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Un vivo depletion of murine CD8 positive T cells impairs survival during infection with a highly virulent strain ofCryptococcus neoformans


Cell-mediated immunity plays an important but incompletely understood role in host defense againstCryptococcus neoformans. Because of their multiple capacities as cytokine-secreting cells, cytotoxic cells, and antigen-specific suppressor cells, CD8 positive T lymphocytes could potentially either enhance or impair host defense againstC. neoformans. To determine whether CD8 T cells enhance or inhibit host defence during an infection with a highly virulent strain ofC. neoformans, we examined the effect of in vivo CD8 cell depletion on suNival and on the number of organisms in mice infected by either the intratracheal or intravenous routes. Adequacy of depletion was confirmed both phenotypically and functionally. Regardless of the route of infection, we found that survival of mice depleted of CD8 T cells was significantly reduced compared to undepleted mice. Surprisingly, however, CD8 depletion did not alter organism burden measured by quantitative CFU assay in mice infected by either route. These data demonstrate that CD8 positive T cells participate in the immune response to a highly virulent strain ofC. neoformans. By contrast to minimally virulent isolates that do not cause a life threatening infection, the immune response to a highly virulent isolate does not alter the burden of organisms, but does enhance host defense as it is necessary for the optimal survival of infected mice.

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colony forming units


Fluorescein isothiocyanate


mixed lymphocyte reaction


phosphate buffered saline


  1. 1.

    Chuck SL, Sande MA. Infections withCryptococcus neoformans in the acquired immunodeficiency syndrome. N Engl J Med 1989; 321: 794–99.

  2. 2.

    Levitz S. The ecology ofCryptococcus neoformans and the epidemiology of cryptococcosis. Rev Inf Dis 1991; 13: 1163–69.

  3. 3.

    Zuger A, Louie E, Holzman RS, Simberkoff MS, Rahal JJ. Cryptococcal disease in patients with the Acquired Immune Deficiency Syndrome. Ann Int Med 1986; 104: 234–40.

  4. 4.

    Bodet CAI, Graybill JR. Cryptococcal pulmonary disease. Orlando: Grune & Stratton, 1986.

  5. 5.

    Baker R, Haugen R. Tissue changes and tissue diagnoses in cryptococcosis. Am J Clin Pathol 1955; 25: 14–24.

  6. 6.

    Gal A, Koss M, Hawkins J, Evans S, Einstein H. The pathology of pulmonary cryptococcal infections in the acquired immunodeficiency syndrome. Arch Pathol Labl Med 1986; 110: 502–7.

  7. 7.

    Kerkering TM, Duma RJ, Shadomy S. The evolution of pulmonary cryptococcosis: Clinical implications from a study of 41 patients with and without compromising host factors. Ann Int Med 1981; 94: 611–16.

  8. 8.

    Meyer RD, Holmberg K. Fungal Infections in HIV-infected patients. In: Holmberg K, Meyer RD, eds. Diagnosis and therapy of systemic fungal infections. New York: Raven Press, 1989: 79–100.

  9. 9.

    Murphy JW. Immunoregulation in cryptococcosis. Immunol Res 1989; 47: 319–45.

  10. 10.

    Hill JO, Harmsen AG. Intrapulmonary growth and dissemination of an avirulent strain ofCryptococcus neoformans in mice depleted of CD4+ or CD8+ T cells. J Exp Med 1991; 173: 755–58.

  11. 11.

    Huffnagle GB, Yates JL, Lipscomb MF. Immunity to a pulmonaryCryptococcus neoformans infection requires both CD4+ and CD8+ T cells. J Exp Med 1991; 173: 793–800.

  12. 12.

    Mody CH, Lipscomb MF, Toews GB. Depletion of CD4+ (L3T4+) lymphocytes in vivo impairs murine host defense toCryptococcus neoformans. J Immunol 1990; 144: 1472–77.

  13. 13.

    Murphy JW, Mosley RL, Moorghead JW. Regulation of cell-mediated immunity in cryptococcosis, II: Characterization of first-order T supressor cells and induction of second-order suppressor cells. J Immunol 1983; 130: 2876–81.

  14. 14.

    Murphy JW, Mosley RL. Regulation of cell mediated immunity in cryptococcosis, III: Characterization of second-order T suppressor cells (Ts2). J Immunol 1985; 134: 577–84.

  15. 15.

