Novel chimpanzee adenovirus-vectored respiratory mucosal tuberculosis vaccine: overcoming local anti-human adenovirus immunity for potent TB protection.

Pulmonary tuberculosis (TB) remains to be a major global health problem despite many decades of parenteral use of Bacillus Calmette-Guérin (BCG) vaccine. Developing safe and effective respiratory mucosal TB vaccines represents a unique challenge. Over the past decade or so, the human serotype 5 adenovirus (AdHu5)-based TB vaccine has emerged as one of the most promising candidates based on a plethora of preclinical and early clinical studies. However, anti-AdHu5 immunity widely present in the lung of humans poses a serious gap and limitation to its real-world applications. In this study we have developed a novel chimpanzee adenovirus 68 (AdCh68)-vectored TB vaccine amenable to the respiratory route of vaccination. We have evaluated AdCh68-based TB vaccine for its safety, T-cell immunogenicity, and protective efficacy in relevant animal models of human pulmonary TB with or without parenteral BCG priming. We have also compared AdCh68-based TB vaccine with its AdHu5 counterpart in both naive animals and those with preexisting anti-AdHu5 immunity in the lung. We provide compelling evidence that AdCh68-based TB vaccine is not only safe when delivered to the respiratory tract but, importantly, is also superior to its AdHu5 counterpart in induction of T-cell responses and immune protection, and limiting lung immunopathology in the presence of preexisting anti-AdHu5 immunity in the lung. Our findings thus suggest AdCh68-based TB vaccine to be an ideal candidate for respiratory mucosal immunization, endorsing its further clinical development in humans.

Acting locally: innate mucosal immunity in resistance to HIV-1 infection in Kenyan commercial sex workers.

Cohort studies of female commercial sex workers (CSWs) in Kenya were among the first to identify highly HIV-1-exposed seronegative (HESN) individuals. As natural resistance is usually mediated by innate immune mechanisms, we focused on determining whether expression and function of innate signaling pathways were altered locally in the genital mucosa of HESN CSWs. Our results demonstrated that selected pattern-recognition receptors (PRRs) were significantly reduced in expression in cervical mononuclear cells (CMCs) from HESN compared with the new HIV-negative (HIV-N) and HIV-positive (HIV-P) groups. Although baseline levels of secreted cytokines were reduced in CMCs of HESN, they were highly stimulated following exposure to ssRNA40 in vitro. Importantly, cervical epithelial cells from HESN also expressed reduced levels of PRRs, but Toll-like receptor 3 (TLR3) and TLR7 as well as nuclear factor-κB and activator protein 1 were highly expressed and activated. Lastly, inflammatory cytokines interleukin (IL)-1ß, IL-8, and RANTES (regulated and normal T cell expressed and secreted) were detected at lower levels in cervicovaginal lavage of HESN compared with the HIV-N and HIV-P groups. Overall, our study reveals a local microenvironment of HIV resistance in the genital mucosa consisting of a finely controlled balance of basal immune quiescence with a focused and potent innate anti-viral response critical to resistance to sexual transmission of HIV-1.

The gp41 epitope, QARVLAVERY, is highly conserved and a potent inducer of IgA that neutralizes HIV-1 and inhibits viral transcytosis.

Mucosal surfaces are the predominant site of human immunodeficiency virus (HIV)-1 transmission. For prophylactic approaches to effectively prevent HIV infection and subsequent dissemination, the induction of mucosally relevant protective immunity will be critical. Here, we have characterized the antibody (Ab) response generated by a highly conserved gp41epitope, QARVLAVERY, in an optimized immunization model that elicits potent epitope-specific Abs in the serum, vaginal washes, and fecal secretions of immunized mice. Our results show that QARVLAVERY is indeed a potent inducer of IgA and importantly, QARVLAVERY-specific IgA was effective in neutralizing HIV and inhibiting viral transcytosis. Intriguingly, QARVLAVERY also generated an approximate 1:1 ratio of IgG:IgA in the serum of immunized mice, independent of the delivery regimen and produced early systemic IgA, even before IgG. In light of the significantly high IgA induction by QARVLAVERY and the functionality of epitope-specific Abs in the inhibition of HIV infection and transcytosis, QARVLAVERY is an attractive epitope to be considered in mucosal vaccination strategies against HIV.

