Phenotypic change of blood-type eosinophils to tissue-type eosinophils is induced by various cytokines. We examined the effect of nerve growth factor (NGF) as a candidate for a constitutive cytokine which is able to induce the phenotypic change of eosinophils. The viability of human peripheral blood eosinophils cultured for 4 d was increased from a mean of 26% to a mean of 50% (P<0.001) by the addition of NGF (50 ng/ml). Cytotoxic activity of eosinophils determined by larvicidal activity was increased 2-3-fold by the addition of NGF (50 ng/ml) (P<0.05). Furthermore, eosinophil chemotactic activity of NGF was demonstrated by the blind well chamber method. Since NGF is produced constitutively from various kinds of cells in local tissues, it is suggested that NGF might be a cytokine responsible for phenotypic change to tissue type eosinophils in conditions without immune stimuli.
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Tritrichomonas species flagellates (IMC strain) were isolated from the
biliary tract of an individual who had developed cholecystitis as a complication of
acquired agammaglobulinemia. Sequence analysis of Tritrichomonas sp. (IMC
clone 2 (cl2)) was performed for several genetic regions including the ITS1-5.8S rDNA-ITS2
region, the cysteine protease (CP)-1,
CP-2 and CP-4 to CP-9 genes, and the
cytosolic malate dehydrogenase 1 gene. In addition to comparison of the variable-length
DNA repeats in the isolate clone with those in T. foetus
(Inui cl2) and the T. mobilensis (U.S.A.: M776 cl2)
reference strains, this analysis showed that the Tritrichomonas sp. (IMC
cl2) was T. foetus (cattle/swine genotype). Injection of
T. foetus (IMC cl2) directly into the livers of CBA
mice resulted in liver abscess formation on Day 7. Moreover, inoculation via orogastric
intubation caused infection in the cecum on Day 5 in CBA mice co-infected with
Entamoeba histolytica (HM-1: IMSS cl6). T.
foetus (IMC cl2) was able to grow in YI-S medium for over 20 days, even
at 5°C. These results indicate that the T. foetus
isolate is able to survive in the feces and edible organ meat of the definitive host for a
prolonged period of time, and it is possible that the parasite could infect humans.
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