Recombinant HIV-1 vaccine candidates based on replication-defective flavivirus vector.

Multiple approaches utilizing viral and DNA vectors have shown promise in the development of an effective vaccine against HIV. In this study, an alternative replication-defective flavivirus vector, RepliVax (RV), was evaluated for the delivery of HIV-1 immunogens. Recombinant RV-HIV viruses were engineered to stably express clade C virus Gag and Env (gp120TM) proteins and propagated in Vero helper cells. RV-based vectors enabled efficient expression and correct maturation of Gag and gp120TM proteins, were apathogenic in a sensitive suckling mouse neurovirulence test, and were similar in immunogenicity to recombinant poxvirus NYVAC-HIV vectors in homologous or heterologous prime-boost combinations in mice. In a pilot NHP study, immunogenicity of RV-HIV viruses used as a prime or boost for DNA or NYVAC candidates was compared to a DNA prime/NYVAC boost benchmark scheme when administered together with adjuvanted gp120 protein. Similar neutralizing antibody titers, binding IgG titers measured against a broad panel of Env and Gag antigens, and ADCC responses were observed in the groups throughout the course of the study, and T cell responses were elicited. The entire data demonstrate that RV vectors have the potential as novel HIV-1 vaccine components for use in combination with other promising candidates to develop new effective vaccination strategies.

Resilient child sexual abuse survivors: cognitive coping and illusion.

This research examined cognitive coping strategies associated with resilience in a nonclinical sample of child sexual abuse (CSA) survivors. In Study 1, 180 college women completed surveys assessing self-enhancing cognitive distortions of reality, known as positive illusions, and CSA history. CSA survivors and nonvictimized women were found to be equally likely to engage in illusion, and for both groups, measures of illusion were strongly associated with psychological well-being. In Study 2, a qualitative study, a subsample of 20 CSA survivors from Study 1 were interviewed regarding their efforts to cope with CSA. Analysis was focused on comparisons between well-adjusted and poorly-adjusted women. The high adjustment group revealed a greater tendency to engage in four types of cognitive strategies: disclosing and discussing CSA, minimization, positive reframing, and refusing to dwell on the experience. The results of both studies highlight the importance of cognitive reappraisal in CSA recovery. Implications for therapists working with CSA survivors are discussed.

Detection of rectal antibodies to HIV-1 by a sensitive chemiluminescent western blot immunodetection method.

Western blot with a time-dependent enhanced chemiluminescence immunodetection method (ECL-WB) was shown to be 100-fold more sensitive than standard commercial colorimetric Western blots (WB) for detecting serum IgG to human immunodeficiency virus type 1 (HIV-1). ECL-WB was then used to test rectal secretions from 15 HIV-1 infected subjects (HIV+) and 7 uninfected subjects (HIV-) to document local IgG, IgA, and secretory component-associated immunoglobulin (SC-Ig) to HIV-1 proteins. Fourteen of 15 HIV+ subjects had rectal IgA to at least 1 HIV-1 protein, most often to gp41 (80%) or p24 (60%) and 14 (93%) had IgG to gp160, gp120, or gp41. Of seven HIV- subjects, none had detectable bands to HIV-1 proteins. SC-Ig to HIV-1 proteins was detected in all five rectal samples tested. However, the antibody profiles differed from those of rectal IgA, suggesting more than one source of rectal IgA to HIV. ECL-WB requires individual optimization and interpretation for each specimen as well as expensive reagents and is, therefore, not currently applicable to screening assays. However, the method offers promise as a sensitive method to characterize low-level immune responses (IgG, IgA, and SC-Ig) to HIV-1 proteins at local sites such as rectal mucosae.

Safety and immunogenicity of a fully glycosylated recombinant gp160 human immunodeficiency virus type 1 vaccine in subjects at low risk of infection. National Institute of Allergy and Infectious Diseases AIDS Vaccine Evaluation Group Network.

Recombinant gp160 derived from human immunodeficiency virus type 1 (HIV-1)IIIB and produced in mammalian tissue culture cells using a vaccinia virus expression system (rgp160-mam) was evaluated as a vaccine in combination with alum and deoxycholate adjuvant. Sixty low-risk, uninfected subjects received 12.5 micrograms, 50.0 micrograms, or adjuvant control at 0, 1, 6, and 12 months in a randomized, double-blind dose-escalation study. A single injection of 200 micrograms of vaccine was given at 18 months in an open study to 9 vaccines who had received 50 micrograms. The vaccine was safe. Six of 16 subjects receiving 50 micrograms developed neutralizing antibody to HIV-1IIIB. Seven of the 9 boosted with 200 micrograms of vaccine at 18 months developed neutralizing antibodies. Lymphocyte proliferation to rgp160-mam and baculovirus-derived rgp160 and rgp120 was induced in both groups (12.5 and 50.0 micrograms) and appeared after the first dose. Further studies with higher doses of rgp160-mam and vaccines derived from other strains of HIV-1 are warranted.

