Effects Of Cell-free Supernatants Research Articles

Immunomodulatory Activity Analyses of Cell-Free Supernatant of Lactobacillus plantarum LP299v Strain in RAW 264.7 Macrophage Cells

The human immune system is essential for defending the body against harmful internal and external elements; immunity includes innate and acquired immunity. Macrophages, the innate immune system's key components, are crucial for the clearance of dead cells and tumor cells, as well as foreign substances by triggering phagocytosis. They also play a role in the adaptive response with the cytokines and mediator molecules they secrete. Lactic acid bacteria (LAB), an important probiotics class, have a strong potential to improve host health and can be used as a functional food. There have been reports of certain LAB strains having immunostimulating effects. However, the effects of cell-free supernatants (CFS) gathered from some LAB strains on macrophage activation have become an important research area in recent years. This study's main objective was to characterize the immunostimulatory activities of Lactobacillus plantarum LP299v in the RAW 264.7 macrophage cell line. For this purpose, the immunomodulatory activity of CFS of the related strain was evaluated by MTT, neutral red assay, and Griess reaction respectively, in terms of proliferation, phagocytosis ability, and nitric oxide (NO) production parameters using the macrophage cell line. Studies have shown that this strain significantly increased proliferation, phagocytosis, and NO levels in RAW264.7 macrophage cells. When considered, these results suggest that the cell-free supernatant, obtained from Lactobacillus plantarum LP299v selected in this study, may be helpful for candidate compounds with immunostimulatory activity.

Isolation of lectin from Musa acuminata for its antibiofilm potential against Methicillin-resistant Staphylococcus aureus and its synergistic effect with Enterococcus species.

Methicillin resistant Staphylococcus aureus (MRSA) is an emerging pathogen posing a considerable burden on the healthcare system due to its involvement in skin and soft tissue infections (SSTIs). Lectins are carbohydrate binding proteins found ubiquitously in animals, plants and microorganisms. Extraction and isolation of proteins from Musa acuminata were performed by using Affinity chromatography with Sephadex G 75 to determine antibiofilm activity against MRSA. Enterococcus strains obtained from dairy products, beans and vegetables were also screened for its potential to inhibit growth and biofilm formation of MRSA by using 96 well microtiter plates. Synergistic effect of cell free supernatant of Enterococcus with proteins from ripe banana were also tested. BanLec was successfully isolated and appeared as 15 KDa band after SDS-PAGE (15%) while multiple bands of unbound protein fractions were observed. The unbound fractions showed inhibition of planktonic cells and biofilm but BanLec exhibited no significant effect. The CFS of Enterococcus faecium (LCM002), Enterococcus lactis (LCM003) and Enterococcus durans (LCM004 and LCM005) displayed antagonistic effects against pathogen. The synergistic effect of CFS from E. lactis (LCM003) and unbound proteins showed inhibition of biofilm and pathogenic growth. This study demonstrates the use of Enterococcus species and plant proteins against pathogens and results suggested that it can inhibit the growth of resistant strains of Staphylococcus aureus and their synergistic effect has opened new ways to tackle emerging resistance. Furthermore, after assessment of Enterococcus as probiotics, this could be used in food industries as well as in treatment of severe skin infections.

Antimicrobial efficacy of Lactobacillus plantarum strain against the B. cereus, B. subtilis, S. aureus and E.coli strains

The current study aimed to detect the antimicrobial effect of cell free supernatant (CFS) of Lactobacillus plantarum strain against Gram +ve and Gram –ve bacterial strains. The strain of Lactobacillus plantarum was isolated using selective media MRS agar. The strain was characterized on the basis of the gram staining, colony morphology, the biochemical tests and the DNA sequencing based method of 16S ribotyping. A total of four test strains (The three already isolated and reported strains (E.coli, S. aureus and B. subtilis) and the one recently identified novel strain (B. cereus) were used for the analysis of antagonistic activity of bacteriocin produced by L. plantarum strain. The CFS of L. plantarum showed zone of inhibition against all the test strains (Gram +ve and Gram –ve bacteria). The conditions favoring the growth of bacteria were associated with the antimicrobial efficacy of CFS. Bacteriocin activity of CFS remained effective after exposure to temperature stress. Wide range of antagonistic potential of CFS of L. plantarum provides an alternative for antibiotics in pharmaceutical industry. Heat resistant feature of bacteriocin suggests its application in food industry.

Antimicrobial Activities and Biopreservation Potential of Lactic Acid Bacteria (LAB) from Raw Buffalo (Bubalus bubalis) Milk.