Immunization with adenovirus at the large intestinal mucosa as an effective vaccination strategy against sexually transmitted viral infection.

The large intestinal mucosa contains immunological structures that may potentially serve as a site for induction of mucosal immunity against infections. Adenovirus (Ad), which is effective in gene transfer to epithelia, may be an ideal antigen delivery system for vaccination at the large intestinal mucosa. To investigate this potential, we immunized mice with recombinant replication-deficient Ad through a single intracolorectal (ICR) administration. Effective transfer of encoded genes was found in both the epithelial layer and lamina propria of the colorectal mucosa. Dendritic cells were able to transfer antigen to the draining lymph nodes, where antigen-specific CD8(+) T cells were primed. Functional antigen-specific CD8(+) T cells and IgA-specific antibodies were detected during the effector phase in the large intestine. Compared to other immunization routes (intranasal, subcutaneous), ICR immunization induced stronger colorectal immune responses and more potent protection against rectal challenge with pathogenic viruses. Further, this immunization strategy provided vaginal protection, more potent than that induced by vaccination in the nose or skin. Therefore, large intestine mucosal immunization using Ad represents an effective vaccination strategy against virus infection at both rectal and vaginal mucosal tissue sites.

Cutaneous neoplasms in pet rabbits: a retrospective study.

Over a 16-year period, 190 tumors and tumorlike lesions from 179 pet rabbits were submitted for histopathologic examination. A total of 23 different tumor types and 1 tumorlike lesion were diagnosed. The most common diagnoses were trichoblastoma, collagenous hamartoma, and Shope fibroma. Viral-induced tumors were Shope fibroma (19) and Shope papilloma (2). Common nonviral epithelial tumors included trichoblastoma (59), squamous cell carcinoma (5), squamous papilloma (4), trichoepithelioma (3), and apocrine carcinoma (3). Common mesenchymal tumors were lipoma (10), liposarcoma (3), myxosarcoma (9), malignant peripheral nerve sheath tumor (8), fibrosarcoma (7), and leiomyosarcoma (4). Malignant melanoma was diagnosed in 8 rabbits. Collagenous hamartomas were diagnosed in 26 rabbits. Mesenchymal proliferations occurred significantly more often in male rabbits than in females. Collagenous hamartomas and myxosarcomas occurred exclusively in male animals, and 3 rabbits had multiple collagenous hamartomas. Immunohistochemistry was applied in cases in which a definite diagnosis could not be reached on hematoxylin and eosin slides. Follow-up information was received in 19 cases. Carcinomas recurred (2 of 3) or metastasized (1 of 3), whereas sarcomas frequently recurred (7 of 12). One malignant melanoma (1 of 3) and one poorly differentiated round cell neoplasm recurred (1 of 1). This is the first comprehensive retrospective analysis on skin neoplasia in pet rabbits.

Intranasal immunization with CpG oligodeoxynucleotides as an adjuvant dramatically increases IgA and protection against herpes simplex virus-2 in the genital tract.

