Assessment of human natural killer and lymphokine-activated killer cell cytotoxicity against Toxoplasma gondii trophozoites and brain cysts

Journal Article · Sun Oct 15 00:00:00 EDT 1989 · Journal of Immunology; (USA)

OSTI ID:5225447

Dannemann, B R; Morris, V A; Araujo, F G; Remington, J S ^[1]

---

1. Palo Alto Medical Foundation, CA (USA)

Because previous work has suggested that NK cells may be important in host resistance against the intracellular parasite Toxoplasma gondii we examined whether human NK cells and lymphokine-activated killer (LAK) cells have activity against trophozoites and cysts of this organism in vitro. A method to radiolabel Toxoplasma trophozoites with 51Cr was developed and direct cytotoxic activity was determined by using modifications of the standard 51Cr release assay. Viability of 51Cr-labeled trophozoites assessed by both methylene blue staining and trypan blue exclusion was greater than 90%. Significantly more 51Cr was released by anti-Toxoplasma antibody and C than by antibody in the absence of C. Incubation of trophozoites with freshly isolated human NK cells or NK cells activated with either rIL-2 or rIFN-alpha did not result in significant release of 51Cr (specific lysis was 0 to 2.3%). In contrast, the average specific lysis of radiolabeled trophozoites by LAK cells was significant. In a series of separate experiments, preincubation of radiolabeled trophozoites with heat-inactivated normal or Toxoplasma antibody-positive human serum increased the cytotoxicity of LAK cells from a mean specific lysis of 15% +/- 4.5 to 39% +/- 8.5, respectively, as assessed by 51Cr release. Because previous work has shown that radioisotope release from parasites may be nonspecific, separate experiments were performed to determine the cytotoxicity of LAK cells against antibody-coated trophozoites by using ethidium bromide-acridine orange staining to assess effector cell damage. LAK cells had a mean specific lysis of 51% against antibody-coated trophozoites by ethidium bromide-acridine orange staining. Preincubation with heat-inactivated Toxoplasma-antibody positive human serum did not increase activity of rIL-2-activated NK cells against 51CR-labeled trophozoites.

• OSTI ID: 5225447
• Journal Information: Journal of Immunology; (USA), Vol. 143:8; ISSN 0022-1767
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
LYMPHOCYTES
BIOLOGICAL FUNCTIONS
PARASITIC DISEASES
PATHOGENESIS
PROTOZOA
VIABILITY
ACRIDINE ORANGE
ANTIBODIES
BRAIN
CHROMIUM 51
COMPLEMENT
DISEASE RESISTANCE
LYMPHOKINES
MAN
MICE
STAINS
TRACER TECHNIQUES
ACRIDINES
AMINES
ANIMAL CELLS
ANIMALS
AROMATICS
AZAARENES
AZINES
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CENTRAL NERVOUS SYSTEM
CHROMIUM ISOTOPES
CONNECTIVE TISSUE CELLS
DISEASES
DYES
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
FUNCTIONS
GROWTH FACTORS
HETEROCYCLIC COMPOUNDS
INFECTIOUS DISEASES
INTERMEDIATE MASS NUCLEI
INVERTEBRATES
ISOTOPE APPLICATIONS
ISOTOPES
LEUKOCYTES
MAMMALS
MATERIALS
MICROORGANISMS
MITOGENS
NERVOUS SYSTEM
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PRIMATES
PROTEINS
PYRIDINES
RADIOISOTOPES
RODENTS
SOMATIC CELLS
VERTEBRATES
550901* - Pathology- Tracer Techniques