Type I interferon receptors and interferon-τ-stimulated genes in peripheral blood mononuclear cells and polymorphonuclear leucocytes during early pregnancy in beef heifers

Abstract

This study characterised the expression of interferon (IFN)-τ-stimulated genes (ISGs) and Type I IFN receptors in circulating polymorphonuclear cells (PMNs) of beef heifers and compared it with expression in peripheral blood mononuclear cells (PBMCs) up to Day 20 of gestation. Nelore heifers (n=26) were subjected to fixed-time AI (FTAI) on Day 0. PMNs and PBMCs were isolated on Days 0, 10, 14, 16, 18 and 20 after FTAI. The abundance of target transcripts (ubiquitin-like protein (ISG15), 2′-5′-oligoadenylate synthetase 1 (OAS1), myxovirus resistance 1 (MX1), myxovirus resistance 2 (MX2), IFN receptor I (IFNAR1) and IFN receptor 2 (IFNAR2)) was determined using real-time quantitative polymerase chain reaction and compared between pregnant (n=8) and non-pregnant (n=9) females. In both PBMCs and PMNs, ISG15 and OAS1 expression was greater in pregnant than non-pregnant heifers on Days 18 and 20. There were no significant differences in the expression of ISGs between PBMCs and PMNs. A time effect on expression was found for IFNAR1 in PBMCs and IFNAR2 in PMNs, with decreased expression of both genes on Days 18 and 20. When the expression of these genes was compared between cell types only in pregnant heifers, IFNAR2 expression in PMNs had an earlier decrease when compared to its expression in PBMCs, starting from Day 18. In conclusion, PMNs do not respond earlier to the conceptus stimulus, and ISG15 and OAS1 expression in both PMNs and PBMCs can be used as a suitable marker for pregnancy diagnosis on Days 18 and 20. In addition, gestational status did not affect IFNAR1 and IFNAR2 expression, but IFNAR2 showed a distinct response between PMNs and PBMCs of pregnant heifers.

New approaches to diagnose and target reproductive failure in cattle

“…Several authors, however, have proposed expression of ISG in peripheral blood leukocytes as a possible tool for early pregnancy diagnosis in ruminants ( Green et al., 2010 ; Pugliesi et al., 2014 ). This technique has been validated in total leukocytes ( Han et al., 2006 ; Stevenson et al., 2007 ; Green et al., 2010 ), peripheral blood mononuclear cells ( Gifford et al., 2007 ; Pugliesi et al., 2014 ; Melo et al., 2020b ) and peripheral blood polymorphonuclear cells ( Kizaki et al., 2013 ; Yoshino et al., 2018 ; Melo et al., 2020a ). In general, significant differences between pregnant and non-pregnant females were found between days 18 and 20 of gestation, with accuracy of positive pregnancy diagnosis ranging from 70 to 90% in beef ( Pugliesi et al., 2014 ; Melo et al., 2020a ) and dairy herds ( Yoshino et al., 2018 ).…”

Comparison of the Ability of High and Low Virulence Strains of Non-cytopathic Bovine Viral Diarrhea Virus-1 to Modulate Expression of Interferon Tau Stimulated Genes in Bovine Endometrium

“…They then showed that measurement of ISG15 mRNA could provide a reliable indicator of early pregnancy on day 18 of gestation in heifers but not in mature cows (81). These findings have since been confirmed in beef breeds using both polymorphonuclear neutrophils and peripheral blood mononuclear cells (82,83) and extending to a number of other ISGs (84). Although the results of ISG15 up-regulation in early pregnancy were highly repeatable between studies, de Melo et al (85) found that ISG15 measurement was less reliable for confirmation of pregnancy than the use of circulating pregnancy-associated glycoprotein or Doppler ultrasound.…”

Conceptus-modulated innate immune function during early pregnancy in ruminants: a review

“…The expression of classic ISG in immune cells has been well studied in ruminants (Yankey et al, 2001;Hyungchul et al, 2006;Gifford et al, 2007). Independently of the cellular type, peripheral blood mononuclear cells (PBMC) or polymorphonuclear cells (PMN), the expression profile is similar with IFN-τ secretion by the trophoblast cells (Shirasuna et al, 2012;Kizaki et al, 2013;Pugliesi et al, 2014;Melo et al, 2020a). In cattle, after ISG expression reaches a peak on day 20 of pregnancy, a decrease to basal levels is observed near day 25 (Hyungchul et al, 2006;Gifford et al, 2007;Shirasuna et al, 2012;Pugliesi et al, 2014).…”