers. These experiments clearly implicated gp160 as the target antigen of HIV-specific ADCC activity following natural infection. Vaccines which stimulate antibodies directed against gp160, which are capable of mediating ADCC against infected cells, could be important for protection against infection by cell-associated virus

Detection of major histocompatibility complex class I-restricted, HIV-specific cytotoxic T lymphocytes in the blood of infected hemophiliacs

Major histocompatibility (MHC)-restricted, human immunodeficiency virus type one (HIV-1)-specific, cytotoxic T lymphocytes (CTLs) were detected in the peripheral blood mononuclear cells (PBMCs) of HIV-1-infected individuals. Using a system of autologous B and T lymphoblastoid cell lines infected with recombinant vaccinia vectors (VVs) expressing HIV-1 gene products, we were able to detect HIV-1-specific cytolytic responses in the PBMCs of 88% of HIV-1-seropositive hemophiliac patients in the absence of in vitro stimulation. These cytolytic responses were directed against both HIV-1 envelope and gag gene products. The responses were resistant to natural killer (NK) cell depletion and were inhibited by monoclonal antibodies (MoAbs) to the T cell receptor, CD8 surface antigens, and MHC class I antigens, suggesting a classical MHC class I restricted, virus-specific CTL response

CD169 (Siglec-1) as a Robust Human Cell Biomarker of Toll-Like Receptor 9 Agonist Immunotherapy

Immunotherapy is a promising therapeutic area in cancer and chronic viral infections. An important component of immunotherapy in these contexts is the activation of innate immunity. Here we investigate the potential for CD169 (Siglec 1) expression on monocytes to serve as a robust biomarker for activation of innate immunity and, particular, as a proxy for IFN-α production. Specifically, we investigated the effects of Toll-like receptor 9 agonism with MGN1703 (lefitolimod) across experimental conditions ex vivo, in humanized mice, and in clinical trial participants. Ex vivo we observed that the percentage of classical monocytes expressing CD169 increased dramatically from 10% pre-stimulation to 97% 24 hrs after MGN1703 stimulation (p\u3c0.0001). In humanized NOG mice, we observed prominent upregulation of the proportions of monocytes expressing CD169 after two doses of MGN1703 where 73% of classical monocytes were CD169 positive in bone marrow following MGN1703 treatment vs 19% in vehicle treated mice (p=0.0159). Finally, in a clinical trial in HIV-infected individuals receiving immunotherapy treatment with MGN1703, we observed a uniform upregulation of CD169 on monocytes after dosing with 97% of classical monocytes positive for CD169 (p=0.002). Hence, in this comprehensive evaluation ex vivo, in an animal model, and in a clinical trial, we find increases in the percentage of CD169 positive monocytes to be a reliable and robust biomarker of immune activation following TLR9 agonist treatment

Development and implementation of natural killer cell simultaneous ADCC and direct killing assay

Assays to quantify natural killer (NK) cell killing efficacy have traditionally focused on assessing either direct killing or antibody dependent cell-mediated cytotoxicity (ADCC) independently. Due to the probability that immunotherapeutic interventions affect NK cell-mediated direct killing and NK cell-mediated ADCC differently, we developed an assay with the capacity to measure NK cell-mediated direct killing and ADCC simultaneously with cells from the same human donor. Specifically, this design allows for a single NK cell population to be split into several experimental conditions (e.g., direct killing, ADCC), thus controlling for potential confounders associated with human-to-human variation when assessing immunotherapy impacts. Our Natural Killer cell Simultaneous ADCC and Direct Killing Assay (NK-SADKA) allows researchers to reproducibly quantify both direct killing and ADCC by human NK cells. Furthermore, this optimized experimental design allows for concurrent analysis of the NK cells via flow cytometric immunophenotyping of NK cell populations which will facilitate the identification of relationships between NK cell phenotype and the subsequent killing potential. This assay will be valuable for assessing the broader impact(s) of immunotherapy strategies on both modes of NK cell killing

Absorbing customer knowledge: how customer involvement enables service design success

Customers are a knowledge resource outside of the firm that can be utilized for new service success by involving them in the design process. However, existing research on the impact of customer involvement (CI) is inconclusive. Knowledge about customers’ needs and on how best to serve these needs (articulated in the service concept) is best obtained from customers themselves. However, codesign runs the risk of losing control of the service concept. This research argues that of the processes of external knowledge, acquisition (via CI), customer knowledge assimilation, and concept transformation form a capability that enables the firm to exploit customer knowledge in the form of a successful new service. Data from a survey of 126 new service projects show that the impact of CI on new service success is fully mediated by customer knowledge assimilation (the deep understanding of customers’ latent needs) and concept transformation (the modification of the service concept due to customer insights). However, its impact is more nuanced. CI exhibits an “∩”-shaped relationship with transformation, indicating there is a limit to the beneficial effect of CI. Its relationship with assimilation is “U” shaped, suggesting a problem with cognitive inertia where initial learnings are ignored. Customer knowledge assimilation directly impacts success, while concept transformation only helps success in the presence of resource slack. An evolving new service design is only beneficial if the firm has the flexibility to adapt to change

Agonism of TLR9 and TLR7 to enhance NK cell-mediated clearance of B-cell lymphoma

