Human T lymphotropic virus I infection deregulates surface expression of the transferrin receptor

Human T-lymphotropic virus I (HTLV-I) is an etiologic agent in adult T cell leukemia. In an effort to understand the relationship between HTLV-I infection and malignant transformation, we have examined transferrin receptor expression in HTLV-I-infected cells. Transferrin receptor expression in normal T cells is tightly regulated and essential for cell proliferation. We have used matched T cell sets originating from a normal donor, consisting of tetanus toxoid-specific normal T cell clones (TM3 and TM5) and their in vitro HTLV-I-infected counterparts (TM3H and TM5H). Using these matched sets of virus-infected and normal T cells, we have determined that HTLV-I infection leads to hyperexpression of surface transferrin receptors (five- to six-fold higher than normal counterparts). Although the growth rates of the virus-infected cells did not differ significantly from their normal controls, HTLV-I-infected cells constitutively hyperexpressed surface transferrin receptors, whereas the level of surface receptor expression of normal counterpart cells varied during the cycle of antigenic stimulation. Immunoprecipitation of total (surface plus cytoplasmic) transferrin expression showed that the HTLV-I-infected cells did not possess a greater total number of transferrin receptors than their normal counterparts. This data was supported by Northern blot analysis, which showed equivalent transferrin receptor mRNA expression in HTLV-I-infected and uninfected cells. Functional analysis revealed a marked defect in 59Fe-transferrin internalization in the HTLV-I-infected cells. Furthermore, the HTLV-I-infected cells showed markedly decreased transferrin receptor phosphorylation and internalization in response to active phorbol ester. Thus the data demonstrate that in peripheral blood T cells, HTLV-I infection is accompanied by surface transferrin receptor overexpression secondary to subcellular redistribution and defective internalization.     

An autoreactive T cell clone that can be activated to provide both helper and suppressor function

To understand further the biologic significance of the autologous mixed lymphocyte reaction, we determined the functional properties of autoreactive T cell lines and clones. Initially, we found that cells in an uncloned autoreactive Leu-3+ T cell line helped immunoglobulin production when added to cultures containing fresh T and non-T cells in the absence of pokeweed mitogen (PWM) but suppressed immunoglobulin production in the same cultures in the presence of PWM. To explain this phenomenon, we studied the immunoregulatory potential of an autoreactive T cell clone termed MTC-4. This clone bore the phenotype Leu-3+, 2-, 8-, 11-, DR+ and underwent proliferation when co-cultured with autologous, but not allogeneic non-T cells. Of interest, the immunoregulatory potential of the MTC-4 cells varied according to how the cells were activated. When MTC-4 cells were cultured with autologous non-T cells in the absence of antigen or mitogen (unactivated non-T cells), polyclonal immunoglobulin production (detected by reverse PFC assay) was observed. This helper activity was MHC-restricted in that it was elicited only by autologous non-T cells or MHC-matched allogeneic non-T cells; however, once activated by autologous non-T cells, it could also help allogeneic non-T cells. In contrast, when MTC-4 cells were cultured with autologous non-T cells in the presence of PWM (activated non-T cells), immunoglobulin production was greatly suppressed. This suppression was also observed when MTC-4 cells were added to cultures containing exogenous T cell help (such as that provided by autologous fresh T cells) and was not due to a direct effect of PWM on the T cell clone, because preincubation of MTC-4 cells with PWM before culture with non-T cells did not result in suppression. On the basis of these data, we conclude that autoreactive T cells can have dual immunoregulatory function that is manifest, at least in part, at the single cell level. Moreover, these regulatory functions are differentially elicited depending on the state of activation of the stimulating autologous non-T cells: when stimulated by MHC antigens present on unactivated B cells, they provide helper activity; and when stimulated by MHC antigens present on activated B cells, they act as suppressor cells. Autoreactive T cells with dual regulatory potential appear to make up a substantial proportion of all autoreactive T cells and are cells that are uniquely adapted to maintain immunologic homeostasis.     

