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Biomedical subjects

D J Carlo

Publications and source records attributed to D J Carlo.

At least 55 records · Page 3Linked to original sources
PubMed1996

Viral load, CD4 percentage, and delayed-type hypersensitivity in subjects receiving the HIV-1 immunogen and antiviral drug therapy.

Two trials of subjects inoculated with the inactivated, gp120-depleted HIV-1 Immunogen are reported. In one study, in which 19 subjects received ZDV and 8 subjects received ddI, treatment with the HIV-1 Immunogen did not affect the pharmacokinetic parameters of the antiviral drugs. In another study, 65 subjects who were previously immunized with the HIV-1 Immunogen over a mean period of 4.0 years (range, 1.2-5.4 years) received inoculations at 0 and 6 months. At some point during this 48-week study, 72% of the subjects (47/65) were receiving antiviral drug therapy. The HIV-1 DNA load in CD4 cells and CD4 percentage were found to be stable over the 48-week period. Delayed-type hypersensitivity to HIV-1 antigens increased after two inoculations with the HIV-1 Immunogen. In these two trials, no serious treatment-related adverse events were documented in the subjects. The two studies presented herein are the first to suggest that an immune-based therapy such as the HIV-1 Immunogen can be combined safely with antiviral drugs, supporting further study to evaluate the clinical utility of this approach.

AIDS Vaccines↗
PubMed1996

Combination therapies against HIV-1 infection: exploring the concept of combining antiretroviral drug treatments with HIV-1 immune-based therapies in asymptomatic individuals.

The deleterious effect of HIV on the immune system begins at the time of infection. At seroconversion the virologic and immunologic factors that ultimately will dictate the rate of disease progression are believed to be already in place. The concept developed in this paper implies that, to impact significantly on the progression of disease, anti-HIV therapies should be initiated as early as possible in asymptomatic individuals. Published results have shown that combination drug therapies are potent in reducing HIV-1 RNA load in plasma in asymptomatic individuals, and that some HIV-1 immune-based therapies have a positive impact on immunological markers of disease progression, including HIV-1 cell-mediated immunity (CMI) and CD4 percent. The strategy discussed is to test a combination of antiretroviral therapy with HIV-1 immune-based therapy, such as the inactivated HIV-1 immunogen preparation, in asymptomatic individuals. The goal of this combination approach is to overcome the limitations of each therapy alone. Preliminary data suggest that antiretroviral therapy and the HIV-1 Immunogen can be combined with no noticeable interference and/or added toxicity in a broad range of HIV-1-infected individuals. Combining both therapies may enhance and expand the impact on key surrogate markers of disease progression, although they likely achieve this impact through different mechanisms. Thus, the primary question remains: Can these effects be synergistic?

Adjuvants, Immunologic↗
PubMed1996

V beta 17 T cell receptor peptide vaccination in rheumatoid arthritis: results of phase I dose escalation study.

OBJECTIVE: To determine whether modulation of activated T cells occurs in patients with rheumatoid arthritis (RA) after immunization with T cell receptor (TCR) V beta 17 peptides, a phase I trial was initiated to investigate the safety and feasibility of TCR peptide immunization as a therapeutic approach in RA. METHODS: 15 patients with moderate to severe RA were given an intramuscular injection of one of 4 doses (10, 30, 100, and 300 micrograms) of the V beta 17 peptide vaccination, followed by a booster injection of the same dose of vaccine 3 weeks later. Patients were followed for 48 weeks. RESULTS: The product was well tolerated and no serious adverse events attributable to the vaccine were observed. This was an uncontrolled phase I trial, however; decreases in patients joint scores were observed at all followup visits starting at 4 weeks after primary immunization. Activated V beta 17 T cells (IL-2R+) in peripheral blood were decreased (> or = 20%) in 3/5 patients in the 100 micrograms group after initial measurement at Week 2 and 3/4 patients in the 300 micrograms group 3 weeks after immunization. Lymphocyte proliferation in response to the V beta 17 peptide was detected at 6 weeks or later after primary inoculation in 6/15 patients (40%) immunized. CONCLUSION: Further controlled studies are required to assess the biologic and clinical efficacy of this treatment approach.