The innate immune system is the front line of the body’s defenses. Innate effector cells, including natural killer cells (NK) cells, represent some of the first immune cells to respond to malignancies or infections. One of two primary mechanisms for NK cell target recognition is antibody-dependent cellular cytotoxicity (ADCC). This mechanism relies on antigen specificity. The clinical efficacy of anti-CD20 (aCD20) antibodies (e.g., Rituximab™) showcase the impact of NK-cell-mediated ADCC on B-cell lymphomas. NK cells are typically activated for performing effector functions by exposure to key cytokines, although these cytokines are not necessarily produced by the NK cells themselves. This represents indirect activation via crosstalk between multiple cell types. Cells that produce these cytokines include monocyte/macrophages and plasmacytoid dendritic cells (pDCs). This activation cascade, for example, occurs following toll-like receptor 9 (TLR9) and toll like receptor 7 (TLR7) agonism in pDCs which in turn produce interferon alpha (IFN-a) that subsequently induces interferon-g production and NK cell activation. This series of signals leads to physiologically relevant levels of cytokines for activating NK cells to perform their effector function: this is precisely the natural route of immune activation that I propose to explore in my study

Differential impacts of toll-like receptor 9 agonism on human natural killer cell cytotoxic functions

The innate immune system is the front line of the body’s defenses. Innate effector cells, including natural killer (NK) cells, represent some of the first immune cells to respond to malignities or infections. There are two mechanisms by which NK cells recognize and kill their targets: (i) direct killing and (ii) antibody dependent cellular cytotoxicity (ADCC). NK cells are typically activated for performing effector functions by exposure to key cytokines which are not necessarily produced by the NK cells themselves. Cells that produce these activating cytokines often trigger signaling cascades. Our research focuses on such a cascade elicited by treating human peripheral blood cells with a toll-like receptor 9 (TLR9) agonist. Then the human NK cells are magnetically enriched and incorporated into our novel Natural Killer cell Simultaneous ADCC and Direct Killing Assay (NK-SADKA). This assay was designed to control for human-to-human variation by ensuring that human NK cells from the same donors are tested for both their ability to mediate direct killing as well as ADCC. Using this approach, we identified differential impacts of TLR9 agonism between human NK cell’s ability to mediate direct killing versus ADCC ex vivo. Specifically, we found that NK cells from the treatment group showed an increase in their ability to mediate direct killing while simultaneously experiencing a decreased ability to mediate ADCC. Experiments to identify the mechanism of this paradoxical effect are ongoing

Marketing of Short Courses

This presentation was part of the session : Universities and Companies Highlight What Works!Anna Mahr: Associate Director of Professional Programs, Professional Education Programs, School of Engineering, Massachusetts Institute of Technology, Cambridge, USA (since 2006). Received Ph.D. in biology from University of Rochester and M.B.A. from Babson College (2001). Postdoctoral research at Harvard Medical School. 6 Research scientist at Integrated Genetics, Applied Biotechnology, IG Labs and Genzyme. Tavish Baker: Online Marketing Manager, Professional Education Programs, School of Engineering, MIT, Cambridge, MA, USA (since 2004). Received B.S. in journalism/advertising from Northeastern University. Website/ecommerce marketing and management at Houghton Mifflin/Sunburst. Dee Moore: Director of Marketing, Professional Education Programs, School of Engineering, MIT, Cambridge, USA (since 2003). Received M.B.A. from Fordham University and M.A. in media studies from New York University. Corporate Marketing positions in the high tech industry and publishing industry prior to joining MIT.IACEE 11th World Conference on Continuing Engineering EducationThe Professional Institute is part of the Professional Education Programs office within the MIT School of Engineering. PI offers 35-45 courses geared to working professional scientists and engineers. Our course directors are regular MIT faculty who make the decision on whom to invite to help teach the course. Because we cannot hire adjunct faculty, our organization is supply-side driven and we can offer only courses that MIT faculty offer to teach. Our courses are promoted in a variety of ways. Chief among them are our Web site, brochures, post cards, print ads and electronic methods. The latter includes e-mail marketing, e-mail and Web-site advertising, search engine marketing, and link-building (from internal sites, events listings, industry blogs, etc). Recent additions include attending conferences as well as sponsoring events and seminars. We will detail our evolving marketing strategies to target niche markets and how we involve our students and professors in the entire process. Because we are supply-side driven, in addition to our students, we also view MIT faculty as our customers. Toward this end, we also reach out to faculty members to inform them about our activities. Our goals are to drive PI enrollment and increase the number of offered courses in a way that is consistent with MIT culture, practices and mission, and to keep the Professional Institute a vibrant and dynamic professional organization offering relevant courses even after more than 50 years.Distance Learning and Professional Education ; International Association for Continuing Engineering Educatio

Models of Learning, Education, and the Role of Immersion in Pedagogy

The Immersive Media Lab started in February of 2017 with a critical focus on the implications of virtual and augmented reality on our society, specifically education. Our mission has always been to explore the possibilities of this media and put UWM at the forefront of its application. Through cross-disciplinary projects, such as the “MoonPhases” STEM teaching tool- a hands-on spatial simulation-- and “Ephemeral Forest” interactive exhibition, our team has begun to establish a framework for understanding the potential this media has as a tool for learning. The support we’ve garnered has taken our research to the next level, zeroing in on the capabilities of immersive media as a tool for mentors and educators everywhere, and allowed for everyone on this team to focus specifically on different facets of this larger issue. “Education” is a large undertaking, and the first step is supporting our teachers. Our team is tempering this media as a tool to empower educators, exceed the “standard of learning,” and help bridge the educational gaps