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Titolo:
Opsonization of yeast cells with equine iC3b, C3b, and IgG
Autore:
Grondahl, G; Johannisson, A; Jensen-Waern, M; Ekdahl, KN;
Indirizzi:
Swedish Univ Agr Sci, Dept Large Anim Clin Sci, S-75007 Uppsala, Sweden Swedish Univ Agr Sci Uppsala Sweden S-75007 Sci, S-75007 Uppsala, Sweden Swedish Univ Agr Sci, Dept Anat & Histol, S-75007 Uppsala, Sweden Swedish Univ Agr Sci Uppsala Sweden S-75007 tol, S-75007 Uppsala, Sweden Univ Hosp, Dept Clin Immunol & Transfus Med, Uppsala, Sweden Univ Hosp Uppsala Sweden t Clin Immunol & Transfus Med, Uppsala, Sweden Univ Kalmar, Dept Chem & Biomed Sci, Kalmar, Sweden Univ Kalmar Kalmar Sweden almar, Dept Chem & Biomed Sci, Kalmar, Sweden
Titolo Testata:
VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY
fascicolo: 3-4, volume: 80, anno: 2001,
pagine: 209 - 223
SICI:
0165-2427(20010810)80:3-4<209:OOYCWE>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
ALTERNATIVE COMPLEMENT PATHWAY; CRYPTOCOCCUS-NEOFORMANS; ACTIVATION; SYSTEM; PHAGOCYTOSIS; ANTIBODIES; SURFACE; PLASMA; C-3; PURIFICATION;
Keywords:
opsonization; phagocytosis; neutrophil; complement; C3; C3b; iC3b; IgG; equine; flow cytometry; SDS-PAGE; western blot;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
32
Recensione:
Indirizzi per estratti:
Indirizzo: Grondahl, G Swedish Univ Agr Sci, Dept Large Anim Clin Sci, POB 7018, S-75007 Uppsala,Sweden Swedish Univ Agr Sci POB 7018 Uppsala Sweden S-75007 a,Sweden
Citazione:
G. Grondahl et al., "Opsonization of yeast cells with equine iC3b, C3b, and IgG", VET IMMUNOL, 80(3-4), 2001, pp. 209-223

Abstract

The main opsonins in serum are antibodies and complement factor C3. The opsonization mechanisms including complement activation and deposition are important in studies of phagocytosis and of mechanisms of microbial immune evasion. The objective of the present study was to monitor the deposition of complement C3 and IgG from equine serum on yeast cells (Saccharomyces cerevisiae) using a flow cytometric immunoassay. Correlations were made between the opsonic coating and phagocytic capacity using equine blood neutrophils. In addition, the bound C3 fragments were characterized by SDS-PAGE and Western blot analyses. Opsonic coating of yeast with equine C3 and IgG occurred rapidly with detectable levels with as little as 0.75% serum. C3 deposition was a result of complement activation and no passive adsorption was observed. When complement was inactivated, the fluorescence indicating IgG deposition increased 3-6-fold, indicating spatial competition between C3 and IgG at binding. Opsonization with 1.5% serum led to suboptimal equine neutrophil phagocytosis ofyeast cells which was dependent on complement activation by the classical pathway. With greater than or equal to6.25% serum, IgG contributed to opsonization and phagocytosis. With 50% serum and more, C3 was deposited also bythe alternative pathway. Phagocytosis rates became optimal with 3% serum, and did not increase further with higher serum concentrations. The main form of C3 on the yeast cells was iC3b and the rest was C3b without any detectable breakdown products (C3c or C3dg). The equine complement components aresimilar in size to the human equivalents. It may be concluded that opsonization of yeast particles leading to phagocytosis, occurs at very low serum concentrations (1.5%) and that it is dependent on activation of the classical complement pathway at this low opsonic level. This is an important finding for efficient host defense, e.g. extravascular phagocytosis at infection sites. (C) 2001 Elsevier Science B.V. Allrights reserved.

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Documento generato il 27/09/20 alle ore 07:14:31