Metal-dependent hydrolysis of myelin basic protein by IgGs from the sera of patients with multiple sclerosis

EAE of Mice: Enzymatic Cross Site-Specific Hydrolysis of H2A Histone by IgGs against H2A, H1, H2B, H3, and H4 Histones and Myelin Basic Protein

Histones play vital roles in chromatin function and gene transcription; however, they are very harmful in the intercellular space because they stimulate systemic inflammatory and toxic responses. Myelin basic protein (MBP) is the major protein of the axon myelin-proteolipid sheath. Antibodies-abzymes with various catalytic activities are specific features of some autoimmune diseases. IgGs against individual histones (H2A, H1, H2B, H3, and H4) and MBP were isolated from the blood of experimental-autoimmune-encephalomyelitis-prone C57BL/6 mice by several affinity chromatographies. These Abs-abzymes corresponded to various stages of EAE development: spontaneous EAE, MOG, and DNA-histones accelerated the onset, acute, and remission stages. IgGs-abzymes against MBP and five individual histones showed unusual polyreactivity in the complex formation and enzymatic cross-reactivity in the specific hydrolysis of the H2A histone. All the IgGs of 3-month-old mice (zero time) against MBP and individual histones demonstrated from 4 to 35 different H2A hydrolysis sites. The spontaneous development of EAE over 60 days led to a significant change in the type and number of H2A histone hydrolysis sites by IgGs against five histones and MBP. Mice treatment with MOG and the DNA-histone complex changed the type and number of H2A hydrolysis sites compared to zero time. The minimum number (4) of different H2A hydrolysis sites was found for IgGs against H2A (zero time), while the maximum (35) for anti-H2B IgGs (60 days after mice treatment with DNA-histone complex). Overall, it was first demonstrated that at different stages of EAE evolution, IgGs-abzymes against individual histones and MBP could significantly differ in the number and type of specific sites of H2A hydrolysis. The possible reasons for the catalytic cross-reactivity and great differences in the number and type of histone H2A cleavage sites were analyzed.

EAE of Mice: Enzymatic Cross Site-Specific Hydrolysis of H2B Histone by IgGs against H1, H2A, H2B, H3, and H4 Histones and Myelin Basic Protein

Histones have vital roles in chromatin functioning and gene transcription. At the same time, they are pernicious in intercellular space because they stimulate systemic inflammatory and toxic responses. Myelin basic protein (MBP) is the major protein of the axon myelin–proteolipid sheath. Antibody-abzymes with various catalytic activities are specific features of some autoimmune diseases. IgGs against five individual histones (H2B, H1, H2A, H3, and H4) and MBP were isolated from the blood of experimental autoimmune encephalomyelitis-prone C57BL/6 mice by affinity chromatography. Abzymes corresponding to various stages of EAE development, including spontaneous EAE, myelin oligodendrocyte glycoprotein (MOG)- and DNA-histone complex-accelerated onset, as well as acute and remission stages, were analyzed. IgG-abzymes against MBP and five individual histones showed unusual polyreactivity in complex formation and enzymatic cross-reactivity in the specific hydrolysis of H2B histone. All IgGs against MBP and individual histones in 3-month-old mice (zero time) demonstrated from 4 to 11 different H2B hydrolysis sites. Spontaneous development of EAE during 60 days led to a significant change in the type and number of H2B hydrolysis sites by IgGs against the five histones and MBP. Mouse treatment with MOG and DNA-histone complex changed the type and number of H2B hydrolysis sites compared to zero time. The minimum number (3) of different H2B hydrolysis sites was found for IgGs against H3 20 days after mouse immunization with DNA-histone complex, whereas the maximum number (33) for anti-H2B IgGs was found 60 days after mouse treatment with DNA-histone complex. Overall, this is the first study to demonstrate that at different stages of EAE evolution, IgG-abzymes against five individual histones and MBP could significantly differ in the specific sites and number of H2B hydrolysis sites. Possible reasons for the catalytic cross-reactivity and significant differences in the number and type of histone H2B cleavage sites were analyzed.

Experimental Autoimmune Encephalomyelitis of Mice: IgGs from the Sera of Mice Hydrolyze miRNAs

It was shown that the spontaneous development of experimental encephalomyelitis (EAE) in C57BL/6 mice occurs due to changes in the profile of bone marrow stem cells differentiation. This leads to the appearance of lymphocytes producing antibodies-abzymes that hydrolyze DNA, myelin basic protein (MBP), and histones. The activity of abzymes in the hydrolysis of these auto-antigens slowly but constantly increases during the spontaneous development of EAE. Treatment of mice with myelin oligodendrocyte glycoprotein (MOG) leads to a sharp increase in the activity of these abzymes with their maximum at 20 days (acute phase) after immunization. In this work, we analyzed changes in the activity of IgG-abzymes hydrolyzing (pA)₂₃, (pC)₂₃, (pU)₂₃, and six miRNAs (miR-9-5p, miR-219a-5p, miR-326, miR-155-5p, miR-21-3p, and miR-146a-3p) before and after mice immunization with MOG. Unlike abzymes hydrolyzing DNA, MBP, and histones, the spontaneous development of EAE leads not to an increase but to a permanent decrease of IgGs activity of hydrolysis of RNA-substrates. Treatment of mice with MOG resulted in a sharp but transient increase in the activity of antibodies by day 7 (onset of the disease), followed by a sharp decrease in activity 20-40 days after immunization. A significant difference in the production of abzymes against DNA, MBP, and histones before and after mice immunization with MOG with those against RNAs may be since the expression of many miRNAs decreased with age. This can lead to a decrease in the production of antibodies and abzymes that hydrolyze miRNAs with age mice.

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

Histones have a specific key role in the remodeling of chromatin and gene transcription. In the blood, free histones are damage-connected proteins. Myelin basic protein (MBP) is the major component of the myelin-proteolipid sheath of axons. Antibodies possessing enzymatic activities (abzymes, ABZs) are the specific features of several autoimmune pathologies. IgGs against five histones, MBP, and DNA were obtained from the sera of multiple sclerosis (MS) patients using several affinity chromatographies. The sites of H3 histone splitting by Abs against five individual histones, MBP, and DNA were revealed by MALDI mass spectrometry. It was shown that the number of H3 splitting sites by IgGs against five various histones is different (number of sites): H3 (11), H1 (14), H2A (11), H4 (17), MBP (22), and DNA (29). IgGs against five different histones hydrolyze H3 at different sites, and only a few them coincide. The main reason for the enzymatic cross-reactivity of Abs against H3 and four other histones, as well as MBP, might be the high level of these proteins’ homology. The effective hydrolysis of the H3 histone at 29 sites with IgGs against DNA can be explained by the formation of chimeric abzymes against hybrid antigenic determinants formed by different histones and MBP at the junction of these protein sequences with DNA. The active centers of such abzymes contain structural elements of canonical DNases and proteases. Since free histones are pernicious proteins, antibodies–ABZs against five histones, MBP, and DNA could have a negative role in the pathogenesis of MS and probably other various autoimmune diseases.

MicroRNAs of Milk in Cells, Plasma, and Lipid Fractions of Human Milk, and Abzymes Catalyzing Their Hydrolysis

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) that hydrolyze 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 extracellular molecules of different human fluids. MiRNAs possess many different biological functions, including the regulation of 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 high concentrations. Here, we determined relative numbers of miRNA copies 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 activities in the hydrolysis of five microRNAs was compared. In general, sIgAs demonstrated higher miRNA-hydrolyzing activities 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 contents of five RNAs in milk plasma, and the relative activities of sIgAs compared to IgGs in hydrolyses, strongly depended on individual microRNA, and changed from −0.01 to 0.80. Thus, it was shown that milk contains specific antibodies (abzymes) that hydrolyze microRNAs specific for human milk.

Experimental Autoimmune Encephalomyelitis of Mice: Enzymatic Cross Site-Specific Hydrolysis of H4 Histone by IgGs against Histones and Myelin Basic Protein

Histones play vital roles in chromatin functioning and gene transcription, but in intercellular space, they are harmful due to stimulating systemic inflammatory and toxic responses. Myelin basic protein (MBP) is the most important protein of the axon myelin–proteolipid sheath. Antibodies-abzymes with different catalytic activities are critical and specific features of some autoimmune diseases. Five IgG preparations against histones (H4, H1, H2A, H2B, and H3) and against MBP corresponding to different spontaneous, MOG (myelin oligodendrocyte glycoprotein of mice), and DNA–histones that accelerated onset, acute, and remission stages of experimental autoimmune encephalomyelitis (EAE; model of human multiple sclerosis) development were obtained from EAE-prone C57BL/6 mice by several affinity chromatographies. IgG-abzymes against five histones and MBP possess unusual polyreactivity in complexation and catalytic cross-reactivity in the hydrolysis of histone H4. IgGs against five histones and MBP corresponding to 3 month-old mice (zero time) in comparison with Abs corresponding to spontaneous development of EAE during 60 days differ in type and number of H4 sites for hydrolysis. Immunization of mice with MOG and DNA–histones complex results in an acceleration of EAE development associated with an increase in the activity of antibodies in H4 hydrolysis. Twenty days after mouse immunization with MOG or DNA–histones complex, the IgGs hydrolyze H4 at other additional sites compared to zero time. The maximum number of different sites of H4 hydrolysis was revealed for IgGs against five histones and MBP at 60 days after immunization of mice with MOG and DNA–histones. Overall, it first showed that at different stages of EAE development, abzymes could significantly differ in specific sites of H4 hydrolysis.

