Injection Of Phytohemagglutinin Research Articles

Olfactory cues of mate quality in mammals: inflammatory response is higher in males of long-nosed bats with odorous dorsal patch

Bats use olfactory signals to provide information of species and individual identity and quality. Males of two species of long-nosed bats, Leptonycteris curasoae and L. yerbabuenae, display an odoriferous dorsal patch during the mating season that is involved in mate choice. The dorsal patch is documented to serve as an indicator of male quality; for instance, males with dorsal patch present larger testes and lower ectoparasite loads. We evaluated the role of the dorsal patch in males of L. curasoae and L. yerbabuenae as an indicator of inflammatory response 6 and 12 h after being injected with phytohemagglutinin (PHA). We found that the inflammatory response of males of both species was not different between reproductively active bats with or without dorsal patch 6 h after PHA injection, but the response was higher in bats with dorsal patch 12 h after the injection. Our study adds to the evidence that the dorsal patch exhibited by males of long-nosed bats indicates their immune quality for mating females. Further work including other branches of the immune system and the potential role of microbiota in the strength of the inflammatory response is warranted.

Relationships between hormone levels, metabolism and immune response in toads from a semi-arid region

Steroid hormones (e.g. androgens [AN] and corticosterone [CORT]) modulate complex physiological functions such as reproduction, energy mobilization, metabolism, and immunity. The effects of these steroids on immunocompetence and its metabolic costs can also be affected by fluctuations in environmental resource availability and other factors such as parasitism. To understand these possible interactions, we studied AN and CORT, immune response [swelling response to phytohemagglutinin (PHA) injection and bacterial killing ability (BKA)], parasite load, resting metabolic rate (RMR) and post-immune challenge (PHA injection) oxygen consumption rates during two different phases of the annual cycle of Rhinella jimi toads from the Brazilian semi-arid region (Caatinga), where environmental conditions are highly seasonal. We observed an increase in O2 consumption rates after both PHA and saline (control) injections, indicating a metabolic response to adverse stimuli rather than the immune challenge. Toads showing higher RMR and VO2 after the adverse stimuli (PHA/saline injections) had lower field AN and CORT plasma levels, suggesting these hormones might mediate a metabolic energy conservation strategy both at baseline levels and after adverse stimuli. Parasite load appear to constrain the metabolic response to PHA and saline injections. Additionally, individuals with a higher swelling response to PHA had higher field CORT plasma levels (particularly when males are breeding), which opposes the idea of a possible trade-off between reproductive activity and other physiological traits, indicating the immunoenhancing effects of elevated CORT at physiological levels. BKA did not show a seasonal variation or correlation with body condition or hormone levels, indicating that the immune surveillance mediated by the complement remains constant despite ecological and physiological changes.

Critical review of the phytohemagglutinin assay for assessing amphibian immunity.

Infectious diseases are a major driver of the global amphibian decline. In addition, many factors, including genetics, stress, pollution, and climate change can influence the response to pathogens. Therefore, it is important to be able to evaluate amphibian immunity in the laboratory and in the field. The phytohemagglutinin (PHA) assay is an inexpensive and relatively non-invasive tool that has been used extensively to assess immunocompetence, especially in birds, and more recently in amphibians. However, there is substantial variation in experimental methodology among amphibian PHA studies in terms of species and life stages, PHA doses and injection sites, and use of experimental controls. Here, we compile and compare all known PHA studies in amphibians to identify knowledge gaps and develop best practices for future work. We found that research has only been conducted on a limited number of species, which may not reflect the diversity of amphibians. There is also a lack of validation studies in most species, so that doses and timing of PHA injection and subsequent swelling measurements may not effectively evaluate immunocompetence. Based on these and other findings, we put forward a set of recommendations to make future PHA studies more consistent and improve the ability to utilize this assay in wild populations, where immune surveillance is greatly needed.

