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Matteucci A, Högberg J, Piussi R, Wernbom M, Franceschetti E, Longo UG, Samuelsson K, Lövgren J, Hamrin Senorski E. Comparison of knee flexor strength recovery between semitendinosus alone versus semitendinosus with gracilis autograft for ACL reconstruction: a systematic review and meta-analysis. BMC Musculoskelet Disord 2024; 25:136. [PMID: 38347523 PMCID: PMC10863077 DOI: 10.1186/s12891-024-07226-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 01/23/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Whether there is a difference in harvesting the semitendinosus tendon alone (S) or in combination with the gracilis tendon (SG) for the recovery of knee flexor strength after anterior cruciate ligament (ACL) reconstruction remains inconclusive. Therefore, this study aimed to assess the recovery of knee flexor strength based on the autograft composition, S or SG autograft at 6, 12, and ≥ 24 months after ACL reconstruction. METHODS A systematic review and meta-analysis was conducted following the PRISMA guidelines. A comprehensive search was performed encompassing the Cochrane Library, Embase, Medline, PEDRo and AMED databases from inception to January 2023. Inclusion criteria were human clinical trials published in English, comprised of randomized controlled trials (RCTs), longitudinal cohort-, cross-sectional and case-control studies that compared knee flexor strength recovery between S and SG autografts in patients undergoing primary ACL reconstruction. Isokinetic peak torques were summarized for angular velocities of 60°/s, 180°/s, and across all angular velocities, assessed at 6, 12, and ≥ 24 months after ACL reconstruction. A random-effects model was used with standardized mean differences and 95% confidence intervals. Risk of bias was assessed with the RoBANS for non-randomized studies and the Cochrane RoB 2 tool for RCTs. Certainty of evidence was appraised using the GRADE working group methodology. RESULTS Among the 1,227 patients from the 15 included studies, 604 patients received treatment with S autograft (49%), and 623 received SG autograft (51%). Patients treated with S autograft displayed lesser strength deficits at 6 months across all angular velocities d = -0.25, (95% CI -0.40; -0.10, p = 0.001). Beyond 6 months after ACL reconstruction, no significant difference was observed between autograft compositions. CONCLUSION The harvest of S autograft for ACL reconstruction yields superior knee flexor strength recovery compared to SG autograft 6 months after ACL reconstruction, irrespective of angular velocity at isokinetic testing. However, the clinical significance of the observed difference in knee flexor strength between autograft compositions at 6 months is questionable, given the very low certainty of evidence and small effect size. There was no significant difference in knee flexor strength recovery between autograft compositions beyond 6 months after ACL reconstruction. TRIAL REGISTRATION CRD42022286773.
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Affiliation(s)
- Angelo Matteucci
- Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168, Rome, Italy
| | - Johan Högberg
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden.
- Sahlgrenska Sports Medicine Center, Sahlgrenska Academy, Gothenburg, Sweden.
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden.
| | - Ramana Piussi
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Sahlgrenska Sports Medicine Center, Sahlgrenska Academy, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
| | - Mathias Wernbom
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
| | - Edoardo Franceschetti
- Fondazione Policlinico Campus Bio-Medico, Via Alvaro del Portillo 200, Rome, Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico, Via Alvaro del Portillo 21, 00128, Rome, Italy
| | - Umile Giuseppe Longo
- Fondazione Policlinico Campus Bio-Medico, Via Alvaro del Portillo 200, Rome, Italy
- Research Unit of Orthopaedic and Trauma Surgery, Department of Medicine and Surgery, Università Campus Bio-Medico, Via Alvaro del Portillo 21, 00128, Rome, Italy
| | - Kristian Samuelsson
- Sahlgrenska Sports Medicine Center, Sahlgrenska Academy, Gothenburg, Sweden
- Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Orthopaedics, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Johan Lövgren
- Active Physio Sports Medicine Clinic, Brogatan 23, 431 30, Gothenburg, Sweden
| | - Eric Hamrin Senorski
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Sahlgrenska Sports Medicine Center, Sahlgrenska Academy, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
- Swedish Olympic Committee, Stockholm, Sweden
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Mion M, Orio A, Lövgren J, Vitale F, Cardinale M. Otolith sectioning reveals higher maximum age in greater weever (Trachinus draco). J Fish Biol 2024. [PMID: 38279785 DOI: 10.1111/jfb.15671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 12/06/2023] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Growth and maximum age are two key parameters that inform resilience of fish populations to exploitation. Existing information on those for greater weever inhabiting the eastern North Sea is based on the analysis of whole otoliths. Here, we present a reanalysis using sectioned otoliths. The results reveal a different growth pattern and a higher maximum age than that previously reported. The higher maximum age makes greater weever populations more vulnerable to exploitation. Such information can serve as a basis for the estimation of the growth curve that can be used for future assessment of the species.
