Moreover, we have found neither DNase nor ATPase Abzs in healthy mice, but the amylase activity in young mice, including the control non-AI mice, was detectable (Table 1). of mice bone marrow haematopoietic stem cells (HSCs) and lymphocyte proliferation in different organs.The highest increase in all abzyme activities was found in mice immunized with DNA, which in comparison with pre-diseased and diseased mice are characterized by a different profile of HSC differentiation and by a suppression of cell apoptosis. Abzyme activities in the serum of pregnant females were comparable with those for pre-diseased mice, but the profile of HSC differentiation and cell apoptosis levels in pregnant and pre-diseased mice were quite different. Right after the beginning of lactation (4 days after delivery) and in a late time of lactation (14 days after delivery) there was an observed increase in cell apoptosis and two different stages of significant change in the HSC differentiation profiles; the first stage was accompanied with a significant increase and the second with a remarkable decrease in abzyme activities. Overall, all mouse groups investigated are characterized by a specific relationship between abzyme activities, HSC differentiation profiles, levels of lymphocyte proliferation, and cell apoptosis in different organs. From our point of view, the appearance of ATPase, DNase activities may be considered the earliest statistically KISS1R antibody significant marker of mouse spontaneous SLE and a further significant increase in their activities correlates with the appearance of SLE visible markers and with an increase in concentrations of anti-DNA Abs and urine protein. However, development of autoimmune (AI)-reactions and the increase Almitrine mesylate in the sera anti-DNA antibodies (Abs) and in the abzyme activities in pregnant and lactating mice do not associate with SLE visible markers and proteinuria. The possible differences in immune system reorganizations during pre-disease, disease, pregnancy and lactation leading to production of different auto-antibodies and abzymes are discussed. Keywords:autoimmune-prone MRL-lpr/lpr mice, catalytic antibodies, colony formation of haematopoietic progenitors == Introduction == Antibodies (Abs) against transition states of reactions and natural abzymes (Abzs) catalysing more than 100 distinct chemical reactions are novel biological catalysts that attracted much interest in the last years [15]. Natural catalytic Abzs hydrolyzing DNA, RNA, polysaccharides, oligopeptides, and proteins exist in the sera of patients with many autoimmune (AI) and viral diseases [25] Abzs hydrolyzing some proteins were found not only in the organisms of AI patients, but also in norm [67] and in patients with diseases like sepsis, which causes many deaths in intensive care units and results from a deleterious systemic host response to infection [8]. Ab amylase activity in healthy donors was 40100-fold lower than in AI patients [911]. Healthy humans can develop Abzs with low DNase and RNase activities, their levels usually on a borderline of the sensitivity of detection methods [25, 1216]. In addition, there was no confirmed nuclease Abzs in the sera of patients with many Almitrine mesylate different diseases with insignificant AI reactions [25, 1314]. Although Abzs with low activity can sometimes be detected in healthy people, the enzymic relative activity (RAs) of AI patients are usually significantly higher and from our point of view different Abzs can present a convenient diagnostic marker of some AI pathologies [25]. We have shown that appearance of Abzs specific for various substrates is among the earliest and clear signs of AI reactions in a number of AI diseases (systemic lupus Almitrine mesylate erythematosus (SLE),Hashimoto’s thyroiditis, polyarthritis, multiple sclerosis) and viral diseases with strong immune system disturbances (AIDS, hepatitis) [25]. According to our data, catalytic activity of nuclease Abzs is usually very easily detectable at the beginning of AI diseases when concentrations of Abs to DNA or other auto-antigens are not yet increased significantly and correspond to their ranges for healthy donors [25]. Anti-VIP Abzs of patients with asthma are cyto-toxic. Since mice immunized with these IgGs develop asthma, they can have an important effect in pathogenesis decreasing concentrations of VIP, which plays a.