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

Histones have a paramount role in chromatin remodeling and gene transcription. Free histones are damage-associated molecules in the blood; administration of histones to animals drives systemic inflammatory and toxic effects. Myelin basic protein (MBP) is the most crucial component of the axon myelin-proteolipid sheath. Antibodies-abzymes with different enzymatic activities are very toxic and an essential feature of some autoimmune diseases. Electrophoretically homogeneous IgGs against H1, H2A, H2B, H3, H4, MBP, and DNA were derived from sera of multiple sclerosis (MS) patients by several affinity chromatographies. Using MALDI-TOFF mass spectrometry, it was shown that IgGs against H2A split H2A at 12 sites; the number of H2A hydrolysis sites by antibodies against other antigens is different: H1 (19), H2B (11), H3 (15), H4 (9), MBP (10), and DNA (23), and they only partly match. Thus, the complex formation polyreactivity and the enzymatic cross-activity of pernicious humans IgGs against five histones, MBP, and DNA have been shown for the first time. The data obtained indicate that the formation of such polyspecific-polyreactive abzymes, whose single active center can recognize and hydrolyze different substrates, can occur due to the formation of antibodies against hybrid antigenic determinants consisting of several histone protein sequences. IgGs with high affinity for DNA with DNase and protease activities may be antibodies against DNA-histone complex antigenic determinants, including protein and DNA sequences. Polyreactive IgGs-abzymes against MBP, five histones, and DNA with extended cytotoxicity can play a very negative role in the pathogenesis of multiple sclerosis and probably other different diseases.

Maximally Expressed miRNAs of Milk in Cells, Plasma and Lipid Fraction of Human Milk and Antibodies-Abzymes Catalyzing Their Hydrolysis

As shown in many studies, one of the earliest statistically significant indicators of the development of many autoimmune diseases (ADs) is the appearance in the blood of antibodies with catalytic activities (abzymes) hydrolyzing different autoantigens. Antibodies-abzymes having different enzymatic activities are a specific and essential feature of some ADs. Most abzymes are harmful to humans. Free histones in the blood are damage-associated proteins, and their administration to animals drives systemic inflammatory and toxic effects. Myelin basic protein (MBP) is the most critical component of the axon myelin-proteolipid sheath. Hydrolysis of MBP by abzymes leads to the disruption of nerve impulses. Here, we analyzed the possible pathways for the formation of unusual antibodies and abzymes that exhibit polyspecificity in recognition during complex formation with partially related antigens and possess the ability to catalyze several different reactions for the first time. Using IgGs of HIV-infected and multiple sclerosis patients against five individual histones (H1–H4), MBP, and DNA, it was first shown that abzymes against each of these antigens effectively recognize and hydrolyze all three antigens: histones, MBP, and DNA. The data obtained indicate that the formation of such polyspecific abzymes, whose single active center can recognize different substrates and catalyze several reactions, can occur in two main ways. They can be antibodies against DNA–protein complex hybrid antigenic determinants containing proteins and nucleic sequences. Their formation may also be associated with the previously described phenomenon of IgG extensive LH half-molecule (containing one L-light and one H-heavy chains) exchange leading to H₂L₂ molecules containing HL halves with variable fragments recognizing different antigens.

Cell Differentiation and Proliferation in the Bone Marrow and Other Organs of 2D2 Mice during Spontaneous Development of EAE Leading to the Production of Abzymes

The exact cellular and molecular mechanisms of multiple sclerosis and other autoimmune diseases have not been established. Autoimmune pathologies are known to be associated with faults in the immune system and changes in the differentiation profiles of bone marrow stem cells. This study analyzed various characteristics of experimental autoimmune encephalomyelitis (EAE) in 2D2 mice. Differentiation profiles of six hematopoietic stem cells of bone marrow were found to significantly differ in 2D2 male and female mice during the spontaneous development of EAE. In addition, we found various properties of B and T cells, CD4+ and CD8+ lymphocytes in blood and several organs (bone marrow, spleen, thymus, and lymph nodes) of 2D2 male and female mice to be considerably different. These changes in hematopoietic stem cells differentiation profiles and level of lymphocyte proliferation in various organs of 2D2 mice were found to induce the production of IgGs against DNA, myelin basic protein, and myelin oligodendrocyte glycoprotein, increasing the number of autoantibodies hydrolyzing these substrates. We compared the changes of these immunological and biochemical parameters in 2D2 mice with those of mice of two other lines (Th and C57BL/6), also prone to spontaneous development of EAE. Some noticeable and even extreme variations were found in the time-related development of parameters between male and female mice of 2D2, Th, and C57BL/6 lines. Despite some differences, mice of all three lines demonstrated the changes in hematopoietic stem cells profiles, lymphocyte content, and production of catalytic autoantibodies. Given that these changes are harmful to mice, we believe them to cause the development of experimental autoimmune encephalomyelitis.

Secretory immunoglobulin A from human milk hydrolyzes 5 histones and myelin basic protein

Mother's milk provides newborns with various nutrients (e.g., enzymes, proteins, peptides, hormones, antibodies) that help babies grow and protect them from bacterial and viral infections. The functions of many components of breast milk can be very different from their corresponding functions in body fluids of healthy adults. Catalytic antibodies (abzymes) that hydrolyze peptides, proteins, DNA, RNA, and oligosaccharides were detected not only in human milk, but also in the blood sera of autoimmune patients. However, abzymes with unexpected synthetic activities (lipids, oligosaccharides, and protein kinase activities) were revealed in milk that were not found in the blood of autoimmune patients. The nutrition of infants with fresh milk has a very specific role; newborns are well protected by antibodies of mother's milk (passive immunity). Protease abzymes were found in the blood sera of autoimmune patients, whereas healthy humans usually do not contain such autoantibodies. Here, we present the first evidence that the milk of healthy mothers contains secretory (s)IgA that effectively hydrolyze 5 histones (e.g., H1, H2A, H2B, H3, and H4) and myelin basic protein (MBP). Several rigid criteria were applied to show that protease activity is an intrinsic property of sIgA. Milk abzymes against 5 histones cannot hydrolyze different control proteins except histones and MBP, whereas autoantibodies against MBP split this protein and 5 histones. Antibodies against histones and MBP exhibit complexation polyreactivity as well as specific and unusual catalytic cross-reactivity. With some exceptions, the specific sites of hydrolysis of H1, H2A, and H2B by sIgA against histones do not coincide with the sites of hydrolysis by abzymes against MBP. On the whole, fresh human milk is a very specific source of many of the most unusual antibodies and abzymes.

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

Histones play a key role in chromatin remodeling and gene transcription. Further, free histones in the blood act as damage-associated molecules. Administration of histones to animals results in systemic inflammatory and toxic effects. Myelin basic protein is the principal constituent element of the myelin-proteolipid sheath of axons. Abzymes (antibodies with catalytic activities) are the original features of some autoimmune diseases. In this study, electrophoretically homogeneous IgGs against H1, H2A, H2B, H3, and H4 histones and myelin basic protein (MBP) were isolated from the blood sera of multiple sclerosis (MS) patients by several affinity chromatographies. Using MALDI mass spectrometry, the sites of H1 histone cleavage by IgGs against H1, H2A, H2B, H3, H4, and MBP were determined. It was shown that IgGs against H1 split H1 at 12 sites, while the number of cleavage sites by abzymes against other histones was lower: H2A (9), H2B (7), H3 (3), and H4 (3). The minimum rate of H1 hydrolysis was observed for antibodies against H3 and H4. A high rate of hydrolysis and the maximum number of H1 hydrolysis sites (17) were found for antibodies against MBP. Only a few sites of H1 hydrolysis by anti-H1 antibodies coincided with those for IgGs against H2A, H2B, H3, H4, and MBP. Thus, the polyreactivity of complexation and the enzymatic cross-activity of antibodies against H1, four other histones, and MBP have first been shown. Since histones act as damage molecules, abzymes against histones and MBP can play a negative role in the pathogenesis of MS and probably other different diseases as well.