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Affiliation(s)
- Monica Mion
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Alessandro Orio
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Johan Lövgren
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Francesca Vitale
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Massimiliano Cardinale
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
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Högberg J, Piussi R, Lövgren J, Wernbom M, Simonsson R, Samuelsson K, Hamrin Senorski E. Restoring Knee Flexor Strength Symmetry Requires 2 Years After ACL Reconstruction, But Does It Matter for Second ACL Injuries? A Systematic Review and Meta-analysis. Sports Med Open 2024; 10:2. [PMID: 38180584 PMCID: PMC10769975 DOI: 10.1186/s40798-023-00666-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024]
Abstract
BACKGROUND It is unknown whether knee flexor strength recovers after anterior cruciate ligament (ACL) reconstruction with a hamstring tendon (HT) autograft and whether persistent knee flexor strength asymmetry is associated to a second ACL injury. OBJECTIVE We aimed to systematically review (1) whether knee flexor strength recovers after ACL reconstruction with HT autografts, and (2) whether it influences the association with a second ACL injury. A third aim was to summarize the methodology used to assess knee flexor strength. DESIGN Systematic review and meta-analysis reported according to PRISMA. METHODS A systematic search was performed using the Cochrane Library, Embase, Medline, PEDRo, and AMED databases from inception to December 2021 and until completion in January 2023. Human clinical trials written in English and conducted as randomized controlled trials, longitudinal cohort, cross-sectional, and case-control studies on patients with index ACL reconstructions with HT autografts harvested from the ipsilateral side were considered. Knee flexor strength was measured isokinetically in both the reconstructed and uninjured limb to enable the calculation of the limb symmetry index (LSI). The Risk of Bias Assessment Tool for Non-Randomized Studies was used to assess risk of bias for non-randomized studies and the revised Cochrane Risk of Bias tool was used for randomized controlled trials. For the meta-analysis, the LSI (mean ± standard error) for concentric knee flexor strength at angular velocities of 60°/second (s) and 180°/s preoperatively and at 3 months, 6 months, 12 months, and 24 months were pooled as weighted means with standard errors. RESULTS The search yielded 64 studies with a total of 8378 patients, which were included for the assessment of recovery of knee flexor strength LSI, and a total of 610 patients from four studies that investigated the association between knee flexor strength and second ACL injuries. At 1 year after ACL reconstruction, the knee flexor strength LSI had recovered to 89.0% (95% CI 87.3; 90.7%) and 88.3% (95% CI 85.5; 91.1%) for the velocities of 60°/s and 180°/s, respectively. At 2 years, the LSI was 91.7% (95% CI 90.8; 92.6%) and 91.2% (95% CI 88.1; 94.2%), for velocities of 60°/s and 180°/s, respectively. For the association between knee flexor strength and second ACL injuries, there was insufficient and contradictory data. CONCLUSIONS There was low to very low certainty of evidence indicating that the recovery of knee flexor strength LSI, defined as ≥ 90% of the uninjured side, takes up to 2 years after ACL reconstruction with HT autografts. Whether knee flexor strength deficits influence the association of second ACL injuries is still uncertain. There was considerable heterogeneity in the methodology used for knee flexor strength assessment, which together with the low to very low certainty of evidence, warrants further caution in the interpretation of our results. REGISTRATION NUMBER CRD42022286773.
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Affiliation(s)
- Johan Högberg
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden.
- Sahlgrenska Sports Medicine Center, Gothenburg, Sweden.
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden.
| | - Ramana Piussi
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Sahlgrenska Sports Medicine Center, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
| | - Johan Lövgren
- Active Physio Sports Medicine Clinic, Brogatan 23, 431 30, Gothenburg, Sweden
| | - Mathias Wernbom
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
- The Rydberg Laboratory for Applied Sciences, Halmstad University, Box 823, 301 18, Halmstad, Sweden
| | - Rebecca Simonsson
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Sahlgrenska Sports Medicine Center, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
| | - Kristian Samuelsson
- Sahlgrenska Sports Medicine Center, Gothenburg, Sweden
- Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Orthopaedics, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Eric Hamrin Senorski
- Sportrehab Sports Medicine Clinic, Stampgatan 14, 411 01, Gothenburg, Sweden
- Sahlgrenska Sports Medicine Center, Gothenburg, Sweden
- Unit of Physiotherapy, Department of Health and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Box 455, 405 30, Gothenburg, Sweden
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Casini M, Lövgren J, Hjelm J, Cardinale M, Molinero JC, Kornilovs G. Multi-level trophic cascades in a heavily exploited open marine ecosystem. Proc Biol Sci 2008; 275:1793-801. [PMID: 18460432 DOI: 10.1098/rspb.2007.1752] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Anthropogenic disturbances intertwined with climatic changes can have a large impact on the upper trophic levels of marine ecosystems, which may cascade down the food web. So far it has been difficult to demonstrate multi-level trophic cascades in pelagic marine environments. Using field data collected during a 33-year period, we show for the first time a four-level community-wide trophic cascade in the open Baltic Sea. The dramatic reduction of the cod (Gadus morhua) population directly affected its main prey, the zooplanktivorous sprat (Sprattus sprattus), and indirectly the summer biomass of zooplankton and phytoplankton (top-down processes). Bottom-up processes and climate-hydrological forces had a weaker influence on sprat and zooplankton, whereas phytoplankton variation was explained solely by top-down mechanisms. Our results suggest that in order to dampen the occasionally harmful algal blooms of the Baltic, effort should be addressed not only to control anthropogenic nutrient inputs but also to preserve structure and functioning of higher trophic levels.