The aim of this study was to investigate the antimicrobial and biopreservation potential of lactic acid bacteria. The potential probiotic culture inhibited the growth of gram-positive and gram-negative foodborne pathogens in agar spot assay with inhibition zones ranging from 10 to 21 mm in diameter. The strains showed coaggregation capabilities ranging from 7 to 71% with tested food pathogens including Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Salmonella enterica subsp. enterica serovar Typhimurium. The effect of cell-free supernatants on the release of 260 nm absorbing material, especially nucleic acids, was evaluated and indicated the antagonistic activity on foodborne pathogens, the highest being Lactobacillus paraplantarum against E. coli (3.77) and S. aureus (3.86) after 60 min. The effect of cell-free supernatant (CFS) on the growth of pathogens showed that Lactobacillus paraplantarum 11 and L. pentosus 93 had the highest inhibitory activity against tested strains. The biopreservation assay indicated that the potential probiotic strains Lactobacillus paraplantarum 11 (BT), Lactiplantibacillus plantarum 19, Lactobacillus pentosus 42, Limosilactobacillus fermentum 60, Lactobacillus pentosus 93, and Limosilactobacillus reuteri 112 were effective in reducing the Listeria monocytogenes population in raw buffalo milk. Complete Listeria monocytogenes inhibition was observed after 6-8 days. This study showed that probiotic LAB from buffalo milk have antimicrobial and biopreservation potential; these strains have the potential to be utilized as biopreservative agents in food products.

Anti-Biofilm Activity of Cell Free Supernatants of Selected Lactic Acid Bacteria against Listeria monocytogenes Isolated from Avocado and Cucumber Fruits, and from an Avocado Processing Plant.

Listeria monocytogenes forms biofilms on food contact surfaces, a niche from where it dislodges to contaminate food products including fresh produce. Probiotics and their derivatives are considered promising alternative strategies to curb the presence of L. monocytogenes in varied food applications. Nonetheless, studies on their anti-biofilm effects against L. monocytogenes from avocados and cucumbers are sparse. This study screened the biofilm formation capabilities of L. monocytogenes strains Avo and Cuc isolated from the avocado and cucumber fruits respectively, and strain 243 isolated from an avocado processing plant; and evaluated the anti-biofilm effects of cell free supernatants (CFS) of Lactobacillus acidophilus La14 150B, Lactiplantibacillus plantarum B411 and Lacticaseibacillus rhamnosus ATCC 53103 against their biofilms formed on polyvinyl chloride (PVC) and stainless steel. All the L. monocytogenes strains formed biofilms (classified either as moderate or strong biofilm formers) on these materials. The presence of CFS reduced the biofilm formation capabilities of these strains and disrupted the integrity of their pre-formed biofilms. Quantitative reverse transcriptase polymerase chain reaction revealed significant reduction of positive regulatory factor A (prfA) gene expression by L. monocytogenes biofilm cells in the presence of CFS (p < 0.05). Thus, these CFS have potential as food grade sanitizers for control of L. monocytogenes biofilms in the avocado and cucumber processing facilities.

Effect of cell free supernatant of Bifidobacterium bifidum combined with chitosan biodegradable film on full thickness wound healing in rats

Effect of cell free supernatant of Bifidobacterium bifidum combined with chitosan biodegradable film on full thickness wound healing in rats

Relative potency of a novel acaricidal compound from Xenorhabdus, a bacterial genus mutualistically associated with entomopathogenic nematodes

Our study aimed to identify the novel acaricidal compound in Xenorhabdus szentirmaii and X. nematophila using the easyPACId approach (easy Promoter Activated Compound Identification). We determined the (1) effects of cell-free supernatant (CFS) obtained from mutant strains against T. urticae females, (2) CFS of the acaricidal bioactive strain of X. nematophila (pCEP_kan_XNC1_1711) against different biological stages of T. urticae, and females of predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, (3) effects of the extracted acaricidal compound on different biological stages of T. urticae, and (4) cytotoxicity of the active substance. The results showed that xenocoumacin produced by X. nematophila was the bioactive acaricidal compound, whereas the acaricidal compound in X. szentirmaii was not determined. The CFS of X. nematophila (pCEP_kan_XNC1_1711) caused 100, 100, 97.3, and 98.1% mortality on larvae, protonymph, deutonymph and adult female of T. urticae at 7 dpa in petri dish experiments; and significantly reduced T. urticae population in pot experiments. However, the same CFS caused less than 36% mortality on the predatory mites at 7dpa. The mortality rates of extracted acaricidal compound (xenocoumacin) on the larva, protonymph, deutonymph and adult female of T. urticae were 100, 100, 97, 96% at 7 dpa. Cytotoxicity assay showed that IC50 value of xenocoumacin extract was 17.71 μg/ml after 48 h. The data of this study showed that xenocoumacin could potentially be used as bio-acaricide in the control of T. urticae; however, its efficacy in field experiments and its phytotoxicity need to be assessed in future.