Application of ozone disinfection to remove Enterococcus seriolicida, Pasteurella piscicida, and Vibrio anguillarum from seawater.

Survival of bacterial fish pathogens, including Enterococcus seriolicida, Vibrio anguillarum, and Pasteurella piscicida, in ozonated seawater was determined in a batch system. Bacterial counts of all fish pathogens decreased at more than 0.040 to 0.060 mg of total residual oxidants (TROs) per liter, whereas no decrease in viable counts was observed at less than 0.018 to 0.028 mg of TROs per liter. The 99% inactivation point was achieved at concentrations of 0.111 mg/liter for E. seriolicida, 0.063 mg/liter for P. piscicida, and 0.064 mg/liter for V. anguillarum within 1 min. Moreover, the mean 99 and 99.9% killing concentration-contact time (C.t) products were 0.123 and 0.186 mg.min/liter for E. seriolicida, 0.056 and 0.084 mg.min/liter for P. piscicida, and 0.081 and 0.123 mg.min/liter for V. anguillarum, respectively. However, the mean 99 and 99.9% C.t products for the mixed population in coastal seawater were 0.200 and 0.621 mg.min/liter. These results strongly suggest that ozone treatment at more than 1.0 mg of TROs per liter for several minutes is able to disinfect seawater for mariculture efficiently.     

Bulb canker of garlic caused byEmbellisia allii,newly found in Japan

Bulb canker of garlic caused byEmbellisia allii was newly detected in Japan. Symptoms of the disease are described and the morphological characteristics of the causal fungus are illustrated and described.     

RFLP analysis for species separation in the generaBipolaris andCurvularia

Restriction fragment length polymorphism (RFLP) of the total DNA ofBipolaris andCurvularia species was analysed using arbitrarily chosen genomic clones of DNA fromCurvularia lunata andBipolaris maydis as probes. Clear differences among species in both genera, resulting in different banding positions, were obtained with some probe-enzyme combinations. Intraspecific polymorphism in banding positions with these probe-enzyme combinations was slight. These analyses allow discrimination between the species. DNA fingerprinting with intrageneric probes is a potentially useful tool for species separation and identification inBipolaris andCurvularia when coupled with another characteristic such as conidial morphology.Curvularia aeria comb. nov. was proposed forCurvularia lunata var.aeria on the basis of differences in RFLP banding patterns and differences in conidial morphology.     

Calf adrenocortical fasciculata cells secrete aldosterone when placed in primary culture

Aldosterone production occurs in the outer area of the adrenal cortex, the zona glomerulosa. The glucocortocoids cortisol and corticosterone, depending upon the species, are synthesized in the inner cortex, the zona fasciculata. Calf zona glomerulosa cells rapidly lose the ability to synthesize aldosterone when placed in primary culture unless they are incubated in the presence of the antioxidants butylated hydroxyanisol and selenous acid, the radioprotectant DMSO, and the cytochrome P-450 inhibitor metyrapone. In the presence of these additives, calf zona fasciculata cells in primary culture synthesize aldosterone at rates which can approach those from cells isolated from the zona glomerulosa. Calf zona glomerulosa and fasciculata cells both responded well to ACTH and angiotensin II, but the zona fasciculata cells respond very poorly compared to glomerulosa cells to increased potassium in the media. Rat zona fasciculata cells in primary culture under similar conditions did not synthesize aldesterone, suggesting that the regulation of the expression of the enzymes responsible for the biosynthesis of aldosterone in the two species is different. Two distinct cytochrome P-450 cDNAs which hydroxylate deoxycorticosterone at the 11β position have been described in the rat, human and mouse. Both cytochrome P-450 cDNAs have been cloned and expressed in non-steroidogenic cells, but only one is expressed in the zona glomerulosa and only this glomerulosa cytochrome P450 can further hydroxylate deoxycorticosterone to generate aldosterone. Two bovine adrenal cDNAs have been described with 11β-hydroxylase activity and their expression products in transiently transfected COS cells can convert deoxycorticosterone into aldosterone. Both enzymes are expressed in all zones of the adrenal cortex. Zonal regulation of aldosterone synthesis in the bovine adrenal gland may be due to an 11β-hydroxylase with aldosterone synthesizing capacity which has not yet been isolated. Alternatively, a single enzyme might be responsible for the several hydroxylations in the pathway between deoxycorticosterone and aldosterone and zonal synthesis might be controlled by unknown factors regulating the expression of C-18 hydroxylation. The incubation of zona fasciculata with antioxidants and metyrapone results in atypical expression of this activity by an unclear mechanism.     

