Skip to main content
NCBI home page
Infection and Immunity logoLink to Infection and Immunity
. 1997 May;65(5):1836–1841. doi: 10.1128/iai.65.5.1836-1841.1997

Cellular charge of Cryptococcus neoformans: contributions from the capsular polysaccharide, melanin, and monoclonal antibody binding.

J D Nosanchuk 1, A Casadevall 1
PMCID: PMC175227  PMID: 9125569

Abstract

Cryptococcus neoformans is a human pathogenic fungus which is unusual in two respects: it has a polysaccharide capsule similar to that found in encapsulated bacteria and it can produce melanin. Capsular and melanization phenotypes are associated with virulence. In this study we analyzed the contributions of the capsular polysaccharide, melanization, and antibody binding to the capsule to the cellular charge of C. neoformans. Cell charge was inferred from measurements of zeta potential. The results indicate that (i) C. neoformans cells are significantly more negatively charged than Saccharomyces cerevisiae cells, (ii) the polysaccharide capsule of C. neoformans is responsible for the high negative charge of the cells, (iii) C. neoformans melanin is negatively charged, (iv) melanization in C. neoformans is associated with an increased negative charge per cell, and (v) antibody binding to the capsule of C. neoformans significantly alters the cell charge. These results suggest that alterations in cell charge attributable to polysaccharide capsule formation, melanization, and antibody binding may affect C. neoformans virulence given that macrophage phagocytosis is effected by the zeta potential of microorganisms.