Adult↗
PubMed1995

CD8+ T-cells in psoriatic lesions preferentially use T-cell receptors V beta 3 and/or V beta 13.1 genes.

Restricted T-cell receptor V beta gene use in animal models of autoimmune disease has led to the development of strategies to treat autoimmune disease by targeting the T-cell receptors of the pathogenic T-cells. Restricted T-cell receptor gene use has been noted in human autoimmune diseases such as rheumatoid arthritis and multiple sclerosis. We report here the finding of restricted T-cell receptor gene use in psoriasis vulgaris, as well. Our results show an elevated skin (over PBL) expression of V beta 3 and/or V beta 13.1 messages in the CD8+ T-cells in a majority of patients studied. CDR3 sequence analysis on these two V beta s from the skin demonstrated monoclonality or marked oligoclonality. A second biopsy performed 3.5 to 8 months later in four patients, at the same or different lesions, again revealed an elevated V beta 3 and/or V beta 13.1 expression and clonality. Moreover, in three of the four patients, the same TcR V beta CDR3 rearrangement was found in both biopsies, although there was no V beta CDR3 homology noted between patients. In two patients in which V beta 3 and/or V beta 13.1 was not elevated in the CD8+ T-cell population, an increase in V beta 17 gene use and clonality was found. The persistence of V beta 3- and/or V beta 13.1-bearing CD8+ T-cells in lesions that did not undergo resolution suggests their role as effector cells rather than as regulatory cells. The effector function of these CD8+ T-cells is further supported by the clonality of TcR V beta sequence data, which indicates they are recruited and expanded in situ. The V beta s identified in this study are candidate targets for selective immunotherapeutic intervention in psoriasis.

Amino Acid Sequence↗
PubMed1995

Insulin-secretory-granule specific T cell clones in human IDDM.

T cell clones reactive to beta-cell antigens prepared from different species were established in order to identify putative pathogenic T cells in human IDDM. We were able to generate T cell clones from patients, but not from controls, reactive specifically to the insulin secretory enriched fraction (ISG) of a rat insulinoma RIN cell line. This finding is suggestive of an in vivo priming by the antigen(s). To examine the relevance of these T cell clones in the pathogenesis of IDDM, we studied their cytokine profile. T cell clones from the newly onset patients had a Th1 cytokine profile, while those from the prediabetic patient were of the Th2 subtype. This segregation suggests that RIN-ISG contains antigen(s) involved in the pathogenesis of this disease, since IDDM is considered a cell-mediated or Th1 disease. Since two of these clones also responded to a hamster insulinoma cell line HIT, at least two antigens in RIN-ISG could be defined by this panel of T cell clones. Examination of CDR3 sequences confirmed the clonality of the dual-reactive T cell clones. The finding of HIT-reactive cells in IDDM patients may be useful in efforts to identify prediabetic patients for immune intervention. Dual reactivity may provide a better prognosis than single reactivity. In contrast to T cell clones reactive to insulinomas, T cell clones reactive to normal human ISG were not found after over 200 clones were screened. In addition, RIN-ISG specific clones did not respond to either normal human or rat ISG, suggesting that IDDM antigens are below detectable levels in normal beta cells.

Amino Acid Sequence↗
PubMed1995

Autoproliferation in HIV-1-infected patients undergoing active HIV-1-specific immunotherapy.

We have observed a treatment-associated autoproliferative response in cultured peripheral blood mononuclear cells (PBMC) of asymptomatic HIV-1-infected subjects receiving a gp120-depleted, inactivated HIV-1 antigen in incomplete Freund's adjuvant (IFA; HIV-1 Immunogen). The frequency and magnitude of the autoproliferative response appeared to be dose-related (P < 0.05), and was not observed in subjects receiving IFA alone. Immunophenotyping of the proliferating cells demonstrated the presence of both CD4+ and CD8+ lymphocytes, with the CD4+ blasts almost exclusively expressing the CD45RO+ phenotype. A comparison of this response with the HIV-1-specific antigen stimulation responses in this cohort revealed a significant correlation between increases in HIV-1-specific cell-mediated immunity and autoproliferation (r2 = 0.61, P < 0.001). These findings suggest that immunization with the HIV-1 Immunogen induces an autoproliferative response that may reflect changes in HIV-1-specific cell-mediated immunity in infected individuals.

AIDS Vaccines↗
PubMed1995

Viral load in peripheral blood mononuclear cells as surrogate for clinical progression.

During the symposium on surrogate markers of HIV, the Scientific Advisory Committee posed the following question: "Which surrogate markers currently deserve the greatest commitment of investigative resources to validate them in a clinical setting?" The Committee concluded that for antiretroviral drugs measurements of HIV RNA in plasma deserve the greatest priority, and for immune-based therapies assessing viral load still had the highest priority. But it was recognized that assessing viral load should not be restricted to plasma RNA because the primary mechanisms of action are different from antiretroviral drugs. Thus, the Committee voted that based on current knowledge, investigating the clinical relevance of changes in HIV-1 DNA and RNA copy number in peripheral blood mononuclear cells (PBMCs) with validated assays should be given equal focus for immune-based therapies. This article reviews the rationale for using HIV-1 DNA and RNA load in PBMCs for the monitoring of clinical trials and presents recent data that indicate that the postseroconversion level and the dissemination of proviral DNA in the blood cells have prognostic value, i.e., high levels correlate with disease progression. In addition, longitudinal studies show that an increase in proviral DNA and/or HIV mRNA load correlates with disease progression. We present evidence that these markers are relevant activity markers for anti-HIV therapies. Changes in both DNA and RNA load can be achieved using either antiretroviral drugs or immune-based therapies. These results suggest that these markers should be evaluated in clinical studies to firmly establish their value as surrogates of clinical progression.

Biomarkers↗
PubMed1995

Safety and immunogenicity of a gp120-depleted, inactivated HIV-1 immunogen: results of a double-blind, adjuvant controlled trial.

We report the safety and immunogenicity results of a double-blind adjuvant controlled trial of the human immunodeficiency virus type 1 (HIV-1) immunogen. Healthy, asymptomatic HIV-1-seropositive individuals received either three 100 microgram doses of the inactivated HIV-1 antigen in incomplete Freund's adjuvant (IFA) or three doses of IFA alone. The results of this study show that this HIV-1 immunogen is safe, with mild and transient adverse events. No difference in the number or type of adverse events was noted between the treatment groups. Rises in HIV-1-specific humoral and cell-mediated immune (CMI) responses were also noted, favoring the HIV-1 immunogen-treated group. The results of this study confirm and extend the safety and immunogenicity profile of this HIV-1 immunotherapeutic agent. The observation that this treatment can augment HIV-1-specific CMI is encouraging because this immunological marker may represent a key surrogate end point in HIV-1 infection and disease.

AIDS Vaccines↗
PubMed1994

CD8+ T cells in psoriatic lesions preferentially use T-cell receptor V beta 3 and/or V beta 13.1 genes.

Psoriasis is an inflammatory skin disorder characterized by epidermal keratinocyte hyperproliferation in association with a cellular infiltrate. There is evidence that activated T cells play a role in psoriatic plaque formation. We examined the T-cell receptor beta-chain variable gene segment (V beta) use of epidermal T cells in shave biopsies of psoriatic lesions. Our results show increased expression of V beta 3 and/or V beta 13.1 messages in the CD8+, but not CD4+, T cells in the lesions of a majority of patients studied. Sequence analysis of complementarity-determining region 3 (CDR3) of these two V beta genes from the skin demonstrated monoclonality or marked oligoclonality. A second biopsy from the same or different lesions, performed 3.5-8 months later in four patients, again revealed increased V beta 3 and/or V beta 13.1 expression and clonality. Moreover, in three of the four patients, the same V beta CDR3 rearrangement was found in both biopsies, although there was no V beta CDR3 homology between patients. In two patients in which V beta 3 and/or V beta 13.1 was not increased, an increase in V beta 17 gene use and clonality was found. The clonality of V beta sequence data indicates these cells are recruited and expanded in situ. The persistence of V beta 3-and/or V beta 13.1-bearing CD8+ T cells in lesions that did not undergo resolution suggests their role as effector cells rather than as regulatory cells.

