Fall 2010 Research Grant Recipients Talk About Their Research

Arnold Chin, MD, PhD
Assistant Professor of Urology

Abstract Title:
Immune and Molecular Profiling in Bladder Cancer for Personalized Therapy

BD: Tell us about your educational background.

Arnold Chin: I took a straightforward route, majoring in chemistry at Princeton University, followed by a combined MD/PhD program at UCLA where I studied signal transduction in immunology. I have since remained at UCLA and completed my residency training in urology. I was subsequently recruited as a faculty member in 2009 to develop the Bladder Cancer Program at UCLA.

BD: How did you become interested in science?

Arnold Chin: I have always been interested in science and medicine. After completing my undergraduate senior thesis, which involved two years of laboratory research—something clicked—and I decided to pursue a combined degree. Now, my career choice allows me to pursue medicine, surgery, and research, which I find both complementary and rewarding.

BD: Please provide an overview of your research interests

Arnold Chin: I study the role of inflammation in cancer. We believe that inflammation in a tumor’s environment can regulate tumor growth, invasion, and metastasis. However, inflammation can be a double-edged sword and lead to both tumor-promoting and inhibiting effects. This understanding will not only contribute to the basic knowledge of tumor immunology, but also help develop novel tumor vaccines. Immunotherapy has a long precedence in urology, as it has been used for decades in bladder cancer in the form of bacillus Calmette-Guerin, a weakened bacterium that stimulates the immune system, and in kidney cancer with interleukin-2. The recent approval of Provenge®, an autologous cell-based immunotherapy, further validates employing inflammation to fight cancer.

BD: Describer the research project for which you received the BD grant.

Arnold Chin: This project involves developing personalized therapies for bladder cancer. Today anti-cancer chemotherapy drugs are used empirically in bladder cancer. But a new generation of targeted therapies, which affect specific tumor pathways, is beginning to emerge. Since we are able to extract cells even from early-stage bladder cancer, there is the opportunity to culture the cells and correlate activation or deactivation of specific tumor pathways with the cells’ sensitivity to targeted therapies or even development-stage drugs. This data could provide a rationale, should the tumor recur or metastasize, for using novel therapies in these patients. Eventually, this could lead to small but highly powerful clinical trials of patient-specific therapies based on some rational readout.

BD: What are your scientific objectives?

Arnold Chin: The main objective is to see if there is truly a correlation between activation of molecular signaling pathways and infiltration of inflammatory cells to sensitivity to treatments in vitro. A second objective is to develop a high-throughput methodology using a microfluidics platform that we will collaborate with our colleagues from bioengineering. Of course, the real test is to see if these treatments are validated in clinical trials.

BD: What are the implications for human health?

Arnold Chin: Treatment failures and recurrences are significant in bladder cancer. From the approach of assessing inflammation and activation of other signaling pathways, we hope to uncover novel targeted agents and immunotherapies that can help these patients. By performing this on an individualized basis, we feel that we can not only better understand this disease, but also tailor therapies to optimize treatment efficacy. In short, personalized therapy provides a possible means to identify patients who will likely respond to drugs, and to prevent unnecessary treatments for non-responders.

BD: How will you use your BD reagents?

Arnold Chin: We will predominantly utilize the BD antibodies, which we have always used, but can be expensive for a start-up laboratory. I am grateful to BD for this opportunity and interest in my area of research.

Arlene Dent, MD, PhD
Assistant Professor of Pediatrics

Abstract Title:
A Novel Assay to Detect Antigen-Specific Memory B Cells

BD: Describe your educational background.

Arlene Dent: I attended Indiana University as an undergraduate in biology with a minor in Russian literature. I stayed at Indiana for my doctoral and medical training as well. My PhD thesis was on cardiogenesis in axolotls, which are aquatic salamanders.

BD: How did you become interested in science?

Arlene Dent: It seems that I have always been interested in medicine and biology. In the third grade I attended a weekend nature camp, where I dissected a crayfish and got a “Quincy Jones” award. My interest in biology expanded while in high school, but I couldn’t decide whether to go into medicine or basic research. Now I’m able to do both.

BD: How would you summarize your research interests?

