الملخص الإنجليزي
The reports from the Ministry of Agriculture and Fisheries suggest that camels suffer
less compared to goats, sheep, and cows from a number of common infectious diseases in
Oman. However, there is no immunological evidence to substantiate this claim. This present
study is, therefore an attempt to study the immunological responses of camels, goats, sheep,
and cows by comparing their oxidative respiratory burst of peripheral blood leukocytes
(PBLs) as a marker of innate immunity occurring during phagocytosis and the mitogenic
responses of their peripheral blood mononuclear leukocytes (PBMLs) as a marker of their
adaptive immune response.
Ten female adult animals (n=10) were selected from each of the four species (goats,
sheep, and cows). The goats, sheep, and cows were maintained at the Agricultural
Experiment Station (AES). The camels were kept at the Royal Camel Corps (RCC). Blood
samples were collected from the jugular vein in 7 ml of heparin and
Ethylenediaminetetraacetic acid (EDTA) vacutainer tubes. The oxidative respiratory burst
of PBLs was measured using a chemiluminescence (CL) assay. Reactants consisted of 75 l
of whole blood diluted (1:50), 75 l of luminol/ isoluminol, and 75 l of zymosan opsonized
with non-heat inactivated serum/ heat-inactivated serum or non-opsonized zymosan. CL
response was measured as relative light units (RLU) and was expressed as the mean count
per minute (CPM) and the peak CL value. The mitogenic response of PBMLs to
concanavalin A (Con A), phytohaemagglutinin (PHA), and pokeweed mitogen (PWM) were
tested using a WST-8 assay and read spectrophotometrically at 450 nm.
The current finding showed that camel PBL are able to generate more reactive
oxygen species (ROS) both intracellularly, as well as extracellularly with the phagocytes
target zymosan opsonized with autologous serum. Camel PBLs demonstrated significantly
higher (P=0.001) response when stimulated with zymosan opsonized with heat-inactivated
serum compared to those of goats, sheep, and cows. Lymphocytes from camels exhibited
significantly higher (P=0.001) stimulation indices than those from goats, sheep, and cows.
The present study suggests that camels are capable of mounting both superior innate
as well as adaptive immune responses and provide immunological evidence supporting the
belief of some authors who have proposed that camels are less susceptible to a number of
common infectious diseases than other domesticated ruminants.
