scholarly journals The generation and regulation of lymphocyte populations: evidence from differentiative induction systems in vitro.

1978 ◽  
Vol 147 (6) ◽  
pp. 1727-1743 ◽  
Author(s):  
M P Scheid ◽  
G Goldstein ◽  
E A Boyse
Keyword(s):  
B Cells ◽  
Cyclic Nucleotides ◽  
General Scheme ◽  
Pharmacological Agents ◽  
Inductive Effects ◽  
Camp Induction ◽  
Camp And Cgmp ◽  
Lymphocyte Populations ◽  
Two Populations

Results with a dual assay, for the induction of Thy-1+ T cells and of CR+ B cells from marker-negative precursors, confirm that thymopoietin is at present the only known selective inducer of prothymocytes. In contrast, various inducers, including ubiquitin, are active in both assays. Pharmacological evidence indicates that there are different cellular receptors for ubiquitin and thymopoietin. Prothymocytes and pro-CR+ B cells compose two distinct populations in bone marrow and spleen; their distribution in density gradients is different, and elimination of either population enriches the other proportionately. There are no noteworthy differences between induction of these two populations in regard to (a) kinetics, (b) dependence on temperature and protein synthesis, (c) activation by cAMP, and (d) inhibition by cGMP. The opposite inductive effects of cAMP and cGMP were corroborated by the use of pharmacological agents that raise or lower the levels of intracellular cyclic nucleotides. In contrast, a third induction assay, which monitors acquisition of the PC+ surface phenotype, indicates that this differentiative step, the last known for B cells, is initiated by cGMP and inhibited by cAMP. Induction of PC is also inhibited by thymopoietin, signifying that the inductive selectivity of thymopoietin is not due to restriction of its receptors to the T lineage cells. Rather it seems that receptors for thymopoietin occur also on PC-inducible and other B cells, although in this case geared biochemically to inhibition rather than expression of the succeeding gene program. This suggests a role for thymopoietin in the coordinated interregulation of lymphocyte classes, in addition to its better-known function as the thymic inducer of prothymocytes. Present data conform to a general scheme in which the cyclic nucleotides cAMP and cGMP, and agents that affect intracellular levels of these mediators, influence reciprocally the early and late (functional) phases of lymphocyte differentiation as a whole, while thymopoietin influences reciprocally the differentiation of the B and T classes of lymphocyte.

CGRP and ANF cause relaxation of opossum internal anal sphincter via different mechanisms

1991 ◽  
Vol 260 (5) ◽  
pp. G764-G769 ◽  
Author(s):  
S. Rattan ◽  
C. Moummi ◽  
S. Chakder
Keyword(s):  
Smooth Muscle ◽  
Anal Sphincter ◽  
Cyclic Nucleotides ◽  
Internal Anal Sphincter ◽  
Camp Content ◽  
Calcitonin Gene ◽  
Before And After ◽  
Camp And Cgmp

This investigation examined and compared the role of cyclic nucleotides in the mediation of internal anal sphincter (IAS) relaxation caused by the addition of neuropeptide calcitonin gene-related peptide (CGRP) and atrial natriuretic factor (ANF). The studies were performed in vitro on smooth muscle strips of opossum IAS. The relaxation produced by CGRP and ANF was examined before and after the addition of tetrodotoxin (TTX) (1 x 10(-6)M). At this concentration, TTX did not have any significant effect on the relaxation produced by either CGRP or ANF, suggesting that these peptides act directly on the smooth muscle. Addition of CGRP (3 x 10(-6) M) produced the maximal relaxation and significantly increased cAMP content without changing cGMP. On the other hand, addition of ANF (3 x 10(-6) M) caused a similar fall in IAS tension that was accompanied by a significant elevation in cGMP without any change in cAMP content. The rises in the levels of cyclic nucleotides preceded the onset of fall in the resting tension of IAS. Our results demonstrate that CGRP and ANF relax isolated strips of opossum IAS by their action directly at the smooth muscle and that this relaxation is associated with an increase in cAMP and cGMP, respectively. The studies suggest the presence of both cAMP and cGMP pathways in the IAS and that the relaxation of IAS smooth muscle in response to different peptides may occur via a specific intracellular biochemical pathway.

