A group specific anamnestic immune reaction against HIV-1 induced by a candidate vaccine against AIDS

The first experimental immunization of humans against the AIDS retrovirus, HIV-1, was started in a series of HIV seronegative, healthy volunteers in November 1986. For the primary vaccination recombinant vaccinia virus (V25) expressing the complete gp160 env protein of the HTLV-IIIB strain of HIV-1 was introduced by scarification. This elicited a weak primary response which we subsequently attempted to enhance by additional immunizations (boosting), using four different immunization protocols. We report here that intravenous injection of paraformaldehyde-fixed autologous cells infected in vitro with V25 (individual D.Z.) gave the best results. This individual received second and third boosts of intramuscular gp160 derived from an HTLV-IIIB clone using the hybrid vaccinia virus/bacteriophage T7 expression system. An anamnestic humoral and cellular immune reaction was achieved for over one year after the original vaccination, with high levels of antibodies to the viral envelope, and neutralizing antibodies against divergent HIV-1 strains such as HTLV-IIIB and HTLV-IIIRF (also called HTLV-III HAT) after the first boost. In addition, group-specific cell-mediated immunity and cell-mediated cytotoxicity against infected T4 cells were obtained after the primary vaccine and enhanced by the boosts. Finally, skin tests showed both immediate and delayed hypersensitivity to gp160 in vivo. Although this protocol is not practical for a large scale vaccine trial, our results show for the first time that an immune state against HIV can be obtained in man.

Comparison of oral MK 421 and propranolol in mild to moderate essential hypertension and their effects on arterial and venous vessels of the forearm

The efficacy of MK 421 and propranolol was compared in 48 patients with mild to moderate hypertension. Each patient was randomly assigned to receive 1 of the drugs for 12 weeks. Additionally, a subgroup of 28 patients underwent studies of forearm arterial and venous circulation by means of pulsed Doppler and mercury-in-silastic plethysmography. Both drugs reduced supine and standing blood pressure (BP) (p less than 0.001). Propranolol reduced heart rate (p less than 0.001), while MK 421 did not change it. Brachial artery diameter, blood velocity and flow increased after MK 421 (p less than 0.001), but were not changed after propranolol therapy. Forearm vascular resistance decreased after MK 421 (p less than 0.001) and after propranolol (p less than 0.05). Forearm venous tone was unaffected on MK 421, but increased after propranolol (p less than 0.01). Thus, in moderate hypertension, 3 months of treatment with MK 421 or propranolol similarly decrease BP, but affect the forearm circulation differently: MK 421 dilates both the brachial artery and the arterioles of the forearm, but does not affect the venous vessels, and propranolol causes little arterial change but increases the forearm venous tone.

Inflammatory lesions of peripheral nerve in a patient with human T-lymphotropic virus type I--associated myelopathy

In a patient with tropical spastic paraparesis associated with a positive titer for human T-lymphotropic virus type I, electrophysiological study detected a mixed, axonal and demyelinating, multifocal neuropathy. Perineural and perivascular infiltrates, moderate axon loss, wallerian degeneration, and demyelinating lesions of isolated fibers were present in the nerve biopsy specimen. These inflammatory lesions resembled those found in the central nervous system of patients with tropical spastic paraparesis.

Even transcriptionally competent proviruses are silent in bovine leukemia virus-induced sheep tumor cells

To investigate the role of proviral integration and expression in cellular transformation induced by bovine leukemia virus (BLV), three BLV-induced tumors harboring a single proviral copy were selected upon restriction and hybridization analysis. Tumors 344 and 395 were shown to contain a full-size proviral copy, whereas in tumor 1345 the provirus appeared to be heavily deleted. RNA gel blot hybridization with an antisense RNA probe showed no transcription of the viral sequences in the fresh tumors or in sheep tumor cells growing in vitro. The proviruses were cloned and transfected in mammalian cell lines. Transient-expression experiments revealed that the complete proviruses were still able to express the trans-activating protein (Tat) as well as structural proteins, demonstrating that the nonexpression of a provirus in a tumor cell does not necessarily imply a structural alteration of the viral information. In contrast, sequence analysis of the provirus with a large deletion and transient-expression assays proved that this truncated provirus, isolated from a tumor, was unable to code for viral proteins. These data indicate that expression of viral genes, including tat, is not required for the maintenance of the transformed state.