Development of vaccines capable of preventing the transmission or limiting the severity of sexually transmitted viruses, such as HSV and HIV, will likely be dependent on the induction of potent long-lasting mucosal immune responses in the genital tract. Recently, synthetic oligodeoxynucleotides (ODN) containing immunostimulatory CpG motifs were shown to serve as potent adjuvants for the induction of mucosal immune responses. Here, we show that intranasal immunization with CpG ODN, plus recombinant glycoprotein B (rgB) of HSV-1, results in significantly elevated levels of specific anti-gB IgA Abs in vaginal washes that remained high throughout the estrous cycle. Additionally, dramatically elevated numbers of specific IgA Ab-secreting cells were present and persisted in the genital tract in response to intravaginal (IVAG) HSV-2 challenge. HSV-2-specific CTL were observed at moderate levels in the spleens of CpG or non-CpG ODN-immunized mice. In contrast, strong CTL responses were observed locally in the genital tissues of both groups following IVAG HSV-2 challenge. Interestingly, mice immunized intranasally with rgB plus CpG ODN, but not non-CpG ODN, were significantly protected following IVAG HSV-2 challenge. Measurement of virus in protected CpG-immunized mice revealed a log lower level of replication within the first few days after infection. In conclusion, these results indicate that intranasal immunization with CpG ODN plus protein mediates immunity in the female genital tract capable of protecting against a sexually transmitted pathogen.

Recombinant adenovirus vectors expressing interleukin-5 and -6 specifically enhance mucosal immunoglobulin A responses in the lung.

In this study, we have examined the in vivo effects of interleukin-5 (IL-5) and IL-6 over-expression on systemic and mucosal immune responses using recombinant human type 5 adenoviruses capable of expressing these cytokines upon infection. A recombinant adenovirus containing the murine IL-5 gene within the E3 region was constructed and found to express high levels of IL-5 protein both in vitro and in vivo. Intranasal inoculation of mice with this vector or a vector expressing murine IL-6 increased adenovirus-specific immunoglobulin A (IgA) titres in lung lavage fluid threefold compared with those elicited by control virus. The simultaneous expression of both cytokines by co-inoculation altered the kinetics of the mucosal anti-adenovirus IgA response and resulted in a more than additive increase in antibody titres. The co-expression effect on IgA synthesis was not due to an increase in numbers of antigen-specific resident lung tissue lymphocytes. When mucosal IgG responses were examined, IL-6 expression had the largest impact on anti-adenovirus levels, whereas co-expression produced an intermediate response. Systemic immune responses were also affected by IL-6 expression as a twofold increase in serum IgG anti-adenovirus titres was observed after a secondary challenge with wild-type adenovirus. These results demonstrate a relevant role for IL-5 and IL-6 in the development of mucosal immune responses in vivo and suggest that the incorporation of either IL-5 and/or IL-6 into recombinant adenovirus vectors may be a useful tool in the development of mucosal vaccines.

HIV-1-specific cellular immune responses among HIV-1-resistant sex workers.

The goal of the present study was to determine whether there were HIV-1 specific cellular immune responses among a subgroup of women within a cohort of Nairobi prostitutes (n = 1800) who, despite their intense sexual exposure to HIV-1, are epidemiologically resistant to HIV-1 infection. Of the 80 women defined to be resistant, 24 were recruited for immunological evaluation. The HIV-1-specific T-helper responses were determined by IL-2 production following stimulation with HIV-1 envelope peptides and soluble gp120. Cytotoxic T lymphocyte responses were determined by lysis of autologous EBV-transformed B cell lines infected with control vaccinia virus or recombinant vaccinia viruses containing the HIV-1 structural genes env, gag and pol. Resistant women had significantly increased HIV-1 specific T-helper responses, as determined by in vitro IL-2 production to HIV-1 envelope peptides and soluble glycoprotein 120, compared with low-risk seronegative and HIV-1-infected controls (P < or = 0.01, Student's t-test). Seven of the 17 (41%) resistant women showed IL-2 stimulation indices > or = 2.0. HIV-1-specific CTL responses were detected among 15/22 (68.2%) resistant women compared with 0/12 low-risk controls (Chi-squared test, P < 0.001). In the two resistant individuals tested, the CTL activity was mediated by CD8+ effectors. Many HIV-1-resistant women show evidence of HIV-1-specific T-helper and cytotoxic responses. These data support the suggestion that HIV-1-specific T-cell responses contribute to protection against HIV-1 infection.

Factors contributing to the lack of human immunodeficiency virus type 1 (HIV-1) transmission in HIV-1-discordant partners.