IL-21 Plus CpG ODN Induces Granzyme B-Dependent Induction of Apoptosis in CD5-Positive B Cells Including B-CLL Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2823-2823
Author(s):  
Sue E. Blackwell ◽  
Bernd Jahrsdoerfer ◽  
James E. Wooldridge ◽  
Jian Huang ◽  
Melinda W. Andreski ◽  
...  
Keyword(s):  
B Cells ◽  
Cord Blood ◽  
Granzyme B ◽  
Lymphocytic Leukemia ◽  
Cpg Odn ◽  
T And B Cells ◽  
B1 Cells ◽  
Lymphocyte Populations

Abstract Interleukin 21 (IL-21), a recently discovered cytokine with structural homology to IL-2, IL-4 and IL-15, has pleiotropic effects on lymphocyte populations including NK, T and B cells and is currently undergoing early clinical evaluation. We explored the effect of the combination of IL-21 and immunostimulatory CpG ODN on B chronic lymphocytic leukemia (B-CLL), and other CD5-positive B cells. IL-21 plus CpG ODN were synergistic in their ability to induce apoptosis of the B-CLL cells, and also induced production and secretion of granzyme B from the B-CLL cells. B-CLL cells treated with IL-21 and CpG ODN were capable of inducing apoptosis of untreated autologous B-CLL cells. This bystander killing was inhibited by anti-granzyme B antibodies. The effect was observed in all cases of CD5-positive B-CLL, but not in CD5-negative B-CLL samples. IL-21 plus CpG ODN also induced granzyme B production and apoptosis of benign CD5-positive B1 cells obtained from umbilical cord blood. In contrast, the number of CD5-negative B2 cells increased in the same samples during in vitro culture, resulting in a decreased ratio of CD5-positive to CD5-negative cord blood B cells (Fig. 1). Our results indicate the combination of IL-21 and CpG ODN is able to induce apoptosis of both benign and malignant CD5-positive B cells. Given the suspected role of B1 cells in autoimmune diseases, our findings could have important implications for the understanding of their pathogenetic mechanisms. These results might also open new avenues for the development of novel therapies for both autoimmune dieseases and CD5-positive B-CLL. Figure 1. IL- 21 and CpG ODN therapy selectively eliminates CD5 positive B cells in cord blood. Figure 1. IL- 21 and CpG ODN therapy selectively eliminates CD5 positive B cells in cord blood.

Sodium regulation of GAF domain function

2007 ◽  
Vol 35 (5) ◽  
pp. 1032-1034 ◽  
Author(s):  
M.J. Cann
Keyword(s):  
Cyclic Nucleotides ◽  
Protein Domain ◽  
Genetic Ablation ◽  
Anabaena Pcc 7120 ◽  
Cyanobacterium Anabaena ◽  
Signal Changes ◽  
Sodium Regulation ◽  
Pcc 7120 ◽  
Camp And Cgmp

Cyclic nucleotide PDEs (phosphodiesterases) regulate cellular levels of cAMP and cGMP by controlling the rate of degradation. Several mammalian PDE isoforms possess N-terminal GAF (found in cGMP PDEs, Anabaena adenylate cyclases and Escherichia coli FhlA; where FhlA is formate hydrogen lyase transcriptional activator) domains that bind cyclic nucleotides. Similarly, the CyaB1 and CyaB2 ACs (adenylate cyclases) of the cyanobacterium Anabaena PCC 7120 bind cAMP through one (CyaB1) or two (CyaB2) N-terminal GAF domains and mediate autoregulation of the AC domain. Sodium inhibits the activity of CyaB1, CyaB2 and mammalian PDE2A in vitro through modulation of GAF domain function. Furthermore, genetic ablation of cyaB1 and cyaB2 gives rise to Anabaena strains defective in homoeostasis at limiting sodium. Sodium regulation of GAF domain function has therefore been conserved since the eukaryotic/prokaryotic divergence. The GAF domain is the first identified protein domain to directly sense and signal changes in environmental sodium.

scholarly journals IDENTIFICATION OF MARROW-DERIVED AND THYMUS-DERIVED SMALL LYMPHOCYTES IN THE LYMPHOID TISSUE AND THORACIC DUCT LYMPH OF NORMAL RATS