Arlene Dent: My major interest is immunity to malaria, particularly in pediatric patients, and the consequences of fetal exposure to the parasite. In some children exposure in the womb produces a robust, beneficial immune response against infection later in life. But other fetuses seem to become tolerant to the malaria antigen. Later on, these children show a weaker immune response when infected, have higher parasite levels, and a greater number of infections, compared to children who have developed the robust fetal response.

BD: Describe the research project for which you received the BD grant.

Arlene Dent: Our study of the development of infant immune responses to malaria is based on antibodies, which come from B cells. To assess antigen-specific memory through traditional enzyme-linked immunosorbent spot (ELISPOT) assays requires approximately one million peripheral blood mononuclear cells (PBMCs) per antigen-specific memory B cell identified or quantified. But it’s only possible to draw about two milliliters of blood from an infant. So we need a technique that assesses the frequency of our target cells without consuming as many PBMCs. Our approach is to attach antigens to a reporter molecule and then to the B cells, and analyze the complexes by flow cytometry. If we’re successful we should be able to quantify several antigen-specific memory B cells using the same quantity of blood that it takes to analyze one B-cell type using ELISPOT assays.

BD: What are your near- and long-term scientific objectives?

Arlene Dent: To relate antigen-specific memory B cell development with in utero malaria exposure and eventually to compare natural infection memory cells and antibodies with those generated from vaccines.

BD: What are the implications for human health?

Arlene Dent: Malaria in pregnancy has serious negative consequences, and serves as a model for other types of in utero exposures. Results of our studies could guide pediatric vaccine development, particularly for malaria.

BD: How do you plan to use the BD reagents?

Arlene Dent: We’ll be using B-cell markers, enrichment kits, and cell culture reagents to develop our assays and, eventually, to study how an infant’s immune system develops.

Edward Diaz
Resident Physician

Abstract Title:
Urothelial Cancer Stem Cells and mTOR Signaling

BD: Tell us about your educational background.

Edward Diaz: I received my undergraduate education at the University of California, Los Angeles (UCLA), with a major in molecular, cell, and developmental biology. I then worked for two years at a biotech company in the San Francisco Bay area, before entering medical school at the University of Southern California (USC). While in medical school I worked in a pathology lab, and upon my graduation entered urology residency at the Cleveland Clinic.

BD: How did you become interested in science?

Edward Diaz: When I entered college I was unsure of what to major in. Eventually I was inspired towards molecular biology after taking courses and performing research at a lab at UCLA. Through my experience working in the biotechnology industry, I also realized that I wanted a career that combined medicine and research.

BD: Summarize your general research interests.

Edward Diaz: My research interests mainly revolve around using immunology to develop novel therapeutics, and in regenerative technologies such as stem cells. During my time in medical school at USC I developed a strong interest in oncology, particularly in urothelial carcinoma. During medical school I also developed an appreciation for both clinical and basic science research.

BD: Explain the role of mTOR in bladder cancer.

Edward Diaz: The Hansel lab, where I work, is pioneering the study of mTOR signaling in urothelial carcinoma. mTOR is a component of the AKT signaling pathway, which regulates proliferation, apoptosis, and other important cellular functions. Early findings suggest that this pathway may be upregulated in urothelial carcinoma. Evidence is based on immunohistochemical staining of pathology specimens, upregulation of phosphorylated S6, a protein component of the mTOR pathway, and expression of phosphorylated mTOR protein in invasive carcinoma specimens.

Studies of in vitro cell lines and their response to incubation with an mTOR inhibitor also show that mTOR inhibition reduces cell proliferation, and tumor volume by much as 50% in a xenograft model. While our early results were obtained without a specific bias towards cancer stem cells, we suspect that the mTOR signaling cascade is crucial to the tumorigenic potential of bladder cancer stem cells.

BD: What are the scientific goals of your research?

Edward Diaz: One of the more accomplishable goals is to isolate and culture a cancer stem cell lineage from urothelial carcinoma so we can study these cells, and gain insight into their role in bladder cancer.

BD: What are short-and long-term implications of your research?

Edward Diaz: If we are able to successfully isolate and propagate a cancer stem cell lineage within urothelial carcinoma, in the short term, we can help provide evidence towards the theory of cancer stem cells in this type of malignancy. In addition, our findings may facilitate further research in this arena. One long term-implication is mTOR inhibitors potentially joining the armamentarium of therapeutics against urothelial carcinoma, and leading to improved outcomes for individuals afflicted with this disease.