Correlates of resistance to infection by human immunodeficiency virus type 1 (HIV-1) are important for defining potential therapeutic interventions and for prophylactic vaccination. In this study, 11 couples discordant in their HIV-1 infection status were prospectively evaluated for the presence of protective factors. Behavioral characteristics of all subjects entailed a high risk of transmission. Cytotoxic T lymphocyte (CTL) responses against viruses isolated from the infected partner, and against laboratory virus isolates, were detected in 5 (45%) of 11 HIV-negative partners, including a CCR5Delta32-homozygous and a heterozygous subject. No CTL responses were observed in 6 control unexposed subjects. Marked variation in lymphocyte susceptibility to viral infection was noted. Resistance attributable to major histocompatibility complex discordance or anti-major histocompatibility complex antibodies was not identified. These results suggest that a combination of factors, including cellular immunity, viral characteristics, and coreceptor integrity, may be involved in the persistent nontransmission of HIV.

RANTES production by T cells and CD8-mediated inhibition of human immunodeficiency virus gene expression before initiation of potent antiretroviral therapy predict sustained suppression of viral replication.

A prospective blinded study was conducted to determine whether immunological differences exist between patients receiving potent antiretroviral therapy who are able to achieve and maintain an undetectable virus load (<50 copies/mL) and those who are not. Eleven patients receiving protease inhibitor-containing antiretroviral therapy were studied for 1 year. After analysis of all baseline samples, patient virus load was disclosed, and patients were classified as suppressors (those who maintained undetectable virus load for 1 year) and nonsuppressors. Baseline virus load and CD4+ T cell count did not differ significantly between the 2 groups. Levels of RANTES production by CD4+ and CD8+ T cells and CD8-mediated inhibition of human immunodeficiency virus type 1 gene expression before initiation of antiretroviral therapy were significantly associated with an undetectable virus load maintained for 1 year (P<.05). Thus, a functionally intact T cell-mediated immune system at the time of initiation of potent antiretroviral therapy may predict long-term virus suppression.

Persistently HIV-1 seronegative Nairobi sex workers are susceptible to in vitro infection.

OBJECTIVE: To evaluate whether resistance to HIV-1 infection in a subset of highly exposed sex workers correlates with resistance at the cellular level. DESIGN: In vitro evaluation of susceptibility to infection by Kenyan HIV-1 isolates and cellular production of potential mediators of resistance. SETTING: Samples were collected in a primary care clinic in Nairobi. PATIENTS: Thirteen individuals from a cohort of sex workers with a similar risk of acquiring HIV infection and six unexposed controls. INTERVENTIONS: Subjects were provided with appropriate primary care and counselling on the prevention of sexually transmitted diseases. RESULTS: No inherent cellular resistance to infection was identified. CD8⁺ cells from a subset of subjects strongly inhibited viral replication. CONCLUSIONS: Lack of infection in this cohort was not attributable to factors inherent to CD4⁺ cells. Resistance to HIV infection is likely to be multifactorial, and products of CD8⁺ cells and unique features of mucosal sites probably contribute to this state.

T cell-derived suppressive activity: evidence of autocrine noncytolytic control of HIV type 1 transcription and replication.

The ability of CD8+ T lymphocytes to suppress the transcription and replication of HIV-1 is well documented. We have demonstrated that the factor(s) responsible for the suppression of HIV-1 LTR-mediated gene expression are not the CC chemokines RANTES, MIP-1alpha, and MIP-1beta. Interestingly, these and other chemokines and cytokines are produced by both CD8+ and CD4+ T lymphocytes. On the presumption that CD4+ T lymphocytes may also be able to modulate HIV-1 expression in vitro we assessed the LTR-modulatory effects of a panel of culture supernatants derived from stimulated CD4+ T lymphocytes from HIV-positive patients and uninfected controls. Supernatants of both CD4+ and CD8+ T cells mediated a suppression of LTR-driven gene expression in Jurkat T cells and an enhancement of gene expression in U38 monocytic cells. On the basis of these results, and using a herpesvirus saimiri (HVS)-transformed CD4+ T lymphocyte clone (HVSCD4), we demonstrate that both suppressive and enhancing effects are dose dependent. Furthermore, we have shown that supernatants of both HVSCD4 and HVSCD8 cells suppress LTR-mediated gene expression and HIV-1 replication in transfected/infected T cells. In U1 monocytic cells, supernatants of both CD4+ and CD8+ lymphocytes from an HIV-1-infected individual enhanced LTR-mediated gene expression, HIV-1 replication, and TNF-alpha production. However, only these effects as induced by CD8+ T cells were sensitive to the G protein inhibitor pertussis toxin. These results indicate that factors produced by both CD4+ and CD8+ T cells exert dichotomous effects on HIV-1 gene expression and replication in T cells and monocytes.

