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Query: UMLS:C0043167 (
pertussis
)
19,595
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We examined the role of augmented formation of intracellular cyclic AMP (cAMP) in the mediation of stromal cell growth factor production that occurs constitutively or upon cytokine stimulation. Clonal murine marrow adherent cell lines were stimulated under serum-free conditions by interleukin-1 (IL-1) or lipopolysaccharide (LPS) and one (+/+ -1.LDA11) was found to produce low quantities of granulocyte macrophage colony-stimulating factor (GM-CSF). GM-CSF identity was confirmed by the ability of supernatants from stromal cells to promote proliferation of the factor-dependent cell line FDC-P1, neutralization of this activity by antiserum to GM-CSF, and by Northern blot analysis. However, optimal concentrations of IL-1 and tumor necrosis factor-alpha (TNF-alpha), in combination, led to synergistic (greater than 5-fold higher quantity) GM-CSF production compared with either stimulus alone in the +/+ -1. LDA11 cell line, capable of GM-CSF production after only single stimulation with IL-1 or LPS. In addition, synergistic stimulation by IL-1 and TNF-alpha led to equivalent high amounts of GM-CSF in another cell line incapable of GM-CSF production after induction with only IL-1 or LPS. Any of several means to raise intracellular cAMP levels, including addition of 8-bromo-cyclic AMP (8Br cAMP) (0.25-1mM),
pertussis
toxin (20-100 ng/ml), or addition of prostaglandin E1 (PGE1) (1 microM), failed to stimulate GM-CSF production alone and strongly inhibited GM-CSF production in stromal cells stimulated by IL-1, LPS, or the synergistic combination of IL-1 and TNF-alpha. In addition, PGE1 and
pertussis
intoxication were agonists of adenylate cyclase in membranes of marrow adherent cells, whereas IL-1 and LPS were not. The role for regulators of intracellular cAMP was specific because any of the cAMP agonists alone, or in the presence of cytokine stimulators of stromal cells, strongly enhanced IL-6 production, an event known to be cAMP-responsive. Thus, acute formation of intracellular cAMP is a negative regulator of stromal cell GM-CSF production mediated by cytokines, but positively regulates IL-6 production and may be an important determinant of cytokine-directed marrow microenvironmental function. These findings on the requirement for augmentation versus inhibition of cytokine-mediated production of hemopoietic growth factors might be applied to an analysis of marrow stromal cell heterogeneity.
Leukemia
1990 Jul
PMID:Role for cyclic AMP in the postreceptor control of cytokine-stimulated stromal cell growth factor production. 216 2
The in vitro differentiation of multipotent stem cells in long-term marrow cultures can be blocked by treatment with agents that modify cholera toxin induced ADP-ribosylation of proteins. The latter agents also inhibit the growth and development of progenitor cells in soft gels in response to interleukin-3 but have little effect upon the development of progenitor cells that respond to the macrophage colony stimulating factor (CSF-1). Cholera toxin, in the same system, inhibits the development of CSF-1 responsive progenitor cells but has little effect on the development of cells that respond to IL-3. Similarly, progenitor cells that respond to IL-3 are relatively more resistant to
pertussis
toxin than cells that respond to CSF-1. These data indicate that ADP-ribosylation may be an important post-translational modification of regulatory proteins concerned with hemopoietic cell differentiation and growth in response to stromal cells or growth factors.
Leukemia
1988 Jan
PMID:The development of hemopoietic cells in response to stromal cells or growth factors is modified by agents that influence ADP-ribosylation. 312 9
cAMP-dependent signal transduction co-operates with retinoids to induce acute promyelocytic leukaemia (APL) cell maturation. The rationale of this work was to determine whether signal cross-talk could be used to decrease the pharmacological doses of retinoids in the treatment of APL. When only the basal level of adenylate-cyclase (AC) activity is present in NB4 cells, up to 1 microM concentration of all-trans retinoic acid (RA) is required for full maturation (100%). In these conditions, with only 10 nM RA less than 20% of cells will differentiate. Although the use of membrane receptor agonists to activate AC has been proved to synergize with RA treatment, these agents were never as potent as cell permeant cAMP analogues. Analogues have disadvantages since cleavage by serum and cellular phosphodiesterases generates metabolites which interfere in cellular response. In the present study, we observed cell maturation by engrafting an autonomous Bordetella
pertussis
AC which steadily delivers natural cAMP into the cell. The enzyme alone had no effect on cell maturation. Importantly, cell maturation was increased in a dose-dependent manner when the bacterial AC (1 ng/ml to 1 microg/ml) was used to potentiate the effects of low doses RA (10 nM). More than 50% of cells matured with only 10 nM of RA and 200 ng/ml of B.
pertussis
AC. The maturation response was significantly increased when lower amounts of enzyme were repetitively added to the culture to compensate for enzymatic decay. These results indicate that a sustained AC activity enhanced cell maturation. We were able to reduce to 3 nM the RA requirement, provided that a minimal amount (20 ng/ml) of B.
pertussis
AC was added every 12 h in culture. Membrane signalling maintaining high the level of cAMP substantially improved the efficacy of APL cell maturation by retinoids. Therefore, therapeutic benefits are expected by lowering the concentration of RA towards physiological (nanomolar) levels, thus reducing the side-effects of the drug. cAMP-elevating drugs that act on a post-cyclase target (cyclic-nucleotide phosphodiesterases) or cell-targeted drug carriers (cAMP and RA loaded liposomes) should be evaluated as maturation therapies combining the activation of multiple signalling pathways.
Leukemia
1998 Nov
PMID:A sustained increase in the endogenous level of cAMP reduces the retinoid concentration required for APL cell maturation to near physiological levels. 982 61
Intensified chemotherapy regimens resulting in improved survival of children with acute lymphocytic leukemia (ALL) lead to concerns about therapy-induced immune damage reflected by the loss of protection of previous immunizations and the efficacy of (re-)vaccination. The severity of secondary immunodeficiency, however, is not clear and knowledge is based on a limited number of studies. We performed a systematic review on literature concerning vaccination data of children with ALL published since 1980. Eight studies fulfilled the inclusion criteria. Regarding antibody titers after treatment, the number of children who had preserved the defined protection level for antibodies differed widely, ranging from 17 to 98% for diphtheria, 27 to 82% for Bordetella
pertussis
, 20 to 98% for tetanus, 62 to 100% for poliomyelitis, 35 to 100% for Haemophilus influenzae type B (HiB), 29 to 92% for mumps, 29 to 60% for measles and 72 to 92% for rubella. Most patients however responded to revaccination, demonstrating immunological recovery. Although the designs and results of the included studies varied widely, it can be concluded that cytostatic therapy for ALL in children results in a temporarily reduction of specific antibody levels. Memory is preserved but revaccination may be warranted. This is the first systematic review and the best possible current approximation of chemotherapy-induced immune damage in children after ALL treatment.
Leukemia
2006 Oct
PMID:Loss of antibodies and response to (re-)vaccination in children after treatment for acute lymphocytic leukemia: a systematic review. 1688 19