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1.
Baby hamster kidney-derived cells (BHK-21 cell line), seeded at low density on gelatin coated dishes and exposed to a 1:1 (v/v) mixture of Dulbecco's modified Eagle's medium and Ham's F-12 medium, proliferate actively when exposed to high density lipoproteins (HDL), transferrin, and basic or acidic fibroblast growth factor (FGF). This serum free medium combination supported cell multiplication at a rate equal to that of serum supplemented medium, and at low cell input (10(3) cells/35-mm dish). Epidermal growth factor (EGF), although mitogenic for BHK-21 cells, was less efficient than either basic or acidic FGF in supporting cell growth. When the potency of basic and acidic FGF were compared, acidic FGF was 10-fold less potent than basic FGF. The requirement of BHK-21 cells for transferrin appears to be minimal since cells exposed to HDL and basic FGF could be serially transferred for at least 50 cumulative population doublings in the absence of transferrin.  相似文献   

2.
Highly purified recombiaant basic fibroblast growth factor (rbFGF) and acidic FGF (aFGF) stimulated the proliferation of human-human (h-h) hybridomas to the extent of over four-fold from a low cell density such as 1×103 cells per ml in a serum-free medium in 24-well plates. The stimulatory effect of rbFGF was also observed in various lymphoid cell lines. Expecting that FGF could be an autocrine growth factor, we introduced bFGF gene into a h-h hybridoma using an expression plasmid induced by dexamethasone. The transformed cells thus obtained, HPO-75.11bbFGF-7, were able to grow well from a low inoculum density in a serum-free medium and antibody production was also increased when bFGF gene expression was induced. The transformed cells could grow at clonal density in a serum-free medium in 96-well plates, though the original cells could not. We also obtained a more practical transfectant, HPO-75.29-H74, using a high-shear stress adapted clone as the recipient and an expression plasmid having bFGF gene under the control of metallothioneine-I promoter. The HOP-75.29-H74 cells were capable of growing and producing human monoclonal antibody against hepatitis B virus surface antigen from an inoculum density of 1×103 cells per ml in an agitation vessel without addition of an inducer.  相似文献   

3.
Bovine adrenal and brain cortex and corpus luteum-derived capillary endothelial cells have been established in culture, taking advantage of their ability to proliferate at clonal density when maintained on extracellular matrix (ECM) coated dishes in the presence of serum supplemented medium. All three cell types formed at confluency a monolayer of small, tightly packed, contact inhibited cells that express factor VIII related antigen. Their proliferative response to basic and acidic FGF when cells were maintained on plastic and exposed to serum supplemented medium was similar to that previously reported for endothelial cells derived from large vessels, with acidic FGF being 30-fold less potent than basic FGF. Their requirement for high density lipoproteins and transferrin in order to proliferate actively when maintained on ECM-coated dishes and exposed to serum-free conditions was also similar to that previously reported for endothelial cells derived from large vessels. Heparin strongly reduced the proliferative response of capillary endothelial cells to either basic or acidic FGF, as well as their response to serum alone, regardless of whether cells were maintained on plastic or on ECM-coated dishes. The present data indicate that bovine endothelial cells derived from large or small vessels are indistinguishable in so far as their response to growth factors, plasma factors, and substrata are concerned.  相似文献   

4.
Summary Stromal-epithelial interactions are pivotal in many aspects of prostatic biology. A defined culture system is critical for the investigation of factors that regulate the growth and differentiation of human prostatic stromal cells. We have identified conditions which promote stromal cell attachment and proliferation in serum-free medium. MCDB 201, originally developed for the clonal growth of chick embryo fibroblasts, proved to be a superior basal medium of those that we tested. Supplementation of MCDB 201 with basic fibroblast growth factor (FGF), insulin-like growth factor (IGF), and platelet-derived growth factor (PDGF) permitted attachment and exponential growth of cells throughout a 7-d period with an initial inoculum as low as 103 cells per well of a 96-well microtiter dish. Using these assay conditions, we subsequently verified that basic FGF and IGF, but not PDGF, were required for optimal growth. No activity was found for heparin, transferrin, or the androgen R1881. Epidermal growth factor (EGF) didn’t stimulate growth when added to medium containing basic FGF and IGF, but was moderately stimulatory when added to basal medium alone. Cholera toxin inhibited growth. This simple and efficient culture medium provides a suitable assay system for more extensive studies of growth regulation and differentiation of human prostatic stromal cells, and will provide the basis for future development of a defined medium that supports clonal growth. Characterization of stromal-epithelial interactions will be facilitated by the use of this defined culture system for stromal cells in conjunction with the serum-free culture systems previously developed for human prostatic epithelial cells.  相似文献   