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Affiliation(s)
- Michele Casini
- Swedish Board of Fisheries, Institute of Marine Research, PO Box 4, 45321 Lysekil, Sweden.
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Lövgren J, Reinikainen M, Persson L. Allochtonous input and trophic level heterogeneity: impact on an aquatic food web. OIKOS 2006. [DOI: 10.1111/j.2006.0030-1299.13737.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
BACKGROUND Human glandular kallikrein 2 (hK2) and prostate-specific antigen (PSA) are members of an extensive kallikrein family of proteases. Both proteases are secreted as zymogens or proenzymes containing a seven amino acid propeptide that must be proteolytically removed for enzymatic activation. The physiological proteases that activate pro-hK2 and pro-PSA are not known. METHODS The pro-hK2 peptide sequence is Val-Pro-Leu-Ile-Gln-Ser-Arg (VPLIQSR). For PSA, the amino acid sequence of the propeptide is Ala-Pro-Leu-Ile-Leu-Ser-Arg (APLILSR). Fluorescent substrates were made by coupling these peptide sequences to 7-amino-4-methylcoumarin (AMC). The hydrolysis of the VPLIQSR-AMC and APLILSR-AMC substrates by hK2, PSA, and a panel of purified proteases was determined. RESULTS HK2 readily cleaved the pro-hK2 peptide substrate VPLIQSR-AMC with a rate of hydrolysis that was approximately 8-fold higher than an equimolar amount of purified trypsin. HK2 also had the highest hydrolysis rate from among a group of other trypsin-like proteases. In contrast, neither hK2 nor PSA was able to appreciably cleave the pro-PSA substrate APLILSR-AMC. The pro-PSA substrate was most readily hydrolyzed by urokinase and trypsin. CONCLUSIONS HK2 can hydrolyze the pro-hK2 substrate suggesting that maturation of pro-hK2 to enzymatically active hK2 involves autoprocessing. As expected, PSA, a chymotrypsin-like protease, was unable to hydrolyze either of the propeptide substrates. Therefore, it is unlikely that PSA can auto-process its own enzymatic function. HK2 has trypsin-like specificity but was unable to hydrolyze the pro-PSA substrate. These results raise the possibility that an additional processing protease may be required to fully process PSA to an enzymatically active form.
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Affiliation(s)
- S R Denmeade
- The Johns Hopkins Oncology Center, Bunting Blaustein Cancer Research Building, Baltimore, Maryland 21231, USA.
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Lövgren J, Tian S, Lundwall A, Karp M, Lilja H. Production and activation of recombinant hK2 with propeptide mutations resulting in high expression levels. Eur J Biochem 1999; 266:1050-5. [PMID: 10583401 DOI: 10.1046/j.1432-1327.1999.00946.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human glandular kallikrein 2 (hK2) is a serine protease expressed mainly by the prostate gland with 80% identity in primary structure to prostate specific antigen (PSA). hK2 has proven to be a useful marker of prostate cancer which can be used in combination with PSA to better discriminate between prostate cancer and benign prostate hyperplasia. The studies on hK2 have been hampered by its very low phyciological levels (6 microgram.mL-1), its close similarity to PSA, and the low expression levels obtained using recombinant procedures to produce hK2 (0.7 mg.L-1). We have now generated propeptide mutations of hK2 which can be used to isolate stable, inactive prohK2 mutants. Compared with wild-type hK2, expression of the propeptide hK2 mutants increases the expression levels up to 15-40-fold giving 10-30 mg hK2.L-1. These results indicate that the low expression levels of wild-type hK2 are related to the activation or autoactivation of the wild-type enzyme and the instability of the active protease in cell culture and possibly also in tissue. The purified mutant hK2 may be activated by either enterokinase or factor Xa to generate an enzyme for use in functional studies with the characteristics of the original wild-type protein. Further, the stable inactive mutant hK2 protein may be used for immunizations to generate novel monoclonal antibodies, used as standard material for clinical assays or in crystallization studies where large quantities of protein are required.