Anti-pituitary antibodies in patients with hypopituitarism and their families: longitudinal observation.

In an attempt to investigate the clinical significance of anti-pituitary antibodies in patients with hypopituitarism, anti-pituitary antibody in plasma was examined in 10 such patients (7 cases of isolated ACTH deficiency, 1 of partial hypopituitarism, and 2 of Sheehan's syndrome), on two or three occasions with an interval of more than 6 months (longitudinal study). In a total of 16 relatives of these 4 patients (2 cases of Sheehan's syndrome, one in each of partial hypopituitarism and isolated ACTH deficiency) and one patient not involved in the longitudinal study, anti-pituitary antibodies were also examined (family study). Anti-pituitary antibodies reacting with rat pituitary cytoplasmic antigens (pituitary cell antibodies: PCA) and pituitary cell surface antibodies (PCSA) reacting with GH3 cells and/or AtT-20 cells were measured with indirect immunofluorescence. The longitudinal study revealed the disappearance of antibodies in 3 patients, 2 PCA positive and one both PCA and PCSA positive. In 3 patients, altered antibody titers or a newly appearing antibody were found during the follow-up period. In 4 patients, the pituitary antibodies were negative during the follow-up periods. Of 16 family members studied, positive PCA was found in 3 members (2 in the families of patients with PCA positive Sheehan's syndrome, and 1 in the family of the patients with PCA positive partial hypopituitarism). Positive PCSA was found in 4 members (one in each of families of patients with partial hypopituitarism and isolated ACTH deficiency and of two cases of Sheehan's syndrome), and weakly positive PCSA was found in one family member of a patients with PCA positive Sheehan's syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Secretory regulation of 19-hydroxyandrostenedione in normal man.

To evaluate the secretory regulation of 19-hydroxyandrostenedione (19-OH-AD), its plasma concentration was measured before and after stimulation and inhibition tests for the ACTH-adrenal axis and the renin-angiotensin system in 50 normal subjects. Basal levels of plasma 19-OH-AD did not correlate with either those of plasma renin activity (PRA) or the plasma aldosterone concentration (PAC), but positively correlated with those of plasma cortisol. Plasma 19-OH-AD was stimulated by 0.25 mg ACTH-(1-24) and was suppressed by 1 mg dexamethasone (DEX) as were plasma cortisol and PAC. On the other hand, with 2-h standing alone or iv 40 mg furosemide plus 2-h standing, plasma 19-OH-AD and cortisol did not increase but PRA and PAC did. With iv furosemide plus 2-h standing with 3 mg DEX pretreatment, plasma 19-OH-AD and cortisol did not respond either, but PRA and PAC increased. With 25 mg oral captopril following 1-h standing with 3 mg DEX pretreatment, plasma 19-OH-AD and cortisol did not change but PAC decreased. These results indicate that the secretion of 19-OH-AD is mainly under the control of the ACTH-adrenal axis rather than the renin-angiotensin system.     

Phosphodiester Amidates of Unsaturated Nucleoside Analogues as Anti-HIV Agents

Abstract

Lipophilic phosphodiester L-alaninates of acyclic unsaturated nucleoside analogues 1d, 1e, 2d, 2e, 3d, 3e, 4d and 5d were prepared and their antiretroviral activity was examined in ATH8 cell culture infected with HIV-1. A possible mechanism of action of these analogues is discussed.