RESUMO Esta pesquisa avaliou a dinâmica dos leucócitos e das subpopulações de linfócitos em vacas Holandesas soropositivas para o BLV no período de transição. Amostras de sangue (n=72) provenientes de 12 vacas foram coletadas entre as semanas -2 e +3 para a realização do leucograma, imunofenotipagem, dosagem de cortisol e haptoglobina (Hp). O perfil leucocitário foi caracterizado por leucocitose, neutrofilia, monocitose e eosinopenia próximo ao parto. Linfocitose e elevada proporção de linfócitos B CD21+ foram achados constantes entre as semanas -2 e +3; assim, as vacas foram testadas e confirmadas soropositivas para o BLV. Os valores das subpopulações de linfócitos T apresentaram-se baixos durante o período de transição, observando-se dois picos máximos que coincidiram com as elevações nas concentrações de cortisol no parto (2,11µg/dL) e semana +3 (1,97µg/dL). Hp apresentou aumento crescente de -2 (166µg/mL) a +3 (576µg/mL), provavelmente associada à elevada taxa de infecções uterinas observadas nas semanas +2 e +3. As vacas soropositivas para o BLV apresentaram leucograma de estresse próximo ao parto, exceto para linfócitos. A linfocitose e as elevadas proporções de células B CD21+, associadas com as baixas proporções de células T, podem ser indicativo de imunossupressão e predisposição aos processos inflamatórios no período pós-parto.

ABSTRACT This research evaluated the dynamics of leukocytes and lymphocytes subsets in seropositive Holstein cows for BLV during the transition period. Blood samples (n=72) from 12 cows were harvested from week -2 up to week +3 to perform leukogram, immunophenotyping, cortisol and haptoglobin (Hp). Leukocytes pattern was characterized by leukocytosis, neutrophilia, monocytosis and eosinopenia around calving. Lymphocytosis and high proportions of B cells CD21+ were a constant finding between week -2 and +3, thus cows were tested and confirmed seropositive for BLV. The values of T lymphocytes subsets were low during the transition period, observing two peaks that coincided with high levels of cortisol at delivery (2.11µg/dL) and week +3 (1.97µg/dL). Hp had gradual increase from week -2 (166µg/mL) until week +3 (576g/mL) probably due to high rate of uterine infection detected between week +2 and +3. The seropositive cows for BLV presented stress leukogram around delivery, except for lymphocytes. Lymphocytosis and the high proportions of B cells, associated with the low proportions of T lymphocytes, can be indicative of immunosuppression and predisposition to the inflammatory process observed in the post-partum period.

This article describes the presence of two new forms of a thrombin-like enzyme, both with apparent molecular masses of 38 kDa, in Bothrops atrox venom. Both share the ability to cleave fibrinogen into fibrin and to digest casein. Both present identical Km on the substrate BApNA. Their N-terminal amino acid sequences are identical for 26 residues, sharing 80% homology with batroxobin and flavoxobin. Two groups of monoclonal antibodies (mAbs) raised against the purified enzyme forms recognized different epitopes of the putative corresponding enzymes present in B. atrox crude venom. On Western blotting analysis of B. atrox crude venom, mAbs 5DB2C8, 5AA10 and 5CF11, but not mAbs 6CC5 and 6AD2-G5, revealed two or more protein bands ranging from 25 to 38 kDa. By immunoprecipitation assays, the 6AD2-G5 mAb was able to precipitate protein bands of 36-38 kDa from B. atrox, B. leucurus, B. pradoi, B. moojeni, B. jararaca and B. neuwiedii crude venoms. Fibrinogen-clotting activity was inhibited when the same venom specimens were pre-incubated with mAb 6AD2-G5, except for B. jararaca and B. neuwiedii.