Lactobacillus reuteri ATCC55730 ve Lactobacillus plantarum FI8595 Supernatantlarının Bazı Balık Bozucu ve Gıda Kaynaklı Patojen Bakterilerine Karşı Antimikrobiyal Etkisi

The effects of cell free supernatants of Lactobacillus reuteri ATCC55730 and Lactobacillus plantarum FI8595 against selected fish spoilage and food-borne pathogen microorganisms were investigated. For detection of the antimicrobial effect of cell free supernatants from two Lactobacillus strains, four food-borne pathogens (Salmonella Paratyphi A NCTC13, Staphylococcus aureus ATCC29213, Klebsiella pneumoniae ATCC700603, and Listeria monocytogenes ATCC19112) and three fish spoilage bacteria (Proteus mirabilis, Enterococcus faecalis and Pseudomonas luteola) were used. The agar well diffusion method was performed to determine the antimicrobial effects. The cell free supernatants of both L. reuteri and L. plantarum were effective on fish spoilage bacteria tested. Especially, E. faecalis showed high sensitivity against both CFS obtained from L. plantarum and L. reuteri with 16.75 and 22.75 mm inhibition zone diameter, respectively. The CFS of L. reuteri exerted a strong ability to inhibit the growth of all food-borne pathogens. The highest antibacterial effect of CFE of L. reuteri was observed on S. aureus, with the diameter of 26.50 mm inhibition zone.

Effects of Lactobacillus acidophilus and Lactobacillus helveticus on biofilm formation by ESBL-producing uropathogenic Escherichia coli

Background: Uropathogenic E. coli (UPEC) are important clinical pathogens and are considered as one of the major causes of urinary tract infection. Unfortunately, the treatment of UPEC infections is becoming more difficult because isolates are increasingly resistant to commonly used antimicrobial agents. The potential ability of UPEC to form biofilm might explain its outstanding antibiotic resistance and survival properties. Objectives: We aimed to assess the effect of cell free supernatants (CFS) of Lactobacillus acidophilus La-5 and Lactobacillus helveticus B-734 on the ability of ESBL-producing UPEC isolates to form biofilm in vitro and to eradicate the already formed biofilm of UPEC isolates. Methodology: A total of 50 isolates of ESBLproducing UPEC, were recovered from different private laboratories, then subcultured on MacConkey’s medium and identified by conventional microbiological methods. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method and confirmed for ESBL production. The ability of UPEC to produce biofilm was determined using Congo red agar (CRA) method and tissue culture plate (TCP) method. CFS of L.acidophilus La-5 and L. helveticus B-734 were prepared and used to assess its effect on the ability of ESBL-producing UPEC isolates to form biofilm in vitro and the eradicationof the already formed biofilm. Results: Biofilm formation was found in 28% of theisolates. Furthermore, the strong biofilm-forming category was detected in 10% of the isolates, whereas the moderate biofilm-forming category was detected in 18%. CFS of L. acidophilus La-5 was more effective (91.12%) in inhibiting the formation of E. coli biofilm than CFS of L. helveticus B-734 (76.44%), while it was almost the same efficacy (83%) regarding eradication of E. coli biofilm. All ESBL- producing UPEC isolates were sensitive to cefoxitin (100%) followed by nitrofurantoin (98%) and imipenem (94%). Conclusion: L. acidophilus La-5 and L. helveticus B-734 may be a new therapeutic options for UTI caused by UPEC.

Suppression of Intestinal Epithelial Cell Chemokine Production by Lactobacillus rhamnosus R0011 and Lactobacillus helveticus R0389 Is Mediated by Secreted Bioactive Molecules.