Milk Thistle (Silybum marianum), Marine Algae (Spirulina platensis) and Toxin Binder Powders in the Diets of Broiler Chickens Exposed to Aflatoxin-B1: Growth Performance, Humoral Immune Response and Cecal Microbiota

This research was performed to investigate the effects of milk thistle (MT), toxin binder (TB) and marine algae (Spirulina platensis; SP) on the performance, blood indices, humoral immunity and cecal microbiota of broiler chickens exposed to aflatoxin-B1 (AFB1). A total of 300 one-day-old male chicks were equally divided into five treatments, with six replicates with 10 birds per treatment. Dietary treatments included: (T1) a control diet (without any feed additive or AFB1); (T2) control diet + 0.6 mg AFB1/kg; (T3) T2 + 10 g/kg MT; (T4) T2 + 1 g/kg TB; and (T5) T2 + 10 g/kg SP. BWG and FI were found to be considerably reduced in broilers given AFB1-contaminated diets (p < 0.05). The FCR was negatively influenced in birds fed AFB1-contaminated diets (p < 0.05). MT, TB, and SP powders also reduced the deleterious effects of AFB1 on the growth of chickens (p < 0.05). In comparison with the control birds and the other treatments, broilers given AFB1-contaminated diets had a higher relative weight of abdominal fat (p < 0.05). The feeding of AFB1 resulted in a substantial rise in AST and ALT activity (p < 0.05). MT, TB, and SP powders significantly decreased blood AST and ALT activity in broilers (p < 0.05). The AFB1 and MT groups had the lowest skin thickness (p < 0.05) twenty-four hours after injection. The phytohemagglutinin injection results showed that the TB and SP were more efficient than the other additives in removing toxins from the feed sources (p < 0.05). The antibody titer against sheep red blood cells (SRBCs) was lower in the AFB1 group compared to the control group at 28 days of age (p < 0.05). When comparing AFB1-fed chicks to the control treatment, there was a significant (p < 0.05) concentration of cecal Coliform bacteria. When MT, TB, and SP powders were added to AFB1-contaminated diet, cecal Coliforms were decreased (p < 0.05). When fed AFB1-contaminated diets, it can be concluded that MT, TB, and SP are suitable for supporting growth performance, immunological function, and the serum biochemical parameters of broiler chickens.

Lambs are more stressed at early weaning when housed with their twin.

The objective of this study was to compare the behavioural and immunological responses of twin lambs housed together with their siblings or not after weaning. The study was performed with seven multiparous Milchschaf ewes and their twin lambs (n = 14), which were weaned abruptly at 63days of age and assigned to two experimental groups: (1) lambs that were housed together with their sibling after weaning (group GT, n = 6) and (2) lambs that were separated from their siblings and remained with other lambs from the same flock (group GS, n = 8). Before and after weaning, the distance between twins, the number of times in which the sibling was the closest lamb, the lambs' behaviours, and the average daily gain were recorded. The lambs' immune response was assessed with the phytohemagglutinin skin test after weaning. The closest lamb before weaning was the sibling in all cases (P < 0.0001 for all). The frequency in which GT lambs were observed closest from its twin increased on the day of weaning (P = 0.002). During the day of weaning, GT lambs vocalised and paced more than GS lambs (P = 0.001 and P = 0.01, respectively). Twenty-four h after the phytohemagglutinin injection, the skinfold thickness was greater in GS than GT lambs (P = 0.03). In conclusion, twin lambs housed together with their siblings were more stressed at weaning, displaying more intensive behavioural changes and a poorer immunological status than twin lambs housed separated from their siblings.

Induction of both local and systemic immunity by in vivo injection of PHA into ginbuna carp fin

Phytohemagglutinin (PHA) is a well-known mitogen inducing activation and proliferation of lymphocytes, particularly T lymphocytes in vitro. PHA has also been used in vivo for assessing cell-mediated immunity in non-mammalian vertebrates, particularly in birds. However, it has been suggested that local inflammation as a direct result of tissue damage could be responsible for skin swelling after PHA injection, in addition to induction of T lymphocyte mitogenesis. In order to understand the complex nature of this response in fish we investigated the accumulation of cell types chronologically in dorsal fin of ginbuna crucian carp Carassius auratus langsdorfii after PHA injection. Neutrophils appeared first and showed a peak response on day 1, decreasing gradually and followed by macrophages and blast cells while lymphocytes increased later with a peak response on day 5. The number of accumulated cells was significantly higher in PHA-injected fish than controls in most cases. Lymphocytes identified as CD4-1+and CD8α+ were significantly more abundant in PHA-injected fish than in control fish throughout the 7-day experimental period except on day 1, while the number of IgM+ lymphocytes was higher in PHA-injected fish only on day 1. In the blast cell fraction, the number of CD4-1+ lymphocytes was significantly higher in PHA-injected fish than in control fish throughout experimental period, except on day 1. We also document the migration of neutrophils from the kidney to the fin through blood, followed by granulopoiesis in the kidney.These results suggest that adaptive immunity as well as innate immunity was induced by in vivo stimulation with PHA.