IgGs-Abzymes from the Sera of Patients with Multiple Sclerosis Recognize and Hydrolyze miRNAs

Autoantibodies-abzymes hydrolyzing DNA, myelin basic protein, and oligosaccharides have been revealed in the sera of patients with multiple sclerosis (MS). In MS, specific microRNAs are found in blood and cerebrospinal fluid, which are characterized by increased expression. Autoantibodies, specifically hydrolyzing four different miRNAs, were first detected in the blood of schizophrenia patients. Here, we present the first evidence that 23 IgG antibodies of MS patients effectively recognize and hydrolyze four neuroregulatory miRNAs (miR-137, miR-9-5p, miR-219-2-3p, and miR-219-5p) and four immunoregulatory miRNAs (miR-21-3p, miR-146a-3p, miR-155-5p, and miR-326). Several known criteria were checked to show that the recognition and hydrolysis of miRNAs is an intrinsic property of MS IgGs. The hydrolysis of all miRNAs is mostly site-specific. The major and moderate sites of the hydrolysis of each miRNA for most of the IgG preparations coincided; however, some of them showed other specific sites of splitting. Several individual IgGs hydrolyzed some miRNAs almost nonspecifically at nearly all internucleoside bonds or demonstrated a combination of site-specific and nonspecific splitting. Maximum average relative activity (RA) was observed in the hydrolysis of miR-155-5p for IgGs of patients of two types of MS-clinically isolated syndrome and relapsing-remitting MS-but was also high for patients with primary progressive and secondary progressive MS. Differences between RAs of IgGs of four groups of MS patients and healthy donors were statistically significant (p < 0.015). There was a tendency of decreasing efficiency of hydrolysis of all eight miRNAs during remission compared with the exacerbation of the disease.

Catalytic antibodies in the bone marrow and other organs of Th mice during spontaneous development of experimental autoimmune encephalomyelitis associated with cell differentiation

Exact mechanisms of autoimmune disease development are still yet unknown. However, it is known that the development of autoimmune diseases is associated with defects in the immune system, namely, the violation of the bone marrow hematopoietic stem cells (HSCs) differentiation profiles. Different characteristics of autoimmune reaction development in experimental autoimmune encephalomyelitis (EAE) prone Th mice characterizing T-lymphocytes response were analyzed using standard approaches. Profiles of several HSCs differentiation of bone marrow (BFU-E, CFU-E, CFU-GM, CFU-GEMM, T- and B-lymphocytes) of Th male and female mice during spontaneous development of EAE were noticeably different. Patterns of total lymphocytes, B- and T-cells proliferation in several different organs (bone marrow, blood, spleen, thymus, and lymph nodes) were also remarkably different. In addition, there were in time noticeable differences in their changes for some organs of male and female mice. Characters of changes in the profiles of CD4 and CD8 cells proliferation in some organs not always coincide with those for total T lymphocytes. The changes in the differentiation profiles of HSCs and the level of lymphocytes proliferation in the bone marrow and other organs were associated with the increase in the concentration of antibodies against DNA, myelin basic protein, and myelin oligodendrocyte glycoprotein, and catalytic antibodies hydrolyzing these substrates. Despite some differences in changes in the analyzed parameters, in general, the spontaneous development of EAE in male and female mice occurs to some extent in a comparable way.

HIV-Infected Patients: Cross Site-Specific Hydrolysis of H3 and H4 Histones and Myelin Basic Protein with Antibodies against These Three Proteins

Histones play important roles in chromatin functioning and gene transcription, but in the intercellular space, they are harmful since they stimulate systemic inflammatory and toxic responses. Electrophoretically homogeneous IgGs against myelin basic protein (MBP), as well as H3 and H4 histones, were isolated from sera of HIV-infected patients. In contrast to known classical proteases, these IgGs split exclusively only histones and MBP but no other control proteins. Among 13 sites of hydrolysis of H3 by IgGs against H3 and 14 sites for anti-MBP IgGs, only two sites of the hydrolysis were the same. Between seven cleavage sites of H4 with IgGs against H4 and 9 sites of this histone hydrolysis by antibodies against MBP, only three sites were the same. The sites of hydrolysis of H3 (and H4) with abzymes against these histones and against MBP were different, but several expended protein clusters containing hydrolysis sites are partially overlapped. The existence of enzymatic cross-reactivity of abzymes against H3 and H4 and MBP represents a great menace to humans since due to cell apoptosis, histones constantly occur in human blood. They can hydrolyze MBP of the myelin sheath of axons and play a negative role in the pathogenesis of HIV-infected patients.

HIV-Infected Patients: Cross Site-Specific Hydrolysis of H2a and H2b Histones and Myelin Basic Protein with Antibodies against These Three Proteins

Anti-DNA antibodies are usually produced against histone-DNA complexes appearing during cell apoptosis, while histones are known as damage-associated molecules. A myelin sheath of axons contains myelin basic protein (MBP) playing an important role in the pathogenesis of autoimmune diseases. Antibodies with enzymatic activities (abzymes) are distinctive features of some autoimmune and viral diseases. Abzymes against different proteins can usually only hydrolyze these specific proteins. Using sequential chromatographies of homogeneous IgG preparations from sera of HIV-infected patients on columns with immobilized MBP, H2a, and H2b histones, the anti-MBP, anti-H2a, and anti-H2b antibodies were obtained. It was first shown that IgGs against H2a and H2b effectively hydrolyze these histones and MBP, while anti-MBP split MBP, H2a, and H2b, but no other control proteins. Using the MALDI mass spectrometry, the cleavage sites of H2a, H2b, and MBP by abzymes against these three proteins were found. Among 14 sites of hydrolysis of H2a by IgGs against H2a and 10 sites by anti-MBP IgGs, only one site of hydrolysis was the same for these abzymes. Eleven cleavage sites of H2b with IgGs against H2b and 10 sites of its hydrolysis with antibodies against MBP were different. Anti-H2a, anti-H2b, and anti-MBP abzymes are unpredictable examples of IgGs possessing not only cross-complexation but also catalytic cross-reactivity, which may be a common phenomenon for such abzymes in patients with different autoimmune diseases. The existence of cross-reactivity of abzymes against H2a and H2b histones and MBP represent a great danger to humans since, in contrast with MBP, histones due to cell apoptosis constantly occur in human blood. Anti-H2a, anti-H2b, and anti-MBP can attack and hydrolyze myelin basic protein of the myelin sheath of axons and plays a negative role in the pathogenesis of several pathologies.

IgGs-Abzymes from the Sera of Patients with Systemic Lupus Erythematosus Hydrolyzed miRNAs

Background and Objectives

Systemic lupus erythematosus (SLE) is an inflammatory disease. The sera of SLE patients contain antibodies-abzymes hydrolyzing myelin basic protein (MBP), DNA, nucleotides, and oligosaccharides. The blood of SLE patients contains an increased amount of some specific miRNAs. This study aimed to analyze a possible hydrolysis of eight microRNAs found in the blood of SLE patients with high frequency by blood antibodies-abzymes.

Patients and Methods

Using affinity chromatography of the serum proteins of SLE patients and healthy donors on protein G-Sepharose and following FPLC gel filtration, electrophoretically homogeneous IgG preparations containing no impurities of canonical RNases were obtained. These preparations were used to analyze their activity in the hydrolysis of eight miRNAs.

Results

It was shown that SLE IgGs hydrolyze very efficiently four neuroregulatory miRNAs (miR-219-2-3p, miR-137, miR-219a-5p, and miR-9-5p) and four immunoregulatory miRNAs (miR-326, miR-21-3p, miR-155-5p, and miR-146a-3p). To demonstrate that the miRNAs hydrolysis is an intrinsic property of SLE IgGs, several rigid criteria were checked. Only some IgGs of healthy donors showed very weak, but reliably detectable activity in the hydrolysis miRNAs. The average activity of SLE patients IgGs according to median values is statistically significant 84.8-fold higher than that of healthy donors. The maximum and comparable average activity (RA) was observed in the hydrolysis of three miRAs: miR-9-5p, miR-155-5p, and miR-326. MiR-9-5p plays an important role in the development of lupus nephritis, while miR-326 activates the production of antibodies by B cells. The major and moderate specific sites of the hydrolysis of each miRNA were revealed. The hydrolysis of eight microRNAs was mostly site specific. Several SLE IgGs hydrolyzed some miRNAs demonstrating a combination of site-specific and non-specific splitting.

Conclusion

Since inflammatory processes in SLE are associated with the change in miRNAs expression, the decrease in their concentration due to hydrolysis by autoantibodies-abzymes may be important for SLE pathogenesis.

