Binding of Fc receptors on blood T and B cells with IgG from healthy cows and cows with chronic lympholeukemia.

Pure population of T and B cells was obtained by a combined method consisting in lymphocyte fractionation through Nylon wool and precipitation of E-rosettes in 17% Verograffin density gradient. Scatchard analysis showed that T and B cells isolated from the blood of healthy cattle bind similar quantities of IgG molecules. Binding of IgG to Fc receptors of T and B cell isolated from animals with chronic lympholeukemia increases. The expression of Fc receptors for IgG is changed in cattle with chronic lympholeukemia.

[The effect of gamma-interferon and phorbol myristate acetate on the Fc gamma-receptor ligand-binding capacity and on the target-conjugating and antibody-dependent cytotoxic activity of blood lymphocytes]. / Vliianie gamma-interferona i forbolomeristicheskogo atsetata na sviazyvaiushchuiu sposobnost' Fc gamma-retseptora s ligandom, mishen'kon''iugiruiushchuiu i antitelozavisimuiu tsitotoksicheskuiu aktivnost' limfotsitov krovi.

We investigated the ability of gamma-interferon (IFN-gamma) and phorbol 12-myristate 13-acetate (PMA) to influence the ligand-binding of Fc-receptors for immunoglobulin G (Fc gamma R) (conjugation of IgG to fluorescein izothiocyanate--FITC) of bovine blood lymphocytes and the antibody-dependent cell-mediated cytotoxic activity (ADCC). The results demonstrate that the IFN-gamma or PMA induced augmentation of ligand-binding capacity of Fc gamma R of bovine lymphocytes, and correlated well with the enhanced capacity to lyse L cells coated with anti-L cell antibody. The number of conjugates effector--target, formed by bovine lymphocytes in the reaction of ADCC, correlates well with ligand-binding capacity of Fc gamma R. It can be suggested that IFN-gamma or PMA may control the ADCC caused by Fc gamma R regulating its expression.

[The determination of microalbuminuria by immunoenzyme analysis]. / Opredelenie mikroal'buminurii metodom immunofermentnogo analiza.

The authors have defined the optimal conditions for inhibitory type enzyme immunoassay of microalbuminuria. The range of albumin detection is 30 to 250 micrograms/ml. The optimal time of antigen binding with antibody is 45 min, the lower threshold level of albumin detection 0.6 +/- 0.02 microgram/ml. Albumin concentration is unchanged after urine storage for 8 weeks at -20 degrees C or for 1 week at 4 degrees C.

Quantitative studies of Fc receptors on bovine leukemic blood lymphocytes: characterization by binding of homologous IgG1 and IgG2.

Receptors for IgG1 and IgG2 (FcR) on peripheral blood lymphocytes from cows with chronic lymphocytic leukemia (CLL) were detected by their ability to bind homologous IgG1 and IgG2 in fluorometric binding assay. Scatchard plots at 4 degrees C demonstrated that IgG1 bound the same number of FcR per cell (3.12 +/- 0.69 X 10(5)) as IgG2 (2.89 +/- 0.69 X 10(5)). The receptors bound IgG2 with an affinity of 4.09 +/- 1.08 X 10(5) 1/M and IgG1 with an affinity of 2.73 +/- 0.55 X 10(5) 1/M, although the difference was not of statistical significance (0.1 greater than P greater than 0.05). Inhibition studies demonstrated that the two ligands could inhibit each other. It might be assumed that FcR for the two subclasses were identical.