Effect of Varying Levels of Hempseed Meal Supplementation on Humoral and Cell-Mediated Immune Responses of Goats.

Simple SummaryHempseed meal (HSM) is a byproduct of hemp oil production and is high in protein, fiber, and fat. With hempseed having an ideal omega 6:3 ratios for human health, a similar ratio is observed in HSM. Currently, HSM is not approved for use in animal feed as there are several safety concerns for both the animal and consumer. In this study, we evaluated the effect of HSM supplementation for goats on their humoral, cell-mediated immune responses and select cytokine expression and serum concentration. Supplementation of HSM improved the cell mediated immune response but decreased the antibody response in goats. Including HSM in the diet of goats could improve the cell-mediated immune response. The objective of this study was to evaluate the effect of varying levels of hempseed meal supplementation on antibody and cell-mediated immune responses, as well as the expression of some of the important immunoregulatory cytokines. Treatments consisted of hempseed meal supplementation at 0 (control), 10, 20, and 30% of the total diet. Goats were randomly assigned to one of the four treatments n = 10. Cell-mediated immune response was evaluated on day 59 of the feeding period by measuring skinfold thickness at 24 h following intradermal injection of phytohemagglutinin. A significant increase in skinfold thickness was observed with increasing levels of supplementation as compared to that of the control group. Serum antibody titers to chicken ovalbumin were not significantly different between treatment groups. Cytokine concentrations of IL-6 increased linearly with increasing level of supplementation (p < 0.05), contrarily to the linear decrease that was observed for TNF-α (p < 0.05). Although IL-2 tended to increase with the 10 and 30% levels of supplementation (p < 0.07), the result was not significant, and no significant differences were obtained with respect to IL-4 concentrations. Cytokine gene expression values measured by RT-PCR, however, demonstrated some significant differences. HSM supplementation had no significant effect on the expression of IL-2 or IL-6. However, significant differences were observed with the 30% supplementation for IL-4 and TNF-α as compared to that of the control group (p < 0.05). IL-4 was down regulated for the 10 and 20% treatment groups but was upregulated for the 30% treatment group. TNF-α was downregulated in the 10% but upregulated for the 20 and 30% treatment groups. No significant differences were observed for the serum cortisol concentration or white blood cell counts. These results suggested that hempseed meal supplementation may improve cell-mediated immune response while having no effect on antibody-mediated immune response. However, more research needs to be conducted to determine the most efficacious inclusion rate.

Metabolic cost of inflammatory response of ruby-throated hummingbirds (Archilochus colubris)

Animals with a slow pace of life and high mass-specific metabolic rates are expected to invest less in innate immune responses. We measured skin inflammation and the resting metabolic rate (RMR) of ruby-throated hummingbirds ( Archilochus colubris) after their immune system was challenged with phytohemagglutinin (PHA) and compared with the response of birds injected a saline solution. The PHA test measures the inflammatory process, a component of the innate response. Ruby-throated hummingbirds belong to a group that is under-represented in avian immunological studies characterized by a slow pace of life and fast metabolic rate. Hummingbirds developed an inflammatory response that lasted &lt;28 h. PHA injection produced a significant increment of RMR (up to ~13%) with respect to RMR values after the injection of the saline solution indicating that immune response involved a metabolic cost for hummingbirds. This increment lies within the range of values previously reported for birds injected PHA (5%–29%).

Antihelminthic treatment alters cellular but not humoral immune components in Magellanic Penguin (Spheniscus magellanicus) chicks

We evaluate whether helminth parasites affect both cellular and humoral components of the immune system of Magellanic Penguin (Spheniscus magellanicus (J.R. Forster, 1781)) chicks. We measured immune components after the administration of an antihelminthic drug to remove parasites. Cellular immune components included the complete white blood cell (WBC) count and the in vivo skin-swelling response to phytohemagglutinin (PHA). Humoral aspects assessed were the ability of plasma to agglutinate foreign particles and the bactericidal capacity of plasma. Antihelminthic treatment resulted in lower total WBC counts supporting the role of circulating leukocytes in fighting macroparasites. Deparasitized chicks showed a reduction in all types of leukocytes. Contrary to our expectation, deparasitized Magellanic Penguin chicks showed lower response to PHA injection than control chicks. The swelling response was positively correlated with body condition and with total WBC in circulation. We hypothesize that the specific helminth community naturally occurring in Magellanic Penguin chicks might have an overall immunostimulatory effect on the PHA response. Antihelminthic treatment did not alter the innate humoral immune parameters measured. Our results support the prediction that, given their relatively low costs of use and maintenance, innate humoral components would not be as affected by antihelminthic treatment as more costly cellular responses.