IgGs from Human Milk Hydrolyze microRNAs

Mother’s milk provides breast-fed infants with various nutrients, including peptides, proteins, DNA, RNA, antibodies, and other bioactive components promoting neonatal growth and protecting infants from viral and bacterial infection. The functions of many human milk components regarding the nutrition and protection of newborns may be very different compared to those of various biological fluids of healthy adults. For example, human milk contains catalytic antibodies (abzymes) with protein, lipid, and oligosaccharide kinase activities, which are absent in the biological fluids of healthy people and autoimmune patients. Obviously, the nutrition of infants with fresh breast milk is a special phenomenon having a very specific and important role. Here, we have shown that mother’s milk IgGs effectively split homo-(pN)23, and four miRNAs: miR-137, miR-219a-5p, miR-219-2-3p, and miR-9-5p. It was shown that ribonuclease activity is a unique property of milk IgGs. On average, individual IgGs hydrolyze (pA)23, (pU)23, and (pC)23 nonspecifically and with comparable efficiency, whereas the hydrolysis of four miRNAs is predominately site-specific. The specific sites of the hydrolysis of four miRNAs by IgGs from the blood of schizophrenic (SCZ) patients and secretory immunoglobulins A (sIgAs) from human milk were found earlier. The sites of the hydrolysis of four miRNAs by milk IgGs and sIgA-abzymes are almost the same, but are significantly different in comparison with those for SCZ IgGs. In addition, in contrast to the SCZ IgGs, milk IgGs and sIgAs efficiently hydrolyzed miRNAs in the duplex regions formed by their terminal sequences.

Extreme Diversity of IgGs Against Histones, DNA, and Myelin Basic Protein in the Cerebrospinal Fluid and Blood of Patients with Multiple Sclerosis

It was recently shown that IgGs from sera of multiple sclerosis (MS) patients are active in the hydrolysis of DNA and myelin basic protein (MBP). We first analyzed the relative concentration of antibodies against five histones (H1, H2a, H2b, H3, and H4) in the cerebrospinal fluid (CSF) and serum of patients with MS. The relative concentrations of blood and CSF IgGs against histones and their activity in the hydrolysis of five histones varied greatly from patient to patient. However, all 28 IgG preparations were hydrolyzed from one to five histones. Relative activities and correlation coefficients among the activities of IgGs from serum and CSF in the hydrolysis of five histones (H1, H2a, H2b, H3, and H4), DNA, and MBP were calculated. It was shown that auto-IgGs from CSF and sera of MS patients are extremely heterogeneous in their affinity to histones, MBP, and DNA. The heterogeneity of IgG-abzymes hydrolyzing DNA, MBP, and histones from CSF and sera was also demonstrated using their isoelectrofocusing. The isofocusing profiles DNase, MBP-, and histone-hydrolyzing activities of IgGs may be very different for various individuals, but the total IgG subfractions with all their activities are distributed from pH 3 to 10.

Production of Abzymes in Th, CBA, and C57BL/6 Mice before and after MOG Treatment: Comparing Changes in Cell Differentiation and Proliferation

Till yet there is no data concerning mechanisms of autoimmune diseases development. Experimental autoimmune encephalomyelitis (EAE) prone C57BL/6 (T- and B-lymphocyte response), non-autoimmune CBA, and Th mice with T cell response were immunized with myelin oligodendrocyte glycoprotein (MOG_35–55) to compare different characteristics of autoimmune reaction development. Bone marrow differentiation profiles of hematopoietic stem cells (HSCs), lymphocyte proliferation in various organs associated with the production of antibodies against DNA, myelin basic protein (MBP), and MOG, as well as abzymes hydrolyzing these antigens, were analyzed before and after immunization. Profiles of HSC differentiation [BFU-E (erythroid burst-forming unit (early erythroid colonies), CFU-E (erythroid burst-forming unit (late erythroid colonies), CFU-GM (granulocytic-macrophagic colony-forming unit), and CFU-GEMM granulocytic-erythroid-megakaryocytic-macrophagic colony-forming unit] and patterns of lymphocyte proliferation in different organs (brain, spleen, thymus, and lymph nodes) were very different for C57BL/6, CBA, and Th mice. We conclude that only C57BL/6 mice were predisposed to spontaneous and MOG-induced acceleration of EAE development. CBA mice are not prone to the development of autoimmune reactions. After immunization, Th mice demonstrate changes in several parameters similar to C57BL/6 and other to CBA mice; Th mice are more prone to developing autoimmune reactions than CBA mice. Our data may be important for understanding the combined presence in mice lymphocytes with T and B cell responses for spontaneous and induced autoimmune diseases.

Antibodies from the Sera of Multiple Sclerosis Patients Efficiently Hydrolyze Five Histones

It is known that intranuclear histones can be pernicious after entering to the extracellular space. In addition, the immunization of animals with exogenous histones leads to systemic inflammatory and toxic reactions. Abzymes—autoantibodies with enzymatic activities—are the distinctive feature of autoimmune diseases and they can be especially dangerous to humans. Here, electrophoretically homogeneous IgGs were isolated from sera of patients with multiple sclerosis (MS) by chromatography on several affinity sorbents. We present evidence that sera of all MS patients contain autoantibodies against histones and 73% of IgGs purified from the sera of 59 MS patients efficiently hydrolyze from one to five histones: H1, H2a, H2b, H3, and H4. The relative average efficiency of the histones hydrolysis was ~3.9-fold higher than that for healthy donors. The relative average activity of IgGs depends on the type of MS and decreased approximately in the following order: debut of MS, secondary progressive multiple sclerosis, remitting multiple sclerosis, remittent progressive multiple sclerosis. Similar to proteolytic abzymes of patients with several autoimmune diseases, histone-hydrolyzing IgGs from MS patients were inhibited in the presence of specific inhibitors of serine and of metal-dependent proteases, but an unexpected significant inhibition of the activity by inhibitors of thiol-like and especially acidic proteases was observed. Since IgGs can efficiently hydrolyze histones, a negative role of abzymes in the development of MS cannot be excluded.

Autoantibodies in HIV-infected patients: Cross site-specific hydrolysis of H1 histone and myelin basic protein

Histones act as damage-associated molecules, while anti-DNA antibodies are directed against histone-DNA nucleosomal complexes. Myelin basic protein (MBP) plays an important role in the pathogenesis of multiple sclerosis. Autoantibodies (Abs) with enzymatic activities are the distinctive feature of some autoimmune and viral diseases. Abzymes with proteolytic activity against different proteins specifically hydrolyze only these specific proteins. Using chromatography of IgGs on columns with immobilized H1 histone and then by chromatography of the fraction having an affinity for the histone (eluted upon loading) on MBP Sepharose, the anti-MBP antibodies were obtained. Anti-H1 antibodies were obtained using these columns in reverse order. IgGs against H1 and MBP effectively hydrolyze both H1 histone and MBP but no other control proteins. Using the MALDI mass spectrometry, the cleavage sites of H1 histone and MBP by abzymes against these proteins are found. The hydrolysis of MBP by anti-MBP IgGs occurs at four clusters (22 sites of the hydrolysis) locating at four known antigenic determinants of MBP. Anti-H1 Abs hydrolyze MBP only at one cluster (11 sites of the hydrolysis); this cluster is only partially overlapped with one of the four MBP clusters. Anti-H1 antibodies hydrolyze H1 at five sites of one cluster of the protein when anti-MBP IgGs cleavage this histone at two clusters containing 17 sites of the cleavage. Anti-H1 and anti-MBP abzymes are the first examples of Abs possessing not only with cross-complexing but also with catalytic cross-reactivity. The existence of cross-reactivity of abzymes against histones and MBP represent great danger to humans. © 2018 BioFactors, 45(2):211-222, 2019.

Changes in cell differentiation and proliferation lead to production of abzymes in EAE mice treated with DNA-Histone complexes

Experimental autoimmune encephalomyelitis (EAE)-prone C57BL/6 mice are used as a model of human multiple sclerosis. We immunize mice with myelin oligodendrocyte glycoprotein (MOG), DNA-histone and DNA-methylated bovine serum albumin (met-BSA) complexes to reveal different characteristics of EAE development including bone marrow lymphocyte proliferation and differentiation profiles of hematopoietic stem cells. Immunization of C57BL/6 mice with MOG35-55 results in the acceleration of EAE development. Anti-DNA antibodies are usually directed against DNA-histone complexes resulting from cell apoptosis. During the acute EAE phase (7-20 days after immunization), catalytic antibodies efficiently hydrolysing myelin basic protein (MBP), MOG and DNA are produced with parallel suppression of antibodies hydrolysing histones. We could show that in contrast to MOG, immunization with histone-DNA results in a reduction of proteinuria, a significant increase in anti-DNA, anti-MBP and anti-MOG antibody titres, as well as an increase in their catalytic activities for antigen hydrolysis, but slightly changes the concentration of cytokines. Contrary to MOG, DNA-histone and DNA-met-BSA only stimulated the formation of anti-DNA antibodies hydrolysing DNA with a long delay (15-20 days after immunization). Our data indicate that for C57BL/6 mice immunization with DNA-met-BSA and DNA-histone complexes may have opposing effects compared to MOG. DNA-histone stimulates the appearance of histone-hydrolysing abzymes in the acute EAE phase, while abzymes with DNase activity appear at significantly later time-points. We conclude that MOG, DNA-histone and DNA-met-BSA have different effects on numerous bone marrow, cellular, immunological and biochemical parameters of immunized mice, but all antigens finally significantly stimulate the development of the EAE.

