Intracellular calcium mobilization in human lymphocytes in the presence of synthetic IgG Fc peptides

Conference · Sat Mar 01 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5462543

Plummer, J M; Panahi, Y P; McClurg, M R; Hahn, G S; Naemura, J R

Certain synthetic peptides derived from the Fc region of human IgG can suppress the mixed lymphocyte response. These peptides were tested for the ability to induce intracellular calcium mobilization in human lymphocytes using fura-2/calcium fluorescence. T cells were isolated by rosetting and were > 90% OKT3 positive. Lymphocytes were incubated with the acetoxymethyl ester of fura-2 (10 ..mu..M) for 60 minutes at 37/sup 0/C. Fluorescence intensity changes at 505 nm were monitored at an excitation lambda of 340 nm. Fura-2 was not cytotoxic compared to quin-2 since fura-2 loaded mononuclear cells incorporated /sup 3/H-thymidine when stimulated by PHA, succinyl Con A, PWM or LPS-STM whereas quin-2 loaded cells showed a dose dependent inhibition of proliferation. Those synthetic peptides (5 to 400 ..mu..g/ml) that suppressed the MLR induced a dose dependent increase in intracellular calcium in mononuclear cells, lymphocytes, non-T cells and T cells. The fura-2 calcium fluorescence time course response was similar for peptide, PHA and succinyl Con A. These results suggest that these immunoregulatory peptides suppress /sup 3/H-thymidine incorporation at a point after intracellular calcium mobilization and that fura-2 has advantages over quin-2 in measuring intracellular calcium levels in lymphocytes.

• Research Organization: Immunetech Pharmaceuticals, San Diego, CA
• OSTI ID: 5462543
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:3
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AGGLUTININS
ALKALINE EARTH METALS
ANIMAL CELLS
ANTIBODIES
AZINES
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CALCIUM
CELL PROLIFERATION
CONCANAVALIN
CONNECTIVE TISSUE CELLS
ELEMENTS
FLUORESCENCE
HEMAGGLUTININS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LECTINS
LEUKOCYTES
LUMINESCENCE
LYMPHOCYTES
MATERIALS
METALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDES
PROTEINS
PYRIMIDINES
RIBOSIDES
SECRETION
SOMATIC CELLS
THYMIDINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS