Skip to main content
PMC home page
Journal of Clinical Laboratory Analysis logoLink to Journal of Clinical Laboratory Analysis
. 2001 Mar 13;14(6):255–259. doi: 10.1002/1098-2825(20001212)14:6<255::AID-JCLA1>3.0.CO;2-J

Biological effects of natural and recombinant mistletoe lectin and an aqueous mistletoe extract on human monocytes and lymphocytes in vitro

U Elsässer‐Beile 1,✉, M Voss 1, R Schühle 1, U Wetterauer 1
PMCID: PMC6808059  PMID: 11138605

Abstract

Mistletoe lectin is thought to constitute the active principle in extract preparations from mistletoe, which are widely used as immunomodulators in adjuvant tumor therapy. However, no study exists which compares the immunological potency of different well‐defined mistletoe lectin preparations on human immune cells. Therefore, in the present study the biological effects of an aqueous mistletoe extract, standardized for mistletoe lectin I (eML), the isolated natural mistletoe lectin (nML), and the recombinant form of this lectin (rML) on human peripheral blood monocytes and lymphocytes were compared with respect to cell viability and cytokine induction. After 48‐hr incubation of peripheral blood mononuclear cells (PBMC) with rML, nML, and eML, a continuous concentration‐dependent decrease in cell viability was found with an IC50 of about 3 ng/ml for rML and nML and 10 ng/ml for eML, respectively. This effect also was seen when isolated lymphocytes and monocytes were separately incubated with the lectin preparations. After incubation of PBMC and isolated monocytes of 5/10 blood donors with eML, an increase in cell viability was found at lectin concentrations between 10 and 1,000 pg/ml. This effect was not seen with the pure lectin preparations nML and rML. After 48‐hr incubation of PBMC with rML, nML, and eML, induction of IL‐1‐β, TNF‐α, IL‐2, IL‐6, and IL‐10 but not IFN‐γ was measured. For IL‐1‐β it could be shown that cytokine induction took place at a broad lectin concentration range (0.1–100 ng/ml). Cytokine levels varied greatly in the PBMC cultures of the different blood donors. When monocytes were separately incubated with eML, nML, and rML for 48 hr, high levels of IL‐1‐β were found. In contrast, in cultures of separated lymphocytes from the same donors only a minimal production of IL‐1‐β and no production of IFN‐γ was found after incubation with rML, nML, and eML. It is concluded that there are quantitative differences in the immunomodulatory effects of the mistletoe lectin preparations on human monocytes and lymphocytes. Therefore, measurement of cell viability and cytokine induction may be a diagnostic laboratory tool to determine the immunological potency of various mistletoe preparations and may help to clarify the clinical benefit of therapies with these substances. J. Clin. Lab. Anal. 14:255–259, 2000. © 2000 Wiley‐Liss, Inc.

Keywords: mistletoe lectin, cytokine induction, immunomodulation, cytotoxicity, human lymphocytes and monocytes