Full Text

The Full Text of this article is available as a PDF (163.6 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ambrose E. J. Electrophoretic behaviour of cells. Prog Biophys Mol Biol. 1966;16:241–265. doi: 10.1016/0079-6107(66)90008-3. [DOI] [PubMed] [Google Scholar]
  2. Bayer M. E., Sloyer J. L., Jr The electrophoretic mobility of gram-negative and gram-positive bacteria: an electrokinetic analysis. J Gen Microbiol. 1990 May;136(5):867–874. doi: 10.1099/00221287-136-5-867. [DOI] [PubMed] [Google Scholar]
  3. Bulmer G. S., Sans M. D., Gunn C. M. Cryptococcus neoformans. I. Nonencapsulated mutants. J Bacteriol. 1967 Nov;94(5):1475–1479. doi: 10.1128/jb.94.5.1475-1479.1967. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chedekel M. R., Ahene A. B., Zeise L. Melanin standard method: empirical formula 2. Pigment Cell Res. 1992 Nov;5(5 Pt 1):240–246. doi: 10.1111/j.1600-0749.1992.tb00543.x. [DOI] [PubMed] [Google Scholar]
  5. Cherniak R., Sundstrom J. B. Polysaccharide antigens of the capsule of Cryptococcus neoformans. Infect Immun. 1994 May;62(5):1507–1512. doi: 10.1128/iai.62.5.1507-1512.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Currie B. P., Casadevall A. Estimation of the prevalence of cryptococcal infection among patients infected with the human immunodeficiency virus in New York City. Clin Infect Dis. 1994 Dec;19(6):1029–1033. doi: 10.1093/clinids/19.6.1029. [DOI] [PubMed] [Google Scholar]
  7. DROUHET E., SEGRETAIN G. Inhibition de la migration leucocytaire in vitro par un polyoside capsulaire de Torulopsis (Cryptococcus) neoformans. Ann Inst Pasteur (Paris) 1951 Dec;81(6):674–676. [PubMed] [Google Scholar]
  8. Dong Z. M., Murphy J. W. Cryptococcal polysaccharides induce L-selectin shedding and tumor necrosis factor receptor loss from the surface of human neutrophils. J Clin Invest. 1996 Feb 1;97(3):689–698. doi: 10.1172/JCI118466. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Dong Z. M., Murphy J. W. Intravascular cryptococcal culture filtrate (CneF) and its major component, glucuronoxylomannan, are potent inhibitors of leukocyte accumulation. Infect Immun. 1995 Mar;63(3):770–778. doi: 10.1128/iai.63.3.770-778.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Dromer F., Charreire J., Contrepois A., Carbon C., Yeni P. Protection of mice against experimental cryptococcosis by anti-Cryptococcus neoformans monoclonal antibody. Infect Immun. 1987 Mar;55(3):749–752. doi: 10.1128/iai.55.3.749-752.1987. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. HIRANO A., ZIMMERMAN H. M., LEVINE S. FINE STRUCTURE OF CEREBRAL FLUID ACCUMULATION. VI. INTRACELLULAR ACCUMULATION OF FLUID AND CRYPTOCOCCAL POLYSACCHARIDE IN OLIGODENDROGLIA. Arch Neurol. 1965 Feb;12:189–196. doi: 10.1001/archneur.1965.00460260079009. [DOI] [PubMed] [Google Scholar]
  12. Huffnagle G. B., Chen G. H., Curtis J. L., McDonald R. A., Strieter R. M., Toews G. B. Down-regulation of the afferent phase of T cell-mediated pulmonary inflammation and immunity by a high melanin-producing strain of Cryptococcus neoformans. J Immunol. 1995 Oct 1;155(7):3507–3516. [PubMed] [Google Scholar]
  13. Illum L., Jacobsen L. O., Müller R. H., Mak E., Davis S. S. Surface characteristics and the interaction of colloidal particles with mouse peritoneal macrophages. Biomaterials. 1987 Mar;8(2):113–117. doi: 10.1016/0142-9612(87)90099-8. [DOI] [PubMed] [Google Scholar]
  14. Jacobson E. S., Emery H. S. Catecholamine uptake, melanization, and oxygen toxicity in Cryptococcus neoformans. J Bacteriol. 1991 Jan;173(1):401–403. doi: 10.1128/jb.173.1.401-403.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Jacobson E. S., Tinnell S. B. Antioxidant function of fungal melanin. J Bacteriol. 1993 Nov;175(21):7102–7104. doi: 10.1128/jb.175.21.7102-7104.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Kawaguchi H., Koiwai N., Ohtsuka Y., Miyamoto M., Sasakawa S. Phagocytosis of latex particles by leucocytes. I. Dependence of phagocytosis on the size and surface potential of particles. Biomaterials. 1986 Jan;7(1):61–66. doi: 10.1016/0142-9612(86)90091-8. [DOI] [PubMed] [Google Scholar]
  17. Kihn J. C., Masy C. L., Mestdagh M. M. Yeast flocculation: competition between nonspecific repulsion and specific bonding in cell adhesion. Can J Microbiol. 1988 Jun;34(6):773–778. doi: 10.1139/m88-131. [DOI] [PubMed] [Google Scholar]
  18. Kozel T. R., Cazin J., Jr Immune response to Cryptococcus neoformans soluble polysaccharide. I. Serological assay for antigen and antibody. Infect Immun. 1972 Jan;5(1):35–41. doi: 10.1128/iai.5.1.35-41.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Kozel T. R. Dissociation of a hydrophobic surface from phagocytosis of encapsulated and non-encapsulated cryptococcus neoformans. Infect Immun. 1983 Mar;39(3):1214–1219. doi: 10.1128/iai.39.3.1214-1219.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Kozel T. R., Gotschlich E. C. The capsule of cryptococcus neoformans passively inhibits phagocytosis of the yeast by macrophages. J Immunol. 1982 Oct;129(4):1675–1680. [PubMed] [Google Scholar]