5.
Bovine adrenal cortex cells maintained on extracellular matrix (ECM)-coated dishes will proliferate actively when serum is replaced by HDL (25 micrograms protein/ml), insulin (10 ng/ml), and FGF (100 ng/ml). The cells have an absolute requirement for HDL in order to survive and grow. The omission of insulin, FGF, or both results in a slower growth rate and lower final cell density of the cultures. A requirement for transferrin (1 microgram/ml) becomes apparent only when cells have been grown for at least four generations in the absence of serum. Early passage (P1-P3) bovine adrenal cortex cells cultured in serum-free medium responded to ACTH (10(-8)M) with increased 11-deoxycortisol production; this effect was not observed in later passage cells (P7-P15). The cells' ability to utilize LDL-derived cholesterol and to respond to db cAMP (1mM) by increased steroid release was preserved in cells cultured for over 60 generations in the serum-free medium. HDL, although also able to increase steroid production in early-passage cultures exposed to ACTH or to ACTH and dibutyryl cyclic AMP (db cAMP), was 10 fold less potent than LDL. It did not support steroidogenesis in cultures not exposed to these trophic agents. The life span of bovine adrenal cortex cells grown in the serum-free medium on fibronectin (FN)- versus ECM-coated dishes was compared. Cells seeded in serum-containing medium and grown in serum-free medium had a life span of 34 versus 60 generations when maintained on fibronectin- or ECM-coated dishes, respectively. Cells seeded in the complete absence of serum in the serum-free medium on ECM- or fibronectin-coated dishes could be passaged for 26 or 13 generations, respectively. While FGF was an absolute requirement for cells cultured on fibronectin-coated dishes, it was not required when cells were maintained on ECM. These observations demonstrate the influence of the ECM not only in promoting cell growth and differentiation but also on the life span of cultured cells.  相似文献   

6.
Summary The growth of WI-38 cells in serum-free growth medium with and without hormone supplementation in the presence of elevated Ca2+ concentrations was investigated. At 5 mM CaCl2, WI-38 cells seeded at low density without serum or hormone supplementation showed up to a 12-fold increased in cell number at saturation density over that obtained at day 1. Saturation densities were comparable when either 5 mM CaCl2 or epidermal growth factor (1 mM CaCl2) was used in the presence of insulin, dexamethasone and transferrin. Combining suboptimal doses of epidermal growth factor and CaCl2 resulted in an additive effect on saturation density. Thus, nornal human diploid cells are capable of substantial growth in serum-free, hormone-free growth medium. In contrast, confluent cultures refed with the same medium are not responsive to elevated Ca2+ concentrations. In fact, elevated Ca2+ concentrations inhibited the proliferative response of confluent cultures to epidermal growth factor, but enhanced their response to the combined treatment of insulin, transferrin and dexamethasone. This work was supported by the United States Public Health Society grants T-32, CA09171 and AG-00378. Editor's Statement This paper rigorously dissects the interplay among external Ca2+ concentration, cell density and specific growth factors on fibroblast growth in defined medium. Wallace L. McKeehan  相似文献   

7.
The effects of various kinds of growth factors or steroids on the proliferation of Shionogi carcinoma 115 (SC115) cells were investigated in cell culture. In a serum-free medium [Ham's F-12:Eagle's minimum essential medium (1:1, vol/vol) containing 0.1% bovine serum albumin], the proliferation of SC-3 cells (a cloned cell line from SC115 cells) estimated by [3H]thymidine incorporation into DNA and cell number reached a plateau at 10(-8) M testosterone (up to 200-fold), 10(-7) M dexamethasone (up to 30-fold) or 1 ng/ml of fibroblast growth factors (FGF; up to 50-fold). However, the proliferation in the serum-free medium was not significantly stimulated by the addition of low to very high concentrations of progesterone, oestradiol-17 beta, epidermal growth factor, platelet derived growth factor or insulin; transforming growth factor beta slightly stimulated the growth (up to 5-fold) but markedly inhibited the growth stimulation induced by testosterone. Furthermore, an epithelial appearance of SC-3 cells grown in the absence of growth factors or steroids was changed to a fibroblast-like appearance only by the addition of testosterone, high concentrations of dexamethasone or FGF. By investigating various kinds of growth factors or steroids, the present study demonstrates that androgen, high concentration of glucocorticoid or FGF alone significantly stimulates the proliferation of SC-3 cells with a change of morphology in the serum-free medium.  相似文献   