Autoimmunity and immune system dysregulation in schizophrenia: IgGs from sera of patients hydrolyze myelin basic protein

Several different theories of schizophrenia (SCZ) were discussed; the causes of this disease are not yet clear. Using ELISA, it was shown that titers of autoantibodies against myelin basic protein (MBP) in SCZ patients are ~1.8-fold higher than in healthy individuals but 5.0-fold lower than in patients with multiple sclerosis. Several rigid criteria were checked to show that the MBP-hydrolyzing activity is an intrinsic property of SCZ IgGs. Approximately 82% electrophoretically homogeneous SCZ IgGs purified using several affinity sorbents including Sepharose with immobilized MBP hydrolyze specifically only MBP but not many other tested proteins. The average relative activity of IgGs from patients with negative symptoms was 2.5-fold higher than that of patients with positive symptoms of SCZ, and it increases with the duration of this pathology. It was shown that abzymes are the earliest statistically significant markers of many autoimmune pathologies. Our findings surmise that the immune systems of individual SCZ patients can generate a variety of anti-MBP abzymes with different catalytic properties, which can attack MBP of the myelin-proteolipid shell of axons. Therefore, autoimmune processes together with other mechanisms can play an important role in SCZ pathogenesis. MBP-hydrolyzing antibodies were previously detected in the blood of 80% to 90% of patients with systemic lupus erythematosus (SLE) and multiple sclerosis (MS). In addition, some similar neuropsychiatric indicators of disease common to SLE, MS, and SCZ were described in the literature. Thus, the destruction of the myelin sheath and the production of MBP-hydrolyzing antibodies can be a common phenomenon for some different diseases.

The DNA-hydrolyzing activity of IgG antibodies from human placenta

OBJECTIVE

Since during pregnancy and lactation women tend to develop autoimmune processes, characterization of placenta immunoglobulins and their possible catalytic functions is a very important step towards understanding the function of placenta.

METHODS

ELISA, affinity chromatography, SDS-PAGE and MALDI mass spectrometry were used.

RESULTS

It was shown, that ten placentas contain in average 1.1 ± 0.33 mg IgGs/g of placenta and 0.11 ± 0.1 mЕ anti-DNA antibodies/g of placenta. All ten individual IgG preparations were characterized by a specific ratio and various combinations of heavy (47.5-51.7 kDa) and light (22.2-33.3 kDa) chains with different molecular masses. All intact IgGs demonstrate DNase but have not amylase activity. Several strict criteria have been used to show that the DNase activity is an intrinsic property of placenta IgGs. The heavy chains of antibodies were catalytically inactive. The light chains of 22-24 kDa of all IgGs demonstrated maximal DNase activity, while the chains of approximately 25-33.2 kDa were significantly less active. IgGs were completely inactive after dialysis against EDTA. The optimal external cofactors of placenta DNase abzymes are Mg²⁺ and Cu²⁺ ions, while, activity in the presence of Mn²⁺ and Ca²⁺ is approximately 3-4-fold lower. Activation of DNase abzymes by Cu²⁺ ions was revealed for the first time. Placental antibodies possess selective cytotoxicity against cancer cells.

CONCLUSION

It was shown previously, that appearance of serum DNase abzymes is the good indicator of the beginning and obvious spontaneous or induced autoimmune diseases. The detection of placenta DNase antibodies indicates that during pregnancy, autoimmune processes can affect this organ.

Blood-Derived RNA- and microRNA-Hydrolyzing IgG Antibodies in Schizophrenia Patients

Abzymes with various catalytic activities are the earliest statistically significant markers of existing and developing autoimmune diseases (AIDs). Currently, schizophrenia (SCZD) is not considered to be a typical AID. It was demonstrated recently that antibodies from SCZD patients efficiently hydrolyze DNA and myelin basic protein. Here, we showed for the first time that autoantibodies from 35 SCZD patients efficiently hydrolyze RNA (cCMP > poly(C) > poly(A) > yeast RNA) and analyzed site-specific hydrolysis of microRNAs involved in the regulation of several genes in SCZD (miR-137, miR-9-5p, miR-219-2-3p, and miR-219a-5p). All four microRNAs were cleaved by IgG preparations (n = 21) from SCZD patients in a site-specific manner. The RNase activity of the abzymes correlated with SCZD clinical parameters. The data obtained showed that SCZD patients might display signs of typical autoimmune processes associated with impaired functioning of microRNAs resulting from their hydrolysis by the abzymes.

Antibodies against H3 and H4 histones from the sera of HIV-infected patients catalyze site-specific degradation of these histones

Histones and their posttranslational modified forms play pivotal roles in chromatin functioning and gene transcription. Also, histones are harmful when they enter the intercellular space; their administration to animals results in systemic inflammatory and toxic responses. Autoantibodies having enzymatic activities (abzymes) are the specific feature of several autoimmune and viral diseases. Electrophoretically homogeneous IgGs containing no canonical proteases were purified from sera of HIV-infected patients by using several affinity chromatographies. In contrast to known canonical proteases, Abs from HIV-infected patients hydrolyzed exclusively only histones but no other control globular proteins. The H3 and H4 histone cleavage sites by antihistone IgGs were determined by matrix-assisted laser desorption/ionization mass spectrometry for the first time. Two clusters of H3 hydrolysis contain major (↕) and minor (*) cleavage sites: 18-K*Q*LA↕TK*A↕AR*KS↕A*P-30 and 34-G*VK*KPHR*YRPGTVA*L*R-50. H4 histone has only 1 cluster of cleavage sites containing additionally moderate (↓) cleavage sites: 15-A↕KR↕HR↕KVLR↓D*NIQ↓GIT*K-31. Sites of these histones cleavage correspond mainly to their known epitopes. It was surprising that most of the cleavage sites of histones are involved in the interaction with DNA of nucleosome core. Because histones act as damage-associated molecules, abzymes against H3 and H4 can play important role in pathogenesis of AIDs and probably other viral and immune diseases.

Substrate specificity of healthy human sera IgG antibodies with peroxidase and oxydoreductase activities

We have carried out an analysis of whether blood IgG antibodies can protect humans from oxidative stress by oxidizing different harmful compounds. A somewhat unexpected result was obtained. We show here for the first time that healthy human sera IgGs with the peroxidase (in the presence H2O2) efficiently oxidize different compounds: 3,3'-diaminobenzidine (1; DAB), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (2; ATBS), o-phenylenediamine (3; OPD), homovanillic acid (4; HVA), α-naphthol (5), 5-aminosalicylic acid (6; 5-ASA) and 3-amino-9-ethylcarbazole (7; AEC), but seven of nine IgG preparations from different volunteers cannot oxidize p-hydroquinone (8: pHQ). The average apparent kcat values in the H2O2-dependent oxidation by human IgGs decreased in the following order (min-1): ATBS (73.7) ≥ DAB (66.3) > AEC (38.0) ≥ HVA (19.8) ≥ α-naphthol (8.6) > OPD (0.62) ≥ 5-ASA (0.48) > pHQ (0.24). In the absence of H2O2 (oxidoreductase activity), the relative average kcat values decreased in the following order (min-1): DAB (52.1) ≥ ATBS (50.5) > OPD (0.25). The peroxidase average activity of human IgGs was higher than the oxidoreductase one: 1.2-, 1.5- and 2.5-fold for DAB, ATBS and OPD, respectively. It should be assumed that antibodies can oxidize in addition to the large number of other different compounds analysed by us. As a whole, the specific wide repertoire of polyclonal human IgGs oxidizing various compounds could play an important role in protecting humans from oxidative stress and serve as an additional natural system destroying H2O2 and different toxic mutagenic and carcinogenic compounds.

Changes in haematopoietic progenitor colony differentiation and proliferation and the production of different abzymes in EAE mice treated with DNA

Immunization of experimental autoimmune encephalomyelitis (EAE)‐prone C57BL/6 mice with MOG_35‐55 (a model used to study aspects of human multiple sclerosis) is known to lead to the production of various abzymes. The production of catalytic IgGs that can efficiently hydrolyse myelin basic protein (MBP), MOG and DNA is associated with changes in the profile of differentiation and level of proliferation of mice bone marrow haematopoietic stem cells (HSCs). As MOG simulates the production of abzymes with high DNase activity, we compared the effects of DNA and MOG immunization on EAE‐prone mice. In contrast to MOG, immunization with DNA leads to a suppression of proteinuria, a decrease in the concentrations of antibodies to MOG and DNA and a reduction in abzyme production. Immunization with DNA only resulted in a significant increase in DNase activity over 40 days where it became 122‐fold higher than before immunization, and fivefold higher when comparing to the maximal activity obtained after MOG treatment. DNA and MOG immunization had different effects on the differentiation profiles of HSCs, lymphocyte proliferation, and the level of apoptosis in bone marrow and other organs of mice. The data indicate that for C57BL/6 mice, DNA may have antagonistic effects with respect to MOG immunization. The usually fast immune response following MOG injection in C57BL/6 mice is strongly delayed after immunization with DNA, which is probably due to a rearrangement of the immune system following the response to DNA.

