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Biomedical subjects

B Ensoli

Publications and source records attributed to B Ensoli.

119 records · Page 7Linked to original sources

Deficiency of natural killer activity, but not of natural killer binding, in patients with lymphoadenopathy syndrome positive for antibodies to HTLV-III.

Blood lymphocytes (BL) of eleven patients with lymphoadenopathy syndrome (LAS) were studied for natural killer (NK) activity against the K562 cell line (using both the standard 51Cr release assay and the single-cell cytotoxicity assay on poly-L-lysine-coated coverslips) and for surface phenotype (employing OKT4, OKT8 and Leu7 monoclonal antibodies). A significant reduction in NK activity and in NK active cells was detected, while the percentage of target binding cells was not affected. Furthermore, the OKT4/OKT8 ratio was found to be inverted, and the Leu7+ subpopulation expanded. The patients had high titers of anti-HTLV-III antibodies. This study indicates that defective NK activity in LAS is secondary to an abnormality in the lytic event itself and not in target binding.

Adult↗

Epidemiological aspects of HTLV-III infection in Italy.

An epidemiological survey on the presence of serum antibodies to human T lymphotropic retrovirus III (HTLV-III) is reported. The study was carried out on people living in large as well as small cities in different Italian regions. Serum samples of 21 patients with AIDS, 402 with ARCS, and 920 from individuals at risk for these diseases were analyzed. The percentage of positive sera varied from 81% in AIDS, to 100% -33.3% in ARC according to the different geographical areas and/or the various categories of people with ARC. The percentage of positive sera in individuals at risk for AIDS or ARC varied from 11.9% in homosexuals, to 21% in drug abusers and 23.1% in haemophiliacs. No positive sera were observed among 660 normal individuals, relatives of patients with AIDS or ARC and in 114 patients suffering from immunological or infectious disease and among people at risk living in small cities. Sera were also negative in patients with classical Kaposi's sarcoma or T-cell chronic lymphocytic leukemia. Since none of the 660 unselected normal adults were positive while a significant percentage of people at risk for AIDS showed antibodies to HTLV-III, we may presume that this infection is prevalent in the Italian categories in which AIDS and ARC are most likely to develop.

AIDS-Related Complex↗

Thymopentin treatment of selective IgA deficiency.

Thymic hormones have been shown to modulate immunoglobulin production in a number of experiments and it is generally agreed that this action is mediated by modulation of helper and/or suppressor T cell activities. The possibility of upregulating the immunoglobulins is of particular relevance in patients with hypogammaglobulinemias and this paper reports on the results of thymopentin treatment in 9 patients with selective IgA deficiency. Two out of 4 patients responded positively in an open-label trial; in one the serum IgA values remained stable up to 8 weeks after discontinuation of treatment whereas there was a rapid fall in the other. Both responders had consistently normal T4/T8 ratios during the treatment, whereas the nonresponders revealed high ratios with large fluctuations of the T4/T8 ratio. In a subsequent (still ongoing) double-blind trial in 5 patients (3 thymopentin, 2 placebo) no significant change of serum or secretory IgA levels has been observed. Taken together, the data suggest that the tested dose regimen of thymopentin (i.e. daily i.m. injections of 1 mg/kg for 2 weeks, then same dose 3 time weekly for 10 weeks) may only work in a subset of patients with selective IgA deficiency. In the present study we did not attempt to distinguish to which of the three known subgroups the 9 patients belonged, nor did we try alternative dose regimens of thymopentin.

Adjuvants, Immunologic↗

Impairment of cellular immunity and OKT4 lymphocytes in symptom-free hemophiliacs with antibodies to human T leukemia virus III (HTLV III).

Antibodies against the human T-leukemia virus III (HTLV III) were detected by immunofluorescence in the sera of 17 out of 48 hemophiliacs (35.4%) without AIDS or ARC, frozen in 1983-84. Immunological data collected at that time were re-evaluated by separating HTLV III-positive and negative subjects. HTLV III positive patients had significantly reduced OKT4 cells (both in %: 26.1 +/- 10.9 vs 41.2 +/- 15.2; P less than 0.01; and in absolute numbers: 469 +/- 291 vs 1,038 +/- 541; P less than 0.005) and OKT3 lymphocytes (in absolute numbers: 1,234 +/- 550 vs 2,050 +/- 1,067; P less than 0.01). Subpopulations identified by other monoclonal reagents (OKT8, Leu 7, OKM1, anti-Tac) showed no significant differences between the two groups. Patients subsequently found to be seropositive had significantly more frequent anergy to skin tests to recall antigens and often an impairment of in vitro response to phytohemagglutinin A. Despite these relevant defects of some tests of cell-mediated immunity, in HTLV III-positive cases no clinical progression toward AIDS-related complex was observed in a mean period of follow-up of more than 1.5 years.

Acquired Immunodeficiency Syndrome↗

New human and simian HIV-related retroviruses possess functional transactivator (tat) gene.

