Cytokine and antioxidant gene profiles from peripheral blood mononuclear cells of Pelibuey lambs after Haemonchus contortus infection

Selection of Molecules with Immunological Potential from Excretory and Secretory Products from the Nematode Haemonchus placei by Cell Proliferation and Gene Expression Assays

The nematodeHaemonchus placeiis a pathogenic parasite, the most seriously affecting ruminant's health and being responsible for enormous economic losses all over the world. The present protocol describes different in vitro techniques to select potential candidate antigens with immune-protective activity from excretory and secretory products (ESP) fromH. placeitransitory infective larvae (xL₃). ESP from xL₃were obtained from the in vitro infective larvae (L₃) maintained in Hank's medium at 37 °C with 5% CO₂for 48 h. Then, the presence of ESP proteins was confirmed by SDS-PAGE to be used in an in vitro proliferation assay with bovine peripheral blood mononuclear cells (PBMCs). The ESP were exposed to the PBMCs during two different periods (24 and 48 h). Genes associated with immune response against the nematode were analyzed using relative gene expression and bioinformatic tools. These are simple, economic, and helpful tools to identify potential immune-protective molecules under in vitro conditions for confirming the efficacy of future in vivo assays. Graphical overview.

Hepatocellular carcinoma-associated antigen 59 and ADP-ribosylation factor 1 with poly (lactic-co-glycolic acid): A promising candidate as nanovaccine against haemonchosis

Haemonchus contortus (H. contortus) ADP-ribosylation factor 1 (Hc-ARF1) and Hepatocellular carcinoma-associated antigen 59 (Hc-HCA59) are recognized to largely regulate the immune responses of host cells. However, studies about the protective efficacy of the two molecules are poorly unknown. In this research, combinations of recombinant Hc-HCA59 (rHc-HCA59) and Hc-ARF1 (rHc-ARF1) proteins were amalgamated with poly (lactic-co-glycolic acid) (PLGA) nanoparticles adjuvant in order to investigate their protection potential against H. contortus in goats. The results demonstrated that the levels of IgG, IgA, IgE, and IL-4 were noticeably enhanced in the rHc-HCA59 and rHc-ARF1 (rHc-HCA59+rHc-ARF1) group before H. contortus third-stage larvae (L3) challenge. After the L3 challenge, the levels of IL-17, IL-9, and TGF-β were considerably upregulated in the rHc-HCA59+rHc-ARF1 group. In the meantime, the abomasal worm burdens and the fecal eggs were reduced by 63.2% and 69.4% respectively in the rHc-HCA59+rHc-ARF1 group. According to the studies, PLGA nanoparticles immobilized with rHc-HCA59 and rHc-ARF1 proteins conferred partial protection and were expected to be a potential candidate for developing nano vaccines to combat goat haemonchosis.

Taenia hydatigena larvae vesicular concentrate reduces the egg shedding of Haemonchus contortus associated with the overexpression of abomasal cytokines in lambs

The expression patterns of some cytokines were compared by RT-qPCR between lambs with and without Taenia hydatigena larvae vesicular concentrate (ThLVC) administration and subsequent infection with Haemonchus contortus. Lambs that received ThLVC prior to infection with H. contortus showed lower (p < 0.03) cumulative FEC (AUC = 18450 ± 3384) than infected lambs who did not receive ThLVC (AUC = 31081 ± 3277). Lambs infected with H. contortus, in general, overexpressed Th1 and Th2 cytokines in abomasal mucosa and abomasal lymph nodes, which seems to indicate a generalized and nonpolarized activation of the immune response by H. contortus. The main immunomodulatory effects of ThLVC were observed in the abomasal fundic region. The lambs that were given ThLVC prior to infection strongly overexpressed most of the studied cytokines representing the Th1 (IFNγ and IL2) and Th2 profiles (IL4, IL5, IL6 and IL10), proinflammatory cytokines (SOD1 and PRDX6) and IgE receptor; in contrast, lambs that were infected but did not receive ThLVC only moderately overexpressed IFNγ, IL4 and IL6. The absence of the significant overexpression of cytokines in lambs that only received ThLVC suggests that this derived from T. hydatigena does not have a stimulating effect per se; however, the presence of H. contortus did produce the highest expression (p < 0.01) cytokine profile among lambs that received ThLVC prior to infection compared to those who did not receive it, so its effect seems to be immunomodulatory and not only immunostimulatory.

