Autoimmune Diseases: Enzymatic cross Recognition and Hydrolysis of H2B Histone, Myelin Basic Protein, and DNA by IgGs against These Antigens

Abstract

Human milk provides neonates with various components that ensure newborns’ growth, including protection from bacterial and viral infections. In neonates, the biological functions of many breast milk components can be very different compared with their functions in the body fluids of healthy adults. Catalytic antibodies-abzymes hydrolyzing peptides, proteins, DNAs, RNAs, and oligosaccharides were detected not only in the blood sera of autoimmune patients but also in human milk. Non-coding microRNAs (18–25 nucleotides) are intra- and extra-cellular molecules of different human fluids. MiRNAs possess many different biological functions, including regulating several hundred genes. Five of them: miR-148a-3p, miR-200c-3p, miR-378a-3p, miR-146b-5p and let-7f-5p were previously found in milk in increased concentrations. Here, we determined number of copies of these miRNAs in 1 mg of analyzed cells, lipid fractions, and plasmas of human milk samples. The relative amount of microRNA decreases in the following order: cells » lipid fraction > plasma. IgGs and sIgAs were isolated from milk plasma, and their activity in the hydrolysis of five microRNAs was compared. In general, sIgAs demonstrated higher miRNA-hydrolyzing activity than IgGs antibodies. The hydrolysis of five microRNAs by sIgAs and IgGs was site-specific. The relative activity of each microRNA hydrolysis was very dependent on the milk preparation. The correlation coefficients between the content of five RNAs in milk plasma and the relative activity of sIgAs than IgGs in their hydrolysis strongly depended on individual microRNA and changed from −0.01 to 0.80. Thus, it was shown that milk contains specific antibodies-abzymes hydrolyzing microRNAs specific for human milk.

Multiple Sclerosis: Enzymatic Cross Site-Specific Recognition and Hydrolysis of H3 Histone by IgGs against H3, H1, H2A, H2B, H4 Histones, Myelin Basic Protein, and DNA

“…As shown previously [ 46 , 47 ], not only Abs against histones and MBP but also IgGs against DNA are able to effectively hydrolyze histones and MBP ( Supplementary Figure S1 ). It was very interesting to ask whether IgGs that have a high affinity for DNA, MBP, and histones can hydrolyze DNA.…”

“…The IgG fraction nonspecifically bound to the affinity sorbent was first eluted with 0.2 M NaCl. Specific anti-MBP IgGs with a high affinity for MBP were eluted using 3.0 M NaCl and Tris-Gly buffer, pH 2.6 [ 46 , 47 ]. For the additional purification of anti-MBP IgGs from the potential impurities of the IgGs against five histones, the anti-MBP IgG fraction was passed through histone5-Sepharose (immobilized five histones).…”

“…The fraction eluted upon loading, without affinity for the previous sorbent, was used for each of the mentioned subsequent chromatographies. Finally, we prepared five IgG preparations against five individual histones: anti-H3, anti-H1, anti-H2A, anti-H2B, and anti-H4 IgGs [ 46 , 47 ].…”

“…As an example, Supplementary Figure S2 shows the data of the analysis of scDNA hydrolysis by several IgGs. One can see that all IgGs hydrolyze DNA [ 46 , 47 ].…”

“…An analysis of the possible complexation polyreactivity and enzymatic cross-reactivity of Abs against the five histones (H1–H4) themselves has been carried out to date only partially. Using MALDI-TOFF mass spectrometry, it was shown that H2A and H2B are hydrolyzed by antibodies against H1, H2A, H2B, H3, H4, MBP, and DNA, and the sites of H2A and H2B histones by these IgGs only partly match [ 46 , 47 ].…”