Reactivity of phagocytic cells during lactation of dairy cows: their implication on the establishment of pregnancy

PERALTA, M.B.; CAINELLI S.; ANGELI, E.; STASSI AF; SALVETTI, N.R.; ORTEGA, H.H.; REY, F.; VELAZQUEZ M.M.L.

Congreso; LXVII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI); 2019

SOCIEDAD ARGENTINA DE INMUNOLOGÍA (SAI)

The cytokines of the interleukin-1 family are closely involved in processes such as resolution of uterine inflammation and are locally produced by macrophages and endometrial cells under stimuli. However, little is known about the role of these cytokines in the absence of disease during postpartum period where conception and pregnancy occur in cattle. The aim of this study was to analyze the gene and protein expression levels of the members of IL-1 family: IL-1α, IL-1β, IL-1RI, IL-1RII and IL-1RA during postpartum period, and their possible association with delayed conception.Endometrial biopsies were obtained from multiparous Holstein cows (n=16) at 45 and 60 days in milk (DIM). All procedures were approved by the Ethics Committee (FCV-UNL). The gene expression of IL-1α, IL-1β, IL-1RI, IL-1RII and IL-1RA was analyzed by real-time PCR. The immunolocalization of the cytokines was assessed by indirect immunohistochemistry.Kaplan?Meier test was used to evaluate the possible association between the gene and protein levels of each cytokine and delayed conception. Then, when the results from Kaplan-Meier showed significant association, we grouped the animals like ?fewer number of days to conception? (FDC) and ?greater number of days to conception? (GDC) for comparison. To analyze the differential expression levels over time in FDC and GDC groups, a Generalized Linear Model was used considering DIM as a fixed factor. The gene expression of all members of IL-1 family showed no significant association with delayed conception. However, the association between the protein expression of IL-1β and IL-1RA in glandular epithelium (GE) and delayed conception was significant. Then, the GLM showed no significant differences in GE between 45 and 60 DIM, both in the FDC and GDC group. These results suggest a potential role of some members from IL-1 family, as IL-1β and IL-1RA, in the mechanisms involved to early conception.