REFERENCES

  • 1. Kleijnen J, Knipschild P. 1994. Mistletoe treatment for cancer. Review of controlled trials in humans. Phytomedicine 1:255–260. [DOI] [PubMed] [Google Scholar]
  • 2. Hauser SP. 1991. Unproven methods in oncology. Eur J Cancer 27:1549–1551. [DOI] [PubMed] [Google Scholar]
  • 3. Hauser SP. 1993. Unproven methods in cancer treatment. Curr Opin Oncol 5:646–654. [DOI] [PubMed] [Google Scholar]
  • 4. Gabius HJ. 1997. Concepts of tumor lectinology. Cancer Invest 15:454–464. [DOI] [PubMed] [Google Scholar]
  • 5. Gabius HJ, Gabius S, Joshi SS, et al. 1994. From ill‐defined extracts to the immunomodulatory lectin: will there be a reason for oncological application of mistletoe? Planta Med 60:2–7. [DOI] [PubMed] [Google Scholar]
  • 6. Bocci V. 1993. Mistletoe (Viscum album) lectins as cytokine inducers and immunoadjuvant in tumor therapy: a review. J Biol Regul Homeostatic Agents 7:1–6. [PubMed] [Google Scholar]
  • 7. Heiny BM, Beuth J. 1994. Mistletoe extract standardized for the galactoside‐specific lectin (ML‐1) induces β‐endorphin release and immunopotentiation in breast cancer patients. Anticancer Res 14:1339– 1342. [PubMed] [Google Scholar]
  • 8. Endo Y, Tsurugi K, Franz H. 1988. The site of action of the A chain of mistletoe lectin I on eukaryotic ribosomes. The RNA N‐glycosidase activity of the protein. FEBS Lett 231:378–380. [DOI] [PubMed] [Google Scholar]
  • 9. Soler MH, Stoeva S, Schwamborn C, Wilhelm S, Stiefel T, Voelter W. 1996. Complete amino acid sequence of the A chain of mistletoe lectin I. FEBS Lett 399:153–157. [DOI] [PubMed] [Google Scholar]
  • 10. Dietrich JB, Ribereau‐Gayon G, Jung ML, Franz H, Beck JP, Anton R. 1992. Identity of the N‐terminal sequences of the three A chains of mistletoe (Viscum album L. ) lectins: homology with ricin‐like plant toxins and single‐chain ribosome‐inhibiting proteins. Anticancer Drugs 3:507–511. [DOI] [PubMed] [Google Scholar]
  • 11. Eschenburg S, Krauspenhaar R, Mikhailov A, Stoeva S, Betzel C, Voelter W. 1998. Primary structure and molecular modeling of mistletoe lectin I from Viscum album . Biochem Biophys Res Commun 247:367–372. [DOI] [PubMed] [Google Scholar]
  • 12. Lee RT, Gabius HJ, Lee YC. 1994. The sugar‐combining area of the galactose‐specific toxic lectin of mistletoe extends beyond the terminal sugar residue: comparison with a homologous toxic lectin, ricin. Carbohydr Res 254:269–276. [DOI] [PubMed] [Google Scholar]
  • 13. Eck J, Langer M, Möckel B, Witthohn K, Zinke H, Lentzen H. 1999. Characterization of recombinant and plant‐derived mistletoe lectin and their B chains. Eur J Biochem 265:788–797. [DOI] [PubMed] [Google Scholar]
  • 14. Eck J, Langer M, Möckel B, et al. 1999. Cloning of the mistletoe lectin gene and characterization of the recombinant A chain. Eur J Biochem 264:775–784. [DOI] [PubMed] [Google Scholar]
  • 15. Eifler R, Pfüller K, Göckeritz W, Pfüller U. 1993. In: Basu J, Kundu P, Chakrabarti P, editors. Lectins: biology, biochemistry, clinical biochemistry, Vol. 9 New Delhi: M/S Willey Eastern Limited; p 144–151. [Google Scholar]
  • 16. Elsässer‐Beile U, von Kleist S, Gallati H. 1991. Evaluation of a test system for measuring cytokine production in human whole blood cell cultures. J Immunol Methods 139:191–195. [DOI] [PubMed] [Google Scholar]
  • 17. Ishiyama M, Tomingaga H, Shiga M, Sasamoto K, Ohkura Y, Ueno K. 1996. A combined assay of cell viability and in vitro cytotoxicity with a highly water‐soluble tetrazolium salt, neutral re and crystal viole. Biol Pharm Bull 19:1518–1520. [DOI] [PubMed] [Google Scholar]
  • 18. Jung ML, Baudino S, Ribereau‐Gayon G, Beck JP. 1990. Characterization of cytotoxic proteins from mistletoe (Viscum album L. ). Cancer Lett 51:103–108. [DOI] [PubMed] [Google Scholar]
  • 19. Büssing A, Suzart K, Bergmann J, Pfüller U, Schietzel M, Schweizer K. 1996. Induction of apoptosis in human lymphocytes treated with Viscum album L. is mediated by the mistletoe lectins. Cancer Lett 99:59–72. [DOI] [PubMed] [Google Scholar]
  • 20. Ribereau‐Gayon G, Dumont S, Muller C, Jung ML, Poindron P, Anton R. 1996. Mistletoe lectins I, II and III induce the production of cytokines by cultured human monocytes. Cancer Lett 109:33–38. [DOI] [PubMed] [Google Scholar]
  • 21. Ribereau‐Gayon G, Jung ML, Frantz M, Anton R. 1997. Modulation of cytotoxicity and enhancement of cytokine release induced by Viscum album L. extracts or mistletoe lectins. Anticancer Drugs 8:S3–S8. [DOI] [PubMed] [Google Scholar]
  • 22. Hostanska K, Hajto T, Weber K, et al. 1996. A natural immunity‐activating plant lectin, Viscum album agglutinin‐I, induces apoptosis in human lymphocytes, monocytes, monocytic THP‐1 cells, and murine thymocytes. Nat Immun 15:295–311. [PubMed] [Google Scholar]
  • 23. Möckel B, Schwarz T, Zinke H, Eck J, Langer M, Lentzen H. 1997. Effects of misteltoe lectin I on human blood cell lines and peripheral blood cells. Cytotoxicity, apoptosis, and induction of cytokines. Arzneim‐Forsch/Drug Res 47:1145–1151. [PubMed] [Google Scholar]
  • 24. Hostanska K, Hajto T, Spagnoli GC, Fischer J, Lentzen H, Herrmann R. 1995. A plant lectin derived from Viscum album induces cytokine gene expression and protein production in cultures of human peripheral blood mononuclear cells. Nat Immun 14:295–304. [PubMed] [Google Scholar]
  • 25. Hajto T, Hostanska K, Frei K, Rordorf C, Gabius HJ. 1990. Increased secretion of tumor necrosis factor α, interleukin 1, and interleukin 6 by human mononuclear cells exposed to β‐galactoside‐specific lectin from clinically applied mistletoe extract. Cancer Res 50:3322–3326. [PubMed] [Google Scholar]
  • 26. Stein G, Berg PA. 1994. Non‐lectin component in a fermented extract from Viscum album L. grown on pines induces proliferation of lymphocytes from healthy and allergic individuals in vitro. Eur J Clin Pharmacol 47:33–38. [DOI] [PubMed] [Google Scholar]
  • 27. Stein GM, Berg PA. 1996. Evaluation of the stimulatory activity of a fermented mistletoe lectin‐1 free mistletoe extract on T‐helper cells and monocytes in healthy individuals in vitro. Arzneim‐Forsch 46:635–639. [PubMed] [Google Scholar]
  • 28. Hajto T, Hostanska K, Fischer J, Saller R. 1997. Immunomodulatory effects of Viscum album agglutinin‐I on natural immunity. Anticancer Drugs 8:43–46. [DOI] [PubMed] [Google Scholar]
  • 29. Stein GM, Berg PA. 1997. Mistletoe extract‐induced effects on immunocompetent cells: in vitro studies. Anticancer Drugs 8:S39–S42. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Clinical Laboratory Analysis are provided here courtesy of Wiley

RESOURCES