Associations between testosterone and immune activity in alligators depend on bacteria species and temperature

LaVere, Ashley A.; Hamlin, Heather J.; Lowers, Russell H.; Parrott, Benjamin B.; Ezenwa, Vanessa O.

doi:10.1111/1365-2435.13756

Cited by 9 publications

(7 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because reptilian immune responses are temperature sensitive [ 13 ], another key question is if immunological functions, such as the ability to respond to pathogens with IgY antibodies, will be more effective. It is now appreciated that external temperatures affect alligator anti-microbial activity against select bacteria, and that testosterone affects these activities [ 46 ], but how these interactions affect pathogen specific and total IgY levels remains to be determined.…”

Section: Discussionmentioning

confidence: 99%

“…The recovery of alligator populations by the late 1980s following two decades of legal protection eventually led to sustainable use of alligators through farming and ranching programs [ 4 ]. As with any commodity species, growing crocodilians at high densities within confined spaces can lead to disease outbreaks [ 46 ]. Many of these bacterial diseases could be treated prophylactically using vaccination protocols, and early success could be monitored by immunodiagnostics as is done for the chicken industry (Munhoz et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Quantifying Circulating IgY Antibody Responses against Select Opportunistic Bacterial Pathogens and Correlations with Body Condition Factors in Wild American Alligators, Alligator mississippiensis

Alston

Rainwater

Parrott

et al. 2022

Biology

Self Cite

View full text Add to dashboard Cite

Little is known about the disease ecology of American alligators (Alligator mississippiensis), and especially how they respond immunologically to emerging infectious diseases and zoonotic pathogens. In this study, we examined serum samples collected from wild alligators in Florida (2010–2011) and South Carolina (2011–2012, 2014–2017) for antibody responses to multiple bacteria. Immunoglobulin Y (IgY) was purified from serum to generate a mouse monoclonal antibody (mAb AMY-9) specific to the IgY heavy chain. An indirect ELISA was then developed for quantifying antibody responses against whole cell Escherichia coli, Vibrio parahaemolyticus, Vibrio vulnificus, Mycobacterium fortuitum, Erysipelothrix rhusiopthiae, and Streptococcus agalactiae. In Florida samples the primary differences in antibody levels were between January–March and late spring through summer and early fall (May–October), most likely reflecting seasonal influences in immune responses. Of note, differences over the months in antibody responses were confined to M. fortuitum, E. rhusiopthiae, V. vulnificus, and E. coli. Robust antibody responses in SC samples were observed in 2011, 2014, and 2015 against each bacterium except E. coli. All antibody responses were low in 2016 and 2017. Some of the highest antibody responses were against V. parahaemolyticus, M. fortuitum, and E. rhusiopthiae. One SC alligator estimated to be 70+ years old exhibited the highest measured antibody response against V. parahaemolyticus and M. fortuitum. By combining data from both sites, we show a clear correlation between body-mass-indices (BMI) and antibody titers in all six of the bacteria examined. Our study provides a critical antibody reagent and a proof-of-concept approach for studying the disease ecology of alligators in both the wild and in captivity.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Quantifying Circulating IgY Antibody Responses against Select Opportunistic Bacterial Pathogens and Correlations with Body Condition Factors in Wild American Alligators, Alligator mississippiensis

Alston

Rainwater

Parrott

et al. 2022

Biology

Self Cite

View full text Add to dashboard Cite

show abstract

“…There is evidence that different reptiles may have differential immunocompetence against Gram‐positive and Gram‐negative bacteria. LaVere et al (2021) noted the reduced bactericidal ability of American alligators ( Alligator mississippiensis ) against Salmonella typhimurium may be caused by the lack of exposure to this pathogen under natural conditions. In our current study, prior pathogen exposure does not impact our results because BKAs are a measure of innate immunity (Demas et al, 2011).…”

