Immunoglobulins as Biomarkers for Gastrointestinal Nematodes Resistance in Small Ruminants: A systematic review

The rise of anthelmintic resistance worldwide has led to the development of alternative control strategies for gastrointestinal nematodes (GIN) infections, which are one of the main constraints on the health of grazing small ruminants. Presently, breeding schemes rely mainly on fecal egg count (FEC) measurements on infected animals which are time-consuming and requires expertise in parasitology. Identifying and understanding the role of immunoglobulins in the mechanisms of resistance could provide a more efficient and sustainable method of identifying nematode-resistant animals for selection. In this study we review the findings on immunoglobulin response to GIN in the literature published to date (june 2019) and discuss the potential to use immunoglobulins as biomarkers. The literature review revealed 41 studies which measured at least one immunoglobulin: 35 focused on lamb immune response (18 used non-naive lambs) and 7 on yearlings. In this review we propose a conceptual model summarizing the role of immunoglobulins in resistance to GIN. We highlight the need for more carefully designed and documented studies to allow comparisons across different populations on the immunoglobulin response to GIN infection

Sarcostemma viminale activates macrophages to a pro-inflammatory phenotype

Sarcostemma viminale (L.) R.Br, also known as caustic or milk bush, is a semi-succulent plant commonly found in the North West of Australia. Local Aboriginal populations have long used the milky white sap from this plant to treat skin cancers. An ethanol extract from S. viminale was tested by exposing the RAW264.7 cell line as an in vitro murine macrophage model, to the extract. Flow cytometric analysis was performed to determine if S. viminale skewed macrophages towards a pro-inflammatory or anti-inflammatory phenotype using a number of cell surface markers. Cell culture supernatants were also analysed by cytometric bead array to determine if S. viminale exposed macrophages produced pro-inflammatory or anti-inflammatory cytokines. After exposure to S. viminale, a significantly greater number of macrophages expressed pro-inflammatory major histocompatibility complex (MHC) class II molecules and significantly greater expression levels of the dendritic cell marker CD11c. Cytometric bead array analysis found that S. viminale induced significant amounts of the potent pro-inflammatory cytokine tumour necrosis factor (TNF) from macrophages. The markers CD40 and ICAM-1 were expressed but were not significantly different from the controls. Also, significantly higher expression of CX3CR1 indicated that macrophages were preparing to migrate. No anti-inflammatory cytokines were produced. No significant production of NO2-, IL-6, IFN-? or IL-12 was found. These results demonstrate that S. viminale drives resting macrophages into a pro-inflammatory phenotype, reminiscent of activated immature dendritic cells. If this activation could be achieved in the peri-tumour environment, then S. viminale could be useful as an adjunct therapy for skin cancer. © 2014 Springer-Verlag London

Mapping of quantitative trait loci for mycoplasma and tetanus antibodies and interferon-gamma in a porcine F-2 Duroc x Pietrain resource population

The aim of the present study was to detect quantitative trait loci (QTL) for innate and adaptive immunity in pigs. For this purpose, a Duroc x Pietrain F-2 resource population (DUPI) with 319 offspring was used to map QTL for the immune traits blood antibodies and interferon-gamma using 122 microsatellites covering all autosomes. Antibodies response to Mycoplasma hyopneumoniae and tetanus toxoid vaccine and the interferon-gamma (IFNG) serum concentration were measured at three different time points and were used as phenotypes. The differences of antibodies and interferon concentration between different time points were also used for the linkage mapping. Line-cross and imprinting QTL analysis, including two-QTL, were performed using QTL Express. A total of 30 QTL (12, 6, and 12 for mycoplasma, tetanus antibody, and IFNG, respectively) were identified at the 5% chromosome-wide-level significant, of which 28 were detected by line-cross and 2 by imprinting model. In addition, two QTL were identified on chromosome 5 using the two-QTL approach where both loci were in repulsion phase. Most QTL were detected on pig chromosomes 2, 5, 11, and 18. Antibodies were increased over time and immune traits were found to be affected by sex, litter size, parity, and month of birth. The results demonstrated that antibody and IFNG concentration are influenced by multiple chromosomal areas. The flanking markers of the QTL identified for IFNG on SSC5 did incorporate the position of the porcine IFNG gene. The detected QTL will allow further research in these QTL regions for candidate genes and their utilization in selection to improve the immune response and disease resistance in pig