Related Experiment Video

Updated: Sep 21, 2026

Bone Marrow-derived Macrophage Production
07:06

Bone Marrow-derived Macrophage Production

Published on: November 22, 2013

J774 macrophages secrete antibiotics via organic anion transporters

C X Cao1, S C Silverstein, H C Neu

  • 1Department of Physiology, Columbia University, New York, New York.

The Journal of Infectious Diseases
|February 1, 1992
PubMed

Insights

Macrophage organic anion transporters secrete antibiotics like penicillin G and norfloxacin. This transport influences antibiotic accumulation, potentially impacting treatments for intracellular bacterial infections.

Area of Science:

  • Cell Biology
  • Pharmacology
  • Immunology

Background:

  • Macrophages play a crucial role in cellular defense and drug transport.
  • Organic anion transporters (OATs) are known to mediate the efflux of various anionic compounds from cells.
  • The role of OATs in antibiotic secretion by macrophages is not fully understood.

Purpose of the Study:

  • To investigate the role of probenecid-inhibitable organic anion transporters in the secretion of antibiotics from J774 macrophage-like cells.
  • To determine if these transporters affect the intracellular accumulation of antibiotics, such as norfloxacin.

Main Methods:

  • Utilized J774 macrophage-like cells.
  • Investigated the transport of anionic dyes and antibiotics (Penicillin G, norfloxacin).
  • Assessed the effect of probenecid, an OAT inhibitor, on antibiotic secretion and intracellular accumulation.

Main Results:

  • J774 cells express probenecid-inhibitable OATs that secrete anionic dyes.
  • These OATs were found to secrete Penicillin G and norfloxacin from the cytoplasm of J774 cells.
  • Probenecid significantly reduced norfloxacin secretion and increased its intracellular accumulation threefold to fourfold.

Conclusions:

  • Organic anion transporters in macrophages actively secrete antibiotics like penicillin G and norfloxacin.
  • This efflux mechanism contributes to the regulation of intracellular antibiotic concentrations.
  • The findings suggest a potential mechanism for the limited efficacy of fluoroquinolones against intracellular pathogens in vivo.

More Related Videos

High Throughput Fluorometric Technique for Assessment of Macrophage Phagocytosis and Actin Polymerization09:22

High Throughput Fluorometric Technique for Assessment of Macrophage Phagocytosis and Actin Polymerization

Published on: November 27, 2014

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages10:33

Isolation of Salmonella typhimurium-containing Phagosomes from Macrophages

Published on: October 25, 2017

Related Concept Videos

ABC Transporters: Importer01:27

ABC Transporters: Importer

ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants.
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
Cells of the Innate Immune Response01:28

Cells of the Innate Immune Response

The innate immune response is an immediate and non-specific response against pathogens, acting swiftly to prevent the spread of infections. The primary cells involved in this response are phagocytes and natural killer (NK) cells.
Phagocytes
Phagocytes police the peripheral tissues by removing cellular debris and responding to the invasion of foreign substances or pathogens. Many phagocytes attack and remove microorganisms even before lymphocytes detect them. The human body has two general...
Antimicrobial Proteins01:23

Antimicrobial Proteins

Antimicrobial proteins are important components of the immune system. They aid the body in combating pathogens by either killing them directly or hindering their replication processes. Four main types of antimicrobial substances are interferons, the complement system, iron-binding proteins, and antimicrobial proteins.
Interferons
Interferons (IFNs) are proteins produced by lymphocytes, macrophages, and fibroblasts infected with viruses. While IFNs cannot prevent viruses from entering and...
Immune Surveillance by NK Cells and Phagocytes01:27

Immune Surveillance by NK Cells and Phagocytes

Immune surveillance is an integral part of the innate immune system, involving the continuous monitoring of peripheral tissues to detect and respond to pathogens, infected cells, or cancerous cells. This surveillance is conducted primarily by natural killer (NK) cells and phagocytes, which employ distinct but complementary mechanisms to identify and eliminate threats.
Natural Killer Cells: The Fast Responders
NK cells are large granular lymphocytes found in the blood and lymphatic system. These...
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
Bacterial Toxins01:12

Bacterial Toxins

Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...