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Affiliation(s)
- J Lövgren
- Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, University Hospital, Malmö, Sweden.
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Lövgren J, Airas K, Lilja H. Enzymatic action of human glandular kallikrein 2 (hK2). Substrate specificity and regulation by Zn2+ and extracellular protease inhibitors. Eur J Biochem 1999; 262:781-9. [PMID: 10411640 DOI: 10.1046/j.1432-1327.1999.00433.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Human glandular kallikrein 2 (hK2) is a serine protease expressed by the prostate gland with 80% identity in primary structure to prostate-specific antigen (PSA). Recently, hK2 was shown to activate the zymogen form of PSA (proPSA) in vitro and is likely to be the physiological activator of PSA in the prostate. hK2 is also able to activate urokinase and effectively cleave fibronectin. We studied the substrate specificity of hK2 and regulation of its activity by zinc and extracellular protease inhibitors present in the prostate and seminal plasma. The enzymatic activity and substrate specificity was studied by determining hK2 cleavage sites in the major gel proteins in semen, semenogelin I and II, and by measuring hydrolysis of various tripeptide aminomethylcoumarin substrates. HK2 cleaves substrates C-terminal of single or double arginines. Basic amino acids were also occasionally found at several other positions N-terminal of the cleavage site. Therefore, the substrate specificity of hK2 fits in well with that of a processor of protein precursors. Possible regulation mechanisms were studied by testing the ability of Zn2+ and different protease inhibitors to inhibit hK2 by kinetic measurements. Inhibitory constants were determined for the most effective inhibitors PCI and Zn2+. The high affinity of PCI for hK2 (kass = 2.0 x 10(5) M-1 x s-1) and the high concentrations of PCI (4 microM) and hK2 (0.2 microM) in seminal plasma make hK2 a very likely physiological target protease for PCI. hK2 is inhibited by Zn2+ at micromolar concentrations well below the 9 mM zinc concentration found in the prostate. The enzymatic activity of hK2 is likely to be reversibly regulated by Zn2+ in prostatic fluid. This regulation may be impaired in CAP and advanced metastatic cancer resulting in lack of control of the hK2 activity and a need for other means of control.
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Affiliation(s)
- J Lövgren
- Department of Laboratory Medicine, Lund University, Malmö, Sweden.
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Lövgren J, Valtonen-André C, Marsal K, Lilja H, Lundwall A. Measurement of prostate-specific antigen and human glandular kallikrein 2 in different body fluids. J Androl 1999; 20:348-55. [PMID: 10386814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
It has been demonstrated that prostate-specific antigen (PSA), in spite of its name, can be detected in body fluids and tumors from a variety of organs. Investigations have shown that human glandular kallikrein 2 (hK2), a related prostate-secreted protease, can activate the zymogen form of PSA, suggesting that the two enzymes might work as a functional unit, with hK2 as the activator molecule and PSA as the effector molecule. If this is true, then hK2 should be found together with PSA in body fluids other than seminal plasma, as well. Recently, a sensitive and specific assay was devised for hK2, enabling its measurement in picogram quantities. With this assay, the concentration of hK2 was determined in samples of seminal plasma, amniotic fluid, breast milk, and saliva. Simultaneously, the samples were assayed for molecular forms of PSA. In seminal plasma, the mean PSA concentration was 0.82 mg/ml, while the hK2 level was around two orders of magnitude lower: mean value, 6.4 microg/ml. Approximately the same ratio of PSA to hK2 as in seminal plasma was found in amniotic fluid and breast milk, but in most samples, the hK2 values were too low for direct measurements and had to be concentrated prior to analysis. Measurable levels of PSA, all in the free form, were detected in amniotic fluid at the thirteenth week of gestation and then gradually increased to levels around and over 1 microg/L from the twentieth week. Significant levels of PSA were detected in amniotic fluid collected at delivery, also. Measurable levels of mammary PSA were primarily detected in colostrum, with a range from less than 0.03 microg/L to 2.1 mg/L. Around half of the molecules were in complex with protease inhibitor. Most surprisingly, determinations on saliva samples showed that none of them had detectable PSA levels but had measurable concentrations of hK2 with a mean value, 0.09 microg/L. The presence in saliva suggests that hK2 can be the human equivalent to one of the mouse salivary kallikreins with important biological function, like the epidermal growth factor-binding protein or the gamma subunit of nerve growth factor. However, this was ruled out, as a phylogenetic analysis showed that the human and mouse glandular kallikreins evolved independently from a common precursor after the separation of the primate and rodent lineages. In conclusion, the measurements show that in addition to the previously known secretion in seminal plasma, hK2 is secreted in amniotic fluid, breast milk, and saliva. Furthermore, the concerted expression of PSA and hK2 in seminal plasma, amniotic fluid, and breast milk suggests that the two proteases might form a functional unit but not always as demonstrated by the sole presence of hK2 in saliva.