CD8+ T cell-mediated enhancement of tumour necrosis factor-alpha (TNF-alpha) production and HIV-1 LTR-driven gene expression in human monocytic cells is pertussis toxin-sensitive.

HIV replication and LTR-mediated gene expression can be modulated by CD8+ T cells in a cell type-dependent manner. We have previously shown that supernatants of activated CD8+ T cells of HIV-infected individuals greatly enhanced p24 levels in human macrophages infected with NSI or SI primary isolates of HIV-1. Here we have examined the effect of culture with CD8+ T cell supernatants on HIV-1 LTR-mediated gene expression in monocytic cells. CD8+ T cell supernatants enhanced LTR-mediated gene expression in U38 cells activated with Tat in the absence or presence of phorbol myristate acetate (PMA) and ionomycin or TNF-alpha. Further, enhancement of LTR-mediated gene expression and virus replication in U38 cells and U1 cells, respectively, was pertussis toxin-sensitive. The enhancement of gene expression and virus replication was associated with increased levels of TNF-alpha and was significantly abrogated by antibody to TNF-alpha. In contrast, the suppression of LTR-mediated gene expression by CD8+ T cell supernatants in Jurkat T cells was not pertussis toxin-sensitive and TNF-alpha levels were not affected. These results demonstrate that factors produced by CD8+ T cells utilize different cellular pathways to mediate their effects on HIV transcription and replication in different cell types.

Enhancement of HIV-1 replication in human macrophages is induced by CD8+ T cell soluble factors.

We previously reported that CD8+ T cell-derived factors enhanced HIV long terminal repeat (LTR)-mediated gene expression and replication in monocytic cell lines. We now report that replication of NSI and SI primary isolates of HIV-1 in human macrophages were significantly enhanced by CD8+ T cell supernatants. The CD8-mediated enhancement of HIV replication was abrogated by pertussis toxin in a dose-dependent manner. The sensitivity to pertussis toxin suggests that the CD8+ T cell-derived enhancing factor is acting through a G protein-coupled signalling pathway. Enhanced HIV replication in macrophages was accompanied by increased levels of HIV-1 mRNA, suggesting that CD8 enhancement was mediated at the transcriptional level. Interestingly, the replication of HIV(Bal), which replicates to high levels in macrophages, was not significantly modulated by culture with CD8+ T cell supernatants. Although direct co-culture of activated CD8+ T cells with HIV(Ada)-infected macrophages did not modulate replication, separation of the CD8+ T cells from macrophages in transwell cultures resulted in significant enhancement of replication. The inability to detect a modulatory effect in direct co-cultures appeared to be due to non-specific lysis of infected macrophages. Thus, soluble factors produced by CD8+ T cells exert strong enhancing effects on HIV-1 replication in human macrophages.

Long-term immunity and protection against herpes simplex virus type 2 in the murine female genital tract after mucosal but not systemic immunization.

