PROJECT SUMMARY:
Captive black rhinoceros, unlike their free-ranging counterparts
or captive white rhinoceros, develop unusual diseases, which include
hemolytic anemia, mucocutaneous ulcerative syndrome and fungal
pneumonia, that adversely impact the ability to propagate this
endangered species.18
The clinical presentation of these disorders suggest impaired
immune function, but little data exists on evaluating immune function
in rhinoceros to substantiate that captive black rhinos are immunocompromised
compared to captive white rhinos. This collaborative proposal
will evaluate immune parameters for innate and cell-mediated immunity.
In addition, mRNA expression of cytokines, proteins which orchestrate
immune function, will be studied. Innate immunity refers to defense
mechanisms not dependent on antigen specific recognition and for
this study will include phagocytosis, respiratory burst, and neutrophil
killing.
Cell-mediated immunity will be evaluated by mitogen and antigen-specific
lymphoproliferative assays. Consensus sequence primers for mammalian
cytokines will be tested in rhinos using reverse transcriptase
quantitative competitive polymerase chain reaction (RT-qc PCR).
Cytokines to be evaluated include interleukin (IL-) 2, IL-12,
and gamma-interferon (g-IFN) which regulate cell-mediated immune
function, and IL-6 and IL-10 which modulate humoral immune function.
Blood samples from 10 black and 10 white rhinos will be collected
at institutions that have conditioned their animals to stand for
blood collection without chemical immobilization. As stress and
chronic iron overload 15,16,28 have been postulated as possible
predisposing conditions, serum will be collected for cortisol
levels, iron and total iron binding capacity, and feces sampled
for corticosterone levels to determine if these values correlate
with measured immune function parameters.