8.
Summary Transforming growth factors (TGFs) are a relatively new category of factors that induce the anchorage-independent growth of non-transformed cells. These factors are usually detected by their ability to induce normal rat kidney (NRK) fibroblasts to grow in soft agar. Until now, this assay has been performed in serum-containing medium (SCM). Unfortunately, the background activity of this assay is variable and dependent on several factors, including passage number of the cells and the serum lot used. Furthermore, the addition of either EGF or TGF-β alone results in the appearance of additional colonies, which decreases the sensitivity of the assay. To circumvent these problems, serum-free media have been developed that support the growth of the NRK cells at low density in both monolayer culture and soft agar. Long-term growth in monolayer cultures occurs in serum-free medium supplemented with laminin, insulin, transferrin, epidermal growth factor (EGF), fibroblast growth factor (FGF) and high density lipoprotein (HDL). Growth in soft agar occurs when TGFs are added to a serum-free medium, AIG medium, that contains insulin, transferrin, FGF and HDL. In contrast to the background activity observed when the assay is performed in SCM, no colonies form in the AIG medium unless TGFs are added and few, if any, colonies form if EGF or TGF-β are added alone. Thus, the AIG medium provides an improved assay for TGFs. In addition, the AIG medium should prove useful for examining other factors, including serum factors, for TGF activity. Editor's Statement This communication describes a modification of the standard assay for transforming growth factors. The techniques employed make use of advantages provided by recent advances in serum-free cell culture to provide a well-defined detection system that is more sensitive than conventional procedures. Experimental approaches described in this article also should be helpful in unraveling differences in cellular behavior encountered under anchorage-dependent vs. anchorage-independent conditions. D. W. Barnes  相似文献   

9.
Heparin protects basic and acidic FGF from inactivation   总被引:58,自引:0,他引:58  
The ability of heparin or that of hexuronyl hexosaminoglycan sulfate (HHS-4) to protect basic or acidic fibroblast growth factor (FGF) from acid or heat inactivation has been analyzed. Both freshly prepared basic and acidic FGF stimulate the growth of baby hamster kidney (BHK-21) cells exposed to medium supplemented with transferrin and insulin. Freshly prepared basic FGF was 10 fold more potent than acidic FGF. The addition of heparin to the medium decreased the potency of basic FGF while it potentiated that of acidic FGF. Upon storage of FGF at -80 degrees C, a decline in potency of both basic and acidic FGF was observed. Heparin, when added to the medium, potentiated their activities, which became similar to that of freshly prepared basic FGF. In order to test whether heparin could protect basic or acidic FGF from inactivation, both mitogens were exposed to acid conditions (1% trifluoroacetic acid, pH 1.08, 2 h) or heat (65 degrees C, 5 min) which inactivate basic or acidic FGF. When exposed to such treatment in the presence of heparin or HHS-4, basic and acidic FGF retained their potency. The effect of heparin and HHS-4 on the bioactivity of basic and acidic FGF is truly of a protective nature, since they had no effect when added after inactivation of the mitogens. Potentiation of the bioactivity of the protected mitogens or of the inactivated one could only be observed when cells were exposed to high heparin or HHS-4 concentrations. This indicates that heparin and HHS-4, in addition to protecting FGF from inactivation, also acts at another locus, as yet unidentified.  相似文献   

