Influence of the combination of stress factors on immune functions in Caiman latirostris (Preliminary Results)

MOLEÓN, MS (EQUAL CONTRIBUTION); LOPEZ GONZALEZ, E (EQUAL CONTRIBUTION); ETCHEVERS, L; ADDONA, S; POLETTA, GL; SIROSKI, PA

Congreso; 26th Working meeting CSG-IUNC; 2022

Exposure to factors like pathogens, toxic substances, food restriction, climatic eventsfactors such as extreme temperatures, drought, etc. are some of the stressful situations thatCaiman latirostris populations could face. In this context, the ability to mount an effectiveimmune response, as well as its regulation after exposure to any of these stressful situations,are very important in the life history of these organisms. Previous studies have indicated thatartificial constant high temperatures appeared to be beneficial, individuals exposed to heattreatment (37 ± 1°C) grew more, showed better body condition, and higher levels of naturalantibodies. However, stress factors in the wild are not found alone. In the present study, weevaluated the effect of 8-weeks exposure to treatments of combinations of potentialsenvironmental factors (food restriction + high temperature: FT, glyphosate + high temperature:GT, and control) and then they were challenged with bacterial (B) or saline solution (SF).Growth (weight, TL and SVL), immunological investment (white blood cells counts, naturalantibody levels, complement system activity) and corticosterone levels of juveniles C.latirostris (10-month-old) were measured. FT treatment showed the lower growth andcorticosterone levels related to caimans of GT+B and control groups, whereas those caimansexposed to GT+B had higher lymphocyte and eosinophil counts than control. Additionally,animals exposed to GT+B had higher activity of the complement system than control. In thisstudy, we also identified and calculated certain broad-snouted caiman immune-related genesexpression (TNF- and IL-6) and they have depicted different patterns during B infection inboth treatments. Our results suggest that C. latirostris juveniles are able to tolerate combinedenvironmental factors without compromise immune system activity.