scholarly journals Mouse spleen lymphoblasts generated in vitro. Their replication and differentiation in vitro

1978 ◽  
Vol 147 (2) ◽  
pp. 297-315 ◽  
Author(s):  
RM Steinman ◽  
BG Machtinger ◽  
J Fried ◽  
ZA Cohn

Mouse spleen lymphoblasts induced with lipopolysaccharide and fetal calf serum were obtained in high yield and purity in their first proliferative cell cycle by floatation in dense bovine plasma albumin columns (3). The blasts were maintained in vitro for 3 more days. The cultures were examined in bulk on each day, and in addition, those cells in S phase initially were tagged with [(3)H]thymidine and followed continuously in vitro. Grain count dilution data indicated that most blasts divided but twice over a 2- to 3-day interval in vitro. [(3)H]Thymidine pulse radiolabeling and flow microfluorometry suggested that at least 50-70 percent of the proliferating blasts withdrew from proliferative activity after 2-3 days of culture. Morphologic studies demonstrated that lymphoblasts persisted as such for 1-2 days in vitro and then matured into typical plasma cells. Many of the blastprogeny had small nuclei and considerable basophilic cytoplasm on Giemsa-stained cell smears; abundant rough endoplasmic reticulum by electron microscopy; and readily detectable cytoplasmic Ig by immunocytochemistry. Reversion of blasts to small lymphocytes could not be detected; however, some blasts persisted even after 3 days of culture. The viability of the cultured lymphoblast was followed by initially tagging the cells with [(3)H]thymidine as well as several other techniques. Little cell death was documented during the first day of culture. The number of labeled progeny increased twofold whereas the grain count halved. But 40- 50 percent of the cell-associated label was lost during each of the second and third days, and fewer labeled progeny than predicted by grain count dilution were identified. The culture medium could not be implicated in this loss of lymphoblast progeny, and we suggest that the maturation of the lymphoblast to a short-lived plasma cell was responsible. Therefore mitogen-stimulated B blasts seem to mature into typical plasma cells after just two cycles of cell division. The plasma cells resemble those produced in situ during an immune response in their cytologic features, withdrawal from active proliferative activity, and short life-span.

1969 ◽  
Vol 43 (3) ◽  
pp. 506-520 ◽  
Author(s):  
M. N. Berry ◽  
D. S. Friend

A new technique employing continuous recirculating perfusion of the rat liver in situ, shaking of the liver in buffer in vitro, and filtration of the tissue through nylon mesh, results in the conversion of about 50% of the liver into intact, isolated parenchymal cells. The perfusion media consist of: (a) calcium-free Hanks' solution containing 0.05% collagenase and 0.10% hyaluronidase, and (b) magnesium and calcium-free Hanks' solution containing 2 mM ethylenediaminetetraacetate. Biochemical and morphologic studies indicate that the isolated cells are viable. They respire in a medium containing calcium ions, synthesize glucose from lactate, are impermeable to inulin, do not stain with trypan blue, and retain their structural integrity. Electron microscopy of biopsies taken during and after perfusion reveals that desmosomes are quickly cleaved. Hemidesmosome-containing areas of the cell membrane invaginate and appear to pinch off and migrate centrally. Tight and gap junctions, however, persist on the intact, isolated cells, retaining small segments of cytoplasm from formerly apposing parenchymal cells. Cells which do not retain tight and gap junctions display swelling of Golgi vacuoles and vacuoles in the peripheral cytoplasm. Cytoplasmic vacuolization in a small percentage of cells and potassium loss are the only indications of cell injury detected. By other parameters measured, the isolated cells are comparable to normal hepatic parenchymal cells in situ in appearance and function.


Blood ◽  
1991 ◽  
Vol 78 (1) ◽  
pp. 180-191 ◽  
Author(s):  
R Greil ◽  
B Fasching ◽  
P Loidl ◽  
H Huber

