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In the dromedary she-camel, the impact of parturition on composition and phenotype of blood immune cells has not been evaluated so far. Therefore, the current study aimed to investigate the composition of blood leukocytes and their cell adhesion molecules expression in she-camels during the periparturient period. Using flow cytometry and membrane immunofluorescence, leukocyte composition and adhesion molecules expression were analyzed in blood samples collected from she-camels at days -28, -14, 0, +14 and +28 relative to calving. At parturition, she-camels showed a significant rise in the number of total leukocytes with increased numbers of neutrophilic granulocytes. Two weeks after calving, the number of total lymphocytes was significantly elevated. Among lymphocytes, the numbers of CD4+ T cells and B cells were expanded. Although the cell number of total monocytes did not change significantly during the periparturient period, significant differences in the fractions of monocyte subsets were observed. The number of the CD14high MHCIIlow monocyte subset was significantly decreased at calving and remained at a low abundance during the postparturient time, while the numbers of the CD14high MHCIIhigh and the CD14low MHCIIhigh monocyte subsets was increased after calving. For neutrophils (at calving and at day +14 after calving) and monocytes (at calving), a significant increase in the expression of the cell adhesion molecule CD11a was observed. Collectively, the present study identified several alterations in the leukogram and distribution of blood monocyte and lymphocyte subpopulations during the periparturient period in dromedary she-camels. [ABSTRACT FROM AUTHOR]

To assess the temporal dynamics of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in dromedary camels, specimens were collected at 1-2 month intervals from 2 independent groups of animals during April 2013-May 2014 in Al-Ahsa Province, Saudi Arabia, and tested for MERS-CoV RNA by reverse transcription PCR. Of 96 live camels, 28 (29.2%) nasal swab samples were positive; of 91 camel carcasses, 56 (61.5%) lung tissue samples were positive. Positive samples were more commonly found among young animals (<4 years of age) than adults (≥4 years of age). The proportions of positive samples varied by month for both groups; detection peaked during November 2013 and January 2014 and declined in March and May 2014. These findings further our understanding of MERSCoV infection in dromedary camels and may help inform intervention strategies to reduce zoonotic infections. [ABSTRACT FROM AUTHOR]

Pregnancy is associated with different local and systemic changes in immune cell phenotype and function. Here, we used flow cytometry and membrane immunofluorescence for the comparison between pregnant (n=18) and non-pregnant she camels (n=21) in terms of immunophenotype of blood leukocytes and phagocytosis activity of neutrophils. Camel blood leukocytes were labeled with monoclonal antibodies to camel antigens and analyzed by flow cytometry. Pregnant she camels displayed higher leukocyte counts than non-pregnant animals. Differential analysis of leukocyte populations revealed higher proportions of monocytes, lymphocytes and CD4-positive T cells but lower proportion of neutrophils in pregnant she camels in comparison to non-pregnant animals. Pregnancy was also associated with enhanced expression of the cell adhesion molecule CD11a on neutrophils but reduced CD11a expression on lymphocytes in pregnant animals. After incubation with FITC-labeled bacteria, flow cytometric exvivo analysis of bacterial phagocytosis by neutrophils showed higher phagocytosis capacity in neutrophils from pregnant than from non-pregnant animals. Together these results indicate significant modulating effects of pregnancy on the immune system of she camels. [ABSTRACT FROM AUTHOR]

Endometritis represents the main cause of reproductive failure in dromedary camels. In dromedary camels, associations between endometritis-causing pathogen-species, disease severity, and systemic changes in the immune system have not been evaluated. In the current study, there was use of flow cytometry and immunofluorescence of membrane proteins for the evaluation of leukocyte subsets and the cellular phenotype in blood of camels with clinical endometritis and evaluations of associations with disease severity and endometritis-causing pathogens. Animals with endometritis had markedly larger numbers of total leukocytes and neutrophils. Although total lymphocyte and monocyte counts did not differ between camels with and without clinical endometritis, there were lesser numbers of total and effector CD4-positive T cells in camels with endometritis. Among monocytes, number of camel inflammatory monocytes (Mo-II) was markedly greater, whereas Mo-III numbers were less in the blood of camels with clinical endometritis. Number of inflammatory monocytes was also indicative of endometritis severity grade. Among camels with clinical endometritis, E. coli- and S. aureus-infected animals had similar endometritis grades and comparable phenotype and composition patterns of leukocytes. Neutrophils and monocytes of camels with clinical endometritis had fewer cell adhesion molecules (i.e., CD11a and CD18). Collectively, the results from the current study allowed for identification of associations between endometritis severity grade and larger numbers of inflammatory monocytes. The results also indicate there is no association between endometritis pathogen-species and changes in phenotype or composition of blood leukocytes., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background and Aim: Different properties of the newborn immune system have been characterized in many species. For the newborn camel calf, however, the phenotype and composition of blood leukocytes have so far not been evaluated. The current study aimed to analyze the distribution of leukocyte subpopulations and their expression pattern of cell adhesion molecules in newborn and adult dromedary camels., Materials and Methods: Blood samples were collected from 17 newborn camel calves and 32 adult camels. For each sample, total leukocytes were separated and analyzed for their composition and cell adhesion molecules expression by flow cytometry., Results: In comparison to adult camels, newborn camel calves had higher leukocyte numbers and higher numbers of neutrophils, monocytes, and lymphocytes but lower numbers of eosinophils in their blood. Among the lymphocyte populations in calves, the fractions of B cells and γ δ T cells were elevated when compared to adults, whereas CD4-positive T cells were reduced. The comparison between camel calves and adult camels revealed significantly lower expression of the cell adhesion molecules CD11a, CD11b, and CD18 on granulocytes, monocytes, and lymphocytes in calves., Conclusion: Newborn camel calves show a distinct composition and phenotype pattern of blood leukocytes when compared to adult camels. The observed rise in many leukocyte populations in calf blood may be due to reduced migratory activity in calf leukocyte populations., (Copyright: © Gaashan, et al.)