Electrofusion of myeloma cells on the single cell level. Fusion under sterile conditions without proteolytic enzyme treatment

A technique is presented which allows electrofusion of single cells under sterile conditions. The electrofusion chamber is placed in a Petri dish. Before a droplet of the fusion medium is pipetted between the electrodes, the chamber is completely covered with vaseline, which prevents the fusion medium evaporating. Additionally, the fusion chamber is treated with solutions containing poly(L)-lysine and pronase which results in a decreased movement of the cells on the glass between the electrodes and which allows electrofusion without any proteolytic pretreatment.

Human normal CTL clones: generation and properties

This study reports the production of clones of human killer T cells grown in the presence of TCGF4 following sensitization in MLC against (1) allogeneic cells, (2) autologous Bebv+ lymphocytes, or (3) autologous lymphoma cells. Sensitization against the tumor cells required the addition of macrophages. The expression of the cytotoxic activity of the cloned T lymphocytes required re-stimulation with the specific stimulator cells. The cytotoxic activity seemed to be MHC-restricted, since (1) cloned allosensitized CTL lysed their corresponding allogeneic targets, but did not lyse autologous Bebv+ cell or K562 cells; (2) cloned CTL sensitized against autologous Bebv+ cells lysed their autologous targets but not allogeneic Bebv+ targets or K562 cells; and (3) cloned CTL sensitized against autologous Burkitt lymphoma cells lysed their corresponding lymphoma targets or autologous Bebv+ targets but did not lyse allogeneic lymphoma cells or Bebv+ cells from the same allogeneic lymphoma cells or Bebv+ cells from the same allogeneic donors. The cloned CTL were homogeneous in expressing the OK T8 molecules and in being negative for T4, T10 or M1. At any given time, 25-45% of the cloned cells manifested lytic activity. The ultrastructural properties and cell surface OK T markers were different from those of cloned human NK cells. Emphasis is focused on the differences between the structural, functional and culture characteristics of CTL clones produced by direct isolation of MLC responder cells forming conjugates with specific target cells and those of clones from transformed T-cell lines or from T hybridomas.

Persistent HIV-2 infection of rhesus macaque, baboon, and mangabeys

Six monkeys of three different species (mangabey, macaque and baboon) were infected with human immunodeficiency type 2 (HIV-2) NIH-DZ using intraperitoneal or intravenous injections of cell-free HIV-2 or autologous HIV-2-infected cells with no prior immunostimulation. Viral expression was demonstrated by reverse transcriptase activity in cells after coculture with human peripheral blood lymphocytes or by electron microscopy. Serum was analyzed by western blot, enzyme-linked immunosorbent assay (detection of antigen and antibody), and neutralization assay carried out using immunofluorescence techniques. The 6 inoculated animals seroconverted during the 1st month after inoculation and remained persistently infected after 6-11 months. We also observed proviral DNA by genomic analysis in the six tested samples. No sign of immunodeficiency disease has been observed so far. The data suggest that HIV-2 infection of nonhuman primates provides an acceptable animal model to investigate vaccination or specific immunotherapeutic procedures.

Production of human T-lymphocyte clones. I. monoclonal culture and functional cytotoxic maturation

Well-defined clones of human T-lymphocytes were produced and monoclonal T-cell cultures were maintained for long periods of time. Single T-lymphocytes were isolated with the help of a micropipette from PBL cultures prior to any cellular stimulation (MLC), collected separately at the bottom of a 200 microliter tissue culture microwell under the control of stereomicroscopic observation, and cultured with irradiated lymphoid cells in the presence of TCGF. After 12 days, 20-50% of the seeded wells exhibited clones of 3 x 104-105 T-lymphocytes, which were transferred to larger tissue culture wells (2 ml, LINBRO) for long-term culture. Recloning of the growing cloned cells under the same conditions as the primary culture was carried out successfully. In the preliminary cytotoxic assays performed in 11 clones (a) a marked activity directed against lectin-coated targets was observed in may clones; (b) an important NK-like activity was exhibited by the clone 45B9 (65% of the tested cells lysed K562 cell targets); (c) 2 clones did not demonstrate cytotoxic activity against either PHA-coated L-1210 cells or K562 cell targets. These results could be explained hypothetically by the difference of functional maturation of T-cells within each clone.