Abstract The c-myc gene plays a pivotal role in mediating the competence state for cell cycle transversion. This biologic role is in contradiction to reports of elevated expression of the gene in multiple myeloma, a tumor with restricted self-renewal capacity. To more clearly define the role of this gene in plasma cells of myeloma patients, c-myc messenger RNA (mRNA) and/or oncoprotein expression were semiquantitatively analyzed on the single cell level in 19 cases of multiple myeloma, among them 1 biclonal case and 1 case with coexistent chronic lymphocytic leukemia (CLL). Performing anti-sense/mRNA in situ hybridization, mature c-myc gene transcripts were detected in 92% (12 of 13) of cases and could definitely be attributed to the plasma cells by our study. The number of Ki 67-positive plasma cells actively passing the cell cycle was less than 1% and independent of c-myc gene expression. However, because the presence of the 152-c-MYC epitope was correlated to extent of marrow plasmacytosis (r = .64; P = .043) and content of plasmablasts (P = .09), the c-myc gene might serve a function different from proliferative activity, but also associated with tumor cell mass. In CLL cells (21 of 22 cases) and their benign counterparts, ie, bone marrow and peripheral blood lymphocytes, the anti-sense/c-myc mRNA hybridization signals remained below the threshold considered as cutpoint between negative and positive. The low amounts of c-myc transcripts were correlated to neither stage of disease (P = .52) nor lymphocyte counts (P = .24). Because the numbers of peripheral blood lymphoma cells were independent of tumor mass and of c-myc gene transcripts expressed, peripheral blood lymphocytosis might more likely reflect homing processes than proliferative activity in CLL.


1968 ◽  
Vol 4 (1) ◽  
pp. 9-13 ◽  
Author(s):  
G. Astaldi ◽  
S. Eridani ◽  
G.B. Ponti

1974 ◽  
Vol 139 (4) ◽  
pp. 1025-1030 ◽  
Author(s):  
Michael J. Bevan ◽  
Ruth Epstein ◽  
Melvin Cohn

Mouse spleen cells which have been depleted of adherent cells do not respond to allogeneic lymphocytes in vitro. Their cytotoxic response can be restored by inclusion of mercaptoethanol in the medium. Mercaptoethanol is shown to have a stimulatory effect also on the response of normal (unseparated) spleen cells to alloantigens. The enhancement of the DNA-synthetic and cytotoxic response is similar, varying from 3.5–15-fold. Cytotoxic cells also appear in unmixed lymphocyte cultures in the presence of mercaptoethanol and fetal calf serum. The specificity of these background cytotoxic cells is not known.


1978 ◽  
Vol 147 (2) ◽  
pp. 279-296 ◽  
Author(s):  
R M Steinman ◽  
B G Machtinger ◽  
J Fried ◽  
Z A Cohn

Mouse spleen lymphoblasts, stimulated to divide in vitro, acquired a low cell density and could be separated by isopycnic techniques. Cultured cells were suspended in BPA columns, rho = 1.080, and spun to equilibrium. The method was simple, fast, accomodated large numbers of cells, and was reproducible. It provided lymphoblasts in high yield and purity (at least 80% of the low density cells were blasts). It allowed for the recovery of proliferating cells in their first cell cycle, and did not alter the subsequent ability of cells to proliferate when recultured in vitro. Certain properties of mouse spleen lymphoblasts were analyzed in detail. Lymphoblasts induced by LPS, FCS, con A (tetravalent and succinylated), and MLC were very similar except in the absolute numbers that were induced. The blasts exhibited the classic cytologic features of enlarged nucleoli and abundant cytoplasmic polyribosomes (basophilia). As a population, they were enlarged in size relative to nondividing cells, but this seemed to apply primarily to cells in the S and G2+ M phase of the cell cycle rather than G1. The cell cycle distribution of lymphoblasts was analyzed by flow microfluorometry. By analyzing low density cells obtained at varying intervals after mitogen stimulation, FMF indicated that lymphoblasts enter the S phase of their first cell cycle beginning at 20-24 h after stimulation.


Blood ◽  
1991 ◽  
Vol 78 (1) ◽  
pp. 180-191 ◽  
Author(s):  
R Greil ◽  
B Fasching ◽  
P Loidl ◽  
H Huber

The c-myc gene plays a pivotal role in mediating the competence state for cell cycle transversion. This biologic role is in contradiction to reports of elevated expression of the gene in multiple myeloma, a tumor with restricted self-renewal capacity. To more clearly define the role of this gene in plasma cells of myeloma patients, c-myc messenger RNA (mRNA) and/or oncoprotein expression were semiquantitatively analyzed on the single cell level in 19 cases of multiple myeloma, among them 1 biclonal case and 1 case with coexistent chronic lymphocytic leukemia (CLL). Performing anti-sense/mRNA in situ hybridization, mature c-myc gene transcripts were detected in 92% (12 of 13) of cases and could definitely be attributed to the plasma cells by our study. The number of Ki 67-positive plasma cells actively passing the cell cycle was less than 1% and independent of c-myc gene expression. However, because the presence of the 152-c-MYC epitope was correlated to extent of marrow plasmacytosis (r = .64; P = .043) and content of plasmablasts (P = .09), the c-myc gene might serve a function different from proliferative activity, but also associated with tumor cell mass. In CLL cells (21 of 22 cases) and their benign counterparts, ie, bone marrow and peripheral blood lymphocytes, the anti-sense/c-myc mRNA hybridization signals remained below the threshold considered as cutpoint between negative and positive. The low amounts of c-myc transcripts were correlated to neither stage of disease (P = .52) nor lymphocyte counts (P = .24). Because the numbers of peripheral blood lymphoma cells were independent of tumor mass and of c-myc gene transcripts expressed, peripheral blood lymphocytosis might more likely reflect homing processes than proliferative activity in CLL.