Haemonchus contortus infection induces a variable immune response in resistant and susceptible Pelibuey sheep

The immune response and phenotypic characteristics of Pelibuey lambs were analysed after the induction of a Haemonchus contortus trickle infection. Male lambs (n = 29; 20 kg live weight) were infected with 100 H. contortus infective larvae per kg of live weight on day 3, 5 and 7 of the experiment. The number of eggs per gram (epg), seven haematological parameters and the immunoglobulin A (IgA) level were analysed for 56 experimental days. In addition, histopathological samples from the fundic abomasal region and the relative expression of 10 immune-related genes from 15 infected and three non-infected lambs were analysed at day 0 and 49 of the experiment. The epg count and some haematological parameters (leucocytes, red blood cells, haemoglobin and total protein) with statistically significant differences (P < 0.01) were used to identify nine resistant and 20 susceptible lambs (1166 ± 1071 and 3171 ± 1463 epg, respectively). Moreover, acute infiltration of immune cells and parasitic granuloma formation were observed in susceptible lambs; the resistant group had moderate inflammatory cell infiltration. With respect to relative gene expression, resistant lambs showed upregulation (P < 0.001) of 10 genes, from 2.2 to 15.99 fold. Moreover, there was a strong indirect correlation (P < 0.05) between the epg count and interleukin 5 (IL5) gene expression. By contrast, there was an average 0.34 fold downregulation in nine of the immune-related genes (P ≤ 0.05) in susceptible lambs (the only exception was Fc fragment of IgE receptor Ia [FCER1A] upregulation). In addition, there was a direct correlation (P ≤ 0.05) between the epg count and the expression of IL8, which encodes an inflammatory chemokine. In conclusion, this study showed differential IL5 and IL8 gene expression during haemonchosis in resistant and susceptible Pelibuey lambs, respectively, together with a variable immune response based on histopathological and haematological parameters.

Genome-wide scan reveals important additive and non-additive genetic effects associated with resistance to Haemonchus contortus in Florida Native sheep

Florida Native sheep is among the sheep breeds best adapted to humid and hot climatic conditions such as those of Florida, USA, and have shown a superior ability to regulate nematode burdens. This is one of the oldest sheep breeds in North America and is an endangered species. To ensure genetic diversity and long-term survival of the breed, protection of the current genetic stock is critical and conservation efforts are required to promote its breeding and production. The objective of the present study was to investigate the importance of additive and non-additive genetic effects on resistance to natural Haemonchus contortus infections in Florida Native sheep using a whole genome scan. A total of 200 sheep were evaluated in the present study. Phenotypic records included faecal egg count (FEC, eggs/gram), FAMACHA® score, packed cell volume (PCV, %), body condition score and average daily gain (ADG, kg). Sheep were genotyped using the GGP Ovine 50K SNP chip and 45.2 k single nucleotide polymorphism (SNP) markers spanning the entire genome were available for quality control procedures. Mixed models were used to analyse the response variables and included the identity by state matrix to control for population structure. Bonferroni correction was used to control for multiple testing and a second arbitrary threshold (0.1 × 10^-3) was used. Fifteen SNPs with additive and non-additive genetic effects and located in Ovis aries chromosome OAR1, 2, 3, 6, 8, 10, 11, 12, 13 and 21 were associated with FEC, FAMACHA® score, PCV and ADG. These SNPs could be potential genetic markers for resistance to natural H. contortus exposure in Florida Native sheep.

Immune response related to Pelibuey sheep naturally infected with gastrointestinal nematodes in a tropical region of Mexico

We analysed the immune response involved in sheep naturally infected with gastrointestinal (GI) nematodes. Fifteen Pelibuey lambs were grazed in paddocks contaminated with GI nematodes for 13 weeks. To assess the infection, the number of eggs per gram (epg) and the percentage of packed cell volume (pcv) were evaluated. Blood and abomasal tissue samples were collected at week 8 post-infection to analyse the expression levels of IL-4, IL-5, IL-6, IL-8, IL-13, TGF-β and FCεR1A genes. The nematode Haemonchus contortus was the main species identified. In addition, two groups of lambs were classified based on the x ± SE of epg and pcv values: G-1, with 151 ± 28 and 29 ± 0.33%, respectively, and G-2, with 475 ± 59.5 and 26 ± 0.38%, respectively. For G-1, upregulation of IL-4, IL-8, IL-13, TGF-β and FCεR1A genes from 2.42- to 14.99-fold was observed in blood and abomasal tissue samples (p > .05), and IL-5, IL-8 and TGF-β genes had significant gene expression levels in blood (p < .05). For G-2, moderate gene expression levels, ranging from 1.22- to 3.45-fold, were observed in abomasal tissue (p > .05), and the IL-5 gene presented significant gene expression in blood (p < .05). Strong positively correlated values (r) between pcv and IL-4, IL-8 and TGF-β genes were observed in G-1. In contrast, significant negative correlations between epg and IL-4, IL-5 and FCεR1A genes indicate acute infection for G-2. Our results suggest that IL-4, IL-5, IL-13, TGF-β and FCεR1A genes are important modulators of GI nematode infections of Pelibuey lambs.