BD: Which BD reagents will you acquire, and how do you plan to use them?

Edward Diaz: We will be using antibodies extensively to isolate the cancer stem cell lineages, and for immunofluorescence staining of tissue samples. We will also utilize BD culture media, cytokines, plates, pipets, and growth factors to culture our cells.

Elena Galkina, PhD
Assistant Professor, Microbiology and Molecular Cell Biology

Abstract Title:
Type 2 Diabetes and Islet Immune Response

BD: Tell us about your educational background.

Elena Galkina: I earned my undergraduate degree in molecular biotechnology from the St. Petersburg State Technological Institute in Russia. I studied for my PhD in immunology at the Institute for Experimental Medicine, also in St. Petersburg. I then completed a post-doc in immunology at the National Institute for Medical Research in London, U.K., and a second post-doc at the University of Virginia. Two years ago, I received a tenure–track position at the Eastern Virginia Medical School, where I now teach and conduct research.

BD: How did you become interested in science?

Elena Galkina: One day when I was very young my father bought me a microscope as a birthday present. I began looking at leaves and other natural objects, and I quickly became hooked.

BD: Briefly describe your current research interests.

Elena Galkina: We’re investigating immune system involvement, particularly inflammatory responses, during the development of type 2 diabetes. We know that many diabetics also have cardiovascular problems, so we’re also interested in how the immune system events that precipitate diabetes also induce accelerated atherosclerosis.

Immune system involvement in type 2 diabetes is not well understood, but we think that inflammation may be occurring locally, in islets, and thereby affecting the functions of beta cells. So this project overlaps two disciplines, immunology and endocrinology. We are collaborating on this project with Dr. Imai and Dr. Nadler (Eastern Virginia Medical School), who are experts in endocrinology.

BD: Explain the importance of chronic inflammation mediated by cytokines as a potentially significant pathway mediating pancreatic beta-cell damage in type 2 diabetes.

Elena Galkina: Beta cells become damaged in type 2 diabetes, perhaps from the inflammatory action of cytokines operating locally. Preliminary data also suggests that immune cells are acting locally in these tissues. This raises three questions: How and why do immune cells migrate to the islets, why do they remain there, and what do they do?

We know that immune cells are present even in healthy islets, and believe that signals generated during the development of type 2 diabetes initiate the recruitment of additional leukocytes. We plan to test this hypothesis by measuring and characterizing populations of T and B cells, NK and NKT cells, dendritic cells, and macrophages in pancreas specimens from healthy and diabetic individuals, as well as in peripheral blood.

BD: What are your scientific goals?

Elena Galkina: First, to understand the alterations in the immune response locally in the islets, and to compare that with what’s going on in peripheral blood in type 2 diabetics, and second, to gain insight into the immune response to possible mediators of type 2 diabetes in human islets.

BD: What are the potential implications for human health?

Elena Galkina: If we can understand the alterations within islets, and the stimuli that affect them, we may be able to prevent the migration of the subpopulations of pro-inflammatory leukocytes into type 2 diabetic islets through new drugs, and thereby reduce or eliminate the damage from inflammatory response within the islets. Another approach might be to reduce inflammatory responses generally.

BD: How will you use the BD reagents in your work?

Elena Galkina: We use multicolor flow cytometry, so we expect to employ numerous BD flow cytometry antibodies carrying different fluorophores. We also expect to use beads for cytometric analysis of cytokine levels in islets.

Kristen Hoek, PhD
Research Fellow

Abstract Title:
B Cell Trafficking in Mucosal Immunology and Autoimmune Disease

BD: Tell us about your educational background.

Kristen Hoek: I received a BS in biology from Sanford University in Birmingham, Alabama. I then received a PhD in microbiology from the University of Alabama at Birmingham. During my first post-doctoral fellowship, at Vanderbilt, I studied B cell receptor (BCR) and BAFF receptor (BAFF-R, BR3) signaling in B lymphocyte development and function.

BD: How did you become interested in science?

Kristen Hoek: I have always liked science, particularly the life sciences, and never considered doing anything else with my life. I enjoy the scientific process, trying to tease things apart.

BD: Please provide an overview of your research interests.

Kristen Hoek: I’m primarily interested in immunology, specifically development, signaling, and function in B cells.

BD: Describe the research project for which you received the BD grant.

