Inhibitor capacity of some purified human serum proteins on hemagglutination by influenza virus

The Crossroads between Host Copper Metabolism and Influenza Infection

Three main approaches are used to combat severe viral respiratory infections. The first is preemptive vaccination that blocks infection. Weakened or dead viral particles, as well as genetic constructs carrying viral proteins or information about them, are used as an antigen. However, the viral genome is very evolutionary labile and changes continuously. Second, chemical agents are used during infection and inhibit the function of a number of viral proteins. However, these drugs lose their effectiveness because the virus can rapidly acquire resistance to them. The third is the search for points in the host metabolism the effect on which would suppress the replication of the virus but would not have a significant effect on the metabolism of the host. Here, we consider the possibility of using the copper metabolic system as a target to reduce the severity of influenza infection. This is facilitated by the fact that, in mammals, copper status can be rapidly reduced by silver nanoparticles and restored after their cancellation.

IMMUNOLOGICAL AND BIOCHEMICAL STUDIES ON SERUM HAPTOGLOBIN

Antibody to purified type 1-1 human serum haptoglobin was obtained in rabbits. Using this antiserum it was demonstrated that the antigenic determinants of the haptoglobin molecule reside in both α- and β-chains. No immunological difference between the normal α^1F- and α^1S-chains of haptoglobin could be detected. A number of healthy individuals whose haptoglobin pattern appeared normal by starch gel electrophoresis were shown to possess a haptoglobin which could be distinguished immunologically from the common haptoglobin types. These immunological atypical haptoglobins have been observed in individuals of types 1-1, 2-1, and 2-2. Combined immunological and chemical studies of purified haptoglobin have enabled the construction of a tentative model for the structure of human type 1-1 haptoglobin.

The relationship of the influenza virus inhibitory activity of glycoproteins to their molecular size and sialic acid content

Twenty-four different glycoproteins were investigated for their ability to inhibit hemagglutination by the A/PRS and the B/Md influenza virus strains. A relationship between activity, the molecular size, and sialic acid content was found. This relationship was readily shown for the A/PR8 virus if the properties of the glycoproteins were compared with one another on a per cent basis. A proportion of approximately 1:1:1 for activity (weight basis) to moles sialic acid content to molecular weight existed for each inhibitory glycoprotein with more than 3 per cent sialic acid, on comparison with any other active glycoprotein.A 1:3 correspondence between viral subunit and sialic acid residues of the inhibitor ovine submaxillary mucin was found experimentally and confirmed by calculation on a molecular model. The most potent inhibitors, were the antigens of the human blood-group MN system and the Tamm-Horsfall urinary glycoprotein.