Differential expression of pattern recognition receptors during the development of foetal sheep

Abstract

Pattern recognition receptors (PRRs) play a crucial role in the initiation of the adaptive immune response. Immunological competence of foetal lambs occurs progressively throughout gestation and in order to understand the role played by PRRs in foetal immunological competence we quantified transcript expression, in the skin and spleen, of the TLRs, key C-type lectins and CARD15 during the critical second trimester. These data show that lambs express the same spectrum of PRRs as the adult but that the level of expression for most is dependent on developmental age. Key findings include: TLR1 and TLR5 are expressed at high levels in the foetus but are low in the adult; in contrast TLR4, CD14 and CARD15 increase with age. In addition, TLR9 and TLR10 are expressed by the spleen and not the skin while CARD15 is low in the spleen and high in the skin Many thanks for the referees comments, they were very helpful. I am glad that they found the paper interesting, of value and worthy of publication, and that by-and-large, their concerns were relatively minor. In response to their specific comments:Referee #1: 1. The major concern is that the same data were published previously (reference 19). To some extent this is true -we have published sheep skin and spleen PRR transcript levels. However, the data in the two papers come from different animals. In this paper adult animals are specifically being compared with foetal animals -and the adult tissues come from yearling sheep of the same breed as the foetuses. Nevertheless, the data are similar. I think this is valid. Incidentally, reference 19 was in the original version -referring to both methods and adult expression levels. 2. I have improved our description of the source of tissues in the animals-adult tissue comes from exactly the same anatomical sites as foetal tissues. 3. I have further explained the statistics. Because there are so many variables, it would be easy to be utterly pedantic and compare every sample with every other sample. Although that has been done -and an examination of the error bars (standard deviations) in Figs 1 and 2 can give an assessment of significance -to explain it all in the text would be unacceptably tedious. I have focussed on interesting comparisonsespecially between foetal and adult samples. I hope this is satisfactory. If required I can give p values for every single comparison -which would be very boring. 4. I have added to the description of the spleen data. However, to generate a separate section comparing skin and spleen is, I think, unnecessary. I have made some comparisons between the two tissues but not in great detail as this is not the main thrust of the paper. Comparing skin with spleen in detail is not particularly informative or for that matter that valid. Mammalian neonates are known to have a reduced response to specific antigens and an increased susceptibility to bacterial infections and sepsis [7,8]. This increased susceptibility is more pronounced after premature birth where it causes significant morbidity and...

Ontogeny of the Immune Response in the Ovine Lung

“…However, they did not find statistical differences in the expression levels of TLR3 and TLR4 between 130 days gestation and newborn animals. The levels of TLRs in sheep skin and spleen have been reported previously (Nalubamba et al, 2008). Although newborn animals were not included in the study, it was reported that the levels of TLR7 and TLR8 in the spleen were significantly higher than that of pre-term lambs, and that the levels of TLR4 in the skin were higher than that of pre-term lambs (Nalubamba et al, 2008).…”

“…The levels of TLRs in sheep skin and spleen have been reported previously (Nalubamba et al, 2008). Although newborn animals were not included in the study, it was reported that the levels of TLR7 and TLR8 in the spleen were significantly higher than that of pre-term lambs, and that the levels of TLR4 in the skin were higher than that of pre-term lambs (Nalubamba et al, 2008). There were also no reported significant differences in TLR3 expression across age groups in the neonatal ovine skin or spleen.…”

“…1D). TLRs have also been reported to be differentially expressed during development in the ovine spleen and skin (Nalubamba et al, 2008). …”

Impact of Climate Change on the Relict Tropical Fish Fauna of Central Sahara: Threat for the Survival of Adrar Mountains Fishes, Mauritania

“…We therefore identified genes that were stable early time points where the majority of the cells are mononucleic and forming small myotubes (culture days, 2-11) those stable in established myotubes (days [11][12][13][14][15][16][17][18][19][20] and those most stable for the entire culture period. When the raw Cq values obtained at each time point are compared ( Figure 3), it is clear that for the majority of the genes examined, stable expression is observed once myotubes have become established in the culture, whereas higher intra and intergroup variation is observed when myotubes are developing.…”

“…The least stable gene identified by all analysis methods was Sdha. Sdha has been used as a reference gene in a number of studies using different tissues [18,19], however its high inter and intragroup variation make it unsuitable for normalisation in salmon myogenic cell cultures.…”