Related Experiment Video

Updated: Sep 20, 2026

Injections of Lipopolysaccharide into Mice to Mimic Entrance of Microbial-derived Products After Intestinal Barrier Breach
08:24

Injections of Lipopolysaccharide into Mice to Mimic Entrance of Microbial-derived Products After Intestinal Barrier Breach

Published on: May 2, 2018

Evidence for a LPS-binding protein in medfly hemocyte surface: mediation in LPS internalization but not in LPS

Aristea Metheniti1, Nikos Giannakas, Haralabos L Katsoulas

  • 1Department of Biology, University of Patras, Patras, Greece.

Archives of Insect Biochemistry and Physiology
|August 28, 2003
PubMed

Insights

Medfly hemocytes release LPS-binding proteins that share epitopes with mammalian CD14. These proteins aid in bacterial uptake but not in LPS signaling, offering insights into insect immunity.

Area of Science:

  • Insect immunology
  • Molecular biology
  • Comparative immunology

Background:

  • Lipopolysaccharide (LPS) is a key component of Gram-negative bacterial outer membranes.
  • CD14 is a pattern recognition receptor in mammals that binds LPS.
  • Medfly hemocytes are immune cells crucial for insect defense.

Purpose of the Study:

  • To investigate the presence and function of LPS-binding proteins in medfly hemocytes.
  • To explore potential functional and structural similarities between medfly LPS-binding proteins and mammalian CD14.
  • To elucidate the role of these proteins in immune responses.

Main Methods:

  • Protein precipitation using LPS.
  • Antibody-based protein recognition using anti-human CD14 antibodies.
  • Analysis of protein localization (membrane-bound vs. soluble) and function in phagocytosis and signaling.

Main Results:

  • A doublet of medfly hemocyte proteins (approx. 55 and 50 kDa) was precipitated by LPS.
  • Antibodies against human CD14 recognized this protein doublet, indicating shared epitopes.
  • The protein doublet was released from hemocytes upon LPS stimulation.
  • A portion localized to the hemocyte surface, while another remained soluble.
  • The membrane-bound form mediated LPS internalization and E. coli phagocytosis, but not LPS signaling.

Conclusions:

  • Medfly hemocytes possess LPS-binding proteins homologous to mammalian CD14.
  • These proteins play a role in innate immunity by facilitating bacterial clearance.
  • The findings highlight conserved mechanisms in innate immunity across species.

More Related Videos

Screening Assays to Characterize Novel Endothelial Regulators Involved in the Inflammatory Response12:50

Screening Assays to Characterize Novel Endothelial Regulators Involved in the Inflammatory Response

Published on: September 15, 2017

Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes08:49

Fluorescence-Based Measurements of Phosphatidylserine/Phosphatidylinositol 4-Phosphate Exchange Between Membranes

Published on: March 14, 2021

Related Concept Videos

Receptor-mediated Endocytosis01:48

Receptor-mediated Endocytosis

Receptor-mediated endocytosis is a process through which bulk amounts of specific molecules can be imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle and give it its round form.Clathrin-Mediated Endocytosis of LDLOne well-characterized example...
Phosphoinositides and PIPs01:42

Phosphoinositides and PIPs

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...