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Incoming links: A. Poltorak
A. Poltorak 2026-11-05
A. Poltorak is the first-listed author of a1998 study connecting altered lipopolysaccharide responses in two mouse strains to mutations in the mouse Tlr4 gene. The gene encodes Toll-like receptor 4, a component of the host response to bacterial material. The verified indexed byline is A. Poltorak; no expanded given name is inferred here.[ref]
Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene by A. Poltorak and others. Science282,2085–2088; indexed byline and Abstract
The comparison made two forms of evidence meet. The
C3H/HeJ strain had an altered coding sequence, whereas C57BL/10ScCr had a mutation eliminating normal receptor function. Both had impaired lipopolysaccharide signalling. Their relative resistance to endotoxin accompanied increased susceptibility to Gram-negative bacterial infection.[ref]The contrast is scientifically important: reduced response to a bacterial product is not automatically improved defence against the bacterium. Linking inherited variation to a molecular receptor helps distinguish recognition of a stimulus from the many downstream consequences of an immune response. The study's host-genetic comparison therefore supplied more information than testing whether a purified substance was inflammatory in one uncharacterized animal.
Endotoxin 2026-11-05
Endotoxin is bacterial lipopolysaccharide associated with the bacterial outer membrane of Gram-negative bacteria. Its ability to provoke a host response is distinct from the ability of a living bacterium to multiply. Detecting an endotoxin-related response and detecting a replicating infection therefore answer different questions.[ref]
Bacterial Endotoxins/Pyrogens by the Food and Drug Administration. Inspection Technical Guide 40, 20 March 1985; Characteristics of Bacterial Endotoxin
An illuminating genetic experiment connected this response to a host recognition pathway. In 1998, A. Poltorak and colleagues examined two mouse strains with weak lipopolysaccharide signaling. One carried a missense mutation in the gene encoding Toll-like receptor 4; the other carried a null mutation of that gene. Independent disruptions converging on the same component supplied evidence for its role in the response.[ref]
Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene by A. Poltorak and others. Science 282, 2085–2088, Abstract: missense and null Tlr4 mutations
The reported animals were relatively resistant to endotoxin effects but susceptible to infection with Gram-negative bacteria. A reduced response to a bacterial component did not amount to improved defence against the living organism. This distinction connects molecular recognition to the protective function of innate immunity, rather than treating every inflammatory response as an independent measure of pathogen abundance.[ref]
Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene by A. Poltorak and others. Abstract, contrasting endotoxin resistance and susceptibility to infection
The genetic result establishes a requirement in a signaling pathway under the studied conditions. By itself it does not reveal every physical contact made by the receptor or show that a measured host response depends only on how much lipopolysaccharide is present. Ligand identity, host genotype and the measured endpoint are separate parts of the explanation.