Host intestinal epithelial cells (IEC) present at the gastrointestinal interface are exposed to pathogenic and non-pathogenic bacteria and their products. Certain probiotic lactic acid bacteria (LAB) have been associated with a range of host-immune modulatory activities including down-regulation of pro-inflammatory gene expression and cytokine production by IEC, with growing evidence suggesting that these bacteria secrete bioactive molecules with immunomodulatory activity. The aim of this study was to determine whether two lactobacilli with immunomodulatory activity [Lactobacillus rhamnosus R0011 (Lr) and Lactobacillus helveticus R0389 (Lh)], produce soluble mediators able to influence IEC responses to Pattern Recognition Receptor (PRR) ligands and pro-inflammatory cytokines [Tumor Necrosis Factor α (TNFα), Interleukin-1β (IL-1β)], signals inducing IEC chemokine production during infection. To this end, the effects of cell-free supernatants (CFS) from Lr and Lh on IEC production of the pro-inflammatory chemokines interleukin (IL)-8 and cytokine-induced neutrophil chemoattractant 1 (CINC-1) induced by a range of host- or pathogen-derived pro-inflammatory stimuli were determined, and the impact on human HT-29 IEC and a primary IEC line (rat IEC-6) was compared. The Lr-CFS and Lh-CFS did not significantly modulate basal IL-8 production from HT-29 IECs or CINC-1 production from IEC-6 cells. However, both Lr-CFS and Lh-CFS significantly down-regulated IL-8 production from HT-29 IECs challenged with varied PRR ligands. Lr-CFS and Lh-CFS had differential effects on PRR-induced CINC-1 production by rat IEC-6 IECs, with no significant down-regulation of CINC-1 observed from IEC-6 IECs cultured with Lh-CFS. Further analysis of the Lr-CFS revealed down-regulation of IL-8 production induced by the pro-inflammatory cytokines IL-1β and TNFα Preliminary characterization of the bioactive constituent(s) of the Lr-CFS indicates that it is resistant to treatment with DNase, RNase, and an acidic protease, but is sensitive to alterations in pH. Taken together, these results indicate that these lactobacilli secrete bioactive molecules of low molecular weight that may modulate host innate immune activity through interactions with IEC.

The effect of cell-free supernatant (CFS) of Escherichia coli on human sperm motility

Escherichia coli were isolated from vaginal and cervical samples during vaginal examination. Fifteen semen samples have been gathered through masturbation after three days of sexual abstinence. The Cell-Free Supernatant (CFS) of Escherichia has been collected by removing the cells from overnight broth cultures and filtered. The effect of (CFS) of Escherichia coli on spermatozoa motility was determined by using Earl’s balanced solution to prepare1:2 to 1:16 dilutions of CSF. Results conducted there was a significant difference in the count number of motile spermatozoa in 15 seminal fluid samples after being treated with CSF at the dilutions1:2 (p≤0.05) ,1:4 (p≤0.05) and 1:8(p≤0.05). The experiment showed a successive significant increase in the count number of motile sperms compatible with the lowering concentration of CSF until the count number of motile sperms reached the highest in the fourth dilution 1:16 ( P≥0.05) . This demonstrates the real effect of CSF on the vitality and activity of sperm. On the other hand, the study showed that the Escherichia Coli, causing genital tract infection, could have a bad effect on the motility and transportation of men’s spermatozoa and might be responsible for infertility.

Inhibition of Insulin Degrading Enzyme and Insulin Degradation by UV-Killed Lactobacillus acidophilus.

Probiotics have beneficial effects on management of type 2 diabetes (T2D). The major hallmarks of T2D are insulin deficiency and insulin resistance which emphasize insulin therapy in onset of disease. Lactobacilli such as Lactobacillus acidophilus (L. acidophilus) have well known properties on prevention of T2D and insulin resistance but not on insulin degradation. Insulin-degrading enzyme (IDE) degrades insulin in the human body. We studied the effects of cell-free supernatant (CFS) and ultraviolet (UV)-killed L. acidophilus (ATCC 314) on IDE activity and insulin degradation in vitro. Cell growth inhibition by CFS and UV-killed L. acidophilus (ATCC 314) was studied and Western blotting and a fluoregenic assay was performed to determine IDE expression and its activity, respectively. Insulin degradation was evaluated by sandwich enzyme-linked immunosorbent assay(ELISA). IDE expression and activity was reduced by CFS and UV-killed L. acidophilus (ATCC 314). Although, decreased enzyme expression and activity was not significant for CFS in contrast to MRL (MRS with same pH as CFS). Also, reduction in IDE activity was not statistically considerable when compared to IDE expression. Insulin degradation was increased by CFS but decreased by UV-killed L. acidophilus (ATCC 314).

Dual Effects of Cell Free Supernatants from Lactobacillus acidophilus and Lactobacillus rhamnosus GG in Regulation of MMP-9 by Up-Regulating TIMP-1 and Down-Regulating CD147 in PMADifferentiated THP-1 Cells.