How human IgGs against myelin basic protein (MBP) recognize oligopeptides and MBP

Myelin basic protein (MBP) is a major protein of myelin-proteolipid shell of axons, and it plays an important role in pathogenesis of multiple sclerosis. In the literature, there are no data on how antibodies recognize different protein antigens including MBP. A stepwise increase in ligand complexity was used to estimate the relative contributions of virtually every amino acid residue (AA) of a specific 12-mer LSRFSWGAEGQK oligopeptide corresponding to immunodominant sequence of MBP to the light chains and to intact anti-MBP IgGs from sera of patients with multiple sclerosis. It was shown that the minimal ligands of the light chains of IgGs are many different free AAs (K_d  = 0.51-0.016 M), and each free AA interacts with the specific subsite of the light chain intended for recognition of this AA in specific LSRFSW oligopeptide. A gradual transition from Leu to LSRFSWGAEGQK leads to an increase in the affinity from 10^-1 to 2.3 × 10^-4  M because of additive interactions of the light chain with 6 AAs of this oligopeptide and then the affinity reaches plateau. The contributions of 6 various AAs to the affinity of the oligopeptide are different (K_d , M): 0.71 (S), 0.44 (R), 0.14 (F), 0.17 (S), and 0.62 (W). Affinity of nonspecific oligopeptides to the light chains of IgGs is significantly lower. Intact MBP interacts with both light and heavy chains of IgGs demonstrating 192-fold higher affinity than the specific oligopeptide. It is a first quantitative analysis of the mechanism of proteins recognition by antibodies. The thermodynamic model was constructed to describe the interactions of IgGs with MBP. The data obtained can be very useful for understanding how antibodies against many different proteins can recognize these proteins.

Antibodies to H2a and H2b histones from the sera of HIV-infected patients catalyze site-specific degradation of these histones

Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into the extracellular space. Administration of histones to animals leads to systemic inflammatory and toxic responses. Autoantibodies with enzymatic activities (abzymes) are distinctive features of some autoimmune and viral diseases. Electrophoretically homogeneous IgGs containing no canonical enzymes were isolated from the sera of HIV-infected patients by chromatography on several affinity sorbents including anti-histone Sepharose. In contrast to canonical proteases (trypsin, chymotrypsin, proteinase K), IgGs from HIV-infected patients specifically hydrolyzed only histones but not many other tested globular proteins. Using MALDI mass spectrometry the sites of H2a and H2b histone cleavage by anti-histone IgGs were determined for the first time. One cluster of H2a hydrolysis contains two major (↕) and four moderate (↓) cleavage sites: 31-H↓R↓L↓L↓R↕K G↕N-38. One major and two moderate sites of cleavage were revealed in the second cluster: 14-A↕KSRS↓SRA↓G-22. The third cluster corresponding to the H2a C-terminal part contains only five minor (†) sites of cleavage: 82-H†LQLAIRNDEELN†KLLG†RV†T†I-102. It was shown that two major and four moderate sites of cleavage were present in the main cluster of H2b hydrolysis: 46-K↕QvhpD↓TgiS↓SkA↓M↕GiM↓N-63. Two moderate sites of cleavage correspond to a relatively short 6-mer cluster: 12-K↓GskK↓A-17. The third relatively long 9-mer cluster contains one major and two minor sites of H2b cleavage: 80-L↕AHYN†KRS†T-88. In the nucleosome core particle, most of the major and moderate cleavage sites are located at the H2a/H2b interaction interface. Minor cleavage sites of H2a are involved in binding with H3 in the nucleosome core. Two moderate cleavage sites of H2b and one major cleavage site of H2a are located in the disordered N-terminal region interacting with DNA. According to the crystal structure of the nucleosome core particle, all identified cleavage sites are expected to affect H2a and H2b folding, nucleosome assembly, and binding of H2a and H2b with DNA. The existence of H2a and H2b hydrolyzing abzymes may be very important for the further understanding of unknown possibilities of immune systems and biological functions of antibodies.

Antibodies to H1 histone from the sera of HIV-infected patients recognize and catalyze site-specific degradation of this histone

Histones and their posttranslational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecules when they are released into the extracellular space. Administration of histones to animals leads to systemic inflammatory and toxic responses. Autoantibodies with enzymatic activities (abzymes) are distinctive feature of some autoimmune and viral diseases. Electrophoretically and immunologically homogeneous IgGs containing no canonical enzymes were isolated from sera of human immunodeficiency virus-infected patients by chromatography on several affinity sorbents. In contrast to canonical proteases (trypsin, chymotrypsin, and proteinase K), IgGs from human immunodeficiency virus-infected patients purified by affinity chromatography on Sepharose containing immobilized histones specifically recognized and hydrolyzed only histones but not many other tested globular proteins. Using matrix-assisted laser desorption/ionization mass spectrometry, the sites of H1 histone (193 amino acids [AAs]) cleavage by anti-H1 histone IgGs were determined for the first time. It was shown that 1 cluster of 2 major and 4 moderate sites of cleavage is located at the beginning (106-112 AAs) of the known antigenic determinants disposed at the long C-terminal sequence of H1. Two clusters of minor and very weak sites of the protein cleavage correspond to middle (8 sites, 138-158 AAs) and terminal (5 sites, 166-176 AAs) parts of the antigenic determinants. It was shown that in contrast to canonical proteases, N-terminal part of H1 histone (1-136 AAs) containing no antigenic determinants is an unpredictably very resistant against hydrolysis by abzymes, while it can be easily cleavage by canonical proteases. Because histones act as damage-associated molecules, abzymes against H1 and other histones can play important role in pathogenesis of acquired immune deficiency syndrome and probably other different diseases.

DNA-hydrolysing activity of IgG antibodies from the sera of patients with schizophrenia

It is believed that damage to the membranes of brain cells of schizophrenia (SCZ) patients induces the formation of autoantigens and autoantibodies. Nevertheless, the importance of immunological changes leading to the loss of tolerance to self-antigens in the genesis of SCZ has not been established. The MALDI mass spectra of the IgG light chains of 20 healthy donors were relatively homogeneous and characterized by one peak with only one maximum. In contrast to the healthy donors, the MALDI mass spectra of IgG light chains corresponding to 20 SCZ patients demonstrated, similarly to 20 autoimmune systemic lupus erythematosus (SLE) patients, two maxima of a comparable intensity. In addition, the MALDI spectra of the IgG light chains of five SLE and four SCZ patients contained a small additional brightly pronounced peak with remarkably lower molecular mass compared with the main one. DNase autoantibodies (abzymes) can be found in the blood of patients with several autoimmune diseases, while the blood of healthy donors or patients with diseases without a significant disturbance of the immune status does not contain DNase abzymes. Here, we present the first analysis of anti-DNA antibodies and DNase abzymes in the sera of SCZ patients. Several strict criteria have been applied to show that the DNase activity is an intrinsic property of IgGs from the sera of SCZ patients. The sera of approximately 30% of SCZ patients displayed a higher content of antibodies (compared with 37% of SLE) interacting with single- and double-stranded DNA compared with healthy donors. Antibodies with DNase activity were revealed in 80% of the patients. These data indicate that some SCZ patients may show signs of typical autoimmune processes to a certain extent.

Comparison of Antibodies with Amylase Activity from Cerebrospinal Fluid and Serum of Patients with Multiple Sclerosis

We have recently shown that IgGs from serum and cerebrospinal fluid (CSF) of MS patients are active in hydrolysis of DNA and myelin basic protein. According to literature data, anti-DNA and anti-MBP abzymes may promote important neuropathologic mechanisms in this chronic inflammatory disorder and in MS pathogenesis development. At the same time, the involvement of antibodies with amylase activity in the pathogenesis of any autoimmune disease has not yet been identified. Electrophoretically and immunologically homogeneous IgGs were obtained by a sequential affinity chromatography of the CSF proteins on protein G-Sepharose and FPLC gel filtration. We are able to present the first unpredictable evidence showing that IgGs from CSF possess amylase activity and efficiently hydrolyze maltoheptaose; their average specific Ab activity is ~30-fold higher than that of antibodies from sera of the same MS patients. Specific average RA (SAA) for IgGs from healthy volunteers was approximately ~1000 lower than that for MS patients. In addition, it was shown that a relative SAA of total proteins of CSF (including Abs) ~15-fold lower than that for purified IgGs, while the relative SAA of the total sera protein is higher than that of sera IgGs by a factor of 1033. This result speaks in favor of the fact that amylolytic activity of CSF proteins is mainly caused by the activity of amylase abzymes. One cannot exclude, that amylase abzymes of CSF can play a, as yet unknown, role in the pathogenesis of MS. Some possible reasons of these findings are discussed.