2015 ◽  
Vol 1720 ◽  
Author(s):  
Graham J. Taylor ◽  
Stephen A. Sarles

ABSTRACTDroplet interface bilayers (DIBs) are physical lipid bilayers that mimic real membranes in living cells, and they are formed quickly using droplets of water and lipids in oil (Fig. 1A). DIBs allow biomolecular sensing and direct detection of transmembrane proteins or peptides and small molecules such as drugs, anesthetics, or even ions. Cell-free expression systems allow in vitro protein synthesis using actual natural machinery extracted from organisms (Fig. 1B). Previous attempts to combine DIBs with cell-free extracts (CFE) encountered bilayer destabilization due to components in the expression system. This study evaluates incorporation of Promega’s T7 S30 High Yield (HY) Expression system with DIBs to pave the way for future in situ expression of light-activated bacteriorhodopsin (BR) and other complex transmembrane proteins in DIBs. A secondary output includes establishing a method for real-time monitoring and modeling of CF expression reactions using minimal volume. The ability to quantify CF output in such small volumes reduces cost per reaction from $20 to around $0.40, and synthesized protein levels reach tens to hundreds of micrograms per milliliter in less than 1 hour at 37°C.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2568-2568
Author(s):  
Bertrand Huard ◽  
Elodie Belnoue ◽  
Thomas Mc Kee ◽  
Thomas Matthes ◽  
Claire-Anne Siegrist ◽  
...  

Abstract Antibody-producing plasma cells depend on their environment for survival, but the molecules involved in this process are still not well defined. Plasma cells are fully equipped to respond to a proliferation inducing ligand (APRIL) from the tumor necrosis factor (TNF) superfamily, by virtue of their constitutive expression of the B-cell maturation antigen (BCMA), as canonical receptor from the TNF receptor superfamily, and the heparan sulfate proteoglycan (HSPG), CD138, as co-receptor. Here, we report that APRIL promoted the in vitro survival of plasma cells by upregulating expression of several anti-apoptotic molecules, such as bcl-2, bcl-xL and mcl-1. We further observed an in situ localization for APRIL consistent with this pro-survival role, both in mucosa-associated lymphoid tissues (MALT) and the bone marrow. In upper MALT, the tonsillar epithelium produced APRIL. Upon infection, APRIL production increased considerably when APRIL-secreting neutrophils, recruited from the blood, infiltrated the crypt epithelium. HSPG retained secreted APRIL in the sub-epithelium of the infected zone to create APRIL-rich niches, wherein IgG-producing plasma cells accumulated. In lower MALT, neutrophils were the unique source of APRIL giving rise to similar niches for IgA-producing plasmocytes in villi of lamina propria. The requirement on an inflammatory reaction in niche establishment implies that plasma-cell survival in mucosa is associated to pathogen presence, and must be short as a consequence. We observed also APRIL in the bone marrow. In this latter organ, maturating granulocytes produced constitutively APRIL. Such constitutive expression of a plasma cell pro-survival explains, at least in part, why plasma-cell longevity in the bone marrow can be so long lasting. These in situ human observations were confirmed in vivo with APRIL-deficient mice.


2020 ◽  
Author(s):  
Ryan R. Richardson ◽  
Marilyn Steyert ◽  
Jeffrey Inen ◽  
Saovleak Khim ◽  
Andrea J. Romanowski ◽  
...  

AbstractCurrent Cas9 reagents can target genomic loci with high specificity. However, when used for knockin, on-target outcomes are inherently imprecise, often leading to unintended knockout rather than intended edits. This restricts applications of genome editing to ex vivo approaches, where clonal selection is possible. Here we describe a workflow using iterative high-throughput in vitro and high-yield in vivo assays to evaluate and compare the performance of CRISPR knockin reagents for both editing efficiency and precision. We tested combinations of Cas9 and DNA donor template variants and determined that Cas9-CtIP with in situ linearized donors display fold-increases of editing precision in cell lines and in vivo in the mouse brain. Iterating this process, we generated novel compound fusions, including eRad18-Cas9-CtIP that showed further fold-increases in performance. Continued development of precision editing reagents with this platform holds promise for direct in vivo knockin across model organisms and future targeted gene therapies.


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