Should the Neuraminidase-1 locus be considered as part of the major histocompatibility complex?

Abstract

In 1947, McCrea [1], as well as Burner and Stone [2], observed that when a filtrate from a culture of Clostridium was added to a suspension of mammalian erythrocytes, the erythrocytes lost their ability to be agglutinated by the influenza virus. The filtrate apparently contained an agent that destroyed the erythrocyte receptor for the virus, and that appeared to have enzyme-like characteristics. Burnet and Stone also pointed out that the agent was similar to a substance present in the influenza virus particles which also destroyed the ability of erythrocytes to be agglutinated by other viruses [3]. Subsequent studies revealed that the substance in the influenza virus liberated enzymatically a compound identified as sialic acid from brain mucolipids [4]. In retrospect, the liberated compound proved to be identical to a low molecular mass substance released from ovomucin by the influenza virus and described by Gottschalk and Lind [5] 7 yr earlier. The enzyme responsible for the release of sialic acid was denoted sialidase by Heimer and Meyer [6] and neuraminidase by Gottschalk [7]. Both terms are now used indiscriminately, although some authors point out that the product of the enzymatic reaction is really sialic acid and not neuraminic acid (sialic acid is the free Nor N,0-substituted derivative of neuraminic acid). Later, studies carried out in several laboratories demonstrated that neuraminidase is present not only in viruses (mostly orthoand paramyxoviruses) and bacteria (in particular in Eubacteriales and Pseudomonadales), but also in mammalian and avian tissues (reviewed in [8]).