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Affiliation(s)
- J Lövgren
- Department of Laboratory Medicine, Lund University, University Hospital, Malmö, Sweden
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Väisänen V, Lövgren J, Hellman J, Piironen T, Lilja H, Pettersson K. Characterization and processing of prostate specific antigen (hK3) and human glandular kallikrein (hK2) secreted by LNCaP cells. Prostate Cancer Prostatic Dis 1999; 2:91-97. [PMID: 12496845 DOI: 10.1038/sj.pcan.4500289] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/1998] [Revised: 12/01/1998] [Accepted: 12/03/1998] [Indexed: 11/09/2022]
Abstract
Prostate specific antigen (PSA, hK3) in serum is predominantly complexed to alpha-1-antichymotrypsin (ACT), but a minor fraction remains in a free form despite the very large excess of serine protease inhibitors and alpha-2-macroglobulin. The fraction of free to total PSA is significantly lower in prostate cancer (CaP) compared to benign prostatic hyperplasia (BPH) which provides improved discrimination of these conditions. The molecular nature of free PSA in the circulation and the reason for its varying concentration in malignant and benign conditions is currently not known. The objective of the present investigation was to study the secretion of PSA and human glandular kallikrein 2 (hK2) by the LNCaP prostate cancer cell line, and to purify and characterize both proteins. LNCaP PSA was thoroughly characterized by immunological characterization, SDS-PAGE, isoelectric focusing, gel filtration, aminoterminal sequencing, reverse-phase chromatography, mass spectrometry and enzymatic activity measurements. LNCAP cells produced approximately equal amounts of zymogen (proPSA) and the one-chain mature form of PSA, whereas there was no evidence for the secretion of any internally cleaved forms. LNCaP cells secreted hK2 into the growth medium at about 3-5% of the amount of PSA. One-chain, mature PSA and hK2 obtained when LNCaP cells were grown in the presence of fetal bovine serum, had no enzymatic activity, but were active when the cells were grown in the absence of serum. Using enzymatically active recombinant hK2, it was possible to activate proPSA secreted by LNCaP cells. ProPSA formed two bands with high isoelectric points (8.2 and 8.4), which disappeared when proPSA was converted to mature PSA with hK2. Cancerous cells produce the zymogen forms of PSA, which by their isoelectric pI points seem to be found in serum of prostate cancer patients, but not BPH patients. Mature, one-chain PSA is inactive in the presence of serum. These findings may be highly relevant for the understanding of the generation of free and complexed PSA in the circulation.
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Affiliation(s)
- V Väisänen
- Department of Biotechnology, University of Turku, Tykistökatu 6, 20520, Turku, Finland
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Denmeade SR, Lou W, Lövgren J, Malm J, Lilja H, Isaacs JT. Specific and efficient peptide substrates for assaying the proteolytic activity of prostate-specific antigen. Cancer Res 1997; 57:4924-30. [PMID: 9354459 PMCID: PMC4124613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Prostate-specific antigen (PSA) is a serine protease secreted by both normal prostate glandular cells and prostate cancer cells. The major proteolytic substrates for PSA are the gel-forming proteins in semen, semenogelin (Sg) I and II. On the basis of the PSA cleavage map for Sg I and II, a series of small peptides (i.e., < or = 7 amino acids) was synthesized and coupled at the COOH terminus to 7-amino-4-methyl coumarin. Using these fluorescently tagged substrates, K(m)s and k(cat)s were determined for PSA hydrolysis, and the substrates were also tested for activity against a panel of purified proteases. Previously, a variety of chymotrypsin substrates have been used to assay the enzymatic activity of PSA. The present studies have identified a peptide sequence with a high degree of specificity for PSA (ie., no detectable hydrolysis by chymotrypsin) and improved K(m)s and k(cat)s over previously used substrates. On the basis of these parameters, the best peptide substrate for PSA has the amino acid sequence HSSKLQ. Using PC-82 human prostate cancer xenografts and human prostate tissues, this PSA substrate was used to document that prostate cancer cells secrete enzymatically active PSA into the extracellular fluid but that once in the blood, PSA is not enzymatically active. On the basis of this information, it should be possible to use the HSSKLQ peptide as a carrier to target peptide-coupled prodrugs for selective activation within sites of PSA-secreting, metastatic prostate cancer cells and not within the blood or other nonprostatic normal tissues.
