• Defining the biology and identifying the receptor and signal transduction pathways of histamine releasing factor (HRF), a novel cytokine.
• Signal transduction in human basophils in a subpopulation of highly allergic patients.
• Investigating downregulation of signaling through the high affinity IgE receptor through the unique domain of the tyrosine kinase, Lyn
Studies in my laboratory led to the cloning of a novel cytokine termed histamine releasing factor (HRF) (Science 269:688-690, 1995). HRF was shown to cause histamine release from a subset of allergic donors' basophils. It was subsequently demonstrated that HRF enhanced IgE-dependent IL-4 and IL-13 secretion from all basophils. More recently, HRF was shown to promote IL-8 secretion and a calcium response in purified human eosinophils and to downregulate cytokine production from human T cells. HRF, which was previously designated p23/TCTP, is a highly conserved molecule from humans to alfalfa plants. While originally described as a growth-related tumor protein, it has also been identified in healthy liver tissue and, more recently, in macrophages, platelets, keratinocytes, erythrocytes and hepatocytes as well as several parasitic organisms. Of note, a malarial homolog was identified from Plasmodium falciparum-infected cultured erythrocytes. This malarial homolog also has biologic activity and causes histamine release from human basophils and IL-8 production from human eosinophils. Efforts in the laboratory are now pursuing additional biologic characteristics of this molecule as well as receptor identification and studies to determine the clinical relevance in vivo (see below).
Previously, HRF was thought to interact with a certain type of IgE on the surface of the basophil termed IgE+. While recent experiments have demonstrated that HRF most probably interacts with its own cell surface receptor, the nature of IgE+ needs to be defined. People with this type of IgE have basophils that release to different stimuli such as IL-3, D2O and HRF. The likely explanation for this releasibility might well be due to signal transduction events, in particular, a down regulation of the phosphatase, SHIP (see below).
The laboratory has two main interests both in basic and clinical research.
Basic Research: Utilizing a library from the Jurkat T cell line, we are currently using the yeast-2- hybrid system to identify a receptor for HRF. As an alternative approach, we are immunoprecipitating Jurkat T cells after incubation with a GST-HRF fusion protein and sequencing after SDS gel electrophoresis. In addition to activating basophils and eosinophils, as mentioned above, HRF also inhibits activation of CD4+ T cells. The biology and the signal transduction events of the HRF interaction on other cell types will continue to be investigated. Currently we are particularly interested in differental upregulation of various NFATs in human basophils and T cells stimulated by HRF.
As mentioned above, individuals with IgE+ on the surface of their basophils appear to have a hyperresponsive state of release of mediators from these cells when stimulated with a variety of substances. We are currently investigating intracellular signaling transduction events including the kinases lyn and syk, as well as SHIP, ERK, Akt and MEK to determine if there is a difference in human basophils from highly allergic patients versus allergic and atopic patients.
Mouse monomeric IgE activates mouse bone marrow-derived mast cells to produce mediators and cytokines as well as phosphorylation of intracellular signaling molecules, and has been termed highly cytokinergic. Therefore, we are also actively investigating if the human IgE+ molecule, as it is defined above, is also highly cytokinergic.
Once the receptor for HRF is identified, studies will be extended to investigate the HRF-induced intracellular signaling transduction events using both Jurkat T cells as well as an eosinophil-like cell line, AML t4-3D10.
Clinical Research: We are investigating the response to HRF among different patient populations including asthmatics, allergic rhinitics, normals and patients with atopic dermatitis. We hypothesize that peripheral blood cells, as well as bronchial alveolar lavage cells from asthmatics, will respond to HRF and produce more HRF than cells from the allergic rhinitics and normals. To test this hypothesis, we recruit patients from the clinic. We are also interested in determining if various treatments affect production of HRF from these patients. Since HRF is a novel cytokine with no homology to any known chemokine, antigen, or interleukin, we are deciphering the cellular biology of this protein. For instance, we know that HRF causes human basophils to secrete IL-4 and IL-13, two critical interleukins for immunoglobulin E (IgE) class switching. We have been able to demonstrate that HRF activates human eosinophils and T cells in addition to basophils. We will extend our clinical studies with these different patient populations and investigate HRF stimulation of intracellular production of mRNA of these interleukins using a novel flow cytometry technique.
We have developed an HRF-specific ELISA to measure the protein in various in vivo clinical samples.
Susan M. MacDonald, MD
Professor of Medicine-Senior Laboratory Investigator
Senior Laboratory Manager
We are currently looking for postdoctoral fellows; one fellow to continue the work on HRF and receptor identification. For a second fellow, we would prefer one with molecular biology expertise to study signal transduction of HRF and its receptor, as well as signal transduction of human basophils from HRF-responders and HRF-nonresponders.
