[Characterization of B1-cells during experimental leukomogenesis.]

BACKGROUND: Bovine leukemia causes a significant polyclonal expansion of CD5+, IgM+ B lymphocytes, known as persistent lymphocytosis (PL), in approximately 30% of infected cattle. However, it is not yet clear what happens to this subpopulation of B cells in the early period of infection of animals. PURPOSE: Quantitative characterization of IgM+ and CD5+ B cells during the immune response, which can provide important information on the mechanisms of lymphocyte priming in BLV infection. MATERIAL AND METHODS: The experiment used BLV-negative calves of black-motley breed at the age of 8 months (n = 11). Animals (n = 8) were intravenously injected with blood of a BLV-positive cow. Control calves (n = 3) were injected with saline. Studies were performed before and after infection on days 5, 7, 14, 21, 28 and 65 of the immune response. The determination of the number of B-lymphocytes in the blood was carried out by the method of immunoperoxidase staining based on monoclonal antibodies to IgM, CD5. RESULTS: As a result of the studies, it was found that the level of CD5+ B cells increases on the 14th day of the primary immune response, characterized by polyclonal proliferation of CD5+ B cells, which are the primary target for BLV. Our research data confirm that in the lymphocytes of experimentally infected cattle, surface aggregation of IgM and CD5 molecules on B-lymphocytes is absent. DISCUSSION: It is known that the wave-like nature of IgM synthesis, which was shown in previous studies, depends on a subpopulation of B1 cells. After 7 days of the immune response, IgM+ and CD5+ cells do not correlate, which shows their functional difference. The increase in CD5+ cells is probably not associated with B cells, but with T cells differentiating under the influence of the virus. CONCLUSIONS: A subset of B1 cells is the primary target of cattle leukemia virus. The 65th day of the immune response is characterized by the expansion of IgM+ B cells, a decrease in the number of CD5+ cells and a uniform distribution of receptors around the perimeter of the cells.

[Detection of specific antibodies of classes G and M to bovine leukemia virus in the blood serum.]

INTRODUCTION: Bovine leukemia is a widespread infection worldwide, the causative agent of which is the bovine leukemia virus (BLV) in structural structure and functional features similar to human T-cell leukemia virus (HTLV-1 and HTLV-2) and It is considered as an actual medical and social problem. The study of the immune response in experimentally infected calves at an early stage of the disease development, synthesis of specific antibodies of classes G and M (IgG and IgM), diagnostic informativeness of detection of IgM in cattle leukemia is relevant and determines the purpose of this study. MATERIAL AND METHODS: Samples of blood and serum of cattle: animals experimentally infected with VLCRS, patients with cattle leukemia; control negative; specific to heterologous pathogens of cattle diseases. Indirect and sandwich variant enzyme-linked immunosorbent assay (ELISA); commercial ELISA kits (IDEXX, USA; Hema LLC, FKP Kursk Biofactory Firm BIOK, Russia) for the detection of specific IgG and IgM for BLV in the agar gel immunodiffusion reaction (RID). RESULTS: The humoral immune response develops shortly after infection - by 1-8 weeks. IgM are detected starting from the 3rd day, and IgG from the 7th day after infection. Up to 97% of coincidence of positive results in RID and indirect variant of TF ELISA based on monoclonal antibodies to cattle IgM (IgMbovine) were found. DISCUSSION: The dynamics of the synthesis of antibodies of classes M and G to the glycoprotein gp 51 BLV has a dosedependent wave-like character, is consistent with the levels of increase / decrease in the absolute and relative number of leukocytes / blood lymphocytes of infected calves. FINDINGS: Serum specific IgM was detected starting 3 days after infection with BLV. Early detection of IgM in serum of cattle can be used as an additional test for the detection of sick animals.