Administration of recombinant interleukin-2 reduces the local parasite load of patients with disseminated cutaneous leishmaniasis.

Three patients with disseminated cutaneous leishmaniasis received three intranodular injections of 10 micrograms of recombinant interleukin 2 (rIL-2) at 48-h intervals. After 7 and 14 days, 4-mm punch biopsies were taken of control and injected nodules and processed for histology, electron microscopy, immunocytochemistry, and parasite culture. Control sites exhibited loose infiltrates of parasitized macrophages and T cells predominantly of the CD8+ phenotype. Amastigotes were present in large numbers and were found distributed within tightly apposed endosomes and larger vacuoles. After the administration of rIL-2, there was a prominent influx of T cells, predominantly of the CD4+ phenotype, and an increased number of plasma cells. At 7 days, leishmanial amastigotes were present in either the same or somewhat reduced numbers but predominantly within large, lucent vacuoles. By 14 days the number of amastigotes was strikingly lower. Lymphokine-treated skin sites became sterile in two patients, as evaluated by parasite culture after rIL-2 injection. The results suggest that the local administration of rIL-2 induces a beneficial enhancement of the cellular immunity with a consequent disposal of parasites in the cutaneous site.

Most CD4+ T cells from human immunodeficiency virus-1 infected patients can undergo prolonged clonal expansion.

We have addressed the capacity of HIV-1 infection to alter the growth of primary CD4+ T cells, but at the clonal level. Single T cells were expanded in the presence of PHA, IL-2, and small numbers of accessory dendritic cells. We report two new findings. First, T cells from seropositive individuals, even those with AIDS and markedly reduced CD4+ counts, exhibit a normal cloning efficiency, and proliferative capacity. This result is in contrast to two prior reports of a low cloning efficiency in CD4+ T cells from HIV-1-infected patients. Second, when we added high doses of exogenous HIV-1 to T cell clones from control subjects, we observed infection but not cytotoxicity or loss of CD4+ cells, following addition of virus stocks at days 0, 3, and/or 7 of clonal growth. The same HIV-1 isolates markedly reduced CD4+ T cells in bulk mononuclear cultures. When tested at day 11, HIV-1 mRNA was expressed in some cells of exogenously infected clones by in situ hybridization; when tested at day 18, several clones could transactivate a TAT-sensitive cell line. These findings suggest that the loss of CD4+ T cells in infected individuals is not the inevitable result of the activation of latent infection, or spread of a productive infection, during clonal growth.

Cellular responses to the intradermal injection of recombinant human gamma-interferon in lepromatous leprosy patients.

The local response to a single intradermal injection of 10 micrograms recombinant gamma-interferon (rIFN gamma) has been studied in 17 patients with lepromatous leprosy. Of these, 2 patients additionally received two intradermal injections of 10 micrograms rIFN gamma at another site. The results were compared with those of 3 patients who received three injections of the same dose at a single site in an earlier study. One to 7 days after lymphokine administration 4-mm punch biopsies were obtained and examined for cellular alterations in the dermis and epidermis. This allowed a kinetic analysis of mononuclear cell infiltration, keratinocyte proliferation and differentiation, and Langerhans cell redistribution. At 24 hours, the migration of large numbers of helper T cells and monocytes was already prominent and associated with induration. Mononuclear cell accumulation peaked at 72 hours but then persisted for 5-7 days. Only small numbers (one-third or less of total T cells) of suppressor/cytotoxic T cells were present at any time, and granulocytes were absent. Two daily injections of rIFN gamma led to a more intense accumulation of cells. Ten micrograms of rIFN gamma resulted in enhanced keratinocyte proliferation, Ia expression, and thickening of the epidermis. At 24-48 hours major histocompatibility Class II (Ia) antigen was first noted on the dividing cells of the basal layer. By 72-96 hours the entire epidermis exhibited strong expression of Ia antigen on cell surfaces. Repeated doses of lymphokine accentuated these changes and resulted in a more prompt keratinization and sloughing of this layer. Whereas a single dose of rIFN gamma resulted in the upward movement of T6+ Langerhans cells (LCs) in the epidermis, two injections led to a 50% reduction in their numbers and three doses were associated with an almost total loss of detectable T6+ LCs from the epidermis. These are probably sloughed along with keratinocytes. In contrast to the situation with a delayed immune response in the skin (purified protein derivative), no LCs accumulated in the dermis in association with helper T cells.