Dynamics of antibody nuclease activity in blood of women during pregnancy and lactation.

In human milk we previously found catalytic antibodies (abzymes) catalyzing hydrolysis of DNA, RNA, NMP, NDP, and NTP and also phosphorylation of proteins and lipids. In the present study we have analyzed nuclease activities of antibodies in blood of women during pregnancy and lactation. Blood of healthy male and female volunteers lacked catalytically active antibodies, whereas antibodies from blood of pregnant women hydrolyzed DNA and RNA and their relative activity varied over a wide range. Relative blood abzyme activities significantly increased after delivery and at the beginning of lactation. The highest abzyme activity was observed in blood of parturient women. Although the dynamics of changes in antibody DNase activity during pregnancy was rather individual for each woman, there was a common trend in the increase in antibody activity in the first and/or third trimester of the pregnancy. The DNase activity of IgG and IgM from blood of healthy pregnant women was 4-5 times less than that from pregnant women with pronounced autoimmune thyroiditis.

[Dynamic of DNAse activity induction in serum of normal animals after heterogeneous DNA injection and in hereditary pathology]. / Dinamika induktsii DNKaznoi aktivnosti v syvorotke krovi zhivotnykh pri vvedenii geterogennoi DNK v norme i pri nasleduemoi patologii.

Studies of reactions in animals with hereditary diseases (Sapphire minks highly sensitive to Aleutian disease virus, ADV; CBA mice with 60-70% incidence of tumors; AKR mice with 90% incidence of leukemia) showed that serum DNAse activity in these animals dropped after injection of a foreign heterogeneous DNA and remained decreased during 72 h. By contrast, serum DNAse activity considerably and persistently increased after injection of DNA in Standard minks resistant to ADV, C57BI/6J mice with 1% tumor incidence, and random-bred albino mice. Presumably the capacity of standard minks to react to a foreign heterogeneous DNA by increase of DNAse activity ensures their resistance to DNA-containing ADV, while incapacity of Sapphire minks to respond to DNA by DNAse activity induction makes them sensitive to ADV. A similar relationship between the capacity to react to DNA by changes in serum DNAse activity and capacity to inherit a disease was detected in mouse strains.

Secretory immunoglobulin A from healthy human mothers' milk catalyzes nucleic acid hydrolysis.

The human milk secretory immune system is the first line of protection for the newborn infant against various pathogens. Secretory IgA (sIgA), the typical immunoglobulin found in secretions, can fight infections through many mechanisms. Using different methods, we have shown that sIgA from the milk of healthy women possesses DNAse and RNAse activities. The catalytic center is localized in the light chain of catalytic sIgA, while the DNA-binding center is predominantly formed by its heavy chain. The enzymic properties and substrate specificity of catalytic sIgA distinguish it from other known DNases and RNases. It is reasonable to assume that the milk DNA- and RNA-hydrolyzing antibodies are capable not only of neutralizing viral and bacterial nucleic acids by binding these antigens as well as by hydrolyzing them. The DNA-hydrolyzing activity of Abs raises the possibility that these catalytic Abs may provide protective functions for the newborn through the hydrolysis of viral and bacterial nucleic acids.

[Time course of serum nuclease activity in mice infected with Plasmodium berghei]. / Dinamika nukleaznoi aktivnosti v syvorotke krovi myshei pri infitsirovanii ikh Plasmodium berghei.

The present paper shows that murine serum nuclease activity increases following P.berghei infection. DNA activity begins increasing just 48 hours after infection. Following 78 hours, it achieves the maximum, by exceeding the baseline level by 6 times. Then DNA activity starts decreasing and following 94 hours after infection it is just thrice higher than the baseline. Serum RNA activity shows only 30% increases 72 hours after infection and returns to the baseline following 94 hours. Microscopic monitoring indicates that only single malaria causative agents appear in the red blood cells in this period. The peak increases in nuclease activities after P.berghei infection are assumed to be associated with the induction of serum infection.

Time course of serum nuclease activity in mice infected with plasmodium malariae.

Time course of DNase and RNase activities in the sera of random-bred mice infected with Plasmodium malariae (chloroquine-sensitive strain H) was studied. Similarly to viral infection, infection with a protozoa eukaryotic parasite was accompanied by increased DNAse and RNAse activities, though Plasmodium malariae biologically differes from viruses.