10.
Summary A serum-free, chemically defined medium for supporting rhythmic contraction, maximum survival, and moderate growth of cardiac cells was achieved by using a combination of hormones and growth supplements in a mixture of equal volumes of Ham’s F12 and Dulbecco’s modified Eagle’s medium. The hormones and growth supplements included insulin, transferrin, selenium, fetuin, bovine serum albumin, hydrocortisone (HC),l-thyroxine (T4), and epidermal growth factor (EGF). Cardiac cells were grown on fibronectin-precoated plates using the above serum-free medium. Cells grow in this medium exhibited a higher beating rate and were maintained for a longer time compared to those cells grown in serum. The effects of T4, EGF, and HC on beating rate and survival time of both cultures of mixed cell population and enriched myoblast cell population were studied. In the enriched myoblast cell cultures grown in serum-supplemented medium, the beating rate ranged from 40 to 200 beats/min, and these cultures survived for 30 d. When these enriched cell cultures were grown in serum-free hormone-supplemented medium, the beating rate ranged from 190 to 240 beats/min, and these cultures survived for more than 90 d. These results show that some hormones affect growth, whereas others affect function.  相似文献   

11.
Experimental conditions have been defined that allow bovine corneal endothelial (BCE) cells to grow in the complete absence of serum. Low density BCE cell cultures maintained on extracellular matrix (ECM)-coated dishes and plated in the total absence of serum proliferate actively when exposed to a synthetic medium supplemented with high density lipoprotein (HDL 500 μg protein/ml), transferrin (10 μg/ml), insulin (5 μg/ml), and fibroblast (FGP) or epidermal growth factor (EGF) added at concentrations of 100 or 50 ng/ml, respectively. Omission of any of these components results in a lower growth rate and/or final cell density of the cultures. BCE cell cultures plated on plastic dishes and exposed to the same synthetic medium grow very poorly. The longevity of BCE cultures maintained on plastic versus ECM and exposed to serum-free versus serum-containing medium has been studied. The use of ECM-coated dishes extended the life span of BCE cultures maintained in serum-supplemented medium to over 120 generations, as compared to less than 20 generations for cultures maintained on plastic. Likewise, BCE cells maintained on ECM and exposed to a synthetic medium supplemented with optimal concentrations of HDL, transferrin, insulin, and FGF underwent 85 generations, whereas control cultures maintained on plastic could not be passaged. The enhancing effect of ECM on BCE cell growth and culture longevity clearly illustrates the importance of the cell substrate in the control of proliferation of these cells.  相似文献   

12.
Summary Normal mouse vaginal epithelial cells isolated from ovariectomized ca. 35-d-old BALB/cCrgl mice were grown in primary culture using collagen gel metrix and a serum-free medium composed of a 1∶1 mixture of Dulbecco’s modified Eagle’s medium and Ham’s F12 (D:H) medium supplemented with insulin (IN), epidermal growth factor (EGF), cholera toxin, transferrin, and bovine serum albumin V (BSA). Three-dimensional cellular outgrowths occurred inside the collagen gel matrix. The contribution of each factor to cell growth was examined by individual addition to the basic D:H medium and by individual deletion from the complete serum-free medium. When added individually, only IN promoted growth. Deletion of IN from the complete serum-free medium markedly, diminished growth; deletion of EGF or BSA slightly diminished growth. When horse, fetal bovine, or chicken serum was added to the basal D:H medium, only with increasing doses of horse serum was there enhanced cell growth. The effect of 17?-estradiol and diethylstilbestrol on the growth of cells was also tested, using a suboptimal medium of D:H supplemented with BSA and IN, or a minimal medium supplemented with IN alone. During the 8-d time period, addition of estrogen did not enhance cell growth in either medium. To date, we have been unable to demonstrate a mitogenic effect of estrogen; rather a dose-dependent inhibition of proliferation is seen. This investigation was supported by grants CA-05388 and CA-09041, awarded by the National Institutes of Health, DHHS, Bethesda, MD.  相似文献   

13.
Summary Low density bovine vacular endothelial cell cultures maintained on dishes coated with an extracellular matrix can be grown in serum-free Dulbecco's modified Eagle's medium supplemented with high density lipoprotein (HDL) and transferrin. Such cultures do not require insulin. Early passage cultures exposed to HDL and transferrin grew as well as cultures exposed to optimal serum concentrations and could be passaged repeatedly in total absence of serum. A requirement for fibroblast growth factor to ensure an optimal growth could be observed only with late-passage cultures. The present results suggest strongly that HDL is involved in supporting the proliferation of vascular endothelial cells in vitro. This may be important for our understanding of the biological role of HDL “in vivo”. This work was supported by Grants HL 23678 and 20192 from the National Institutes of Health, Bethesda, MD.  相似文献   

