Phenotypical Characterization of Peripheral Blood Leucocytes in the Newborn Calf

Abstract

The present study was undertaken to establish reference values for the composition of blood leucocyte populations in neonatal calves by differential leucocyte cnunts and immunophenotyping. Neonatal calves 1 h post parturn @.p.) wcrc found to have a vcry high absolute number of granulocytes whde the number of peripheral blood mononuclear cclls was lower than in calves aged 3-9 weeks. The relative numbers of T cell subpopulations were similar in newborn and older calves, but newborn calves had lower percentages of B cells and MtIC class I1 posltive cells. Within the first 4 h of life the relauve numbers of CD2', CD6', and CD8' 1' cells dcclincd in colostrum-fed as well as in colostrum-deprived calves. In contrast, the percentage o f M H C class I1 positive cells and monocytes increased from 1 h to 4 h p.p. particularly in colostrum-fed calvcs. Although there is some evidence for immatunty o f lymphocytes in neonatal calves, the immune system of these animals seems to be fully present at birth.

Composition and Functional Capacity of Blood Mononuclear Leukocyte Populations from Neonatal Calves on Standard and Intensified Milk Replacer Diets

“…The percentage of B cells increased with time, most notably from 32 to 60 d of age. Similar age-dependent increases in the proportion of circulating B cells in young calves have been reported (Senogles et al, 1978;Menge, et al, 1999;Nonnecke et al, 1999) and also is typical of the maturing immune system of the calf. The transient, early increase in percentages of CD4 + T cells and cells expressing activation antigens (i.e., MHC class II antigen and IL-2r expression increased on stimulated lymphocytes and monocytes) may be indicative of a state of immune activation.…”

Bovine Ileal Intraepithelial Lymphocytes Represent Target Cells for Shiga Toxin 1 fromEscherichia coli

“…Immediately after preparation or at the end of the cultivation period, IEL were thoroughly resuspended and transferred to V-shaped microtiter plates (Greiner, Frickenhausen, Germany) for immunolabeling as described previously (22,25). Briefly, the cells were centrifuged (at 137 ϫ g and 4°C for 7 min) and resuspended in 50 l of cell culture medium as a negative control or with supernatants or diluted ascites fluid of hybridoma cell lines.…”

Verotoxin 1 fromEscherichia coliAffects Gb3/CD77+Bovine Lymphocytes Independent of Interleukin-2, Tumor Necrosis Factor-α, and Interferon-α

“…After stimulation. PBMC were thoroughly resuspended and transferred to V-shaped microtiter plates (Greiner, Frickenhausen, Germany) at the end of the cultivation period and were pelleted by centrifugation (150g at 4°C for 7 min) as described by Menge et al (23). The pellets were resuspended in 50 J.LI of cell culture medium as a negative control or with supernatant of hybridoma cell lines (lL-A 43 for BoCD2, IL-A II for BoCD4, IL-A I05 for BoCD8, IL-A65 for BoCD21.…”