Objective Recent studies have reported dysregulated expression of matrix metalloproteinases (MMPs), especially MMP-2, MMP-9, tissue inhibitor of metalloproteinase-1, -2 (TIMP-1, TIMP-2), and extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in activated macrophages of patients with inflammatory diseases. Therefore, MMP-2, MMP-9, and their regulators may represent a new target for treatment of inflammatory diseases. Probiotics, which are comprised of lactic acid bacteria, have the potential to modulate inflammatory responses. In this experimental study, we investigated the anti-inflammatory effects of cell-free supernatants (CFS) from Lactobacillus acidophilus (L. acidophilus) and L. rhamnosus GG (LGG) in phorbol myristate acetate (PMA)-differentiated THP-1 cells. Materials and Methods In this experimental study, PMA-differentiated THP-1 cells were treated with CFS from L. acidophilus, LGG and uninoculated bacterial growth media (as a control). The expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNAs were determined using real-time quantitative reverse transcription polymerase chain reaction (RT- PCR). The levels of cellular surface expression of CD147 were assessed by flow cytometry, and the gelatinolytic activity of MMP-2 and MMP-9 were determined by zymography. Results Our results showed that CFS from both L. acidophilus and LGG significantly inhibited the gene expression of MMP-9 (P=0.0011 and P=0.0005, respectively), increased the expression of TIMP-1 (P<0.0001), decreased the cell surface expression of CD147 (P=0.0307 and P=0.0054, respectively), and inhibited the gelatinolytic activity of MMP-9 (P=0.0003 and P<0.0001, respectively) in PMA-differentiated THP-1 cells. Although, MMP-2 expression and activity and TIMP-2 expression remained unchanged. ConclusionOur results indicate that CFS from L. acidophilus and LGG possess anti-inflammatory properties and can modulate the inflammatory response.

Bacterial Remediation of Polyethylene by &lt;i&gt;Serratia marcescens sub sp. marcescens&lt;/i&gt; and its Supernatant

Improper disposal of commodity plastics such as polyethylene (PE) in the environment causes land pollution and soil infertility. It is unsightly and strongly threatens plant and animal life. The current effort describes the bacteria-mediated biodegradation of polyethylene bySerratia marcescens marcescens(SM) without prior exposure to thermo-oxidative aging. This study further describes the mechanism involved in the biodegradation of PE, in which a carbonless medium containing essential minerals and vitamins and powdered PE, were placed in the presence of overnight cultures ofSM.The samples were incubated at 30°C, centrifuged at a speed of 141 revolutions per minute (rpm) in a rotary shaker for ten weeks in order to observe the degradation process. The effects of cell-free supernatants (from theSMcultures) upon the degradation of sterile PE are elucidated. The results show that the supernatants fromSMdegrade PE faster than the bacteria, with a 37.5 percent of degradation rate within a month. The SEM micrographs suggest that the biodegradation of polyethylene involves the formation and coalescence of microvoids. The DSC results revealed that the feeding activity of SM is mostly favored at the crystalline region due to its high energy.

Antibacterial and immunomodulatory effect of cell free supernatant ofLactobacillus plantarumagainstShigella flexneri

Antibacterial and immunomodulatory effect of cell free supernatant of<i>Lactobacillus plantarum</i>against<i>Shigella flexneri</i>

Effects of Bacillus subtilis extracts on weed seed germination of Sorghum halepense and Amaranthus hybridus

The effects of cell-free supernatants (S) and anionic fractions (Q) from three different strains of Bacillus subtilis were evaluated on weed seed germination. The plant growth promoting rhizobacteria (PGPR) strains DN and Car13, as well as a non-promoting strain (PY79), were tested on pigweed (Amaranthus hybridus L.) and Johnson grass (Sorghum halepense L. pers). The application of anionic fractions QCar13, QDN and QPY caused a drastic decrease in the germination rates of both pigweed and Johnson grass seeds relative to controls. These results suggest the presence of one or several metabolites capable of inhibiting germination in both weeds, while acting more effectively on dicotyledonous seeds. This work shows the potential of essayed fractions in weed control. Key words: Bacterial metabolites, germination inhibition, weed control.