1972 ◽  
Vol 135 (2) ◽  
pp. 200-219 ◽  
Author(s):  
Jonathan C. Howard ◽  
S. V. Hunt ◽  
J. L. Gowans
Keyword(s):  
Thoracic Duct ◽  
Lymphoid Tissue ◽  
Germinal Centers ◽  
Thoracic Duct Lymph ◽  
Lymphoid Tissues ◽  
Uridine Uptake ◽  
Duct Lymph ◽  
Lymphocyte Populations ◽  
Two Populations

These experiments show that small lymphocytes from the thoracic duct of rats are normally a mixture of thymus-derived and marrow-derived cells, and define the traffic areas in lymphoid tissues through which the two populations recirculate. Thoracic duct lymphocytes were labeled in vitro with uridine-3H and their histological distribution in the lymphoid tissues of normal recipients was demonstrated by radioautography. Labeled lymphocytes occupied two adjacent areas distinguished by a marked difference in the intensity of labeling; heavily labeled cells were found in thymus-dependent traffic areas of lymphocyte recirculation, while lightly labeled cells localized in the thymus-independent follicular areas around germinal centers. A corresponding heterogeneity of uridine uptake among small lymphocytes from normal donors was demonstrated by sedimentation at 1 g; slowly sedimenting cells incorporated little uridine and localized in follicular areas after transfusion while rapidly sedimenting cells incorporated more uridine and localized in thymus-dependent areas after transfusion. Experimentally prepared marrow-derived small lymphocytes behaved in sedimentation studies and after transfusion like a pure population of the lightly labeled small lymphocytes in normal lymph. Artificially reconstituted mixtures of marrow-derived and thymus-derived lymphocytes were qualitatively indistinguishable from normal lymphocyte populations.

scholarly journals Effect of cAMP on bovine oocyte maturation in vitro

2021 ◽  
Vol 285 ◽  
pp. 03013
Author(s):  
Valeria Makutina ◽  
Albina Isaeva ◽  
Anna Krivonogova ◽  
Alexey Deykin
Keyword(s):  
Oocyte Maturation ◽  
Cyclic Nucleotides ◽  
Camp Accumulation ◽  
Bovine Oocyte ◽  
Maturation In Vitro ◽  
Camp And Cgmp

Cyclic nucleotides cAMP and cGMP are among the main molecules that control the maturation of mammal oocytes. The in vitro simulated physiological oocyte maturation (SPOM) method was used to model cAMP accumulation in the oocyte. In the current study, we preincubated the oocytes of cows (not primed with FSH) with cAMP modulators: N 6,2’-O-dibutyryladenosine 3’,5’-cyclomonophosphate (dbcAMP) and 3-isobutyl-1-methylxanthine (IBMX). The use of SPOM increased the yield of bovine blastocysts.

scholarly journals Antifluorescein affinity columns. Isolation and immunocompetence of lymphocytes that bind fluoresceinated antigens in vivo or in vitro.

1976 ◽  
Vol 144 (1) ◽  
pp. 69-78 ◽  
Author(s):  
D W Scott
Keyword(s):  
B Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
New Method ◽  
Lymphocyte Populations

A new method for the isolation of specific immunocompetent lymphocytes has been described in which lymphocyte populations are exposed to fluoresceinated antigens (FLAGs) in vivo or in vitro, and the FLAG-binding cells retained on antifluorescein affinity columns. Specific cells are then eluted with an unrelated FL-labeled protein and shown to be fully immunocompetent. This methodology has been applied successfully in diverse antigenic systems including polymerized flagellin and TNP-specific B cells and alloantigen-reactive cytotoxic T lymphocytes. The method is rapid, inexpensive (requiring only antifluorescein beads), and can be applied to any antigens (or antibodies) in which a fluorescein group can be introduced.

Chronic Lymphocytic Leukemia Cells Have Increased Expression of Cyclic Nucleotide Phosphodiesterase 7B, Which May Serve as Disease-Specific Therapeutic Target.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2802-2802
Author(s):  
Lingzhi Zhang ◽  
Fiona Murray ◽  
Joan R. Kanter ◽  
Daisy Chou ◽  
Laura Rassenti ◽  
...  
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
Cyclic Nucleotides ◽  
Cyclic Nucleotide ◽  
Lymphocytic Leukemia ◽  
Cyclic Nucleotide Phosphodiesterase ◽  
Target Cells ◽  
Drug Induced ◽  
Induced Apoptosis