Immunocompetence and parasite infestation in a melanistic and normally-coloured population of the lacertid lizard, Podarcis siculus

Abstract Melanism is the occurrence of individuals that are darker in skin pigmentation than their conspecifics, which is a common colour polymorphism among vertebrates. Due to the pleotropic effects of the POMC gene that is responsible for melanin-based colouration, dark pigmentation often co-varies with a range of other phenotypic traits. Still, not much is known on the link between melanin-based colouration and immunity in lizards. In this study, we examined and compared the immunocompetence and degree of ectoparasite infestation of Podarcis siculus lizards from a fully melanistic population on an islet in the Tyrrhenian Sea, with conspecifics from a ‘normally’-coloured population on the mainland. Our findings show that both males and females from the melanistic population were less parasitized by ectoparasites and had a greater cellular immune response to a phytohemagglutinin injection than normally-coloured conspecifics. This outcome is in line with the “genetic link hypothesis”, which predicts that melanistic individuals will be more resistant to parasites than non-melanistic individuals due to the pleiotropic POMC gene. In addition, we found correlative evidence for a link between ectoparasite load and PHA immune response, but this was only true for males from the normally-coloured population. Immunological data on additional melanistic and non-melanistic populations of Podarcis siculus in the Mediterranean basin would provide us better insight into patterns of co-variation between immunity and melanism in lizards.

Combination Effects of Organic and Inorganic Chromium on Production Performance, Reproductive Response, Immune Status, and Maternal Antibody Transmission in Breeder Quails Under Heat Stress.

This experiment was carried out to investigate the combination effects of organic and inorganic chromium (Cr) on egg production, egg quality, reproductive response, and immune status of breeder quails and their offspring under heat stress. A total of 140 7-week-old Japanese breeder quails (120 females and 20 males) according to a completely randomized design were used in four treatment groups (five replicate and seven birds per each) lasted for 8weeks. Quails exposed to 35°C for 8h/day for induction of cyclic heat stress treatments consisted of diets supplemented with (1) 1mg CrCl3 per kilogram of diet as control (CNT); (2) 1mg Cr-L-Met per kilogram of diet as organic Cr (OCr); (3) 0.5mg CrCl3 plus 0.5mg Cr-L-Met per kilogram of diet (ISO); (4) 1mg CrCl3 plus 0.5mg Cr-L-Met per kilogram of diet (On-top). Productive performance and egg quality parameters were determined weekly. Fertility, hatchability, and embryonic mortality were measured at the end of experiment. Humoral immunity was assessed by primary and secondary antibody titer in sheep red blood cells (SRBC) and Newcastle disease (ND) tests. Cell-mediated immunity was assessed by the cutaneous basophil hypersensitivity (CBH) test to phytohemagglutinin (PHA) at days 20 and 45 of age. White blood cell count and immunoglobulin Y (IgY) content in serum and yolk of breeders and in serum and yolk residues of offspring were also measured. Results showed that maximum egg production, egg shell thickness, and Haugh unit were observed in birds fed ISO and On-top diets (P ≤ 0.05). The highest (P ≤ 0.05) antibody levels in ND test were observed in birds fed with OCr, ISO, and On-top diets. The highest cellular response (P ≤ 0.05) was in 12h after primary PHA injection and 12 and 24h after secondary PHA injection in birds fed with On-top diets. The highest count of heterophil and (H/L) were gained in breeder quails fed with CNT diet, and the lowest of them were reached with On-top diet (P ≤ 0.05). Results showed that the highest IgY level in serum of breeder and their offspring and that of yolk suck and egg yolk were observed in birds fed with On-top diet (P ≤ 0.05). These results suggest that extra supplemental organic Cr in combination with CrCl3 could lead to higher egg production, egg quality, and immune status of breeder quails and their offspring.