  21. Kozel T. R., Hermerath C. A. Binding of cryptococcal polysaccharide to Cryptococcus neoformans. Infect Immun. 1984 Mar;43(3):879–886. doi: 10.1128/iai.43.3.879-886.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Kozel T. R., Reiss E., Cherniak R. Concomitant but not causal association between surface charge and inhibition of phagocytosis by cryptococcal polysaccharide. Infect Immun. 1980 Aug;29(2):295–300. doi: 10.1128/iai.29.2.295-300.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Kwon-Chung K. J., Rhodes J. C. Encapsulation and melanin formation as indicators of virulence in Cryptococcus neoformans. Infect Immun. 1986 Jan;51(1):218–223. doi: 10.1128/iai.51.1.218-223.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Lachica R. V., Zink D. L. Plasmid-associated cell surface charge and hydrophobicity of Yersinia enterocolitica. Infect Immun. 1984 May;44(2):540–543. doi: 10.1128/iai.44.2.540-543.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Lee S. C., Casadevall A., Dickson D. W. Immunohistochemical localization of capsular polysaccharide antigen in the central nervous system cells in cryptococcal meningoencephalitis. Am J Pathol. 1996 Apr;148(4):1267–1274. [PMC free article] [PubMed] [Google Scholar]
  26. Levitz S. M., Tabuni A., Kornfeld H., Reardon C. C., Golenbock D. T. Production of tumor necrosis factor alpha in human leukocytes stimulated by Cryptococcus neoformans. Infect Immun. 1994 May;62(5):1975–1981. doi: 10.1128/iai.62.5.1975-1981.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Magnusson K. E., Stendahl O., Tagesson C., Edebo L., Johansson G. The tendency of smooth and rough Salmonella typhimurium bacteria and lipopolysaccharide to hydrophobic and ionic interaction, as studied in aqueous polymer two-phase systems. Acta Pathol Microbiol Scand B. 1977 Jun;85(3):212–218. doi: 10.1111/j.1699-0463.1977.tb01698.x. [DOI] [PubMed] [Google Scholar]
  28. Mitchell T. G., Perfect J. R. Cryptococcosis in the era of AIDS--100 years after the discovery of Cryptococcus neoformans. Clin Microbiol Rev. 1995 Oct;8(4):515–548. doi: 10.1128/cmr.8.4.515. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Mozes N., Léonard A. J., Rouxhet P. G. On the relations between the elemental surface composition of yeasts and bacteria and their charge and hydrophobicity. Biochim Biophys Acta. 1988 Nov 22;945(2):324–334. doi: 10.1016/0005-2736(88)90495-6. [DOI] [PubMed] [Google Scholar]
  30. Mukherjee J., Scharff M. D., Casadevall A. Protective murine monoclonal antibodies to Cryptococcus neoformans. Infect Immun. 1992 Nov;60(11):4534–4541. doi: 10.1128/iai.60.11.4534-4541.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Mukherjee S., Lee S. C., Casadevall A. Antibodies to Cryptococcus neoformans glucuronoxylomannan enhance antifungal activity of murine macrophages. Infect Immun. 1995 Feb;63(2):573–579. doi: 10.1128/iai.63.2.573-579.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Mukherjee S., Lee S., Mukherjee J., Scharff M. D., Casadevall A. Monoclonal antibodies to Cryptococcus neoformans capsular polysaccharide modify the course of intravenous infection in mice. Infect Immun. 1994 Mar;62(3):1079–1088. doi: 10.1128/iai.62.3.1079-1088.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Muratsugu M., Miyake Y., Ishida N., Hyodo A., Terayama K. Decrease in surface charge density of Klebsiella pneumoniae treated with cefodizime and enhancement of the phagocytic function of human polymorphonuclear leucocytes stimulated by the drug-treated bacteria. Biol Pharm Bull. 1995 Sep;18(9):1259–1263. doi: 10.1248/bpb.18.1259. [DOI] [PubMed] [Google Scholar]
  34. Murphy J. W., Cozad G. C. Immunological unresponsiveness induced by cryptococcal capsular polysaccharide assayed by the hemolytic plaque technique. Infect Immun. 1972 Jun;5(6):896–901. doi: 10.1128/iai.5.6.896-901.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Murphy J. W., Mosley R. L., Cherniak R., Reyes G. H., Kozel T. R., Reiss E. Serological, electrophoretic, and biological properties of Cryptococcus neoformans antigens. Infect Immun. 1988 Feb;56(2):424–431. doi: 10.1128/iai.56.2.424-431.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Nagura H., Asai J., Katsumata Y., Kojima K. Role of electric surface charge of cell membrane in phagocytosis. Acta Pathol Jpn. 1973 May;23(2):279–290. doi: 10.1111/j.1440-1827.1973.tb00792.x. [DOI] [PubMed] [Google Scholar]
  37. Polacheck I., Kwon-Chung K. J. Melanogenesis in Cryptococcus neoformans. J Gen Microbiol. 1988 Apr;134(4):1037–1041. doi: 10.1099/00221287-134-4-1037. [DOI] [PubMed] [Google Scholar]
  38. Ramadan M. A., Tawfik A. F., Shibl A. M., Gemmell C. G. Post-antibiotic effect of azithromycin and erythromycin on streptococcal susceptibility to phagocytosis. J Med Microbiol. 1995 May;42(5):362–366. doi: 10.1099/00222615-42-5-362. [DOI] [PubMed] [Google Scholar]
  39. Rhodes J. C., Polacheck I., Kwon-Chung K. J. Phenoloxidase activity and virulence in isogenic strains of Cryptococcus neoformans. Infect Immun. 1982 Jun;36(3):1175–1184. doi: 10.1128/iai.36.3.1175-1184.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Richmond D. V., Fisher D. J. The electrophoretic mobility of micro-organisms. Adv Microb Physiol. 1973;9:1–29. doi: 10.1016/s0065-2911(08)60375-6. [DOI] [PubMed] [Google Scholar]