The degree and duration of immunity against herpes simplex virus type 2 (HSV-2) infection of the female genital tract were assessed after intranasal (i.nl.) or intraperitoneal (i.p.) immunization with a recombinant adenovirus vector expressing HSV glycoprotein B (AdgB8). After intravaginal HSV-2 challenge, control mice rapidly developed disease and displayed high virus titers in vaginal washes. In contrast, virus titers decreased significantly and at similar rates in i.nl. and i.p. immunized mice and by day 7 were undetectable in vaginal wash samples. Assessment of genital pathology and survival showed that only i.nl. immunization provided long-term protection. Examination of antibody-secreting cells (ASCs) during the decline in vaginal virus titers revealed that gB-specific IgA ASCs were only observed in the genital tissues of i.nl. immunized mice. These results indicate that mucosal immunization provides a high and long-lasting level of immunity from sexually transmitted viral infections of the female genital tract.

Challenges for vaccination against sexually-transmitted diseases: induction and long-term maintenance of mucosal immune responses in the female genital tract.

The ability to develop vaccines capable of preventing or protecting against sexually transmitted viruses, such as herpes simplex virus (HSV) and HIV is likely to depend on the induction of long-term mucosal immune responses. We have utilized a recombinant adenovirus capable of expressing HSV glycoprotein B (AdgB8) to demonstrate that intranasal (i.n.) immunization induces HSVgB-specific IgG and IgA antibodies in the serum and vaginal washes of mice. In contrast, systemic immunization only resulted in IgG antibodies in vaginal fluids. We also observed that although i.n. and i.p. AdgB8 immunization induced short-term CTL responses, only i.n. immunized mice maintained long-term CTL responses in the genital-associated lymphoid tissues. When compared to systemic immunization, mice immunized i.n. with the same dose of AdgB8 were better protected for a longer time period from a lethal intravaginal HSV-2 challenge. Protection occurred despite the fact that mice were initially infected (i.e. not sterile immunity) and the enhanced survival occurring in i.n. immunized mice correlated with the presence of HSVgB-specific IgA antibody-secreting cells in the genital tissues and with memory CTL, recall responses. Together, these results indicate that mucosal immunization is important for the induction and long-term maintenance of mucosal immune responses.

CD8+ T-cell-mediated suppression of HIV-1 long terminal repeat-driven gene expression is not modulated by the CC chemokines RANTES, macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta.

OBJECTIVE: To assess the role of RANTES, macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta in modulation of HIV-1 long terminal repeat (LTR)-mediated gene expression and determine whether these chemokines share identity with CD8+ T-lymphocyte-derived HIV-1 LTR-suppressive factors. DESIGN: HIV-1 LTR-directed reporter gene expression is a model for transcription that is susceptible to inhibition by factors produced by CD8+ lymphocytes of HIV-1-infected individuals. The effect of recombinant chemokines on LTR-directed gene expression was examined. The ability of chemokines found to be present in CD8 supernatants to suppress HIV-1 LTR-mediated gene expression was determined by antibody inhibition assays. METHODS: The concentrations of RANTES, MIP-1 alpha and MIP-1 beta in a panel of CD8+ T-lymphocyte-derived supernatants were determined by enzyme-linked immunosorbent assay. Recombinant chemokines were added to freshly transfected (pLTR-CAT and pSV40-tat) human Jurkat T cells. Excessive polyclonal neutralizing antibodies to these chemokines were added to transfected Jurkat T cells cultured in the presence of strongly inhibitory CD8+ T-cell-derived supernatants with known chemokine concentrations. RESULTS: The concentrations of RANTES, MIP-1 alpha and MIP-1 beta in a panel of CD8+ lymphocyte-derived supernatants were found to correlate with their relative ability to suppress the LTR-mediated gene expression (r = 0.679, 0.764 and 0.48, respectively). The addition of recombinant CC chemokines had no effect over a broad range of doses on HIV-1 LTR-mediated gene expression. The CD8-suppressive effect on HIV-1 LTR-driven gene expression was not abrogated by a combination of antibodies of RANTES, MIP-1 alpha and MIP-1 beta. CONCLUSIONS: RANTES, MIP-1 alpha and MIP-1 beta do not alter HIV-1 LTR-directed gene expression at doses up to 100 ng/ml. Although present in varying concentrations in supernatants derived from CD8+ lymphocytes from HIV-positive individuals, these chemokines are not responsible for the powerful CD8-derived suppressive effect on HIV-1 LTR-mediated gene expression observed in our system.