New human retroviruses antigenically related to HIV and even more closely to STLV-III have been recently isolated from individuals from some West African countries. One of these viruses, HTLV-IVP, was reportedly isolated from lymphocytes of a healthy female prostitute. Another isolate, LAV-2FG, was obtained from an AIDS patient and third, SBL-6669, from an individual with lymphadenopathy. Current epidemiological studies indicate that some of these virus isolates cause immune deficiency whereas others may not or may be less efficient at inducing immune deficiency. Similarly, STLV-III apparently does not cause immune deficiency in its natural host, African green monkey. A novel feature of HIV is the possession of a gene termed tat, which is implicated in its pathobiology. We report here that, like HIV, HTLV-IVP, LAV-2FG (HIV-2) and SBL-6669, as well as STLV-IIIAGM possess the putative tat gene, irrespective of their pathogenic potential in vivo. Interestingly, HTLV-IVP/LAV-2FG long terminal repeat (LTR) is equally well transactivated by the HTLV-IVP/LAV-2FG and HTLV-IIIB tat function, HTLV-IIIB LTR responds better to its own tat function.

Acquired Immunodeficiency Syndrome↗

Lytic growth of human herpesvirus 8: morphological aspects.

The human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus, is a gamma herpesvirus associated with AIDS-related body cavity-based lymphomas (BCBL), also called primary effusion lymphomas (PEL). These are a rare form of non-Hodgkin lymphomas in which HHV-8 is present, often associated with Epstein-Barr virus (EBV) infection. HHV-8 is also present in a latent state or in a state of low-level persistence in different primary effusion lymphoma-derived cell lines, such BCBL-1 cells, that lack EBV infection. This cell line was induced to produce mature virions by treatment with 12-O-tetradecanoyl phorbol-13-acetate (TPA) and the characteristic ultrastructural features of HHV-8 lytic replication were identified and compared to those of the other members of Herpesviridae family.

Apoptosis↗

Human herpesvirus-8 and other viral infections, Papua New Guinea.

We studied residents of remote villages and the capital (Port Moresby) of Papua New Guinea to determine the distribution of human herpesvirus-8 (HHV-8) infection. Our data suggest that HHV-8 has been endemic on the island for a long time and that the epidemiologic pattern of HHV-8 is more similar to that of herpes simplex virus-2 than hepatitis C virus.

Adult↗

Control of viral replication and disease onset in cynomolgus monkeys by HIV-1 TAT vaccine.

The Tat protein of HIV is produced early after infection and it is essential for viral replication and transmission. Tat is released by infected lymphocytes and is detected in the serum of HIV-infected patients. Extracellular Tat enters cells, where promotes HIV replication. Several studies suggest that humoral and cellular anti-Tat immunity have a protective role and may control disease progression. Of importance, Tat is conserved in its immunogenic regions among all viral subtypes except O subtype. Thus, the immunization with Tat cannot block virus entry but might block HIV replication and progression to disease. To test this hypothesis, monkeys (Macaca fascicularis) were immunized with a biologically active Tat protein. Tat was non toxic and induced specific humoral and cellular immune responses. High titers of anti-Tat antibodies capable of neutralizing Tat activity and the in vitro infection with the SHIV89.6P, Tat-specific proliferation, CTLs, TNFalpha production and skin tests were detected in the vaccinated monkeys. Most importantly, upon challenge with the highly pathogenic SHIV89.6P (10 MID50, i.v.), 5/7 of the vaccinated monkeys showed no signs of infection nor CD4+-T cell decline over a 19 months of follow-up, whereas 3/3 controls were highly infected. Thus, a Tat-vaccine is capable of controlling the acute phase of infection in nonhuman primates. These data open new avenues for the development of an AIDS vaccine.

AIDS Vaccines↗

Recombinant alpha-2a interferon treatment in patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC): clinical and immunological evaluation.

We evaluated clinical efficacy and tolerability of recombinant alpha 2a interferon (IFN), in a group of 16 patients with AIDS and ARC, including 3 children. All patients were followed up monthly for clinical and immunological studies. The frequency of oportunistic infections (OI) in AIDS, and the following symptoms in all patients were studied: fever, night sweats, fatigue, diarrhoea, weight loss. Immunological parameters (CD3+, CD4+, CD8+ lymphocytes, skin tests to recall antigens, NK activity, lymphoproliferative response to PHA) were also evaluated. Adult patients were treated with 3-6 million IU of r-alpha 2a IFN daily im for 3 months and the 3 times weekly up to 12 months. Pediatric cases were treated with lower doses of 0.5-1.5 million IU using the same time schedule. We observed clinical improvement and reduction of severe infections in 10/15 evaluable patients (4/4 ARC and 6/11 AIDS). Immunological parameters were transiently improved in one third of cases. We observed only mild side effects in r-alpha IFN treatment. We suggest therapy with r-alpha 2a IFN at low dosage should be tried in patients with AIDS for its beneficial effects on OI development.

AIDS-Related Complex↗