14.
Summary A serum-free clonal density growth assay was developed for the quantification of the biological activity of human recombinant insulin-like growth factor I (IGF-I). The assay measures IGF-I stimulated growth of Balb/c 3T3 cells cultured over 4 d on poly-d-lysine-coated plastic surfaces in a serum-free medium formulation composed of a 1∶1 (vol/vol) mixture of Ham's F12 and Dulbecco's modified Eagle's media, supplemented with 3.0 ng/ml bovine basic fibroblast growth factor (bFGF), 10 μg/ml human transferrin, 100 μg/ml ovalbumin, and 1.0 μM dexamethanose. Low-temperature trypsinization of serum-supplemented stock cultures combined with the use of poly-d-lysine-coated plates made it unnecessary to use serum or fibronectin to promote cell attachment and survival. Serum-free growth conditions were optimized with respect to the concentrations of the supplements. Addition of IGF-I resulted in 3.5-fold more cells than control cultures without IGF-I after 4 d. Deletion of bFGF resulted in no IGF-I stimulation of growth. The concentrations of various preparations of IGF-I required to achieve one-half maximal stimulation of cell number (ED50), ranged between 1.25 and 4.7 ng/ml. In parallel assays, IGF-I was 6.6 times more potent than human recombinant insulin-like growth factor II and 32 times more potent than insulin. When cells were seeded into medium containing IGF-I, transferrin, ovalbumin, and dexamethasone but no bFGF, growth was minimal. Dose-response addition of bFGF showed an ED50, of 0.9 ng/ml. The methods reported are useful to monitor the biological potency of recombinant and natural-source growth factors as well as providing a new means of studying the multiple growth factor requirements of Balb/c 3T3 cells in cultures. This work was supported by a contract from IMCERA Bioproducts, Inc.  相似文献   

15.
Summary NIH3T3 cells grow in a serum-free basal nutrient medium supplemented with fibronectin, transferrin, insulin, epidermal growth factor (EGF) and high density lipoprotein (HDL). The individual omission from the serum-free medium of insulin, EGF, or HDL results in greatly reduced cell growth. These growth-restrictive conditions can be used to select for cells transformed with SV40, the polyomavirus middle T antigen gene, the activated humanras gene, and the mouse c-myc gene. This work was supported by grants ES-00-210 from the National Institutes of Health (NIEHS) and MV-182 from the American Cancer Society. Dr. L.-C. Chiang is a Visiting Research Scientist from PPG Industries, Inc. Editor’s statement This paper represents a new approach to the identification of oncogenes that would escape the screening methods currently in use. Inherent in the method is the assignment of function to oncogenes.  相似文献   

16.
Human epithelial cells that had grown out from a maxillary carcinoma were examined for their responsiveness to putative growth-controlling factors in a serum-free medium. Among the factors examined, bovine brain acidic fibroblast growth factor (FGF) at 1 to 10 ng/ml significantly promoted DNA synthesis of the cells in the presence of 5 U/ml heparin, whereas type beta transforming growth factor inhibited it in a dose-dependent manner. Fetal bovine serum at 0.6% inhibited DNA synthesis of the cells by approximately 15%, but no significant influence was observed at higher concentrations up to 10%. Epidermal growth factor, bovine pituitary gland FGF and basic FGF exhibited no significant effect on DNA synthesis of the cells. The present result suggests that acidic FGF, a known mitogen for endothelial cells, is also mitogenic for human epithelial cells derived from maxillary carcinoma.  相似文献   

