Tese
Efeitos do parapoxvirus ovis inativado sobre eventos da resposta imune inata em camundongos
Fecha
2013-11-08Registro en:
ANZILIERO, Deniz. Effects of inactivated parapoxvirus ovis in events of the innate immune response in mice. 2013. 87 f. Tese (Doutorado em Medicina Veterinária) - Universidade Federal de Santa Maria, Santa Maria, 2013.
Autor
Anziliero, Deniz
Institución
Resumen
The immunostimulatory properties of inactivated parapoxvirus ovis (iPPVO) have been
investigated in different animal species and experimental settings. This study investigated the
effects of administration of iPPVO on selected events of the innate response in mice.
Neutrophil activation, phagocytic activity of macrophages, serum bactericidal activity,
induction and antiviral activity of interferon type I (IFN - I) and expression of several classes
of cytokines were assayed following intraperitoneal inoculation of Mus musculus with iPPVO
(107 TCID50). Serum from iPPVO-treated animals showed IFN-I activity against murine
encephalomyocarditis virus (EMCV) between 6 and 12 hours post infection (hpi), as shown
by plaque reduction. A significant activation of neutrophils at 6hpi was observed by NBT
reduction test in animals treated with the iPPVO. Peritoneal macrophages from mice treated
with iPPVO demonstrated a significant increase (p<0.01) in phagocytic activity against
Candida albicans both in vivo (between 12 and 96 hpi) and in vitro (24 and 72 hpi). iPPVO
treated mice showed increased serum bactericidal activity against Escherichia coli (p<0.05) at
two periods (24 and 72 hpi). A second study evaluated the expression of cytokines in response
to inoculation of iPPVO. For this, spleens and serum samples were collected from mice
treated with iPPVO at different intervals after inoculation and subjected to quantification of
messenger RNA (mRNA) by real time PCR (qRT-PCR) and detection/quantification of serum
cytokines by ELISA. Quantification of mRNA identified a significant and transient increase
in the expression of various cytokines, with variable magnitude and kinetics. mRNA
expression of proinflammatory cytokines (IL-1β, TNF-α and IL-8) peaked at 24 hpi (5.4 times
increase) and 48 hpi (3 and 10 times, respectively). A 15-fold increase in expression of INF-γ
and 6-fold for IL-12 was observed at 48 and 24 hpi, respectively. An increase in the
expression of self-regulatory cytokines (Th2) cells, especially IL-10 and IL-4 was detected at
later periods (72 and 96 hpi) with peaks of 4.7 and 4.9 fold, respectively. The determination
of the concentration of serum cytokines by ELISA showed an increase in IL-1β, TNF-α, IL-
12, IFN-γ and IL-10 with kinetics similar to that observed by qPCR, especially for IL-1 and
INF-γ. In summary, these results demonstrate that inoculation with iPPVO stimulates
transiently a number events associated with cellular and humoral innate immune responses. If
taken together, these effects would likely contribute for the enhanced resistance to certain
pathogens observed in animals treated with iPPVO.