Electrophoretic and immunoelectrophoretic characteristics of IgG as a constituents of peg precipitable immune complexes in preruminant calves' sera

Abstract

Preruminant calves encounter numerous antigens, and formation of immune complexes is necessary for antigens elimination. The capability of immunologically immature calves to form immune complexes has not yet been studied in detail. For immune complexes studies, selective precipitation by PEG was performed, in combination with agarose gel electrophoresis and immunoelectrophoresis, with an aim to determine some properties of IgG, as constituents of immune complexes. In our previous work it was shown that the level of PEG precipitable immune complexes increased in the period from birth to 48-hours of life, decreased at day 10, increased in one month old animals, and after that, stayed unchanged until 4th month of age. Electrophoretic and immunoelectrophoretic analysis showed that until one month of age, calves' sera and PEG precipitates contained only one part of IgG molecules which corresponded to fast, anionic γ globulins. Although at the age of one month, preruminant calves' sera contained all molecular forms of IgG molecules present in the sera of adult cattle, only one part of serum IgG (fast, anionic IgG) was precipitated by PEG. In older calves, all molecular forms of serum IgG had the capacity to form PEG precipitable immune complexes. Presented data, as well as the results of our previous work, can be used as parameters with reference to physicochemical and immunochemical characteristics of IgG immune complexes of preruminant calves under pathological conditions.

Telad od rođenja dolazi u kontakt sa velikim brojem antigena za čije je efikasno uklanjanje neophodno formiranje imunokompleksa. Sposobnost ovih, još uvek imunološki nezrelih, životinja da formiraju iminokomplekse, kao i sastav njihovih konstituenata, nisu detaljno ispitivani. U ovom radu smo imunokomplekse iz seruma teladi izolovali precipitacijom polietilen glikolom (PEGom), a osobine IgG, kao potencijalnih konstituenata imunokompleksa, analizirali metodama elektroforeze i imunoelektroforeze. U našem prethodnom radu dokazali smo da se nivo PEG precipitabilnih imunokompleksa menja sa uzrastom teladi. On raste od rođenja do 48. sata, opada desetog dana, ponovo raste u prvom mesecu, nakon čega ostaje nepromenjen do četvrtog meseca starosti. Elekroforetske i imunoelektroforetske analize su ukazale da se u serumu i PEG precipitatima seruma teladi do mesec dana starosti nalazi samo jedna molekulska frakcija IgG koja odgovara brzim, anjonskim IgG. Iako se u serumima teladi već u prvom mesecu starosti nalaze sve molekulske forme IgG koje se nalaze i u serumu odraslih krava, samo jedan njihov deo (brzi, anjonski γ globulini) ima sposobnost da formira imune komplekse. Kod starijih teladi, kao i kod odraslih krava, sve molekulske forme serumskih IgG mogu da formiraju imune komplekse. Ovi rezultati, zajedno sa rezultatima našeg predhodnog rada, se mogu koristiti za dobijanje referentnog sistema vrednosti nivoa i sastava imunokompleksa kod zdravih teladi, a koji bi se mogao koristiti za određivanje nivoa i sastava imunokompleksa kod teladi u patološkim uslovima.