This is a revised proposal to extend ongoing studies on regulation of phenotypic expression in mononuclear phagocytes, a heterogeneous but important component of the immune system. The bone seeking isotope 89Sr, is used to create bone marrow (BM) deprived monocyte- depleted mice for the study of tissue macrophage functions. Such mice rapidly lose the capacity to express an immunosuppressive prostaglandin-secreting splenic Mphi (PGSM) induced by the immunomodulator, C. parvum. Eicosanoid metabolism in peritoneal Mphi, however, is unaffected by BM ablation. We wish to determine the origin of PGSM and the nature of regulatory influences of BM and spleen on Mphi eicosanoid metabolism. In addition, we wish to investigate another aspect of Mphi activation and the effects of enhanced IL-1 release on insulin release.
Specific aim (SA) 1. To determine mechanisms regulating the expression of PGSM by C. parvum and other Mphi activators. Synthesis and release of eicosanoids by Mphi will be assessed by RIA, HPLC and TLC in relation to BM and spleen cell interactions in vivo and in vitro. Populations will be defined by differential radiosensitivity and selective shielding of BM and spleen. Contributions of cell-bound and soluble factors will be studied in vitro by incubating spleen and bone marrow cells from C. parvum primed and unprimed mice either mixed or separated by microporous filters. Restoration of PGSM in vivo will be studied by transfusions of BM from primed and unprimed donors into primed and unprimed syngeneic recipients. SA 2: To assess influences of microenvironmental factors on PGSM expression with in vivo grafts of primary BM stromal cells and the MC-1 stromal cell line in conjunction with in vitro co-cultures of stromal cells and splenic Mphi. SA 3: To determine the relationship of the Fcy1/y2b receptor, phospholipase A2 activity and Ca++ in flux to PGSM expression. Expression of this receptor correlates with PGSM activity following ip C. parvum in normal mice. SA 4: To determine whether Mphi metabolism altered by activation results in IL-modulation of insulin release. The project should provide useful information concerning environmental regulatory influences on Mphi function relating to metabolism, inflammation and non- specific aspects of immunologic activity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI017162-12
Application #
3127016
Study Section
Experimental Immunology Study Section (EI)
Project Start
1988-12-01
Project End
1994-06-30
Budget Start
1992-12-01
Budget End
1994-06-30
Support Year
12
Fiscal Year
1993
Total Cost
Indirect Cost
Name
East Carolina University
Department
Type
Schools of Medicine
DUNS #
City
Greenville
State
NC
Country
United States
Zip Code
27858
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Shibata, Y (1995) Prostaglandin E2 release triggered by phagocytosis of latex particles. A distinct association with prostaglandin synthase isozymes in bone marrow macrophages. J Immunol 154:2878-87
Shibata, Y; Bjorkman, D R; Schmidt, M et al. (1994) Macrophage colony-stimulating factor-induced bone marrow macrophages do not synthesize or release prostaglandin E2. Blood 83:3316-23
Shibata, Y; McCaffrey, P G; Minowada, J et al. (1992) Regulation of phospholipase A2 activation and arachidonic acid metabolism in an interleukin-3-dependent macrophage-like cell line. J Leukoc Biol 51:32-8
Oghiso, Y; Yamada, Y; Shibata, Y (1992) Exudation of proliferative macrophages in local inflammation in the peritoneum. J Leukoc Biol 52:421-4
Shibata, Y; Volkman, A (1991) Restoration of prostaglandin releasing macrophage populations in lethally irradiated mice with spleen cells from bone marrow-depleted donors. J Leukoc Biol 49:397-406
Hoffman, D R; Jacobson, R S; Schmidt, M et al. (1991) Allergens in Hymenoptera venoms. XXIII. Venom content of imported fire ant whole body extracts. Ann Allergy 66:29-31
Treadwell, E L; Muller, U R; Volkman, A (1991) Extraction and differentiation of the Su autoantigen from calf thymus nuclei. J Immunol Methods 142:157-67
Shibata, Y; McCaffrey, P G; Sato, H et al. (1990) Calcium ionophore but not phorbol ester promotes eicosanoids release by proliferating interleukin-3-dependent bone marrow cells. Blood 76:1586-92
Hoffman, D R; Smith, A M; Schmidt, M et al. (1990) Allergens in Hymenoptera venom. XXII. Comparison of venoms from two species of imported fire ants, Solenopsis invicta and richteri. J Allergy Clin Immunol 85:988-96

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