Effects of dietary physical form and dietary inclusion of probiotic and enzyme on growth performance, cellular and humoral immunity, and relative weights of lymphoid organs at early period of broiler chickens fed triticale-based diets

The aim of the present study was to investigate interactions between feed form and dietary inclusion of probiotics (live organisms) and enzymes on growth performance, cellular and humoral immunity, and relative weights of lymphoid organs of broiler chicks fed a triticale-based diet. A total of 640 broiler chicks were allocated to eight treatments when they were one day old, with four replicates (n = 20 chicks in each). The dietary treatments consisted of feed form (pellets or mash) and dietary supplementation with or without a Bacillus-based probiotic (0.03% diet) and enzyme (carbohydrase, 0.05% diet) in a 2 × 2 × 2 factorial arrangement. Feed conversion ratio (FCR) was calculated based on feed intake (FI) and weight gain (WG). The WG of the broiler chicks fed the pelleted diets containing the enzyme and probiotic (alone or in combination) was greater than that of the birds fed the mash diets without these additives. Significant interaction effects of the enzyme and probiotic on FCR and FI were observed in the starter period. The heterophil : lymphocyte (H : L) ratio of the chicks fed the pelleted diet containing the enzyme and probiotic was lower than that of the birds fed the other diets. The cellular immunity of the birds fed this diet increased after 24 hours, as shown by the results of a challenge experiment with dinitrochlorobenzene (DNCB) or an injection of phytohemagglutinin (PHA). In conclusion, feed form and supplementation of a triticale-based diet with feed enzymes and probiotics can greatly improve the growth performance and immunity of broiler chicks. Keywords : Dinitrochlorobenzene, Di-Pro probiotic, phytohemagglutinin, Rovabio enzyme, spleen, viscosity

CD4+ T cells dominate the leukocyte infiltration response initiated by intra-dermal injection of phytohemagglutinin into growing feathers in chickens

Phytohemagglutinin (PHA) is commonly used to evaluate cell-mediated immunocompetence. In chickens, PHA is typically injected intra-dermally (i.d.) into the skin (e.g., wing web, wattle, or footpad), and the tissue swelling response is monitored, whereby the extent of tissue swelling positively relates to the individual's cell-mediated immune system capabilities. Although i.d. injected PHA was shown to stimulate mononuclear cell and basophil infiltration to the site of injection, reports on temporal, qualitative, and quantitative aspects of the local cutaneous PHA response are limited. The objective of this study was to use the growing feather (GF) as a cutaneous test site to assess and monitor the type and relative amounts of leukocytes present in the pulp of PHA-injected GF. For this study, male, non-vaccinated Light-brown Leghorn chickens reared at the Arkansas Experiment Station Poultry Health Laboratory were used. At 9 wk of age, the dermis of 20 18-day-old regenerating GF was injected with 10 μL of either PBS diluent or 300μg/mL PHA-P (5 chickens per treatment). GF were collected from each chicken before (zero) and at 0.25, 1, 2, 3, 4, 5, and 7 d post injection. At each time point, one GF was collected for immunofluorescent staining of pulp cell suspensions and leukocyte population analysis by flow cytometry, and another GF for histological analysis. Histological analysis confirmed participation of granulocytes and mononuclear cells, primarily lymphocytes, in the cutaneous PHA response. As revealed by flow cytometric cell population analysis, T cells, especially CD4+ T cells, constituted the major portion of the mononuclear cell infiltrate. Levels of CD4+ T cells were greatly elevated in PHA-injected GF within 6h and remained elevated throughout the 7-day examination period. γδ T cells, CD8+ T cells, and B cells also infiltrated in response to PHA although at lower levels and with different time-course patterns from CD4+ T cells. The dominant presence of CD4+ T cells at the site of PHA injection further affirms this polyclonal response as an indicator of cell-mediated immunity.