CD8+ T cell-mediated suppression of HIV long terminal repeat-driven gene expression is not associated with improved clinical status.

OBJECTIVES: To determine the associations between the suppression of HIV-1 long terminal repeat (LTR)-mediated gene expression by CD8+ T-cell supernatants and clinical correlates of well-being, including CD4+ and CD8+ T-cell counts, beta-chemokine production and clinical stage of disease. METHODS: Culture supernatants of activated CD8+ T cells derived from a panel of HIV-1-infected subjects were assessed for their ability to suppress HIV-1 LTR-mediated chloramphenicol acetyl transferase (CAT) expression. The percentage suppression of gene expression was correlated with CD4+ and CD8+ T-cell counts and clinical stage of infection. Some individuals within this group were followed at 2-3 month intervals over time to assess the consistency of the suppression. Selected CD8+ T-cell culture supernatants of diverse suppressive ability were screened for the levels of the beta-chemokines macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta and RANTES. RESULTS: The ability of CD8+ T cells of HIV-1 infected subjects to suppress HIV-1 LTR-mediated gene expression did not show a dependence upon high CD4+ T-cell counts or on the clinical stage or duration of infection. The ability to suppress gene expression did show a relationship with higher CD8+ T-cell counts and correlated with the levels of beta-chemokines in the culture supernatants. In contrast, strong suppression was mediated by CD8+ T-cell supernatants from some subjects with very low CD8+ T-cell counts and relatively low chemokine levels. CONCLUSIONS: Although the suppression of gene expression by CD8+ T-cell culture supernatants showed statistical correlation with beta-chemokine levels and with higher CD8+ T-cell count, no correlation could be found with correlates of clinical well-being.

Adrenal gland disease in ferrets.

Adrenocortical disease is a frequent problem affecting pet ferrets in the United States. This article describes the typical history, signs, and diagnostic test results to be expected in ferrets with this disease. Treatment options are discussed. A newly developed diagnostic technique is also described.

CD8+ T cell supernatants of HIV type 1-infected individuals have opposite effects on long terminal repeat-mediated transcription in T cells and monocytes.

CD8+ T lymphocytes of HIV-1-infected individuals can efficiently suppress HIV-1 replication in CD4+ T lymphocytes via soluble factors. We compared the effect of CD8+ T cell-derived supernatants on HIV-1 LTR-driven gene expression in T cells and monocytic cell lines. Our results demonstrate that CD8+ T cell supernatants that suppressed HIV-1 LTR-driven gene expression in Jurkat T cells significantly enhanced expression in Tat-activated U38 monocytic cells in the presence and absence of mitogenic stimulation. Examination of a panel of CD8+ T cell-derived supernatants form HIV-infected individuals demonstrated that the extent of enhancement of transcription in U38 cells was mirrored in most cases by a similar level of suppression of transcription in Jurkat T cells. In latently infected U1 cells treated with TNF-alpha, culture with CD8+ T cell supernatants markedly enhanced virus production. In addition, the percentage increase in the enhancement of HIV-1 LTR-driven CAT expression by CD8+ T cell supernatants correlated strongly (r = 0.911) with the level of p24 detected. The level of LTR-mediated gene expression in U38 cells was not influenced by rhMIP-1 alpha rhMIP-1 beta, or rhRANTES over a wide range of chemokine concentration. Treatment of CD8+ T cell supernatant with a combination of antibodies to these chemokines resulted in a further augmentation of LTR-mediated CAT expression in U38 cells. Taken together, these results demonstrate that CD8+ T cell suppressive factors may have opposite effects on HIV-1 LTR-driven gene expression and replication dependent on target cell type and further suggest that the beta-chemokines do not influence HIV-1 LTR-mediated gene expression in monocytic cells.