Secondary phytohaemagglutinin (<scp>PHA</scp>) swelling response is a good indicator of T‐cell‐mediated immunity in free‐living birds

Santiago‐Quesada, Francisco; Albano, Noelia; Castillo-Guerrero, José Alfredo; Fernández, Guillermo; González‐Medina, Erick; Sánchez‐Guzmán, Juan M.

doi:10.1111/ibi.12295

Cited by 8 publications

(7 citation statements)

References 35 publications

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“…Although data on immune response variables were not available for many species, we did find differences between males and females. The four immune assays analysed reflect innate immunity, except the PHA test that, if repeated more than once, also includes components of the adaptive immunity 85 . The PHA test and the haemolysis assay were significantly male-biased during breeding, although the latter estimate was obtained only from three effect sizes.…”

Section: Discussionmentioning

confidence: 99%

Seasonal variation in sex-specific immunity in wild birds

Valdebenito

Halimubieke

Lendvai

et al. 2021

Sci Rep

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Whilst the immune system often varies seasonally and exhibits differences between males and females, the general patterns in seasonality and sex differences across taxa have remained controversial. Birds are excellent model organisms to assess these patterns, because the immune system of many species is well characterised. We conducted a meta-analysis using 41 wild bird species from 24 avian families to investigate sex differences and seasonal (breeding/non-breeding) variations in immune status, including white blood cell counts, phytohaemagglutinin (PHA) test, bacteria-killing ability (BKA), haemolysis and haemagglutination assays. We found male-biased macrophage concentration, BKA and haemolysis titers, but only during the breeding season. Sex-specific heterophil concentrations, heterophil/lymphocyte ratios and PHA responses differed between breeding and non-breeding, suggesting larger changes in males than in females. Importantly, sex differences in immune status are stronger during the breeding period than during the non-breeding period. Taken together, our study suggests that both seasonal variation and sex differences in immune system are common in birds, although their associations are more complex than previously thought.

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Section: Discussionmentioning

confidence: 99%

Seasonal variation in sex-specific immunity in wild birds

Valdebenito

Halimubieke

Lendvai

et al. 2021

Sci Rep

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“…Indeed, challenges traditionally used in immunoecology are less specific than initially thought and they involve the action of multiple actors. For instance, much effort has been undertaken to understand the effect of PHA on activation of the immune system (Kennedy & Nager, ; Martin et al, ; Santiago‐Quesada et al, ; Tella et al, ). This has revealed a complex action of both innate and acquired immunity, and some authors have even suggested the inappropriateness of PHA tests as a direct proxy of T‐cell responsiveness or adaptive immunity (Vinkler, Bainová, & Albrecht, ).…”

Section: Discussionmentioning

confidence: 99%

Lack of statistical power as a major limitation in understanding MHC‐mediated immunocompetence in wild vertebrate populations

et al. 2019

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Disentangling the sources of variation in developing an effective immune response against pathogens is of major interest to immunoecology and evolutionary biology. To date, the link between immunocompetence and genetic variation at the major histocompatibility complex (MHC) has received little attention in wild animals, despite the key role of MHC genes in activating the adaptive immune system. Although several studies point to a link between MHC and immunocompetence, negative findings have also been reported. Such disparate findings suggest that limited statistical power might be affecting studies on this topic, owing to insufficient sample sizes and/or a generally small effect of MHC on the immunocompetence of wild vertebrates. To clarify this issue, we investigated the link between MHC variation and seven immunocompetence proxies in a large sample of barn owls and estimated the effect sizes and statistical power of this and published studies on this topic. We found that MHC poorly explained variation in immunocompetence of barn owls, with small‐to‐moderate associations between MHC and immunocompetence in owls (effect size: .1 ≥ r ≤ .3) similar to other vertebrates studied to date. Such small‐to‐moderate effects were largely associated with insufficient power, which was only sufficient (>0.8) to detect moderate‐to‐large effect sizes (r ≥ .3). Thus, studies linking MHC variation with immunocompetence in wild populations are underpowered to detect MHC effects, which are likely to be of generally small magnitude. Larger sample sizes (>200) will be required to achieve sufficient power in future studies aiming to robustly test for a link between MHC variation and immunocompetence.

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“…Likewise, it was clear from the results of the CBH test that feeding the birds with 2 ppm AFB1 implies a significant decrease in cellular immunity. The PHA skin test is used to evaluate cellular immunity, since PHA is a potent stimulant that activates immune cells infiltrating tissue from peripheral blood, causing local temporary inflammation at the injection site [ 52 ]. In the present study, AFB1 chickens also showed the lowest response to CBH at both, 12 and 24 h, after PHA injection.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of Cellulosic Polymers and Curcumin to Reduce Aflatoxin B1 Toxic Effects on Performance, Biochemical, and Immunological Parameters of Broiler Chickens

Solís-Cruz

Hernández-Patlán

Petrone

et al. 2019

Toxins

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To evaluate the effect of cellulosic polymers (CEL) and curcumin (CUR) on aflatoxin B1 (AFB1) toxic effects on performance, and the biochemical and immunological parameters in broiler chickens, 150 one-day-old male broiler chicks were randomly allocated into five groups with three replicates of 10 chickens per pen: Negative Control (feed); AFB1 (feed + 2 ppm AFB1); CUR (feed + 2 ppm AFB1 + Curcumin 0.2%); CEL (feed + 2 ppm AFB1 + 0.3% Cellulosic polymers); and, CEL + CUR (feed + 2 ppm AFB1 + 0.3% Cellulose polymers + 0.2% Curcumin). Every week, body weight, body weight gain, feed intake, and feed conversion ratio were calculated. On day 21, liver, spleen, bursa of Fabricius, and intestine from five broilers per replicate per group were removed to obtain relative organ weight. Histopathological changes in liver, several biochemical biomarkers, antibody titers, and muscle and skin pigmentation were also recorded. Dietary addition of 0.3% CEL and 0.2% CUR separately significantly diminished some of the toxic effects resulting from AFB1 on performance parameters, relative organs weight, histopathology, immune response, and serum biochemical variables (P < 0.05); however, the combination of CUR and CEL showed a better-integrated approach for the management of poultry health problems that are related with the consumption of AFB1, since they have different mechanisms of action with different positive effects on the responses of broiler chickens.

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Secondary phytohaemagglutinin (PHA) swelling response is a good indicator of T‐cell‐mediated immunity in free‐living birds

Cited by 8 publications

References 35 publications

Seasonal variation in sex-specific immunity in wild birds

Seasonal variation in sex-specific immunity in wild birds

Lack of statistical power as a major limitation in understanding MHC‐mediated immunocompetence in wild vertebrate populations

Evaluation of Cellulosic Polymers and Curcumin to Reduce Aflatoxin B1 Toxic Effects on Performance, Biochemical, and Immunological Parameters of Broiler Chickens

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