Phenotypic diversity within clones of human normal T cells

Human normal T cells were selected for in vitro cloning according to the expression of T4, T8 or T10 antigens on individual cells. Clones were produced from each of these cells irrespective of the antigenic phenotype of the parental cell. The cloned progeny manifested, in many cases, shifts in antigen expression. Thus, T4+T8- cells gave clones expressing predominantly T4-T8+ and vice versa. The clonal expression of T4 and T8 seemed to be mutually exclusive. Antigenic shifts were recorded also in clones derived from T4-T8-T10- cells, resulting in T10+ clones which were also either T4+ or T8+ and from T4+T8-T10+ cloned cells yielding clones of either T4+ or T8+ cells. Testing functional properties we found that NK activity was mediated not only by T10+ cells but also, in some cases, by T4+ and T8+ cells. Moreover, TCGF production, which may reflect helper activity, was mediated not only by T4+ cells. Only the cytotoxic (CTL) activity seems to be confined to the T8 phenotype. Thus, it appears that T antigens, which seemed to be molecular markers of differentiation, are not markers for terminal differentiation and do not always reflect defined functional properties. These conclusions are drawn from cloning of normal T cells which manifest properties different from those of T-cell lines or T hybridomas.

Lisinopril versus atenolol: decrease in systolic versus diastolic blood pressure with converting enzyme inhibition

In a multicenter, parallel, double-blind study, lisinopril, a new converting enzyme inhibitor, was compared with atenolol in the treatment of mild to moderate essential hypertension. Four hundred ninety patients were randomized to once-a-day treatment with lisinopril 20 mg or atenolol 50 mg for 4 weeks, and the doses of lisinopril or atenolol were increased at 4-week intervals up to 80 mg or 200 mg, respectively, if sitting diastolic blood pressure (SDBP) was not well controlled. Lisinopril and atenolol reduced SDBP to a similar extent. All reductions from baseline in sitting diastolic and systolic blood pressure were significant (p less than 0.01). Lisinopril produced a significantly greater reduction (p less than 0.01) in sitting systolic blood pressure (SSBP) than atenolol. The predominant reduction in SSBP could not be explained on the basis of age, race, or severity of hypertension. It is suggested that the increase in arterial compliance reported for converting enzyme inhibitors could explain the predominant decrease in systolic blood pressure.

Repair of the in vitro HIV-1-induced immunosuppression and blockade of the generation of functional suppressive CD8 cells by anti-alpha interferon and anti-Tat antibodies

The acute human immunodeficiency virus type 1 (HIV-1) infection of activated peripheral blood mononuclear cells (PBMCs) from normal donors results in inhibition of cell proliferation and generation of functional suppressive T cells. Cultured HIV-1 infected PBMCs but not uninfected PBMCs, following irradiation, can inhibit the proliferation of antigen-activated autologous T cells in a dose-dependent way. CD8+ cell subpopulation is responsible for this inhibition. The presence of anti-alpha interferon (IFN alpha) and anti-Tat antibodies in the culture medium counteracts the HIV-1-induced immunosuppression and prevents the generation of suppressive T cells by these PBMCs. The reported data should have major implications for strategies of AIDS treatment which, in association with antiviral drugs, aim at targetting immune disorders.

Alteration of Pressure-Induced Vasodilation in Aging and Diabetes, a Neuro-Vascular Damage

Skin is constantly subjected to pressure at different levels. Pressure-induced vasodilation (PIV) is one of the response mechanisms to low pressure that maintains the homeostasis of the skin. PIV results from the interaction of primary afferent nerves and vascular endothelium of skin vessels. Thanks to this cutaneous neuro-vascular interaction, the cutaneous blood flow increase allows the maintenance of an optimal level of oxygenation and minimizes the lack of vascularization of the skin tissue under low pressure. It seems to be associated with the cutaneous protection mechanisms to prevent pressure ulcers. In some contexts, where microangiopathy and neuropathy can occur, such as aging and diabetes, PIV is impaired, leading to a dramatic early decrease in local skin blood flow when low pressure is applied. In aging, PIV alteration is due to endothelial dysfunction, essentially from an alteration of the nitric oxide pathway. In the inflamm-aging context, oxidative stress increases leading to endothelial cell and nerve damages. An age-related sensory neuropathy will exacerbate the alteration of PIV during the aging process. In diabetes, non-controlled hyperglycaemia leads to an increase in several pathological biochemical pathways that involve oxidative stress and can affect PIV. Sorbinil, alagebrium and alpha-lipoic acid are able individually to restore PIV through a possible oxidative stress reduction. Candesartan, an angiotensin II type 1 receptor blocker, is also able to restore PIV and prevent pressure ulcer formation. The possibility of preventing pressure ulcer associated to diabetes and/or aging with the restoration of PIV seems to be a promising research path.