Local and systemic immune responses to different types of phytohemagglutinin in the green anole: Lessons for field ecoimmunologists

The phytohemagglutinin (PHA) skin test is commonly used by ecologists to assess cell-mediated immune function of wild animals. It can be performed quickly and easily in the field, involving injection of PHA and measurement of the resultant swelling. There are multiple formulations of PHA used in ecological studies, with potentially differing outcomes that could produce inconsistent results. We tested two common types of PHA in the green anole (Anolis carolinensis) to identify local and systemic immune responses underlying the resultant swelling at 6, 18, 24, and 48hr post injection. There were differences in both local (injection site) and systemic (blood) leukocyte responses to PHA-L versus PHA-P. PHA-P injection produced a greater overall increase in local heterophil count at the injection site compared with PHA-L, and this response was greatest at 6 and 24hr post injection. Systemically, heterophil percentage was higher in the blood of PHA-P- versus PHA-L-injected anoles at 24hr post injection; the time point at which heterophil percentage peaked in PHA-P-injected anoles. These results indicate that although both PHA types are effective tests of immune function in green anoles, the PHA-P swelling response invokes a much stronger heterophilic response. PHA-L is a more specific test of lymphocyte function, particularly at 24hr post injection, making it preferable for ecoimmunology studies.

Immune responsiveness to phytohemagglutinin displays species but not sex differences in three anuran species.

Phytohemagglutinin (PHA)-induced skin swelling response is widely used as a rough surrogate of integrative cell-mediated and innate immunity across multiple vertebrate taxa due to its simplification and feasibility. However, little is known whether there are sex and interspecific differences of immune responsiveness to PHA in ectotherms, especially for anurans. Therefore, we studied sex and species differences of PHA response in three anurans, Asiatic toads (Bufo gargarizans), Dark-spotted frogs (Pelophylax nigromaculatus) and Mongolian toads (Pseudepidalea raddei), captured in northern regions of Anhui Province (China). Footpad thickness was measured prior to (0 h) and after (6, 12, 24, 48 and 72 h) a PHA injection and normalized against saline injection in the opposite footpad. Body mass was recorded at the beginning (0 h) and end of each assay (72 h). Results showed effects of PHA assay, sex and taxa on body mass. Relative maximum swelling response (PHAmax) ranged from 18.58–29.75%, 9.77 to 20.56% and 21.97 to 31.78% and its occurrence over time was apparent 10.6–19.72 h , 7.74–14.01 h and 17.39–23.94 h postinjection for Asiatic toads, Dark-spotted frogs and Mongolian toads, respectively. Finally, the magnitude or timing of PHAmax in Dark-spotted frogs was significantly thinner and faster than in Mongolian toads, and Asiatic toads had an in-between value, not different from the other two species. The magnitude of PHAmax was significantly positively correlated with the timing of PHAmax considering individuals altogether, but not when analyzed within species. Our results indicate that male and female anuran species respond similarly to PHA antigen stimulation, but the magnitude and timing of PHAmax is species-specific. Briefly, we provide new evidence for the suitability of PHA assay in non-model anuran species with different body sizes, and exhort the need to further investigate the nature of PHA assay at the hematological and histological levels in order to extend its application in ecoimmunological studies of amphibians.

Dominant male song performance reflects current immune state in a cooperatively breeding songbird.

Conspicuous displays are thought to have evolved as signals of individual "quality", though precisely what they encode remains a focus of debate. While high quality signals may be produced by high quality individuals due to "good genes" or favourable early-life conditions, whether current immune state also impacts signalling performance remains poorly understood, particularly in social species. Here, we experimentally demonstrate that male song performance is impaired by immune system activation in the cooperatively breeding white-browed sparrow weaver (Plocepasser mahali). We experimentally activated the immune system of free-living dominant males via subcutaneous injection of phytohemagglutinin (PHA) and contrasted its effects with those of a control (phosphate buffered saline) injection. PHA-challenged males showed significant reductions in both the duration and the rate of their song performance, relative to controls, and this could not be readily attributed to effects of the challenge on body mass, as no such effects were detected. Furthermore, male song performance prior to immune-challenge predicted the scale of the inflammatory response to the challenge. Our findings suggest that song performance characteristics are impacted by current immune state. This link between current state and signal performance might therefore contribute to enforcing the honesty of signal performance characteristics. Impacts of current state on signaling may be of particular importance in social species, where subordinates may benefit froman ability to identify and subsequently challenge same-sex dominants in a weakened state.