Kristen Hoek: I began work on this project in early 2009, after exciting preliminary data revealed that the transcription factor, Kruppel-like factor 2 (Klf2), affected the B cell compartment. Specifically, loss of Klf2 changes the homing patterns of B cells. By migrating to inappropriate locations, mature B cells are exposed to antigens or pathogens that they normally would not encounter. What’s surprising is that this effect represents a gain in function—Klf2-deficient animals show a stronger immune response to certain types of antigens than wild type animals. So the question is: Why would the body want to inhibit a more robust immune response? The reason, we hypothesize, is to prevent autoimmunity.

Immune system cells normally aggregate in specific locations, where they either respond to antigens they see, or interact with other immune cells to induce the correct immune response. Because the B cells we study are not expressing homing receptors correctly, they migrate to inappropriate compartments where they encounter normally sequestered antigens or pathogens. We believe that exposure to antigens they normally would not see, such as self-antigens, might predispose them to highly undesirable autoimmune responses.

We are in the process of introducing the loss of Klf2 onto autoimmune mouse models. We believe that if Klf2 normally works to prevent autoimmunity, loss of Klf2 might promote autoimmune-type responses. Therefore, if we eliminate this transcription factor in an autoimmune-susceptible animal, the disease should be even worse. This unique work would demonstrate the feasibility of controlling autoimmune diseases by limiting B cell circulation.

BD: What are your near- and long-term scientific objectives?

Kristen Hoek: It will take us a while to delete Klf2 in autoimmune-susceptible mice, which is our first objective. There are also a number of things to do beyond acute autoimmunity. We’re interested in how Klf2 affects long-term immunity and immunological memory.

BD: What are the implications for human health?

Kristen Hoek: If we can define how aberrant B cell trafficking affects the autoimmune process, we can potentially find new approaches to combat disease. Targeted activation or deactivation of this transcription factor may allow us to control B cell trafficking.

BD: How do you plan to use the BD reagents you will acquire through this grant?

Kristen Hoek: Ninety percent of what I do is flow cytometry (BD FACS™)-based, and our entire core facility relies on BD instruments and reagents. Experiments proposed in this grant will require FACS-sorting and analysis, so I’d be most interested in antibodies for up to eight-color flow cytometric analysis.

Veronica Martinez Cerdeno, PhD
Assistant Professor, Pathology and Laboratory Medicine

Abstract Title:
Antibodies Present in the Plasma of Women with Autistic Progeny Alter the Neurogenic Divisions of Precursor Cells in the Prenatal Mouse Cerebral Cortex and the Social Behavior of Adult Mice

BD: Tell us about your educational background.

Veronica Martinez Cerdeno: I completed my undergraduate degree from Universidad Complutense, in Spain, where I studied biology and biomedicine. From there I moved to Universidad Autónoma de Madrid for my PhD in neuroscience and neuroanatomy. I had two post-doctoral appointments: Columbia University, where I studied neurodevelopment, and the University of California, San Francisco, where I worked on cortical development and stem cell neurotransplantation. I did additional training at the University of California, Davis MIND Institute, where I became involved in autism research. I was appointed assistant professor at the Institute for Pediatric medicine two years ago.

BD: How did you become interested in science?

Veronica Martinez Cerdeno: I’ve been curious since I was a young girl about how and why things happen, about animals, and how everything in nature seems to work so well. I knew very early on that I was going into research. It’s an exciting time to be in neuroscience because everything is so new—our understanding about the brain is about as advanced now as our understanding of the liver was a hundred years ago.

BD: Briefly describe your broad research interests.

Veronica Martinez Cerdeno: Although I’m studying specific niches of neuroscience, I’m attracted to the entire subject—anything related to how the nervous system works. My interests in research include anything related to normal or abnormal cerebral cortex development.

BD: Tell us about your BD Grant project.

Veronica Martinez Cerdeno: Autism spectrum disorders (ASDs) are heterogeneous disorders defined by abnormalities in socialization and communication that likely occur during brain development. Nevertheless, few studies have investigated a possible prenatal etoliologic component. We are investigating whether maternal antibodies and auto-antibodies to neural proteins, in other words the mother’s immune status during pregnancy, may play a role. We will determine if antibodies that are present in maternal serum can impact developmental processes in the embryo, and therefore constitute a prenatal etiology for autism.