Antibodies from the sera of HIV-infected patients efficiently hydrolyze all human histones

Histones and their post-translational modifications have key roles in chromatin remodeling and gene transcription. Besides intranuclear functions, histones act as damage-associated molecular pattern molecules when they are released into the extracellular space. Administration of exogenous histones to animals leads to systemic inflammatory and toxic responses through activating Toll-like receptors and inflammasome pathways. Here, using ELISA it was shown that sera of HIV-infected patients and healthy donors contain autoantibodies against histones. Autoantibodies with enzymic activities (abzymes) are a distinctive feature of autoimmune diseases. It was interesting whether antibodies from sera of HIV-infected patients can hydrolyze human histones. Electrophoretically and immunologically homogeneous IgGs were isolated from sera of HIV-infected patients by chromatography on several affinity sorbents. We present first evidence showing that 100% of IgGs purified from the sera of 32 HIV-infected patients efficiently hydrolyze from one to five human histones. Several rigid criteria have been applied to show that the histone-hydrolyzing activity is an intrinsic property of IgGs of HIV-infected patients. The relative efficiency of hydrolysis of histones (H1, H2a, H2b, H3, and H4) significantly varied for IgGs of different patients. IgGs from the sera of 40% of healthy donors also hydrolyze histones but with an average efficiency approximately 16-fold lower than that of HIV-infected patients. Similar to proteolytic abzymes from the sera of patients with several autoimmune diseases, histone-hydrolyzing IgGs from HIV-infected patients were inhibited by specific inhibitors of serine and of metal-dependent proteases, but an unexpected significant inhibition of the activity by specific inhibitor of thiol-like proteases was also observed. Because IgGs can efficiently hydrolyze histones, a negative role of abzymes in development of acquired immune deficiency syndrome cannot be excluded. Copyright © 2016 John Wiley & Sons, Ltd.

Features of hydrolysis of specific and nonspecific globular proteins and oligopeptides by antibodies against viral integrase from blood of HIV-infected patients

It was shown previously that, as differentiated from canonical proteases, abzymes against myelin basic protein (MBP) from blood of patients with multiple sclerosis and systemic lupus erythematosus effectively cleaved only MBP, while antibodies (ABs) against integrase (IN) from blood of HIV-infected patients specifically hydrolyzed only IN. In this work, all sites of effective hydrolysis by anti-IN antibodies (IgG and IgM) of 25-mer oligopeptide (OP25) corresponding to MBP were identified using reversed-phase and thin-layer chromatographies and MALDI mass spectrometry. It was found that amino acid sequences of OP25 and other oligopeptides hydrolyzed by anti-MBP abzymes were partially homologous to some fragments of the full sequence of IN. Sequences of IN oligopeptides cleavable by anti-IN abzymes were homologous to some fragments of MBP, but anti-MBP abzymes could not effectively hydrolyze OPs corresponding to IN. The common features of the cleavage sites of OP25 and other oligopeptides hydrolyzed by anti-MBP and anti-IN abzymes were revealed. The literature data on hydrolysis of specific and nonspecific proteins and oligopeptides by abzymes against different protein antigens were analyzed. Overall, the literature data suggest that short OPs, including OP25, mainly interact with light chains of polyclonal ABs, which had lower affinity and specificity to the substrate than intact ABs. However, it seems that anti-IN ABs are the only one example of abzymes capable of hydrolyzing various oligopeptides with high efficiency (within some hours but not days). Possible reasons for the efficient hydrolysis of foreign oligopeptides by anti-IN abzymes from HIV-infected patients are discussed.

Changes in different parameters, lymphocyte proliferation and hematopoietic progenitor colony formation in EAE mice treated with myelin oligodendrocyte glycoprotein

Myelin oligodendrocyte glycoprotein (MOG) is an antigen of the myelin sheath, which may trigger immune cell responses and the production of auto-antibodies in multiple sclerosis (MS). In this study, we used MOG(35-55) -induced experimental autoimmune encephalomyelitis (EAE), a model of human MS, to assess the production of catalytically active immunoglobulin G (IgG) antibodies or abzymes which have been shown to be present in sera of patients with several autoimmune diseases. Here, we show that IgGs from the sera of control C57BL/6 mice are catalytically inactive. During development of EAE, a specific reorganization of the immune system of mice occurred leading to a condition which was associated with the generation of catalytically active IgGs hydrolysing DNA, myelin basic protein (MBP) and MOG which was associated with increased proteinuria, changes in differentiation of mice bone marrow hematopoietic stem cells (HSCs) and an increase in proliferation of lymphocytes in bone marrow, spleen and thymus as well as a significant suppression of cell apoptosis in these organs. The strongest alterations were found in the early disease phase (18-24 days after immunization) and were less pronounced in later EAE stages (40 days after EAE induction). We conclude that a significant increase in DNase and proteolytic activities of antibodies may be considered the earliest statistically significant marker of MOG-induced EAE in mice. The possible differences in immune system reorganizations during preclinical phases of the disease, acute and late EAE, leading to production of different auto-antibodies and abzymes as well other changes are discussed.

IgG abzymes with peroxidase and oxidoreductase activities from the sera of healthy humans

We present the evidence showing that small fractions of electrophoretically homogeneous immunoglobulin G (IgGs) from the sera of healthy humans and their Fab and F(ab)2 fragments oxidize 3,3'-diaminobenzidine through a peroxidase activity in the presence of H2 O2 and through an oxidoreductase activity in the absence of H2 O2 . During purification on protein G-Sepharose and gel filtration, the polyclonal IgGs partially lose the Me(2+) ions. After extensive dialysis of purified Abs against agents chelating metal ions, the relative peroxidase activity decreased dependently of IgG analyzed from 100 to ~10-85%, while oxidoreductase activity from 100 to 14-83%. Addition of external metal ions to dialyzed and non-dialyzed IgGs leads to a significant increase in their activity. Chromatography of the IgGs on Chelex non-charged with Cu(2+) ions results in the adsorption of a small IgG fraction bound with metal ions (~5%), while Chelex charged with Cu(2+) ions bind additionally ~38% of the total IgGs. Separation of Abs on both sorbents results in IgG separation to many different subfractions demonstrating various affinities to the chelating resin and different levels of the specific oxidoreductase and peroxidase activities. In the presence of external Cu(2+) ions, the specific peroxidase activity of several IgG subfractions achieves 20-27 % as compared with horseradish peroxidase (HRP, taken for 100%). The oxidoreductase activity of these fractions is ~4-6-fold higher than that for HRP. Antioxidant enzymes such as superoxide dismutases, catalases, and glutathione peroxidases are known to represent critical defence mechanisms for preventing oxidative modifications of DNA, proteins, and lipids. Peroxidase and oxidoreductase activities of human IgGs could also play an important role in the protection of organisms from oxidative stress and toxic compounds.

Comparison of antibodies hydrolyzing myelin basic protein from the cerebrospinal fluid and serum of patients with multiple sclerosis

It was found that antibodies (Abs) against myelin basic protein (MBP) are the major components of the antibody response in multiple sclerosis (MS) patients. We have recently shown that IgGs from sera of MS patients are active in the hydrolysis of MBP. However, in literature there are no available data concerning possible MBP-hydrolyzing Abs in cerebrospinal fluid (CSF) of MS patients. We have shown that the average content of IgGs in their sera is about 195-fold higher than that in their CSF. Here we have compared, for the first time, the average content of lambda- and kappa-IgGs as well as IgGs of four different subclasses (IgG1-IgG4) in CSF and sera of MS patients. The average relative content of lambda-IgGs and kappa -IgGs in the case of CSFs (8.0 and 92.0%) and sera (12.3 and 87.7%) are comparable, while IgG1, IgG2, IgG3, and IgG4: CSF - 40.4, 49.0, 8.2, and 2.5% of total IgGs, respectively and the sera - 53.6, 36.0, 5.6, and 4.8%, decreased in different order. Electrophoretically and immunologically homogeneous IgGs were obtained by sequential affinity chromatography of the CSF proteins on protein G-Sepharose and FPLC gel filtration. We present first evidence showing that IgGs from CSF efficiently hydrolyze MBP and that their average specific catalytic activity is unpredictably ∼54-fold higher than that of Abs from sera of the same MS patients. Some possible reasons of these findings are discussed. We suggest that anti-MBP abzymes of CSF may promote important neuropathologic mechanisms in this chronic inflammatory disorder and in MS pathogenesis development.