    Fung PYS, Murphy JW. In vitro interactions of immune lymphocytes andC. neoformans. Infect Immun 1982; 36: 1128–38.

  16. 16.

    Mody CH, Tyler CL, Sitrin RG, Jackson C, Toews GB. Interferon-gamma activates rat alveolar macrophages for anticryptococcal activity. Am J Resp Cell Mol Biol 1991; 5: 19–26.

  17. 17.

    Cobbold SP, Jayasuriya A, Nash A, Prospero TD, Waldmann H. Therapy with monoclonal antibodies by elimination of T-cell subsets in vivo. Nature 1984; 312: 548–51.

  18. 18.

    Galfre G, Milstein C, Wright B. Rat × rat hybrid myelomas and a monoclonal anti-Fd portion of mouse IgG. Nature 1979; 277: 131–3.

  19. 19.

    Hoogenraad N, Helman T, Hoogenraad J. The effect of pre-injection of mice with pristane on ascites tumor formation and monoclonal antibody. J Immunol Methods 1983, 61: 317–20.

  20. 20.

    Cauley LK, Murphy JW. Response of congenially athymic [nude] and phenotypically normal mice toCryptococcus neoformans infections. Infect Immun 1979;23: 644–51.

  21. 21.

    Dubois M, Gilles JK, Hamilton PA, Rebers PA, Smith F. Colorimetric method for the determination of sugars and related substances. Anal Chem 1956; 28: 350–56.

  22. 22.

    Mody CH, Toews GB, Lipscomb MF. Cyclosporin-A inhibits the growth ofCryptococcus neoformans in a murine model. Infect Immun 1988; 56: 7–12.

  23. 23.

    Julius MH, Simpson E, Herzenberg LA. A rapid method for the isolation of functional thymic-derived murine lymphocytes. Eur J Immunol 1973; 3: 645–49.

  24. 24.

    Hansen TH, Spinella DG, Lee DR, Shreffler DC. The immunogenetics of the mouse major histocompatibility gene complex. Ann Rev Genet 1984; 118: 99–129.

  25. 25.

    Lipscomb MF, Alvarellos T, Toews GB, Tompkins R, Evans Z, Koo G. Role of natural killer cells in resistance toC. neoformans in mice. Am J Path 1987, 128: 354–61.

  26. 26.

    Mody CH, Toews GB, Lipscomb MF. Treatment of murine cryptococcosis with cyclosporin-A in normal and athymic mice. Am Rev Respir Dis 1989; 139: 8–13.

  27. 27.

    Graybill JR, Craven PC, Mitchell LF, Drutz DJ. Interaction of chemotherapy and immune defenses in experimental murine cryptococcosis. Antimicrob Agents Chemother 1978; 14: 659–67.

  28. 28.

    Marquis G, Montplaisir S, Pelletier M, Mousseau S, Auger P. Genetic resistance to murine cryptococcosis increase susceptibility in the CBA/N XID muted strain. Infect Immun 1985; 47: 282–87.

  29. 29.

    Salkowski CA, Balish E. A monoclonal antibody to gamma interferon blocks augmentation of natural killer cell activity induced during systemic Cryptococcosis. Infect. Immun 1991; 59: 486–93.

  30. 30.

    Gessner A, Moskophidis D, Lehmann-Grube F. Enumeration of single IFN-gamma-producing cells in mice during viral and bacterial infection. J Immunol 1989; 142: 1293–98.

  31. 31.

    Johnson HM, Torres BA. Phorbol ester replacement of helper cell and interleukin-2 requirements in gamma interferon production. Infect. Immun 1982; 36: 911–14.

  32. 32.

    Schofield L, Villaquiran J, Ferreira A, Schellekens H, Nussenzweig R, Nussenzweig V. Gamma interferon, CD8+ T cells and antibodies required for immunity to malaria sporozoites. Nature 1987; 330: 664–66.

  33. 33.

    Bolanos B, Mitchell TG. Phagocytosis and killing ofCryptococcus neoformans by rat alveolar macrophages in the absence of serum. J Leuk Biol 1989; 46: 521–28.

  34. 34.

    Bolanos B, Mitchell TG. Killing ofCryptococcus neoformans by rat alveolar macrophages. J Med Vet Mycology 1989, 27: 219–28.

  35. 35.

