NAJAR H, RUHI S, BRU-CAPDEVILLE A C A, PETERS P J. CYCLIC NUCLEOTIDES CONTROL DIFFERENTIATION OF HUMAN MONOCYTES INTO EITHER HIGHLY ACCESSORY CELLS OR MACROPHAGES. Med J Islam Repub Iran 1988; 2 (3) :219-228
URL:
http://mjiri.iums.ac.ir/article-1-1253-en.html
From the Department of Immunology, University of Gottingen, West Germany
Abstract: (4264 Views)
Human peripheral blood monocytes have been found to undergo a
transitory state of high accessory activity before they fully become macrophages.
Time kinetics were done to follow this accessory potential.
Studying the regulation of accessory activity, we have found that monocyte
derived accessory cells (m-AC) pass through two phases of development,
both of which are adversely controlled by cyclic nucleotides. Phase I is
positively correlated by intracellular cAMP increase and can be blocked by
increase of cGMP, whereas phase II positively correlates with increase of
intracellular cGMP and can be completel y blocked by cAMP and synergystic
agents. In addition to cAMP, non-cyclic adenine nucleotides and adenosine
also mimic all cAMP effects. This behavior is explained by the known
presence of surface 5- nucleotidase and adenosine receptors which in turn
leads to activation of adenyl ate cyclase. At phase II, serum is required to
convert m-AC into macrophages. In the absence of serum, cells were
arrested in the m-AC state. Adenine nucleotides effectively counteract
serum induction, leading to the development of m-AC even in the presence
of serum. Monocyte/macrophage markers such as Fc receptors and nonspecific
esterase strictly correlate negatively with the expression of accessory
activity, whereas morphologically the appearance of veils positively correlates
with all experimental situations of high accessory activity. Therefore, it
is evident that serum contains regulatory factors that strongly modify the
accessory potency of the m-AC via the cyclic nucleotide system, thus
presenting a new immunoregulatory principle at the beginning of the
immune cascade.