17.
Summary This study was conducted to identify a defined, serum-free culture medium that supports cell dependent contraction of a collagen lattice. Collagen lattices were found to contract in cultures containing human foreskin fibroblasts (HFF) or rabbit aortic smooth muscle (RASM) cells incubated in serum-free medium. HFF and RASM cells required different supplements to contract the collagen gels. HFF cultured in Dulbecco’s modified Eagle’s (DME) medium supplemented with bovine serum albumin (BSA) and either endothelial cell growth supplement (EnGS), insulin (In), or platelet derived growth factor (PDGF) supported collagen lattice contraction. Replacement of BSA with casein without the addition of other supplements improved contraction. In contrast, RASM cells supplemented with BSA, EnGS, In, and PDGF were able to contract collagen gels only minimally. Similar to HFF, RASM cells cultured in DME medium supplemented with casein, but without the addition of other supplements, contracted collagen lattices. HFF-mediated collagen contraction was inhibited by prostaglandins E1 or E2, fibronectin, or ascorbic acid. The reported serum-free model provides a useful in vitro method to investigate the role of serum and nonserum factors regulating cell mediated-contraction of insoluble collagen fibrils. Presented in part as abstract 1963 in the 1985 Federation of American Societies for Experimental Biology, April 21–26, Anaheim, California, and published in Fed. Proc. (44):747; 1985.  相似文献   

18.
One of the major concerns regarding the use of insect cells and baculovirus expression vectors for the production of recombinant proteins is the drop in production observed when infecting cultures at high cell densities; this work attempts to understand this so-called cell density effect in the scope of baculovirus production for gene therapy purposes. A Spodoptera frugiperda insect cell line (Sf-9) was cultured and infected in serum-free medium, and the patterns of production of a recombinant baculovirus expressing the green fluorescent protein (GFP) were analyzed at different cell concentrations at infection (CCIs) and multiplicities of infection (MOIs). The results confirm that a cell density effect on productivity occurs which is dependent on the MOI used, with a high MOI “delaying” the drop in production to higher cell densities. Medium replacement at the time of infection using a high MOI considerably improved baculovirus production, with the different production indicators, namely the titer, specific yield, amplification factor, and time of harvesting, increasing with cell concentration for the CCI range tested. Virus titers as high as 2.6 × 1010 IP.mL−1 were obtained in cultures infected at 3.5 × 106 cells.mL−1, while the amplification factor was roughly 19 times higher than the highest value obtained without medium exchange.  相似文献   

19.
The growth-promoting activity of human high-density lipoproteins (HDL) and of their apolipoprotein components on bovine vascular endothelial cells in vitro has been compared. When maintained on plastic culture dishes and exposed to medium containing lipoprotein-deficient serum and fibroblast growth factor, these cells do not proliferate. Addition of either HDL or the total HDL apolipoproteins induces significant cell proliferation. Apolipoprotein CI, purified by chromatography on the ion-exchanger resin Polybuffer exchanger 94, has an effect on the cell growth similar to that of the total apolipoproteins of HDL.  相似文献   

20.
Animal cells can be cultured both in basal media supplemented with fetal bovine serum (FBS) and in serum-free media. In this work, the supplementation of Grace’s medium with a set of nutrients to reduce FBS requirements in Spodoptera frugiperda (Sf9) cell culture was evaluated, aiming the production of Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) at a cost lower than those for the production using Sf900 II medium. In Grace’s medium supplemented with glucose, Pluronic F68 (PF68) and yeast extract (YE), the effects of FBS and milk whey ultrafiltrate (MWU) on cell concentration and viability during midexponential and stationary growth phase were evaluated. In spite of the fact that FBS presented higher statistical effects than MWU on all dependent variables in the first cell passage studies, after cell adaptation, AgMNPV polyhedra production was comparable to that in Sf900 II. Batch cultivation in Grace’s medium with 2.7 g l−1 glucose, 8 g l−1 YE and 0.1% (w/v) PF68 supplemented with 1% (w/v) MWU and 3% (v/v) FBS increased viable cell concentration to about 5-fold (4.7×106 cells ml−1) when compared to Grace’s containing 10% (v/v) FBS (9.5×105 cells ml−1). AgMNPV polyhedra (PIBs) production was around 3-fold higher in the MWU supplemented medium (1.6×107 PIBs ml−1) than in Grace’s medium with 10% FBS (0.6×107 PIBs ml−1). This study therefore shows a promising achievement to significantly reduce FBS concentration in Sf9 insect cell media, keeping high productivity in terms of cell concentration and final virus production at a cost almost 50% lower than that observed for Sf900 II medium. C.A. Pereira is recipient of a CNPq fellowship.  相似文献   

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