1 MacDonald, S.M., Rafnar, T., Langdon, J., Lichtenstein, L.M. Molecular identification of an IgE-dependent histamine releasing factor. Science 269:688-690, 1995.
2 Schroeder, J.T., Lichtenstein, L.M., MacDonald, S.M. An immunoglobulin E-dependent recombinant histamine releasing factor induces IL-4 secretion from human basophils. J. Exp. Med. 183:1-6, 1996.
3 Kleine-Tebbe, J., Kagey-Sobotka, A., MacGlashan Jr., D.W., Lichtenstein, L.M., MacDonald, S.M. Lectins do not distinguish between heterogeneous IgE molecules as defined by differential activity of an IgE-dependent histamine releasing factor. J. Allergy Clin. Immunol. 98:181-188, 1996.
4 MacDonald, S.M. The IgE-dependent histamine releasing factor. ACI Int. 8/1:34-37, 1996.
5 Dvorak, A.M., Schroeder, J.T., MacGlashan, D.W., Bryan, K.P., Morgan, E.S., Lichtenstein, L.M. and MacDonald, S.M. Comparative ultrastructural morphology of human basophils stimulated to release histamine by anti-IgE, recombinant IgE-dependent histamine-releasing factor, or monocyte chemotactic protein-1. J. Allergy Clin. Immunol. 98:355-370, 1996.
6 MacDonald, S.M. Human recombinant histamine releasing factor (HrHRF). Int. Arch. Allergy Appl. Immunol. 113:187-190, 1997
7 Schroeder, J.T., Lichtenstein, L.M., MacDonald, S.M. Recombinant histamine-releasing factor enhances IgE-dependent IL-4 and IL-13 secretion by human basophils. J. Immunol. 159:447-452, 1997.
8 Schroeder, J.T., MacGlashan, Jr., D.W., MacDonald, S.M., Kagey-Sobotka, A. and Lichtenstein, L.M. Regulation of IgE-dependent IL-4 generation by human basophils treated with glucocorticoids. J. Immunol. 158:5448-5454, 1997.
9 Bheekha-Escura, R., Chance, S.R., Langdon, J.M., MacGlashan, Jr., D.W., MacDonald, S.M. Pharmacologic regulation of histamine release by the human recombinant IgE-dependent histamine-releasing factor (HrHRF). J. Allergy Clin. Immunol. 103:937-943, 1999.
10 MacDonald, S. M., Chakravarti, A, Paznekas, W. A., Jabs, E, W. Chromosomal localization of tumor protein, translationally controlled 1 (TPT1) also called human histamine releasing factor (HRF) to 13q14. Cytogenetics and Cell Genetics. 84:128-129, 1999.
11 Wantke, F, MacGlashan, Jr., D. W., Langdon, J.M., MacDonald, S. M. The Human Recombinant Histamine Releasing Factor HrHRF): Functional Evidence that HrHRF Does Not Bind to the IgE Molecule. J. Allergy Clin, Immunol. 103:642-648, 1999.
12 Bheekha-Escura, R., MacGlashan, Jr.,D.W., MacDonald, S.M. The Human Recombinant Histamine Releasing Factor (HrHRF) Activates Human Eosinophils and the Eosinophilic-like Cell Line, AML14-3D10. Blood 96:2191-2198, 2000.
13 MacDonald, M.D., Bhisutthibhan, J., Shapiro, T.A., Rogerson, S.J., Taylor, T.E., Tembo, M., Langdon, J.M., and Meshnick, S.R. Immune mimicry in malaria: Plasmodium falciparum secretes a functional histamine-releasing factor homolog in vitro and in vivo.. Proc. Natl. Acad. Sci. U.S.A. 98:10829-10832, 2001.
14 Vonakis, B.M., Gibbons, S., Sora, R., Langdon, J.M. and MacDonald, S.M. Src homology 2 domain-containing inositol 5' phosphatase is negatively associated with histamine release to human recombinant histamine-releasing factor in human basophils. J. Allergy Clin. Immunol. 108:822-31, 2001.
15 Vonakis, B.M., Sora, R., Langdon, J.M., Casolaro, V. and MacDonald, S.M. Inhibition of cytokine gene transcription by human recombinant histamine-releasing factor in human T lymphocytes. J. Immunol. 171:3742-3750, 2003.
16 Langdon, J.M., Vonakis, B.M., MacDonald, S.M. Identification of the Interaction between the Human Recombinant Histamine Releasing Factor/Translationally Controlled Tumor Protein and Elongation Factor-1 delta (also known as eElongation Factor-1B beta). Biochem. Biophys. Acta 1688:232-236, 2004.
Last Updated: 3/31/06