Previous research at UCD has shown that about twenty percent of mothers who give birth to autistic children have autoantibodies that are absent in mothers of children without any known disease. When we inject serum from these women into the brains of fetal mice, we notice changes in socialization in around fifty percent of the test animals, and have also noted changes in the proliferative behavior of stem cells in prenatal cerebral cortex.

BD: What are your scientific goals?

Veronica Martinez Cerdeno: We are still finding new types of stem cells in the cerebral cortex. Our goals are to learn how they arise and mature, and what diseases are associated with their abnormal behavior. In the long term we would like to understand how stem cells migrate and differentiate.

BD: What are the long-term implications for human health?

Veronica Martinez Cerdeno: At some point, once we understand the roles of stem cells and maternal antibodies, we may be able to prevent diseases like autism, or perhaps treat them by focusing on the appropriate pharmacologic targets.

BD: What BD reagents do you expect to use, and for what purposes?

Veronica Martinez Cerdeno: Since we are a new lab we need everything, from general supplies to glassware and equipment. We will probably use a lot of antibodies to identify and characterize stem cell lines.

Asifa Zaidi, PhD
Instructor, Clinical Immunology

Abstract Title:
Basophils and Murine Experimental Model of Asthma

BD: Tell us about your educational background.

Asifa Zaidi: I completed my undergraduate degree in Chemistry (Honors), at Aligarh Muslim University, Aligarh, India. I then received a master’s degree in Biotechnology from the Indian Institute of Technology (IIT), Roorkee, and my PhD in Biochemistry at the University of Mumbai. I did my postdoctoral fellowship in immunology at the University of Pennsylvania.

BD: How did you become interested in science?

Asifa Zaidi: When I was very young my brother died from cancer, and later on, while I was in college, my father also succumbed to cancer. Those events motivated me to become a scientist and study incurable diseases.

BD: Please provide an overview of all your research interests.

Asifa Zaidi: My research focus is to understand the regulation of allergic and inflammatory processes with an emphasis on how the basophils and mast cells modulate the type of inflammation that results in acute and chronic hypersensitivity reactions.

BD: Describe the research project for which you received the BD grant.

Asifa Zaidi: The main focus of this research is to test the hypothesis that basophils are involved, and required, for allergen-induced airway hypersensitivity (AHR). Both human and murine basophils secrete large amounts of Th2 cytokines, which are major modulators in the development of asthmatic responses. Studies with human subjects demonstrated the presence of basophils in significantly increased numbers in the airways of asthmatics and individuals who died from asthma. Furthermore, basophils are recruited to the bronchial mucosa after segmental bronchial allergen challenge in subjects with atopic asthma. These observations provide evidence that basophils are involved in asthma pathology. However, the specific roles of basophils in the development of effector phase of asthma have not yet been determined. We will determine the contribution of basophils using an allergen-induced experimental murine model of asthma in the presence or absence of basophils. We will use allergens such as proteases, fungus, dust mite, cockroach, and papain for immunization and challenge protocols that are relevant to human asthma.

We anticipate that basophils will be recruited to the lungs in greater numbers to all allergens during both the allergen immunization and challenge phases, and will be associated with severity of experimental asthma symptoms.

BD: Can basophils be studied in human subjects?

Asifa Zaidi: Yes, it’s possible to study basophil function ex vivo by isolating them from blood. However, to understand the function of basophils in vivo, an experimental animal model is required.

BD: What are the implications of your work for human health?

Asifa Zaidi: Because the mechanisms of asthma pathogenesis are complex, multifactorial, and incompletely understood, management of many asthmatic patients is difficult. Alternative approaches, in addition to currently available therapy, are necessary for control of severe asthma. Knowledge obtained from testing this hypothesis will provide novel basophil-specific approaches for additional and more effective therapeutic treatments for asthma patients, including subjects with severe asthma.

BD: How do you plan to use the reagents you acquire through this grant?

Asifa Zaidi: Since we are looking for basophil function, we will be using antibodies that will help us identify and purify basophils, particularly antibodies for detection, sorting, and purification of these cells through flow cytometry. We have been using a BD FACSAria™ flow cytometer located in our core facility at Johns Hopkins to identify and sort basophils from blood, bone marrow, spleen, and lung tissues of mice. We also expect to use reagents for basophil activation and, for detecting basophils in tissues, immunohistochemistry reagents.