Discriminating between protective and enhancing HIV antibodies

Most attempts to produce a vaccine against HIV-1 infection are utilizing envelope protein components. Hypothetically such vaccine candidates could stimulate production of antibodies that enhance HIV-1 infection via the macrophage route of entry and, consequently, cannot be detected in the conventional neutralization assay. To study this hypothesis we report an assay designed to evaluate the protective/enhancing activity of serum from seropositive immunized or infected individuals. Highly purified activated FcR-bearing monocytes-macrophages were infected with HIV-1 in the presence of the sera, then washed and cocultured with activated peripheral blood mononuclear cells (PBMC) from a normal donor. Productive viral infection, as evaluated by p24 antigen semiquantitative assay in the culture supernatants, allow evaluation of protective/enhancing activity of the sera. The data clearly show that protective rather than enhancing activity is present in the serum of env protein-immunized individuals.

Biological effect of active anti-IFN alpha immunization in HIV-infected patients

Circulating interferon (IFN) was investigated in HIV-1 seropositive patients by measuring the IFN alpha antiviral effect in the serum. While serum of healthy seronegative individuals exhibits an antiviral effect, not due to IFNs, considered as background, serum of seropositive patients showed an additional antiviral effect due to the abnormal presence of IFN alpha. Increased titers of IFN alpha were found in the course of the HIV infection and seemed to correlate with the evolution of AIDS disease. Furthermore, patients immunized against IFN alpha had both stabilized CD4 cell count and decreased IFN alpha in their serum. HIV-1-infected patients also exhibited higher titers of natural anti-IFN antibodies than seronegative controls and the level of specific antibodies (Abs) markedly increased in immunized patients. Finally, serum from immunized patients, when compared to seronegative controls, exhibits an interferon neutralizing capacity.

Rationale for ACE inhibition in the elderly: treatment of arterial hypertension with enalapril

A randomized, double-blind, placebo-controlled trial was conducted with 32 elderly patients (aged 75-97 years) with uncomplicated essential hypertension, to evaluate the efficacy and tolerance of enalapril, an angiotensin-converting enzyme inhibitor. It was given over an 8-week period in doses from 20 to 40 mg/day and was compared with an identical placebo. Enalapril caused a significant reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) by the 2nd week, an effect that persisted through to the 8th week (190 +/- 16/102 +/- 7 to 151 +/- 19/85 +/- 11 mm Hg); 67% of patients had their pressures normalized (less than 160/95 mm Hg). BP was also significantly decreased by the 8th week under placebo (183 +/- 16/101 +/- 9 to 165 +/-21/91 +/- 13 mm Hg), but only 35% of patients attained a normal pressure. Heart rate did not change with treatment. Enalapril caused an increase in plasma renin activity (1.22 +/- 0.08 to 3.66 +/- 2.50 ng/ml/h), whereas aldosterone levels remained unchanged. There was a mild, significant elevation of creatinine level with enalapril but other laboratory parameters, including serum potassium, were unaltered. Two deaths occurred in the enalapril group, but were not considered to be treatment-related. The drug was otherwise well tolerated. Serum enalapril concentration was assessed in 10 patients taking 20 mg/day over an 8-day period. At equilibrium, the level was 22.3 +/- 5.0 ng/l and it correlated both with converting enzyme inhibition and with renal function. Enalapril is shown to be an effective and well-tolerated antihypertensive medication in elderly patients.

Sensitive Skin Syndrome: A Low-Noise Small-Fiber Neuropathy Related to Environmental Factors?

Background and Objectives

Patients frequently complain of mild, transient, unpleasant skin sensations that cannot be diagnosed as common neuropathies. Dermatologists have termed these symptoms “sensitive skin syndrome.” This narrative review was performed for a better knowledge by other specialists.

Databases and Data Treatment

Publications on pain in sensitive skin syndrome were obtained from PubMed.