  41. Saito H., Tomioka H., Watanabe T., Sato K. Mechanisms of phagocytosis of Mycobacterium leprae and other mycobacteria by human oligodendroglial cells. Infect Immun. 1986 Jan;51(1):163–167. doi: 10.1128/iai.51.1.163-167.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Salas S. D., Bennett J. E., Kwon-Chung K. J., Perfect J. R., Williamson P. R. Effect of the laccase gene CNLAC1, on virulence of Cryptococcus neoformans. J Exp Med. 1996 Aug 1;184(2):377–386. doi: 10.1084/jem.184.2.377. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Sanford J. E., Lupan D. M., Schlageter A. M., Kozel T. R. Passive immunization against Cryptococcus neoformans with an isotype-switch family of monoclonal antibodies reactive with cryptococcal polysaccharide. Infect Immun. 1990 Jun;58(6):1919–1923. doi: 10.1128/iai.58.6.1919-1923.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Schlageter A. M., Kozel T. R. Opsonization of Cryptococcus neoformans by a family of isotype-switch variant antibodies specific for the capsular polysaccharide. Infect Immun. 1990 Jun;58(6):1914–1918. doi: 10.1128/iai.58.6.1914-1918.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Spitzer E. D., Spitzer S. G., Freundlich L. F., Casadevall A. Persistence of initial infection in recurrent Cryptococcus neoformans meningitis. Lancet. 1993 Mar 6;341(8845):595–596. doi: 10.1016/0140-6736(93)90354-j. [DOI] [PubMed] [Google Scholar]
  46. Stendahl O., Normann B., Edebo L. Influence of O and K antigens on the surface properties of Escherichia coli in relation to phagocytosis. Acta Pathol Microbiol Scand B. 1979 Apr;87B(2):85–91. doi: 10.1111/j.1699-0463.1979.tb02408.x. [DOI] [PubMed] [Google Scholar]
  47. Tabata Y., Ikada Y. Effect of the size and surface charge of polymer microspheres on their phagocytosis by macrophage. Biomaterials. 1988 Jul;9(4):356–362. doi: 10.1016/0142-9612(88)90033-6. [DOI] [PubMed] [Google Scholar]
  48. Takahashi S., Nagano Y., Nagano N., Fujita K., Taguchi F., Okuwaki Y. Opsonisation of group B streptococci and restriction endonuclease digestion patterns of their chromosomal DNA. J Med Microbiol. 1993 Mar;38(3):191–196. doi: 10.1099/00222615-38-3-191. [DOI] [PubMed] [Google Scholar]
  49. Vecchiarelli A., Retini C., Pietrella D., Monari C., Tascini C., Beccari T., Kozel T. R. Downregulation by cryptococcal polysaccharide of tumor necrosis factor alpha and interleukin-1 beta secretion from human monocytes. Infect Immun. 1995 Aug;63(8):2919–2923. doi: 10.1128/iai.63.8.2919-2923.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  50. Wang Y., Aisen P., Casadevall A. Cryptococcus neoformans melanin and virulence: mechanism of action. Infect Immun. 1995 Aug;63(8):3131–3136. doi: 10.1128/iai.63.8.3131-3136.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Wang Y., Aisen P., Casadevall A. Melanin, melanin "ghosts," and melanin composition in Cryptococcus neoformans. Infect Immun. 1996 Jul;64(7):2420–2424. doi: 10.1128/iai.64.7.2420-2424.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Wang Y., Casadevall A. Growth of Cryptococcus neoformans in presence of L-dopa decreases its susceptibility to amphotericin B. Antimicrob Agents Chemother. 1994 Nov;38(11):2648–2650. doi: 10.1128/aac.38.11.2648. [DOI] [PMC free article] [PubMed] [Google Scholar]
  53. Wang Y., Casadevall A. Susceptibility of melanized and nonmelanized Cryptococcus neoformans to nitrogen- and oxygen-derived oxidants. Infect Immun. 1994 Jul;62(7):3004–3007. doi: 10.1128/iai.62.7.3004-3007.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  54. Wibawan I. W., Lämmler C. Influence of capsular neuraminic acid on properties of streptococci of serological group B. J Gen Microbiol. 1991 Dec;137(12):2721–2725. doi: 10.1099/00221287-137-12-2721. [DOI] [PubMed] [Google Scholar]
  55. Williamson P. R. Biochemical and molecular characterization of the diphenol oxidase of Cryptococcus neoformans: identification as a laccase. J Bacteriol. 1994 Feb;176(3):656–664. doi: 10.1128/jb.176.3.656-664.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  56. Wong J. D., Miller M. A., Janda J. M. Surface properties and ultrastructure of Edwardsiella species. J Clin Microbiol. 1989 Aug;27(8):1797–1801. doi: 10.1128/jcm.27.8.1797-1801.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  57. Xiu J. H., Magnusson K. E., Stendahl O., Edebo L. Physicochemical surface properties and phagocytosis by polymorphonuclear leucocytes of different serogroups of Salmonella. J Gen Microbiol. 1983 Oct;129(10):3075–3084. doi: 10.1099/00221287-129-10-3075. [DOI] [PubMed] [Google Scholar]
  58. Zuger A., Louie E., Holzman R. S., Simberkoff M. S., Rahal J. J. Cryptococcal disease in patients with the acquired immunodeficiency syndrome. Diagnostic features and outcome of treatment. Ann Intern Med. 1986 Feb;104(2):234–240. doi: 10.7326/0003-4819-104-2-234. [DOI] [PubMed] [Google Scholar]

Articles from Infection and Immunity are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES