TY - JOUR
T1 - Protein kinase C-θ (PKCθ) distribution analysis in hematopoietic cells
T2 - Proliferating T cells exhibit high proportions of PKCθ in the particulate fraction
AU - Meller, Nahum
AU - Elitzur, Yair
AU - Isakov, Noah
N1 - Funding Information:
Work at our laboratory is supported, in part, by grants from the Israel Academy of Sciences and Humanities, the USA–Israel Binational Science Foundation, the Chief Scientist of the Ministry of Health, the Israel Cancer Research Association, and the Israel Cancer Research Fund.
PY - 1999/5/1
Y1 - 1999/5/1
N2 - A comparative analysis of protein kinase C-θ (PKCθ) protein expression was performed in various mouse organs and tissues, freshly isolated populations of mouse and human hematopoietic cells, primary leukemias, and established cell lines of different histological origins. Results demonstrated a predominant expression of PKCθ in lymphoid tissues and skeletal muscle. Expression levels of PKCθ, as well as PKCα, δ, ε, ζ, and η in the thymus, were not markedly changed during postnatal development. High levels of expression were observed in CD4+ and CD8+ single-positive T cells and CD4+ CD8+ double-positive thymocytes, while B cells were completely devoid of PKCθ. PKCθ was found also in platelets, but relatively low levels or no detection of PKCθ expression were observed in neutrophils, monocytes, and macrophages. Highly proliferating leukemic T cells of established lines or primary tumors, but not freshly isolated resting peripheral blood T cells, exhibited high levels of membrane-bound PKCθ. Increased proportions of PKCθ in the particulate fraction was not restricted to malignant cells but correlated with the extent of proliferation of the T cells. Thus, human peripheral blood T cells that were induced to proliferate by exposure to mitogen and IL-2 expressed increased levels of PKCθ in the particulate fraction. Significantly lower proportions of membrane-bound PKC were observed for five other isoenzymes expressed in T cells. The occurrence of PKCθ in T, but not B, cells and its subcellular distribution in proliferating cells implicate PKCθ in cellular mechanisms regulating the sustained proliferation of T cells.
AB - A comparative analysis of protein kinase C-θ (PKCθ) protein expression was performed in various mouse organs and tissues, freshly isolated populations of mouse and human hematopoietic cells, primary leukemias, and established cell lines of different histological origins. Results demonstrated a predominant expression of PKCθ in lymphoid tissues and skeletal muscle. Expression levels of PKCθ, as well as PKCα, δ, ε, ζ, and η in the thymus, were not markedly changed during postnatal development. High levels of expression were observed in CD4+ and CD8+ single-positive T cells and CD4+ CD8+ double-positive thymocytes, while B cells were completely devoid of PKCθ. PKCθ was found also in platelets, but relatively low levels or no detection of PKCθ expression were observed in neutrophils, monocytes, and macrophages. Highly proliferating leukemic T cells of established lines or primary tumors, but not freshly isolated resting peripheral blood T cells, exhibited high levels of membrane-bound PKCθ. Increased proportions of PKCθ in the particulate fraction was not restricted to malignant cells but correlated with the extent of proliferation of the T cells. Thus, human peripheral blood T cells that were induced to proliferate by exposure to mitogen and IL-2 expressed increased levels of PKCθ in the particulate fraction. Significantly lower proportions of membrane-bound PKC were observed for five other isoenzymes expressed in T cells. The occurrence of PKCθ in T, but not B, cells and its subcellular distribution in proliferating cells implicate PKCθ in cellular mechanisms regulating the sustained proliferation of T cells.
UR - http://www.scopus.com/inward/record.url?scp=0032938157&partnerID=8YFLogxK
U2 - 10.1006/cimm.1999.1478
DO - 10.1006/cimm.1999.1478
M3 - Article
C2 - 10222061
AN - SCOPUS:0032938157
SN - 0008-8749
VL - 193
SP - 185
EP - 193
JO - Cellular Immunology
JF - Cellular Immunology
IS - 2
ER -