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Affiliation(s)
- S R Denmeade
- The Johns Hopkins Oncology Center, Johns Hopkins School of Medicine, Baltimore, Maryland 21231-1001, USA
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Abstract
Mouse seminal vesicles secrete four major protein components with estimated molecular masses of 95, 38, 17, and 16 kDa. Amino acid sequencing revealed that the 95-kDa component represents a protein with an unknown structure, while the 38-kDa component was identified as semenoclotin, the 17-kDa component as seminal-vesicle-secreted protein IV, and the 16-kDa component as seminal-vesicle-secreted protein V. Semenoclotin and the 95-kDa component were readily cross-linked by transglutaminase, suggesting that the two proteins are involved in the formation of the mouse copulatory plug. Treatment of mouse seminal vesicle fluid with human prostate-specific antigen rapidly degraded semenoclotin, indicating a structural resemblance of this protein to human semenogelins, despite the vast difference in primary structure. As previously reported for other seminal-vesicle-secreted proteins, the semenoclotin transcripts are shown to be under androgen control.
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Affiliation(s)
- A Lundwall
- Lund University, Department of Laboratory Medicine, University Hospital, Malmö, Sweden.
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14
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Lövgren J, Rajakoski K, Karp M, Lilja H. Activation of the zymogen form of prostate-specific antigen by human glandular kallikrein 2. Biochem Biophys Res Commun 1997; 238:549-55. [PMID: 9299549 DOI: 10.1006/bbrc.1997.7333] [Citation(s) in RCA: 157] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Prostate-specific antigen (PSA) and human glandular kallikrein 2 (hK2) are glandular kallikreins secreted by the prostate gland. Both enzymes are synthesized with a propeptide that is supposedly cleaved off in the prostate to yield the mature forms found in semen. We have purified and characterised recombinant PSA and hK2 produced in eucaryotic cells. Recombinant PSA was recovered as a zymogen and recombinant hK2 was recovered in mature form. The zymogen form of PSA had no or very low enzymatic activity. After incubation with hK2, proPSA was activated, as shown by the cleavage of the seminal gel proteins and a peptide substrate; the hK2-proPSA ratio used was similar to the enzyme-substrate ratio that prevails under phyciological conditions. Our results indicate that hK2 is responsible for the activation of proPSA, a finding that may be very important for understanding of the role of these two kallikreins in the reproductive system and in prostate cancer biology.
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Affiliation(s)
- J Lövgren
- Department of Clinical Chemistry, Lund University Hospital, Malmö, S-205 02, Sweden.
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15
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Rajakoski K, Piironen T, Pettersson K, Lövgren J, Karp M. Epitope mapping of human prostate specific antigen and glandular kallikrein expressed in insect cells. Prostate Cancer Prostatic Dis 1997; 1:16-20. [PMID: 12496928 DOI: 10.1038/sj.pcan.4500206] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/1997] [Revised: 05/08/1997] [Accepted: 05/17/1997] [Indexed: 11/09/2022]
Abstract
Two human prostate gland proteases were expressed in insect cells using recombinant baculovirus expression system. Prostate specific antigen (PSA) is an established serum marker of prostate cancer whereas the clinical utility of its close homologue, human glandular kallikrein (hK2) is presently unknown. The production levels using Trichoplusia ni cells were roughly 300 &mgr;g/l and 6 mg/l for hK2 and PSA, respectively. On western-blot we estimated the size for both proteins to be approximately 33 kDa which was consistent with PSA purified from seminal plasma. Nine anti-PSA monoclonal antibodies (Mabs) out of 26 tested, representing five independent epitopes, also reacted with hK2. The results obtained in this study may help in designing more accurate diagnostic assays for detection and monitoring of prostate cancer.
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Affiliation(s)
- K Rajakoski
- Department of Biotechnology, University of Turku, Tykistökatu 6, 6th Floor, FIN-20520 Turku, Finland
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16
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Eerola R, Piironen T, Pettersson K, Lövgren J, Vehniäinen M, Lilja H, Dowell B, Lövgren T, Karp M. Immunoreactivity of recombinant human glandular kallikrein using monoclonal antibodies raised against prostate-specific antigen. Prostate 1997; 31:84-90. [PMID: 9140120 DOI: 10.1002/(sici)1097-0045(19970501)31:2<84::aid-pros2>3.0.co;2-h] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The gene encoding human glandular kallikrein (KLK2) was expressed in Escherichia coli, and the corresponding protein (hK2) was produced by fermentation. The hK2 was characterized by Western blotting and epitope map using monoclonal antibodies (MAbs) specific for another protease, prostate-specific antigen (PSA) with high structural identity (80%). MAbs that recognized three different epitopes were bound to hK2, representing 7 out of 23 MAbs tested. One epitope was localized to the sequence region around amino acid position 78, which is believed to be glycosylated in hK2. The affinities of MAbs recognizing hK2 were similar to those for PSA, suggesting that common epitopes seem to contain very conserved structures. The results may help in designing specific diagnostic assays for the assessment of prostate cancer.
