Immune responses and acute inflammation in common carp Cyprinus carpio injected by E.coli lipopolysaccharide (LPS) as affected by dietary oils

Eicosanoids, resolvins, and lipoxins formed from long-chain polyunsaturated fatty acids (LC-PUFAs) are the main lipid mediators in the inflammatory processes explaining the influence of dietary lipid sources on the immune system. The current study aimed to determine the effects of dietary plant oils instead of fish oil or LC-PUFA supplementation in these oils on fish immune and inflammatory responses under normal and LPS-stimulated conditions. Six iso-nitrogenous (ranging from 30.4 to 31.1%) and iso-lipidic (from 11.2 to 11.6%) diets were formulated using three oil sources: cod liver oil (CLO, as fish oil control); linseed oil (LO, rich in α-linolenic acid, ALA); sesame oil (SO, rich in linoleic acid, LA); a blend of LO and SO (SLO, v:v 1:1); and two pure plant oil diets supplemented with docosahexaenoic acid, DHA (SO + DHA, SOD) or arachidonic acid, ARA (LO + ARA, LOA). Fish were fed the experimental diets to satiation for 42 days. On day 43, they were injected with E.coli lipopolysaccharide (LPS) at 100 μg/fish. Fish plasma and tissues such as head kidney and liver were collected on day 42 and one day after LPS injection (day 44) for humoral immune variables and gene expression analyses, respectively. After 42 days of feeding, no influences of dietary oils were found on fish survival, growth, feed utilization, and humoral immune responses. On the other hand, LPS injection significantly stimulated immune responses and induced an acute inflammation in common carp through an increase of the complement activity and the up-regulation of genes involved in the innate immune system (c2), pro-inflammatory response (tlr-4, tnf-α, il-1, il-6, il-8, and cxc), eicosanoid metabolism (pla2, cox-1, 5-lox, and pge2), and anti-inflammatory response (tgf-β1 and nf-fki). Further, the expression of hsp70 was stimulated by LPS injection. The effects of dietary oil sources were observed after LPS injection, with a significant modification in the expression of almost all candidate genes. The highest pro-inflammatory responses induced by LPS were observed in CLO-fed fish while the mixture of plant oils (SLO) and LC-PUFA-supplemented diets induced significantly higher modulations in anti-inflammatory responses (il-10 and nf-kbi), general stress status (hsp70), and cytoprotection (gpx-1) compared to fish oil control and other pure plant oil groups. In conclusion, the immune response of common carp has been modified by the dietary fat sources. The fish oil-based diet supported an increase of the pro-inflammatory responses while the mixture of plant oil or LC-PUFA supplemented diets improved the anti-inflammatory responses and cytoprotection.

Polymorphisms of mannose-binding lectin-associated serine protease 1 (MASP1) and its relationship with milk performance traits and complement activity in Chinese Holstein cattle

OBJECTIVE

Mannose-binding lectin (MBL)-associated serine protease1 (MASP1) is the central enzyme in the innate immune system, which has biological functions of antibacterial and anti-inflammatory activities. Moreover, MASP1 represents a candidate gene reflecting the complement activity. This study is to investigate the entire exons of MASP1 in Chinese Holstein cattle with DNA sequencing to identify novel single nucleotide polymorphisms (SNPs).

METHODS

Novel SNPs were identified through gene sequencing and genotyped by the PCR Restriction Fragment Length Polymorphism (PCR-RFLP) and Created Restriction Site PCR (CRS-PCR). The relationship between the milk performance traits and complement activity in Chinese Holstein cattle was analyzed using the General Linear Model (GLM) procedure with the SAS software (version 8.0).

RESULTS

Two novel SNPs (i.e., g.5766A > G and g.51228A > C) were detected. The SNP g.5766A > G was located in the first intron and the SNP g.51228A > C was located in the 3'-untranslated regions of MASP1. The polymorphism at g.5766A > G was correlated with protein percentage (P < 0.05). Moreover, the polymorphism at g.51228A > C had only two genotypes, and this SNP had no significant correlation with CH50, ACH50, fat percentage, protein percentage, 305-day milk yields, or SCS scores.

CONCLUSION

MASP1, reflecting the complement activity, may not be significantly related to mastitis. However, MASP1 could be implemented in the breeding program to improve the production performance of Chinese Holstein cattle.

Comparison of the susceptibility and resistance of four marine perciform fishes to Cryptocaryon irritans infection

Cryptocaryon irritans is a type of marine ectoparasitic ciliate that infects teleost fishes. To illustrate the susceptibility and innate immune mechanism of fishes to C. irritans, four species of marine perciform fishes were selected in Fujian Province, a high-prevalence area of cryptocaryoniasis in China. The survival, diameter/number of tomonts, and infection ratio among Larimichthys crocea, Lateolabrax japonicus, Pagrus major, and Nibea albiflora were compared after artificial infection. Meanwhile, the immobilization titers of four fish species with no C. irritans infection were detected. Results showed that survival and serum immobilization titer of N. albiflora were significantly higher than those of the other three fish species. A strong negative linear correlation was found between the survival/serum immobilization titer and the mean tomont diameter. In addition, the smallest C. irritans infection ratio was found in N. albiflora, implying that the serum of fishes especially that of N. albiflora, inhibited the development of parasitic C. irritans cells, and the smallest tomont size was directly related to the number of infective theronts corresponding to the highest survival of fish. Moreover, complement activity inhibition assays suggested that the alternative complement pathway might play a major role in C. irritans resistance.