Section: Discussionmentioning

confidence: 99%

Immune and stress physiology of two captively‐housed tortoise species

et al. 2022

View full text Add to dashboard Cite

Ecoimmunology affords us the ability to better understand immunological processes through consideration of external factors, such as the thermal microenvironment. This consideration is imperative when examining the immunological processes of ectothermic organisms like reptiles. Reptiles uniquely rely heavily on their innate immune function but remain poorly understood in immunological studies. In this study, we examined innate immunity in two zoo‐housed tortoise species, the Indian star tortoise (Geochelone elegans, Schoepff, 1795) and northern spider tortoise (Pyxis arachnoides brygooi, Vuillemin & Domergue, 1972). Bacterial killing assays (BKAs) were optimized and used to assess the monthly immunocompetence of these tortoises to three different bacteria: Escherichia coli, Salmonella enterica, and Staphylococcus aureus. We evaluated differences in blood biochemistry values (lactate and glucose) among months and species as well as fecal corticosterone (CORT) between species. Lastly, we examined the potential influences of individual thermal microenvironments on bactericidal ability. Both G. elegans and P. a. brygooi demonstrated immunocompetence against all bacterial challenges, but only bactericidal ability against E. coli varied over months. Optimal BKA serum dilutions, blood glucose levels, and fecal CORT concentrations differed between the two species. Finally, there was evidence that the thermal microenvironment influenced the tortoises’ bactericidal ability against E. coli. Through use of nonmodel organisms, such as tortoises, we are given insight into the inner workings of innate immunity and a better understanding of the complexities of the vertebrate immune system.

show abstract

“…The swelling response to PHA increased with the baseline values of testosterone in free-ranging tree sparrows (Passer montanus; [59]), but an experimental treatment with testosterone decreased the swelling response in common wall lizards (Podarcis muralis; [60]), dark-eyed juncos (Junco hyemalis; [61]), and European starlings (Sturnus vulgaris; [62]), but not in house sparrows (P. domesticus; [63]). Testosterone had a positive correlation with the BKA in free-living Grant s gazelle (Nanger granti; [64]), but this relationship was negative in red-winged blackbirds (Agelaius phoeniceus; [65]) and in American alligators (Alligator mississippiensis; [66]). Among bats, the relationship between testosterone levels and the immune response has been examined in a handful of studies, but with different immune components from those included in our study.…”

Section: Immune Response and Its Relationship With Steroid Sex Hormonesmentioning

confidence: 99%

Physiological and Ecological Correlates of the Cellular and Humoral Innate Immune Responses in an Insular Desert Bat: The Fish-Eating Myotis (Myotis vivesi)

et al. 2022

View full text Add to dashboard Cite

The immune response is affected by aridity, but it has been rarely examined in desert-dwelling bats. For two consecutive years, we examined the seasonal variation in the innate immune response of an insular desert bat, the fish-eating myotis (Myotis vivesi), in relation to its reproductive activity and ectoparasite load. We evaluated the reproductive activity based on external morphological traits and testosterone levels in the plasma for males and progesterone and estradiol for females. We injected phytohemagglutinin (PHA) into the footpads of the bats to estimate the innate cellular response, and we measured the bacterial killing ability (BKA) of the blood plasma to determine the innate humoral response. Both the external morphological traits and hormone levels indicate that the females were pregnant in spring and lactating in summer, and that the males were reproductively active in autumn, when mating probably occurred. The swelling response of the female and male bats was lower in spring. The BKA in the males did not vary seasonally; the BKA in the females varied seasonally but only in the first year of the study, with lower values in spring and summer. The BKA in spring was lower in the first year of the study, when the females appeared to be in early pregnancy, compared to the second year, when the females were in advanced pregnancy. The swelling increased as the body mass and body conditions of the males increased, but the BKA was not correlated with body mass or body condition in either sex. Ectoparasite abundance and prevalence did not vary among seasons. Ectoparasite abundance was not correlated with the PHA response in both sexes; it was not correlated with the BKA in females, but it was inversely correlated in males. Of the three hormones measured, only estradiol was correlated with the immune response: females with higher estradiol levels had a higher PHA response and BKA. Our findings indicate that the cellular and humoral innate immune responses of the fish-eating myotis varied throughout the year, following the seasonal reproductive pattern of the species. Our evaluation of the proximal factors affecting the expression of the immune response points to the potential immunoregulatory role of sex hormones and body mass.

show abstract

Associations between testosterone and immune activity in alligators depend on bacteria species and temperature

Cited by 9 publications

References 66 publications

Quantifying Circulating IgY Antibody Responses against Select Opportunistic Bacterial Pathogens and Correlations with Body Condition Factors in Wild American Alligators, Alligator mississippiensis

Quantifying Circulating IgY Antibody Responses against Select Opportunistic Bacterial Pathogens and Correlations with Body Condition Factors in Wild American Alligators, Alligator mississippiensis

Immune and stress physiology of two captively‐housed tortoise species

Physiological and Ecological Correlates of the Cellular and Humoral Innate Immune Responses in an Insular Desert Bat: The Fish-Eating Myotis (Myotis vivesi)

Contact Info

Product

Resources

About