Prenatal Exposure to Soy Isoflavones Altered the Immunological Parameters in Female Rats

Information on the effects of phytoestrogens on animals has increased recently; however, there were only few studies on prenatal exposure on cellular immune response. Pregnant rats were assigned to 3 groups (12 rats per group), the first was fed control diet, the second was fed low-dose (6.5 g/100 g of diet) soy isoflavones, while the third was fed high-dose (26 g/100 g of diet) soy isoflavones. The female offspring cell-mediated immune response was determined using phytohemagglutinin (PHA) injection, and intumesce index was calculated on postnatal day 50. After 24 hours of PHA injection, blood samples were collected for tumor necrosis factor α, interferon γ (IFN-γ), and interleukin (IL)-12 determination. Spleen, thymus, and PHA-injected footpads were fixed for histopathology. Intumesce index was significantly (P < 0.05) reduced in rats' offspring born from dams fed low- and high-dietary soy isoflavones than that in control groups. Thymic relative weights in offspring of rats fed high-dietary soy isoflavones showed a significant (P < 0.05) decrease compared to that in the control group. Female offspring where low and high-dietary soy isoflavones were fed to their dams showed a significant (P < 0.05) decrease in IFN-γ and IL-12 than that in control ones. Spleen of rats born from dams fed high dose of dietary soy isoflavones showed lymphocytic depletion in white pulp. Taking together, it is clear that dietary soy isoflavones at prenatal period had immunosuppressive effect on female offspring after PHA stimulation. This effect was mediated through reduced IFN-γ that interplayed in IL-12 production pathway thus reducing its level.

Effects of antihelminthic treatment on cell-mediated immunity in Gentoo penguin chicks

Fil: Bertellotti, Nestor Marcelo. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Nacional Patagonico; Argentina

Transcriptomic Characterization of Innate and Acquired Immune Responses in Red-Legged Partridges (Alectoris rufa): A Resource for Immunoecology and Robustness Selection.

Present and future challenges for wild partridge populations include the resistance against possible disease transmission after restocking with captive-reared individuals, and the need to cope with the stress prompted by new dynamic and challenging scenarios. Selection of individuals with the best immune ability may be a good strategy to improve general immunity, and hence adaptation to stress. In this study, non-infectious challenges with phytohemagglutinin (PHA) and sheep red blood cells allowed the classification of red-legged partridges (Alectoris rufa) according to their overall immune responses (IR). Skin from the area of injection of PHA and spleen, both from animals showing extreme high and low IR, were selected to investigate the transcriptional profiles underlying the different ability to cope with pathogens and external aggressions. RNA-seq yielded 97 million raw reads from eight sequencing libraries and approximately 84% of the processed reads were mapped to the reference chicken genome. Differential expression analysis identified 1488 up- and 107 down-regulated loci in individuals with high IR versus low IR. Partridges displaying higher innate IR show an enhanced activation of host defence gene pathways complemented with a tightly controlled desensitization that facilitates the return to cellular homeostasis. These findings indicate that the immune system ability to respond to aggressions (either diseases or stress produced by environmental changes) involves extensive transcriptional and post-transcriptional regulations, and expand our understanding on the molecular mechanisms of the avian immune system, opening the possibility of improving disease resistance or robustness using genome assisted selection (GAS) approaches for increased IR in partridges by using genes such as AVN or BF2 as markers. This study provides the first transcriptome sequencing data of the Alectoris genus, a resource for molecular ecology that enables integration of genomic tools in further studies.

Correlations between phytohemagglutinin response and leukocyte profile, and bactericidal capacity in a wild rodent.

Phytohemagglutinin (PHA)-induced swelling is widely used to investigate cell-mediated and innate immunity across different vertebrate taxa. However, its physiological mechanism is still an open question due to the complexity of the involved immune components. In the present study, we measured the synchronous variations of PHA response, the proportion of different subtypes of leukocytes, as well as serum bactericidal capacity in circulation blood at 6, 12 and 24 h after PHA versus PBS injection in striped hamster, Cricetulus barabensis. First, the results showed that PHA responses reached a peak at 6 h postinjection, then sharply declined at 12 h and 24 h postinjection. Serum bactericidal capacity was higher at 6 h and 12 h than at 24 h. The proportion of different subtypes of leukocytes, as well as the ratio of neutrophils to lymphocytes did not display significant changes across different time points. Second, PHA response was positively correlated with the proportion of neutrophils and serum bactericidal capacity. The proportion of monocytes was negatively correlated with that of eosinophils and neutrophils. The proportion of basophils was negatively correlated with that of lymphocytes. Our results indicate that earlier enhanced PHA response is important for the striped hamster to cope with changing environmental conditions due to its small body mass, and the increased components of innate immunity in circulation blood may contribute to the enhancement of PHA swelling response.