Galectins are a protein family defined by their affinity for beta-galactosides and consensus protein sequences. These proteins have been identified with diverse biological processes and to function both inside and outside the cell. We discovered the anti-apoptotic function of galectin-3 and substantiated this function by using cells from galectin-3- deficient (gal3-/-) mice. We have demonstrated that exogenously added galectin-3 induces migration of monocytes/macrophages both in vitro and in vivo and obtained preliminary data supporting a role for endogenous galectin-3 in the migration of macrophages. We found that gal3-/- macrophages are defective in FcgammaR-mediated phagocytosis of IgG-opsonized erythrocytes and apoptotic thymocytes both in vitro and in vivo. Confocal microscopic analysis of macrophages containing phagocytosed erythrocytes revealed localization of galectin-3 in the phagosomes. We have obtained a substantial amount of data supporting a role of galectin-3 in defense against microorganisms. Our collaborators found that galectin-3 accumulates in Mycobacterium-containing phagosomes during the course of infection and, more significantly, that gal3-/- mice are severely impaired in their ability to clear the late mycobacterial infection. We also discovered a new galectin family member, galectin-12, and demonstrated its activity in regulation of the cell cycle and cell differentiation. We have obtained data supporting the role of this lectin in the differentiation of macrophages and neutrophils. Thus, the existing information in the literature suggests that galectins play important roles in innate immunity. We will focus in the next funding period on the role of galectins in innate immunity, by addressing the following three specific aims: 1. Elucidation of the mechanism of galectin-3's regulation of phagocytosis 1) establish the role of galectin-3 in maturation of phagosomes 2)elucidate the mechanism by which galectin-3 associates with phagosomes 2. Investigation of the mechanisms by which galectin-3 contributes to host defense against M. tuberculosis 1) establish the role of galectin-3 in monocyte recruitment/granuloma formation in M. tuberculosis infection 2) demonstrate the anti-apoptotic activity of galectin-3 in macrophages infected by M. tuberculosis 3) establish the role of galectin-3 in phagocytosis of apoptotic macrophages infected by M. tuberculosis 4) demonstrate the association between galectin-3 and glycolipids from M. tuberculosis in the cytosol 3. Investigation of the function of galectin-12 in differentiation of macrophages and neutrophils 1) study the effect of the galectin-12 expression on the differentiation of bipotent myeloid cell lines in vitro 2) investigate whether galectin-12 expression affects the determination of cell fate in hematopoitic cells in vivo 3) elucidate the interplay between galectin-12 and major myeloid transcription factors

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI020958-21
Application #
6889487
Study Section
Special Emphasis Panel (ZRG1-SSS-F (01))
Program Officer
Winter, David B
Project Start
1984-04-01
Project End
2009-04-30
Budget Start
2005-05-01
Budget End
2006-04-30
Support Year
21
Fiscal Year
2005
Total Cost
$297,000
Indirect Cost
Name
University of California Davis
Department
Dermatology
Type
Schools of Medicine
DUNS #
047120084
City
Davis
State
CA
Country
United States
Zip Code
95618
Yang, Ri-Yao; Xue, Huiting; Yu, Lan et al. (2016) Identification of VPS13C as a Galectin-12-Binding Protein That Regulates Galectin-12 Protein Stability and Adipogenesis. PLoS One 11:e0153534
Chung, Andrew W; Sieling, Peter A; Schenk, Mirjam et al. (2013) Galectin-3 regulates the innate immune response of human monocytes. J Infect Dis 207:947-56
Choy, David F; Hsu, Daniel K; Seshasayee, Dhaya et al. (2012) Comparative transcriptomic analyses of atopic dermatitis and psoriasis reveal shared neutrophilic inflammation. J Allergy Clin Immunol 130:1335-43.e5
Yang, Ri-Yao; Yu, Lan; Graham, James L et al. (2011) Ablation of a galectin preferentially expressed in adipocytes increases lipolysis, reduces adiposity, and improves insulin sensitivity in mice. Proc Natl Acad Sci U S A 108:18696-701
Larsen, Larissa; Chen, Huan-Yuan; Saegusa, Jun et al. (2011) Galectin-3 and the skin. J Dermatol Sci 64:85-91
Markowska, Anna I; Liu, Fu-Tong; Panjwani, Noorjahan (2010) Galectin-3 is an important mediator of VEGF- and bFGF-mediated angiogenic response. J Exp Med 207:1981-93
Saravanan, Chandrassegar; Liu, Fu-Tong; Gipson, Ilene K et al. (2009) Galectin-3 promotes lamellipodia formation in epithelial cells by interacting with complex N-glycans on alpha3beta1 integrin. J Cell Sci 122:3684-93
Deng, Zhao; Zink, Tiffany; Chen, Huan-yuan et al. (2009) Impact of actin rearrangement and degranulation on the membrane structure of primary mast cells: a combined atomic force and laser scanning confocal microscopy investigation. Biophys J 96:1629-39
Chen, Huan-Yuan; Fermin, Agnes; Vardhana, Santosh et al. (2009) Galectin-3 negatively regulates TCR-mediated CD4+ T-cell activation at the immunological synapse. Proc Natl Acad Sci U S A 106:14496-501
Saegusa, Jun; Hsu, Daniel K; Chen, Huan-Yuan et al. (2009) Galectin-3 is critical for the development of the allergic inflammatory response in a mouse model of atopic dermatitis. Am J Pathol 174:922-31

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