Complement functional tests for monitoring eculizumab treatment in patients with atypical hemolytic uremic syndrome: an update

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy (TMA) characterized by platelet consumption, hemolysis, and organ damage. Eculizumab (ECU), a humanized antibody that blocks complement activity, has been successfully used in aHUS, but the best treatment schedule is not yet clear.

METHODS

Here, we report our experience with ECU maintenance treatment and the interval between subsequent doses being extended based on global classical complement pathway (CCP) activity aimed at <30% for maintaining aHUS into remission.

RESULTS

We report on 38 patients with aHUS, 13 children, 21 female, with a median age of 25.0 years (range 0.5-60) at disease onset treated with ECU standard schedule for a median of 2.6 months (range 0.4-24.6). Once stable TMA remission was obtained, the interval between ECU doses was extended based on complement function, with a target CCP activity of <30%. With this approach, 22 patients regularly receive ECU infusion every 28 days and 16 every 21. During a median observation period on ECU, an extended interval of 26.9 months (range 0.8-80.9), with a cumulative observation period of 1,208 months, none of the patients relapsed.

CONCLUSION

Monitoring complement activity allows a safe reduction in the frequency of ECU administration in aHUS while keeping the disease in remission.

Proliferative kidney disease in rainbow trout (Oncorhynchus mykiss) under intensive breeding conditions: Pathogenesis and haematological and immune parameters

Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematological findings and immune functions. Diseased and reference fish were sampled monthly and time course of natural infection was followed up from the onset of clinical signs (September 2014) to full recovery (January 2015). PKD- associated cumulative mortality was 30% with a peak value in October, while immunohistochemical testing indicated a continuous significant decrease in T. bryosalmonae numbers from September to December; with no parasites detected in January. During peak clinical infection, a significant decrease in red blood cell counts, haematocrit values, haemoglobin concentration, along with a reduction in lymphocytes and a significant phagocyte elevation corresponding with an increase in phagocyte oxidative burst were measured in comparison to control animals. Complement activity and total immunoglobulin plasma concentrations were also elevated, though only during the initial monitoring period (September). Individuals surviving PKD, recovered and were able to fully regenerate both renal structure and haematopoietic parameters to normal levels. Changes in the red blood cell parameters indicate anaemia and a decreased oxygen transportation capacity during the clinical disease phase. Together with an increased oxygen demand at higher temperatures and decreased oxygen solubility this could lead to decompensation and elevated mortality. The stimulation of immune parameters, and especially oxidative phagocytic burst, is likely to have had a strong effect on both, regeneration and elimination of the pathogenic agent.

Endocrine-reproductive-immune interactions in female and male Galápagos marine iguanas

Endocrine-immune interactions are variable across species and contexts making it difficult to discern consistent patterns. There is a paucity of data in non-model systems making these relationships even more nebulous, particularly in reptiles. In the present study, we have completed a more comprehensive test of the relationship among steroid hormones and ecologically relevant immune measures. We tested the relationship between baseline and stress-induced levels of sex and adrenal steroid hormones and standard ecoimmunological metrics in both female and male Galápagos marine iguanas (Amblyrhynchus cristatus). We found significant associations between adrenal activity and immunity, whereby females that mounted greater corticosterone responses to stress had lower basal and stress-induced immunity (i.e., bactericidal ability). Males showed the opposite relationship, suggesting sex-specific immunomodulatory actions of corticosterone. In both sexes, we observed a stress-induced increase in corticosterone, and in females a stress-induced increase in bactericidal ability. Consistent with other taxa, we also found that baseline corticosterone and testosterone in males was inversely related to baseline bactericidal ability. However, in females, we found a positive relationship between both testosterone and progesterone and bactericidal ability. Multivariate analysis did not discern any further endocrine-immune relationships, suggesting that interactions between adrenal, sex steroid hormones, and the immune system may not be direct and instead may be responding to other common stimuli, (i.e., reproductive status, energy). Taken together, these data illustrate significant endocrine-immune interactions that are highly dependent on sex and the stress state of the animal.

Improved ex vivo method for microbiocidal activity across vertebrate species

The field of ecoimmunology is currently undergoing rapid expansion, whereby biologists from a wide range of ecological disciplines are increasingly interested in assessing immunocompetence in their study organisms. One of the key challenges to researchers is determining what eco-immune measures to use in a given experiment. Moreover, there are limitations depending on study species, requirements for specific antibodies, and relevance of the methodology to the study organism. Here we introduce an improved ex vivo method for microbiocidal activity across vertebrate species. The utility of this assay is that it determines the ability of an organism to remove a pathogen that could be encountered in the wild, lending ecological relevancy to the technique. The applications of this microbiocidal assay are broad, as it is readily adaptable to different types of microbes as well as a wide variety of study species. We describe a method of microbiocidal analysis that will enable researchers across disciplines to effectively employ this method to accurately quantify microbial killing ability, using readily available microplate absorbance readers.