Abstract Non-specific inhibition of cyclic nucleotide phosphodiesterase (PDE) in chronic lymphocytic leukemia (CLL) cells leads to intracellular accumulation of cyclic nucleotides, which in turn can sensitize the CLL cells to spontaneous and/or drug-induced apoptosis. Recent studies have identified at least 11 isoforms of PDE, each of which catalyzes the hydrolysis of cAMP and/or cGMP and regulates the intracellular levels of cyclic nucleotides. The finding that various tissues differentially express selected PDE isoforms has prompted development of isoform-specific inhibitors that can selectively increase intracellular levels of cyclic nucleotides in target cells that over-express the inhibited PDE isoform. Accordingly, we examined for differential expression of PDE isoforms by CLL B cells by assessing the levels of mRNA encoding each of the 11 different PDE isoforms in CLL cells and normal blood lymphocytes using quantitative real-time RT-PCR. CLL cell samples (n = 24) and lymphocytes of healthy adults (n = 16) each expressed detectable levels of PDE isoforms 1A, 1B, 2A, 3A, 3B, 4A, 4B, 4C, 4D, 5A, 7A, 7B, 8A, 8B, and 9A. However, we discovered that CLL cells of each patient had significantly higher levels of PDE7B mRNA (2.8-fold to 368-fold) and significantly lower levels of PDE3B mRNA (5-fold to 138 fold) than did lymphocytes from healthy donors (n = 16). As such, the ratios of PDE7B/PDE3B in CLL cell samples were >3 (ranging from 3 to 1019), whereas normal lymphocytes had ratios of < 0.3 (ranging from 0.006 to 0.23). The mean PDE7B/PDE3B ratio for CLL cells (123.6 ± 45.0, S.D., n=24) was significantly higher than that for B-lymphocytes of normal donors (3.8 ± 1.1, n=10) (P<0.0001). Immunoblot analyses demonstrated that CLL cells uniformly expressed high levels of PDE7B and low levels of PDE3B relative to those of normal lymphocytes. Moreover, we found that PDE7B contributed predominantly to the total PDE activity in CLL cells but not in normal lymphocytes. We thus studied effect of a selective PDE7 inhibitor (BRL-50481) on CLL cells and normal lymphocytes in vitro and found that BRL-50481 dose-dependently promoted apoptosis of CLL cells, but not normal lymphocytes. Collectively these findings indicate that CLL B cells selectively over-express PDE7B and under-express PDE3B relative to normal lymphocytes or isolated blood B cells and suggest that selective inhibitors of PDE7B may be effective in the treatment of this disease.

Haemostatic Platelet Plug Formation in the Isolated Rabbit Mesenteric Preparation - An Analysis of Red Blood Cell Participation

1980 ◽  
Vol 44 (01) ◽  
pp. 006-008 ◽  
Author(s):  
D Bergqvist ◽  
K-E Arfors
Keyword(s):  
Whole Blood ◽  
Platelet Rich Plasma ◽  
Adenosine Diphosphate ◽  
In Vitro Test ◽  
Pharmacological Agents ◽  
Vitro Test ◽  
Releasing Effect ◽  
Plug Formation

SummaryIn a model using an isolated rabbit mesenteric preparation microvessels were transected and the time until haemostatic plugs formed was registered. Perfusion of platelet rich plasma gave no haemostasis whereas whole blood did. Addition of chlorpromazine or adenosine to the whole blood significantly prolonged the time for haemostasis, and addition of ADP to the platelet rich plasma significantly shortened it. It is concluded that red cells are necessary for a normal haemostasis in this model, probably by a combination of a haemodynamic and ADP releasing effect.The fundamental role of platelets in haemostatic plug formation is unquestionable but there are still problems concerning the stimulus for this process to start. Three platelet aggregating substances have been discussed – thrombin, adenosine diphosphate (ADP) and collagen. Evidence speaking in favour of thrombin is, however, very minimal, and the discussion has to be focused on collagen and ADP. In an in vitro system using polyethylene tubings we have shown that "haemostasis" can be obtained without the presence of collagen but against these results can be argued that it is only another in vitro test for platelet aggregation (1).To be able to induce haemostasis in this model, however, the presence of red blood cells is necessary. To further study this problem we have developed a model where haemostatic plug formation can be studied in the isolated rabbit mesentery and we have briefly reported on this (2).Thus, it is possible to perfuse the vessels with whole blood as well as with platelet rich plasma (PRP) and different pharmacological agents of importance.

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