Chicken Peripheral Blood Mononuclear Cells Research Articles

The use of flow cytometry to discriminate avian lymphocytes from contaminating thrombocytes

Evaluation of peripheral blood mononuclear cells (PBMC) in avian species by flow cytometry is complicated by the presence of large numbers of nucleated thrombocytes. With light scattering properties similar to those of lymphocytes, variations in the proportion of thrombocytes in PBMC can result in apparent shifts in percentages of lymphocyte subpopulations. We have applied a dual-labeling procedure for flow cytometric analyses to exclude thrombocytes from the analyzed population by labeling with K55 monoclonal antibody (MAb), which differentially labeled leukocyte and thrombocyte populations. Flow cytometric analyses with K55 labeled chicken PBMC differentiated leukocytes into three populations according to their intensity of fluorescence. Using the Kl MAb, the K55-low population was shown to consist of thrombocytes. Dual-labeling with K55 MAb and MAb specific for B lymphocyte, CD4 or CD8 markers indicated that the K55 intermediate population consisted of lymphocytes. Therefore, concentrations of CD4 + and CD8 + T lymphocytes could be determined from the lymphocyte fraction by gating specifically on the K55 intermediate cells. Selecting cross-reactive chicken MAbs that included K55, this protocol was shown to identify CD4 + and CD8 + T lymphocytes in PBMC of another avian species, the endangered Attwater's prairie chicken.

High level expression of C-terminal truncated recombinant chicken interferon-gamma in baculovirus vector system.

Chicken interferon-gamma (ChIFN-gamma) was expressed by baculovirus in a C-terminal truncated form, namely ChIFN-gammaT, to accelerate the secretion of the expressed protein. It is also expressed as ChIFN-gammaT bearing poly His tag, ChIFN-gammaTHis, for easy purification. The expressed proteins were detected by SDS-PAGE analysis with Coomassie brilliant blue staining. The purified ChIFN-gammaTHis with nickel chelated column showed anti-viral activity in vitro and stimulation of the secretion of nitrogen intermediates such as nitric oxide in chicken peripheral blood mononuclear cells. Antiserum against ChIFN-gammaTHis recognized the 15 kDa, 16 kDa, and 32 kDa bands that seemed to be an unglycosylated monomer, a glycosylated monomer, and a homodimer of ChIFN-gammaTHis in the culture supernatant, respectively. The anti-serum also recognized around 14 kDa and 28 kDa bands in the sera of chickens or concanavalin A stimulated spleen cell culture supernatants that seemed to be monomeric and dimeric forms of a natural ChIFN-gamma, respectively.

Transformation-associated cytokine 9E3/CEF4 is chemotactic for chicken peripheral blood mononuclear cells

9E3/CEF4, which is released from transformed chicken embryo fibroblasts (CEF), is a member of the platelet factor 4 family of inflammatory proteins and may be the avian homolog of interleukin-8. Since the function of 9E3/CEF4 is unknown, we examined the effect of the protein on mitogenicity and chemotaxis, as well as its expression, in fibroblasts and peripheral blood cells. 9E3/CEF4 mRNA was expressed in chicken peripheral blood monocytes, and its expression was stimulated by incubation of the monocytes with lipopolysaccharide or phorbol myristic acetate. Boyden double-membrane analysis of chemotaxis showed that 9E3/CEF4 was chemotactic for chicken peripheral blood mononuclear cells, as well as for heterophils. Untransformed CEF and CEF transformed with Rous sarcoma virus also migrated to 9E3/CEF4 protein, as measured by Boyden single-membrane analysis. 9E3/CEF4 was slightly mitogenic for CEF, causing a doubling of [3H]thymidine uptake when added to serum-starved CEF.9E3/CEF4 was found associated not only with the cell and in the culture medium of Rous sarcoma virus-transformed CEF but also with the extracellular matrix. The in vivo role of 9E3/CEF4 may be involved with chemotaxis and metastasis, rather than with direct stimulation of mitogenicity.