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Affiliation(s)
- R Eerola
- Department of Biotechnology, University of Turku, Finland
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17
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Piironen T, Lövgren J, Karp M, Eerola R, Lundwall A, Dowell B, Lövgren T, Lilja H, Pettersson K. Immunofluorometric assay for sensitive and specific measurement of human prostatic glandular kallikrein (hK2) in serum. Clin Chem 1996; 42:1034-41. [PMID: 8674186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Prostate-specific antigen (PSA) and human prostatic glandular kallikrein (hK2) have 79% identity with the primary structure. When we used recombinant hK2 protein, only 7 of 23 monoclonal anti-PSA IgGs (monoclonal antibodies, MAbs) cross-reacted with hK2, which enabled us to design a novel immunofluorometric MAb-MAb assay for the specific detection of hK2. In the first incubation, an excess of MAb 2H11, which does not cross-react with hK2, is added to prevent both free and complexed PSA from reacting in subsequent immunoreactions. In the second incubation, biotinylated MAb H50, which cross-reacts with hK2 by an epitope overlapping with MAb 2H11, served to bind only hK2 to the microtitration wells coated with streptavidin. In the third step, Eu-labeled MAb H117, which cross-reacts with hK2, detected the immobilized hK2. The hK2 assay was calibrated with recombinant hK2. The detection limit of the assay was 0.1 microgram/L, and the cross-reactivity with recombinant PSA was < or = 0.7%. The concentration of hK2 was measured in serum samples from 334 males with total PSA concentrations ranging from 1 to 3400 microgram/L. Most of the samples (57%) had hK2 concentrations below the detection limit. The proportions of hK2 relative to total PSA were 0-2% in 79%, 2-5% in 14%, 5-10% in 4%, and >10% in 3% of the samples. Gel filtration of 10 serum samples with increased hK2 concentrations showed a single peak of hK2 immunoreactivity with an apparent molecular size of approximately 30 kDa, corresponding to that of recombinant hK2 and free PSA.
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Affiliation(s)
- T Piironen
- Department of Biotechnology, University of Turku, Finland.
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18
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Piironen T, Lövgren J, Karp M, Eerola R, Lundwall A, Dowell B, Lövgren T, Lilja H, Pettersson K. Immunofluorometric assay for sensitive and specific measurement of human prostatic glandular kallikrein (hK2) in serum. Clin Chem 1996. [DOI: 10.1093/clinchem/42.7.1034] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Prostate-specific antigen (PSA) and human prostatic glandular kallikrein (hK2) have 79% identity with the primary structure. When we used recombinant hK2 protein, only 7 of 23 monoclonal anti-PSA IgGs (monoclonal antibodies, MAbs) cross-reacted with hK2, which enabled us to design a novel immunofluorometric MAb-MAb assay for the specific detection of hK2. In the first incubation, an excess of MAb 2H11, which does not cross-react with hK2, is added to prevent both free and complexed PSA from reacting in subsequent immunoreactions. In the second incubation, biotinylated MAb H50, which cross-reacts with hK2 by an epitope overlapping with MAb 2H11, served to bind only hK2 to the microtitration wells coated with streptavidin. In the third step, Eu-labeled MAb H117, which cross-reacts with hK2, detected the immobilized hK2. The hK2 assay was calibrated with recombinant hK2. The detection limit of the assay was 0.1 microgram/L, and the cross-reactivity with recombinant PSA was < or = 0.7%. The concentration of hK2 was measured in serum samples from 334 males with total PSA concentrations ranging from 1 to 3400 microgram/L. Most of the samples (57%) had hK2 concentrations below the detection limit. The proportions of hK2 relative to total PSA were 0-2% in 79%, 2-5% in 14%, 5-10% in 4%, and >10% in 3% of the samples. Gel filtration of 10 serum samples with increased hK2 concentrations showed a single peak of hK2 immunoreactivity with an apparent molecular size of approximately 30 kDa, corresponding to that of recombinant hK2 and free PSA.
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Affiliation(s)
- T Piironen
- Department of Biotechnology, University of Turku, Finland.
| | - J Lövgren
- Department of Biotechnology, University of Turku, Finland.
| | - M Karp
- Department of Biotechnology, University of Turku, Finland.
| | - R Eerola
- Department of Biotechnology, University of Turku, Finland.
| | - A Lundwall
- Department of Biotechnology, University of Turku, Finland.
| | - B Dowell
- Department of Biotechnology, University of Turku, Finland.
| | - T Lövgren
- Department of Biotechnology, University of Turku, Finland.
| | - H Lilja
- Department of Biotechnology, University of Turku, Finland.
| | - K Pettersson
- Department of Biotechnology, University of Turku, Finland.