Results

There is a growing body of data supporting the concept that sensitive skin is a type of small-fiber neuropathy. The arguments are based on clinical data, a decrease in intra-epidermal nerve fiber density, quantitative sensory testing abnormalities and an association with irritable bowel syndrome and sensitive eyes. Sensitive skin is triggered by environmental factors. Sensitive skin is a frequent condition, with a lifetime prevalence of ~50% according to self-reports.

Conclusions

Mild levels of skin pain or itch are frequently experienced by patients, who rarely report them. There is a need for a better knowledge of sensitive skin because it can be the first level of small-fiber neuropathies.

Calcium Increase and Substance P Release Induced by the Neurotoxin Brevetoxin-1 in Sensory Neurons: Involvement of PAR2 Activation through Both Cathepsin S and Canonical Signaling

Red tides involving Karenia brevis expose humans to brevetoxins (PbTxs). Oral exposition triggers neurotoxic shellfish poisoning, whereas inhalation induces a respiratory syndrome and sensory disturbances. No curative treatment is available and the pathophysiology is not fully elucidated. Protease-activated receptor 2 (PAR2), cathepsin S (Cat-S) and substance P (SP) release are crucial mediators of the sensory effects of ciguatoxins (CTXs) which are PbTx analogs. This work explored the role of PAR2 and Cat-S in PbTx-1-induced sensory effects and deciphered the signaling pathway involved. We performed calcium imaging, PAR2 immunolocalization and SP release experiments in monocultured sensory neurons or co-cultured with keratinocytes treated with PbTx-1 or P-CTX-2. We demonstrated that PbTx-1-induced calcium increase and SP release involved Cat-S, PAR2 and transient receptor potential vanilloid 4 (TRPV4). The PbTx-1-induced signaling pathway included protein kinase A (PKA) and TRPV4, which are compatible with the PAR2 biased signaling induced by Cat-S. Internalization of PAR2 and protein kinase C (PKC), inositol triphosphate receptor and TRPV4 activation evoked by PbTx-1 are compatible with the PAR2 canonical signaling. Our results suggest that PbTx-1-induced sensory disturbances involve the PAR2-TRPV4 pathway. We identified PAR2, Cat-S, PKA, and PKC that are involved in TRPV4 sensitization induced by PbTx-1 in sensory neurons.

Evidence for HTLV-III/LAV expression by primary cultures of T8 cells

The selective targets for HTLV-III/LAV, the causal infectious agent of AIDS and AIDS-related complex (ARC), are T4 cells, apparently because the virus receptor is associated with T4 antigen determinants. This accounts for T4 cell depletion in AIDS and for a decrease of IL-2 production by AIDS peripheral blood lymphocytes (PBL) after in vitro PHA activation. By contrast, T8 cells are not targets for HTLV-III/LAV, since T8 cells from PBL and from long-term cultured T cells (CTC) could not be infected by the virus. We describe 2 samples of PBL from Zairian patients with HTLV-III infection in which HTLV-III was expressed by T8 cells. Evidence that T8 cells were expressing virus was obtained by complement cytotoxicity experiments performed in the presence of OKT8 monoclonal antibody (MAb), which removed HTLV-III-positive cells from cultured T cells producing the virus, and by double labelling experiments, in which some cells exhibit both T8 antigens detected either by IFA (rhodamine) or by rosetting in presence of OKT8 MAbs and HTLV-III antigens detected by IFA (fluorescein) with of anti-HTLV-III p24 and p15 MAbs. Since normal T cells have previously been shown to undergo antigenic diversity, we think these results can be explained by HTLV-III infection of T4 cells which later lost T4 antigens and acquired the T8 phenotype.

Evidence for an antiviral effect and interferon neutralizing capacity in human sera; variability and implications for HIV infection

The antiviral effect (AVE) and interferon neutralizing capacity (INC) of sera originating from either seronegative or HIV-infected individuals were determined. As a rule, sera from seropositive subjects exhibited higher AVE titers than sera from seronegative individuals. Similarly, the INC of sera from HIV-infected patients, was most often stronger than that of sera from seronegative individuals. Furthermore, sera from HIV-infected patients actively immunized with i-IFN alpha invariably expressed INC in response to treatment, which was not the case for sera from control unimmunized patients. All sera from HIV-infected patients were found by ELISA to contain antibodies specifically directed to IFN alpha.