Skip to main content

The Expression of Endotoxic Activity in the Limulus Test as Compared to Cytokine Production in Immune Cells

Buy Article:

$63.00 plus tax (Refund Policy)

Abstract:

Lipopolysaccharides (LPS, endotoxins) belong to the strongest elicitors of the mammalian immune system due to the induction of a series of cytokines such as tumor-necrosis-factor-α (TNFα) in immunocompetent cells like mononuclear cells. Since the effects of LPS on human health may be pathologically at too high concentrations (e.g., septic shock syndrome), it is of uttermost importance to have a reliable assay for measuring the concentrations of endotoxins in vitro and in vivo (human body fluids). The activation of the clotting cascade from the horseshoe crab (Limulus polyphemus), the Limulus amoebocyte lysate test (LAL), has been the standard and most sensitive assay to detect bacterial endotoxins. However, there are restrictions with this test. It was found in some clinical trials that the results from the LAL test did not correlate with the presence of bacteremia due to Gram-negative organisms or with the mortality but correlated with the presence of fungal bloodstream infections. This resulted from the fact that the LAL assay does not only respond to bacterial endotoxins but is activated also by (1→3)-β-D-glucan. Furthermore, in extensive studies the structural requirements for activation of the LAL test were analyzed, and it was found that the LAL activity correlated with pyrogenicity but not with activation of the complement cascade. Furthermore, there was no correlation of the LAL activity with cytokine expression (for example tumor-necrosis-factor-α and interleulkins-1 and 6) in mononuclear cells when the 4/2 acyl chain pattern of enterobacterial lipid A was changed, or when the cytokine production induced by LPS from various different species in the whole blood assay was compared with the response from the LAL test. To clarify the questions raised by the different experimental findings, data from literature are summarized to get a more closer insight where the Limulus test confidentially monitors the endotoxicity of LPS and other compounds and where this is not the case, and which are the decisive epitopes for recognition of the LPS molecules. These data are very crucial for example in clinical tests, whether the LAL assay can reliably describe the effectivity of an antibacterial therapy.

Keywords: Endotoxin; LPS; Limulus test; aggregate structure; lipid A

Document Type: Research Article

DOI: https://doi.org/10.2174/092986709788682001

Affiliations: Forschungszentrum Borstel, Biophysik, Parkallee 10, D-23845 Borstel, Germany.

Publication date: 2009-07-01

More about this publication?
  • Current Medicinal Chemistry covers all the latest and outstanding developments in medicinal chemistry and rational drug design. Each issue contains a series of timely in-depth reviews written by leaders in the field covering a range of the current topics in medicinal chemistry. Current Medicinal Chemistry is an essential journal for every medicinal chemist who wishes to be kept informed and up-to-date with the latest and most important developments.
  • Access Key
  • Free ContentFree content
  • Partial Free ContentPartial Free content
  • New ContentNew content
  • Open Access ContentOpen access content
  • Partial Open Access ContentPartial Open access content
  • Subscribed ContentSubscribed content
  • Partial Subscribed ContentPartial Subscribed content
  • Free Trial ContentFree trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more