Construction of a knockout targeting vector to generate an Interleukin-13 Receptor α1 deficient Balb/c mouse

Abstract only availableA recent publication from our lab has provided evidence for the involvement of the α1 chain of the Interleukin-13 cytokine receptor (IL-13Rα1) in the development of the neonatal immune system. Specifically, we have shown that cell death of T helper type 1 (Th1) effector cells can be prevented by antibody-mediated blockade of IL-13Rα1. Currently, a knockout mouse deficient in expression of IL-13Rα1 is not available and the development of an IL-13Rα1 knockout mouse will provide new insights on the relationship between IL-13Rα1 signaling and neonatal immunity. In this effort we have begun construction of a targeting vector that will bear sufficient homology to the IL-13Rα1 wild-type locus to allow for deletion of exons 7, 8, and 9 via homologous recombination, thereby rendering that allele non-functional. After construction of the targeting vector, a collaborative effort between the Transgenic Animal Core facility here at the University of Missouri will continue throughout the remainder of the cell culture, embryonic manipulation, and screening processes.Life Sciences Fellowships/Meyerhoff Scholars Progra

Delayed maturation of an IL-12–producing dendritic cell subset explains the early Th2 bias in neonatal immunity

Primary neonatal T cell responses comprise both T helper (Th) cell subsets, but Th1 cells express high levels of interleukin 13 receptor α1 (IL-13Rα1), which heterodimerizes with IL-4Rα. During secondary antigen challenge, Th2-produced IL-4 triggers the apoptosis of Th1 cells via IL-4Rα/IL-13Rα1, thus explaining the Th2 bias in neonates. We show that neonates acquire the ability to overcome the Th2 bias and generate Th1 responses starting 6 d after birth. This transition was caused by the developmental maturation of CD8α+CD4− dendritic cells (DCs), which were minimal in number during the first few days of birth and produced low levels of IL-12. This lack of IL-12 sustained the expression of IL-13Rα1 on Th1 cells. By day 6 after birth, however, a significant number of CD8α+CD4− DCs accumulated in the spleen and produced IL-12, which triggered the down-regulation of IL-13Rα1 expression on Th1 cells, thus protecting them against IL-4–driven apoptosis

Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt Mission

The New Horizons instrument named Ralph is a visible/near infrared multi-spectral imager and a short wavelength infrared spectral imager. It is one of the core instruments on New Horizons, NASA's first mission to the Pluto/Charon system and the Kuiper Belt. Ralph combines panchromatic and color imaging capabilities with IR imaging spectroscopy. Its primary purpose is to map the surface geology and composition of these objects, but it will also be used for atmospheric studies and to map the surface temperature. It is a compact, low-mass (10.5 kg), power efficient (7.1 W peak), and robust instrument with good sensitivity and excellent imaging characteristics. Other than a door opened once in flight, it has no moving parts. These characteristics and its high degree of redundancy make Ralph ideally suited to this long-duration flyby reconnaissance mission.Comment: 18 pages, 15 figures, 4 tables; To appear in a special volume of Space Science Reviews on the New Horizons missio

Examination of neonatal immunity in IL-13 receptor alpha 1 deficient mice

Thesis advisor: Habib Zaghouani.Title from PDF of title page (University of Missouri--Columbia, viewed on January 5, 2010).The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Vita.Ph. D. University of Missouri-Columbia 2009.[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Recent work in our lab has demonstrated a role for interleukin-13 receptor alpha 1 (IL-13R[alpha]1) in the induction of apoptosis of T helper type 1 (Th1) cells in the neonatal immune system. Apoptosis of Th1 cells results in neonatal Th2-bias, which confers susceptibility to both microbial infections and allergic reactions. Unfortunately, there have been few molecular tools developed to study IL-13R[alpha]1 in the mouse despite these findings. Therefore, in order to further examine the role of IL-13R[alpha]1 in neonatal immunity, and also in allergy and asthma, we developed a monoclonal antibody that detects IL-13R[alpha]1 and we have generated mice that deficient in the expression of IL-13R[alpha]1. Using these reagents, IL-13R[alpha]1 was found to influence the primary T helper cell response to antigen, which expands upon it's role, since the role of IL-13R[alpha]1 in apoptosis of neonatal Th1 cells was previously observed upon secondary encounter with antigen. Furthermore, we demonstrate that when IL-13R[alhpa]1 deficient T cells are transferred to wild-type BALB/c mice, neonatal Th2-bias is effectively reversed to yield a Th1-dominated response. These observations strengthen IL-13R[alpha]1's candidacy as a molecular target in neonatal vaccines and also in therapies to prevent the formation of allergies.Includes bibliographical reference

Generating a neutralizing antibody against IL13R1? [abstract]

Abstract only availableFaculty Mentor: Habib Zaghouani, Molecular MicrobiologyEach year approximately 1.44 million deaths result from neonatal infection. Initial insights into the differences between the adult and neonatal immune systems were revealed by Sir Peter Medawar during his studies of organ transplantation. He discovered that skin grafts between different strains of mice, which normally result in a rejection of the graft between adult mice, could be successful if the recipient was initially transferred with splenic cells from the donor mouse during its neonatal stage of development. The phenomenon of neonatal tolerance has gone largely unexplained for nearly 50 years. Recent data from our lab supports a theoretical model for neonatal tolerance in which apoptosis of CD4+ T helper type I cells precludes rejection of the transplant. More specifically, we have demonstrated the involvement of the type II IL4 cytokine receptor in initiating this apoptotic signal. The IL13Rα1 cytokine receptor subunit is one component of this heterodimeric receptor, creation of an antibody that functionally inactivates this subunit would therefore provide a useful reagent to carry out more articulate studies of the neonatal immune system. Utilizing a baculovirus vector encoding the extracellular domain of IL13Rα1, we have expressed and purified recombinant IL13Rα1 and have further immunized Armenian hamsters to initiate an antibody response. Soon, we will fuse the B cells derived from these animals with immortalized myeloma cells to generate a permanent cell line expressing an antibody specific for IL13Rα1

The study of neonatal immunity: Creation of an IL13R[alpha]1 deficient mouse [abstract]

Abstract only availableEach year approximately 1.44 million newborns worldwide die from infections during the first four weeks of life. This is due in part to the inability of the developing neonatal immune systems to mount a Th1 immune response, which is responsible for clearing bacterial and viral infections. Previous studies in our laboratory have shown that expression of the IL-13 receptor alpha 1 subunit (IL13R[alpha]1) is upregulated in neonatal Th1 cells, and this overproduction is hypothesized to signal for their death. Currently, a knockout mouse deficient in expression of IL-13R[alpha]1 is not available and the development of an IL-13R[alpha]1 knockout mouse will allow studies to substantiate this hypothesis and possibly provide new insights into the relationship between IL-13R[alpha]1 signaling and neonatal immunity. If we can better understand the mechanisms that involve IL13R[alpha]1 and the development of Th1 immune responses, then this receptor can be targeted in novel vaccine strategies to protect newborns from infection.Life Sciences Undergraduate Research Opportunity Progra