Bhavya B Sharma

Publications (4)28.53 Total impact

• Article: Mast cells

  Bhavya B. Sharma, John R. Apgar, Fu-Tong Liu
  Clinical Reviews in Allergy & Immunology 04/2012; 22(2):119-148. · 3.68 Impact Factor
• Article: Role of galectin-3 in mast cell functions: galectin-3-deficient mast cells exhibit impaired mediator release and defective JNK expression.

  Huan-Yuan Chen, Bhavya B Sharma, Lan Yu, Riaz Zuberi, I-Chun Weng, Yuko Kawakami, Toshiaki Kawakami, Daniel K Hsu, Fu-Tong Liu
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  ABSTRACT: Galectin-3 is a member of the beta-galactoside-binding animal lectin family expressed in various cell types, including mast cells. To determine the role of galectin-3 in the function of mast cells, we studied bone marrow-derived mast cells (BMMC) from wild-type (gal3(+/+)) and galectin-3-deficient (gal3(-/-)) mice. Cells from the two genotypes showed comparable expression of IgE receptor and c-Kit. However, upon activation by FcepsilonRI cross-linkage, gal3(-/-) BMMC secreted a significantly lower amount of histamine as well as the cytokine IL-4, compared with gal3(+/+) BMMC. In addition, we found significantly reduced passive cutaneous anaphylaxis reactions in gal3(-/-) mice compared with gal3(+/+) mice. These results indicate that there is a defect in the response of mast cells in gal3(-/-) mice. Unexpectedly, we found that gal3(-/-) BMMC contained a dramatically lower basal level of JNK1 protein compared with gal3(+/+) BMMC, which is probably responsible for the lower IL-4 production. The decreased JNK1 level in gal3(-/-) BMMC is accompanied by a lower JNK1 mRNA level, suggesting that galectin-3 regulates the transcription of the JNK gene or processing of its RNA. All together, these results point to an important role of galectin-3 in mast cell biology.
  The Journal of Immunology 11/2006; 177(8):4991-7. · 5.79 Impact Factor
• Source

  Available from: ncbi.nlm.nih.gov

  Article: Critical role of galectin-3 in phagocytosis by macrophages.

  Hideki Sano, Daniel K Hsu, John R Apgar, Lan Yu, Bhavya B Sharma, Ichiro Kuwabara, Shozo Izui, Fu-Tong Liu
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  ABSTRACT: Galectin-3 is a member of a large family of animal lectins. This protein is expressed abundantly by macrophages, but its function in this cell type is not well understood. We have studied the effect of galectin-3 gene targeting on phagocytosis, a major function of macrophages. Compared with wild-type macrophages, galectin-3-deficient (gal3-/-) cells exhibited reduced phagocytosis of IgG-opsonized erythrocytes and apoptotic thymocytes in vitro. In addition, gal3-/- mice showed attenuated phagocytic clearance of apoptotic thymocytes by peritoneal macrophages in vivo. These mice also exhibited reduced IgG-mediated phagocytosis of erythrocytes by Kupffer cells in a murine model of autoimmune hemolytic anemia. Additional experiments indicate that extracellular galectin-3 does not contribute appreciably to the phagocytosis-promoting function of this protein. Confocal microscopic analysis of macrophages containing phagocytosed erythrocytes revealed localization of galectin-3 in phagocytic cups and phagosomes. Furthermore, gal3-/- macrophages exhibited a lower degree of actin rearrangement upon Fcgamma receptor crosslinkage. These results indicate that galectin-3 contributes to macrophage phagocytosis through an intracellular mechanism. Thus, galectin-3 may play an important role in both innate and adaptive immunity by contributing to phagocytic clearance of microorganisms and apoptotic cells.
  Journal of Clinical Investigation 09/2003; 112(3):389-97. · 15.39 Impact Factor
• Article: Mast cells. Receptors, secretagogues, and signaling.

  Bhavya B Sharma, John R Apgar, Fu-Tong Liu
  Clinical Reviews in Allergy & Immunology 05/2002; 22(2):119-48. · 3.68 Impact Factor