Why specific anti-integrase antibodies from HIV-infected patients can efficiently hydrolyze 21-mer oligopeptide corresponding to antigenic determinant of human myelin basic protein

Human immunodeficiency virus-infected patients possess anti-integrase (IN) catalytic IgGs and IgMs (abzymes), which, unlike canonical proteases, specifically hydrolyze only intact globular IN. Anti-myelin MBP abzymes from patients with multiple sclerosis and systemic lupus erythematosus efficiently hydrolyze only intact MBP. Anti-MBP and anti-IN abzymes do not hydrolyze several other tested control globular proteins. Here, we show that anti-IN abzymes efficiently hydrolyze a 21-mer oligopeptide (OP21) corresponding to one antigenic determinant (AGD) of MBP, whereas anti-MBP abzymes extremely poorly cleave oligopeptides corresponding to AGDs of IN. All sites of IgG-mediated and IgM-mediated proteolysis of OP21 by anti-IN abzymes were found for the first time by a combination of reverse phase and thin layer chromatography and mass spectrometry. Several clustered sites of OP21 cleavage were revealed and compared with the cleavage sites within the complete IN. Several fragments of OP21 had good homology with many fragments of the IN sequence. The active sites of anti-IN abzymes are known to be located on their light chains, whereas heavy chains are responsible for the affinity for protein substrates. Interactions of intact IN with both light and heavy chains of the abzymes provide high affinity for IN and the specificity of its hydrolysis. Our data suggest that OP21 interacts mainly with the light chains of polyclonal anti-IN abzymes, which possess lower affinity and specificity for substrate. The hydrolysis of the non-cognate OP21 oligopeptide may be also less specific than the hydrolysis of the globular IN because in contrast to previously described serine protease-like abzymes against different proteins, anti-IN abzymes possess serine, thiol, acidic, and metal-dependent protease activities.

Physiological IgM class catalytic antibodies selective for transthyretin amyloid

Peptide bond-hydrolyzing catalytic antibodies (catabodies) could degrade toxic proteins, but acquired immunity principles have not provided evidence for beneficial catabodies. Transthyretin (TTR) forms misfolded β-sheet aggregates responsible for age-associated amyloidosis. We describe nucleophilic catabodies from healthy humans without amyloidosis that degraded misfolded TTR (misTTR) without reactivity to the physiological tetrameric TTR (phyTTR). IgM class B cell receptors specifically recognized the electrophilic analog of misTTR but not phyTTR. IgM but not IgG class antibodies hydrolyzed the particulate and soluble misTTR species. No misTTR-IgM binding was detected. The IgMs accounted for essentially all of the misTTR hydrolytic activity of unfractionated human serum. The IgMs did not degrade non-amyloidogenic, non-superantigenic proteins. Individual monoclonal IgMs (mIgMs) expressed variable misTTR hydrolytic rates and differing oligoreactivity directed to amyloid β peptide and microbial superantigen proteins. A subset of the mIgMs was monoreactive for misTTR. Excess misTTR was dissolved by a hydrolytic mIgM. The studies reveal a novel antibody property, the innate ability of IgMs to selectively degrade and dissolve toxic misTTR species as a first line immune function.

Comparison of DNA-hydrolyzing antibodies from the cerebrospinal fluid and serum of patients with multiple sclerosis

It was found that high-affinity anti-DNA antibodies were one of the major components of the intrathecal IgG response in multiple sclerosis (MS) patients [Williamson et al., PNAS, 2001]. Recently we have shown that IgGs from the sera of MS patients are active in the hydrolysis of DNA. Here we have shown, for the first time, that average concentration of total proteins (132-fold), total IgGs (194-fold) and anti-DNA antibodies (200-fold) in the sera is significantly higher than that in the cerebrospinal fluid (CSF) of fifteen MS patients. The relative activities of total protein from sera and CSFs varied remarkably from patient to patient. It was surprising that the specific DNase activity of the total protein of CSF reparations were 198-fold higher than the serum ones. Electrophoretically and immunologically homogeneous IgGs were obtained by sequential affinity chromatography of the CSF proteins on protein G-Sepharose and FPLC gel filtration. We present first evidence showing that IgGs from CSF not only bind but efficiently hydrolyze DNA and that average specific DNase activity of homogeneous antibodies from CSF is unpredictably ∼49-fold higher than that from the sera of the same MS patients. Some possible reasons of these findings are discussed. We suggest that DNase IgGs of CSF may promote important neuropathologic mechanisms in this chronic inflammatory disorder and MS pathogenesis development.

Metal-dependent amyloid β-degrading catalytic antibody construct

Catalytic antibodies (catabodies) that degrade target antigens rapidly are rare. We describe the metal-dependence of catabody construct 2E6, an engineered heterodimer of immunoglobulin light chain variable domains that hydrolyzes amyloid β peptides (Aβ) specifically. In addition to the electrophilic phosphonate inhibitor of serine proteases, the metal chelators ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthroline completely inhibited the hydrolysis of Aβ by catabody 2E6. Formation of catabody-electrophilic phosphonate inhibitor adducts was unaffected by EDTA, suggesting that the metal exerts a favorable effect on a catalytic step after the initial catabody nucleophilic attack on Aβ. The EDTA inactivated catabody failed to disaggregate fibrillar Aβ, indicating the functional importance of the Aβ hydrolytic activity. Treating the EDTA-inactivated catabody with Zn(2+) or Co(2+) restored the Aβ hydrolytic activity, and Zn(2+)-induced catabody conformational transitions were evident by fluorescence emission spectroscopy. The studies reveal the absolute catabody dependence on a metal cofactor.

Systemic lupus erythematosus: molecular cloning of several recombinant DNase monoclonal kappa light chains with different catalytic properties

An immunoglobulin light chain phagemid library derived from peripheral blood lymphocytes of three patients with systemic lupus erythematosus was used. Phage particles displaying DNA binding light chains were isolated by affinity chromatography on DNA-cellulose, and the fraction eluted by an acidic buffer (pH 2.6) was used for preparation of individual monoclonal light chains (MLChs, 28 kDa). Thirty three of 687 individual colonies obtained were randomly chosen for study of MLCh DNase activity. Nineteen of 33 clones contained MLChs with DNase activity. Four preparations of MLChs were expressed in Escherichia coli in soluble form, purified by metal chelating chromatography followed by gel filtration, and studied in detail. Detection of DNase activity after SDS-PAGE in a gel containing DNA demonstrated that the four MLChs are not contaminated by canonical DNases. The MLChs demonstrated one or two pH optima. They were inactive after the dialysis against ethylenediaminetetraacetic acid but could be activated by several externally added metal ions; the ratio of relative activity in the presence of Mg(2+) , Mn(2+) , Ni(2+) , Ca(2+) , Zn(2+) , and Co(2+) was individual for each MLCh preparation. K(+) and Na(+) inhibited the DNase activity of various MLChs at different concentrations. Hydrolysis of DNA by all four MLCh was saturable and consistent with Michaelis-Menten kinetics. These clones are the first examples of recombinant MLChs possessing high affinity for DNA (Km  = 3-9 nM) and demonstrating high kcat values (3.4-6.9 min(-1) ). These observations suggest that the systemic lupus erythematosus light chain repertoire can serve as a source of new types of DNases.

Multiple sites of the cleavage of 21- and 25-mer encephalytogenic oligopeptides corresponding to human myelin basic protein (MBP) by specific anti-MBP antibodies from patients with systemic lupus erythematosus

IgGs from patients with multiple sclerosis and systemic lupus erythematosus (SLE) purified on MBP-Sepharose in contrast to canonical proteases hydrolyze effectively only myelin basic protein (MBP), but not many other tested proteins. Here we have shown for the first time that anti-MBP SLE IgGs hydrolyze nonspecific tri- and tetrapeptides with an extreme low efficiency and cannot effectively hydrolyze longer 20-mer nonspecific oligopeptides corresponding to antigenic determinants (AGDs) of HIV-1 integrase. At the same time, anti-MBP SLE IgGs efficiently hydrolyze oligopeptides corresponding to AGDs of MBP. All sites of IgG-mediated proteolysis of 21-and 25-mer encephalytogenic oligopeptides corresponding to two known AGDs of MBP were found by a combination of reverse-phase chromatography, TLC, and MALDI spectrometry. Several clustered major, moderate, and minor sites of cleavage were revealed in the case of 21- and 25-mer oligopeptides. The active sites of anti-MBP abzymes are localised on their light chains, while heavy chains are responsible for the affinity of protein substrates. Interactions of intact globular proteins with both light and heavy chains of abzymes provide high affinity to MBP and specificity of this protein hydrolysis. The affinity of anti-MBP abzymes for intact MBP is approximately 1000-fold higher than for the oligopeptides. The data suggest that all oligopeptides interact mainly with the light chains of different monoclonal abzymes of total pool of IgGs, which possesses a lower affinity for substrates, and therefore, depending on the oligopeptide sequences, their hydrolysis may be less specific than globular protein and can occur in several sites.