ABSTRACT
Thai bitter gourd protein (MRK29) was isolated from Momordica charantia ripe fruit and seed. The purification was performed by ammonium sulfate fractionation and gel filtration chromatography. MRK29 possessed one isoelectric point of (pI) > or = 9, and the time of flight mass spectrum (TOFMS) indicated its molecular weight at 28.6 kD. The twenty amino acid sequence from the N-terminus was in the following order: 1Asp Val Asn Phe Arg Leu Ser Gly Ala 10Asp Pro Arg X Tyr Gly Met Phe Ile Glu 20Asp. MRK29 inhibited the HIV-1 reverse transcriptase with 50% IR at the concentration of 18 micrograms/ml. MRK29 was concentrated in the 30-60% salt precipitated fraction, at which the concentration of 0.175 microgram/ml exerted 82% reduction of viral core protein p24 expression in HIV-infected cells. MRK29 might have modulatory role on immune cells, because it increased 3-fold TNF activity.
Subject(s)
Anti-HIV Agents/isolation & purification , Cucurbitaceae/chemistry , Fruit/chemistry , N-Glycosyl Hydrolases , Plant Proteins/isolation & purification , Plants, Medicinal/chemistry , Reverse Transcriptase Inhibitors/isolation & purification , Seeds/chemistry , Amino Acid Sequence , Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Chromatography, Gel , Electrophoresis, Polyacrylamide Gel , HIV Core Protein p24/analysis , HIV Core Protein p24/immunology , Humans , Lymphocytes/immunology , Macrophages/immunology , Mass Spectrometry , Molecular Weight , Plant Proteins/chemistry , Plant Proteins/pharmacology , RNA-Directed DNA Polymerase/blood , Reverse Transcriptase Inhibitors/chemistry , Reverse Transcriptase Inhibitors/pharmacology , Ribosome Inactivating Proteins, Type 2 , Sequence Analysis, Protein , Tumor Necrosis Factor-alpha/metabolism , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
This paper reviews the information concerning immunological memory T and B cells. It shows that the existence of different or a single lineage of memory and naive cells is still a question. The recirculation pattern of memory cells is different from naive cells. A unique recirculation for memory T or B cells is suggested while the bcl2 gene expression possibly plays role in the longevity of memory cells. Various phenotypic markers are demonstrated only on memory or on naive cells; however, a reliable and convenient method for the detection of memory cells still needs to be explored.
Subject(s)
B-Lymphocytes/immunology , Immunologic Memory , T-Lymphocytes/immunology , Animals , HumansABSTRACT
The effect of caffeine (naturally occurring plant methylxanthine) on immunological cell activities in Sprague-Dawley rat both in vivo and in vitro was studied. A cytotoxic assay was done to study natural killer (NK) cells and a proliferation assay was performed for T and B cell activities. Three different doses of caffeine i.e., 2, 6 and 18 mg/kg/day were administered chronically to Sprague-Dawley rats to assess the effects in vivo. Both NK cell cytotoxicity and B cell proliferative response to pokeweed mitogen (PWM) showed significant decreases (P less than 0.05) in rats treated with 6 mg/kg/day, whereas the T cell proliferative response to phytohemagglutinin-P (PHA-P) was significantly increased (P less than 0.05) in the rats treated with 18 mg/kg/day. In vitro, caffeine significantly decreases (P less than 0.05) B and T cell proliferative responses to PWM and PHA-P at added caffeine concentrations of 10, 20 and 40 micrograms/ml. However, no effect was observed on NK cells activity. Furthermore, in vitro, a broader dose range of caffeine (1, 10, 100 and 1,000 micrograms/ml) exhibited dose-dependent inhibition of both B and T cell proliferative responses.