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19
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Blomberg K, Hautala R, Lövgren J, Mukkala VM, Lindqvist C, Akerman K. Time-resolved fluorometric assay for natural killer activity using target cells labelled with a fluorescence enhancing ligand. J Immunol Methods 1996; 193:199-206. [PMID: 8699033 DOI: 10.1016/0022-1759(96)00063-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
A time-resolved fluorometric assay for the measurement of natural killer cell activity against target cells labelled with the acetoxymethyl ester of the fluorescence enhancing ligand 2,2':6',2"-terpyridine-6,6"-dicarboxylic acid (TDA) is described. The hydrophobic esterified form of TDA (bis(acetoxymethyl) 2,2':6',2"-terpyridine-6,6"-dicarboxylate, BATDA) diffuses readily through the cell membrane of viable cells. BATDA is hydrolysed by intracellular esterases resulting in accumulation of membrane impermeable TDA inside the target cells. After incubation of labelled K-562 cells with effector cells the TDA released from lysed cells into the supernatant is chelated with Eu3+. The natural killer cell activity is then quantified by measuring the intense fluorescence of the EuTDA chelates formed. Target cells are rapidly labelled when incubated with BATDA, TDA is released from target cells faster than 51Cr, the spontaneous release permits a short-term release assay to be set up and the detection of EuTDA is fast (5 min/96 well plate). Furthermore, this non-radioactive method permits the use of complex culture media since, in contrast to methods based on prompt fluorometry, the problem with autofluorescence can be avoided by the use of time-resolved fluorometry.
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MESH Headings
- 2,2'-Dipyridyl/analogs & derivatives
- 2,2'-Dipyridyl/chemistry
- 2,2'-Dipyridyl/metabolism
- Chelating Agents
- Cytotoxicity Tests, Immunologic
- Dicarboxylic Acids/chemistry
- Dicarboxylic Acids/metabolism
- Fluorescence
- Fluorometry
- Humans
- Killer Cells, Natural/chemistry
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Leukemia, Erythroblastic, Acute
- Ligands
- Pyridines/chemistry
- Pyridines/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- K Blomberg
- Wallac Biochemical Laboratory, Turku, Finland
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20
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Lövgren J, Piironen T, Overmo C, Dowell B, Karp M, Pettersson K, Lilja H, Lundwall A. Production of recombinant PSA and HK2 and analysis of their immunologic cross-reactivity. Biochem Biophys Res Commun 1995; 213:888-95. [PMID: 7544581 DOI: 10.1006/bbrc.1995.2212] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Measurements of prostate-specific antigen (PSA) in serum are widely used to monitor patients with prostate cancer, but the attenuation of the assay response by PSA complexed to protease inhibitors has been shown to affect the results in certain assay designs. Moreover, the human glandular kallikrein-2 (hK2), a kallikrein-like serine protease that is 80% similar to PSA, might interfere with the specific detection of PSA by immunological cross-reactivity. We have expressed hK2 and PSA in eucaryotic cells using the Semliki Forest Virus expression system and studied the reactivity of 18 monoclonal anti-PSA IgGs. Five of them cross-reacted with identical affinities to recombinant hK2 whereas 13 recognized PSA alone. The antibodies that recognized both PSA and hK2 bind to a region of the protein that is exposed when PSA is complexed to alpha-1-antichymotrypsin.
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Affiliation(s)
- J Lövgren
- Department of Clinical Chemistry, Lund University, University Hospital, Malmö, Sweden
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21
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Lövgren J, Blomberg K. Simultaneous measurement of NK cell cytotoxicity against two target cell lines labelled with fluorescent lanthanide chelates. J Immunol Methods 1994; 173:119-25. [PMID: 8034979 DOI: 10.1016/0022-1759(94)90289-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We describe a cytotoxicity assay which permits the simultaneous measurement of natural killer cell activity against two different cell lines. The target cell lines are labelled either with a fluorescent europium chelate or with a fluorescent terbium chelate and cell death is quantified by measuring the chelate release. K-562, Molt4 and Daudi cell lines have been used as targets. The release of the two chelates from the target cells can be detected with the help of time resolved fluorometry. As the measurements are made after background fluorescence has decayed no additional steps are needed to correct for the background from the medium. The assay procedure used for measurement of cytotoxicity against two target cell lines is very similar to the widely used 51Cr release assay.
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Affiliation(s)
- J Lövgren
- Department of Biochemistry and Pharmacy, Abo Akademi University, Turku, Finland
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