    Smith LE, Rodrigues M, Russell DG. The interaction between CD8+ cytotoxic T cells andLeishmania-infected macrophages. J Exp Med 1991; 174: 499–505.

  36. 36.

    Harmsen AG, Muggenberg B, Snipes M, Bice D. The role of macrophages in particle translocation from lungs to lymph nodes. Science 1985; 230: 1277–80.

  37. 37.

    Bulmer G, Sans M, Gunn C.Cryptococcus neoformans, Nonencapsulated mutants. J Bacteriol 1967; 94: 1475–79.

  38. 38.

    Drouhet E, Segretain G, Aubert J. Polyside capsulaire d'un champignon pathogeneTorulopsis neoformans: Relation avec la virulence. Ann Inst Pasteur Paris 1950; 79: 891–900.

  39. 39.

    Kozel TR, Gotschlich EC. The capsule ofCryptococcus neoformans passively inhibits phagocytosis of the yeast by macrophages. J Immunol 1982; 129: 1675–80.

  40. 40.

    Mitchell TG, Friedman L. In vitro phagocytosis and intracellular fate of variously encapsulated strains ofCryptococcus neoformans. Infect Immun 1972; 5: 491–98.

  41. 41.

    Collins HL, Bancroft GJ. Encapsulation ofCryptococcus neoformans impairs antigen-specific T-cell responses. Infect Immun 1991; 59: 3883–88.

  42. 42.

    Mody CH, Syme RM. Effect of polysaccharide capsule and methods of preparation on human lymphocyte proliferation in response toCryptococcus neoformans. Infect. Immun 1993; 61: 464–69.

  43. 43.

    Kozel TR, Gulley WF, Cazin J. Immune response toCryptococcus neoformans soluble polysaccharide: Immunological unresponsiveness. Infect Immun 1977; 18: 701–7.

  44. 44.

    Dykstra MA, Friedman L, Murphy JW. Capsule size ofCryptococcus neoformans: control and relationship to virulence. Infect Immun 1977; 16: 129–35.

  45. 45.

    Littman M, Tsubura E. Effect of degree of encapsulation upon virulence ofCryptococcus neoformans. Proc Soc Exp Biol Med 1959; 101: 773–77.

  46. 46.

    Sprent J, Schaefer M, Korngold R. Functions of purified L3T4+ and Lyt-2+ cells in vitro and in vivo. Immunol Rev 1986; 91: 195–218.

  47. 47.

    Hill JO. CD4+ T cells cause multinucleated giant cells to form aroundCryptococcus neoformans and confine the yeast within the primary site of infection in the respiratory tract. J Exp Med 1992; 175: 1685–95.

  48. 48.

    Mody CH, Paine R, Jackson CJ, Toews GB. CD8 cells mediate delayed hypersensitivity following intrapulmonary infection withCryptococcus neoformans. Chest 1993; 103: 118s.

  49. 49.

    Dromer F. Charreire J. Improved amphotericin-B activity by a monoclonal anti-Cryptococcus neoformans antibody: Study during murine cryptococcosis and mechanism of action. J Infect Dis 1991; 163: 1114–20.

  50. 50.

    Mosmann TR, Coffman RL. TH1 and TH2 cells: different pattems of lymphokine secretion lead to different functional properties. Annu Rev Immunol 1989; 7: 145–73.

  51. 51.

    Finkelman F, Pearce E, Urban JJ, Sher A. Regulation and biological function of helminth-induced cytokine responses. Immunol Today 1991; 12: 62–66.

  52. 52.

    Locksley RM, Scott P. Helper T-cell subsets in mouse leishmaniasis: Induction, expansion and effector function. Immunol. Today 1991; 12: A58-A61.

  53. 53.

    Gajewski TF, Fitch FW. Anti-proliferative effect of IFN-gamma in immune regulation, I: IFN-gamma inhibits the proliferation of Th2 but not Th1 murine helper lymphocyte clones. J Immunol 1988; 140: 4245–52.

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Correspondence to Christopher H. Mody.

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Mody, C.H., Chen, G., Jackson, C. et al. Un vivo depletion of murine CD8 positive T cells impairs survival during infection with a highly virulent strain ofCryptococcus neoformans . Mycopathologia 125, 7–17 (1994).

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Key words

  • Cryptococcus
  • Host defense
  • Lymphocyte subsets
  • Mice
  • Mixed Lymphocyte Reaction