Capability of Lactobacillus acidophilus supernatant to inhibit production of lipase from methicillin-resistant Staphylococcus aureus

The ability of acid supernatants of Lactobacillus acidophilus isolated from a vinegar were tested against methicillin resistant Staphylococcus aureus (MRSA) with lipolytic activity isolated from acne pimple. Results revealed a significant effect of cell free supernatant on MRSA isolates in comparison with control. Furthermore, subinhibitory concentrations of acid supernatants found to be very effective in inhibiting the production of lipase from biofilm and planktonic cells of MRSA isolates. What's more, acid supernatants of L. acidophilus showed inhibiting effect on the crude lipase in egg yolk agar plates

PROBIOTIC BACTERIA AS A TOOL TO PREVENT FUNGAL GROWTH AND AFLATOXINS PRODUCTION BY Aspergillus parasiticus

Lactobacillus strains are used as probiotic bacteria in fermented dairy products and other fermented food products, whereas they are known to prolong the shelf life of these products. The inhibitory effect of cell free supernatant (CFS) of several Lactobacillus species on mycelium growth and the aflatoxin production by the aflatoxigenic strain of Aspergillus parasiticus was studied. A complete inhibition (100%) of mycelium growth and aflatoxin production was recorded when cell free supernatant of Lactobacillus casei was placed in a dialysis sac or in the medium without a dialysis sac or on the insertion of A. parasiticus after 16 hours with L. casei. Both L. reuteri and L. gasseri inhibited mycelium growth and aflatoxin production but to a lesser extent. Cell free supernatant of L. acidophilus and L. bulgaricus showed the lowest effect on aflatoxin production as well as on mycelium growth. The inoculation of bacterial strains of L. casei, L. gasseri and L. reuteri before fungal growth inoculation by 16 hours caused inhibitory effects on mycelium growth and aflatoxin production. But these indications were not observed for the other treatments of L. acidophilus or L. bulgaricus. The probiotic strains (L. casei, L. reuteri) with higher antifungal activity were used and incorporated in the manufacture of Ras cheese to replace the normal starters (S. thermophilus, L. bulgaricus), where they prevented the growth of fungi during the three month of the storage period. In conclusion probiotic bacteria may be able to produce active substances that can inhibit aflatoxins production by A. parasiticus in most treatments used, and the inhibitory effect depends on the type of lactic acid and / or the treatment used.

Effect of stimulated neutrophils on cyclic nucleotide content in isolated rat glomeruli

In this study we examined the effect of cell-free supernatants from stimulated neutrophils on the adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) content in isolated rat glomeruli. Cell-free supernatants obtained from unstimulated and stimulated (with opsonized zymosan for 30 min at 37 degrees C) cells were incubated for 5 min with glomeruli and tubules. Cell-free supernatants from stimulated neutrophils significantly increased the cAMP content in the glomeruli from 34.7 +/- 2.3 to 99.7 +/- 7.0 pmol/mg protein (n = 23; P less than 0.001). The cAMP content in the tubules and the cGMP content in the glomeruli or tubules was not altered by the cell-free supernatants from stimulated neutrophils. The cAMP response of the glomeruli was not modified when supernatants were obtained from neutrophils stimulated in the presence of superoxide dismutase, a scavenger of superoxide anion. In contrast, the glomerular response to supernatants obtained from neutrophils stimulated in the presence of catalase, a scavenger of hydrogen peroxide, or in the presence of methionine or taurine, scavengers of hypochlorous acid, was significantly reduced (P less than 0.001). Additional experiments that used prostaglandin synthesis inhibitors (meclofenamate and ibuprofen) and phospholipase inhibitor (quinacrine) suggested that the reactive oxygen metabolites increase the cAMP content in glomeruli by stimulating phospholipase activity and thus enhancing prostaglandin synthesis. These data show that reactive oxygen metabolites generated by stimulated neutrophils increase cAMP content in glomeruli and suggest that neutrophils may modulate the glomerular function and the inflammatory response in glomerular disease by altering the cAMP content.

Lymphoblastogenesis inhibitory factor produced by human lung cancer cell lines.

A comparative study of the inhibitory effect of cell-free supernatants (CFS) from human lung cancer cell lines (ChaGo and PC-1) and from a human embryo fibroblast cell line on lymphocyte blastogenesis indicated that both lung cancer cell lines produce a large amount of the inhibitory factor while the production of such a factor from a control noncancer cell line is essentially very minimal or absent. The inhibitory effect of CFS of the lung cancer cell lines is not due to direct cytotoxicity. The inhibitory effect is found to be partially sensitive to heat treatment. A significant inhibition is still seen, even when the CFS of the lung cancer cell lines were present for 1 hour prior to the addition of phytohemagglutinin (PHA).