Adult↗
PubMed1994

Effect of immunization with inactivated gp120-depleted human immunodeficiency virus type 1 (HIV-1) immunogen on HIV-1 immunity, viral DNA, and percentage of CD4 cells.

A 1-year study measured the effect of administration of an inactivated human immunodeficiency virus type 1 (HIV-1) immunogen in incomplete Freund's adjuvant (IFA) on HIV-1-specific immunity and viral burden in asymptomatic HIV-1-infected patients. A total of 103 patients were enrolled in this double-blind, randomized study comparing immunogen in adjuvant with adjuvant alone. This study was conducted at nine medical centers throughout the United States. Significant differences in cell-mediated immune responses to HIV-1 and p24 core antigen were observed between the treated and control groups (P < .01). Compared with controls, treated patients as a group had a significantly lower rate of increase in viral DNA as determined by quantitative HIV-1 DNA-polymerase chain reaction (P = .016). Significant differences in the rate of percent CD4 cell decline were also observed between the 2 groups (P = .024). These data suggest that augmentation of HIV-1-specific immunity via immunotherapy may alter the rate of increase of HIV-1 DNA in peripheral blood mononuclear cells and stabilize the percent of CD4 cell decline in relatively healthy HIV-1-infected persons.

AIDS Vaccines↗
PubMed1994

HIV-1 immunogen induction of HIV-1-specific delayed-type hypersensitivity: results of a double-blind, adjuvant-controlled, dose-ranging trial.

OBJECTIVE: To investigate the capacity of an HIV-1 immunogen to induce or augment HIV-1-specific delayed-type hypersensitivity (DTH) over a range of doses in asymptomatic HIV-1-seropositive adults. DESIGN: A single center, double-blind, adjuvant-controlled, dose-ranging trial involving 48 HIV-1-seropositive asymptomatic patients. Each dose group consisted of 12 subjects, eight receiving HIV-1 immunogen and four incomplete Freund's adjuvant (IFA). The doses studied were 50, 100, 200, or 400 micrograms (total protein). The HIV-1 immunogen was administered intramuscularly every 4 weeks for 36 weeks, with dosing contingent on the lack of an HIV-1 immunogen DTH response. A maximum of six doses was permitted. METHODS: Immunogenicity was assessed every 4 weeks by DTH skin testing to the inactivated HIV-1 antigen in saline with > 9 mm induration representing a response to immunization. Changes in p24-antibody levels were determined by endpoint titration using an enzyme-linked immunosorbent assay and Western blot. RESULTS: At doses of > or = 100 micrograms, all treated patients demonstrated significant differences in the ability to mount an HIV-1-specific cell-mediated response relative to adjuvant controls. Dose-related response patterns were observed in the period between doses and the occurrence of rises in HIV-1 DTH. Treatment appeared to increase p24-antibody titers as well as reactivities to other HIV-1 antigens as determined by Western blots. The HIV-1 immunogen was well tolerated. CONCLUSIONS: The minimum dose of the HIV-1 immunogen in IFA required to induce HIV-1 DTH relative to the IFA control group was 100 micrograms in this patient population.

Adult↗
PubMed1994

Inactivated HIV-1 Immunogen: impact on markers of disease progression.

The pursuit of valid markers of disease progression in human immunodeficiency virus type 1 (HIV-1) infection is especially relevant considering the potential treatment alternatives that presently are under evaluation. Because HIV-1 infection results in a virally induced immune suppression characterized by the loss of cell-mediated immunity (CMI), depletion of CD4+ cells, loss of core antibody, and an increase in viral burden, these markers seemed to be appropriate to monitor in a controlled study. We monitored a number of virologic, immunologic, and cytologic markers of disease progression in 103 subjects who were enrolled in a 12-month, double-blind, randomized, adjuvant-controlled study of the HIV-1 inactivated Immunogen. The markers included HIV-1 DNA, HIV-1 RNA, CD4 percent, p24 antibody, and lymphocyte proliferation. Analysis of HIV-1 DNA with a quantitatively polymerase chain reaction (PCR) assay indicated a treatment effect on viral burden in the HIV-1 Immunogen-treated group. Analysis of HIV-1 RNA revealed a similar trend favoring the Immunogen-treated group. In addition, a significant effect was shown on CD4 percent and CMI in the Immunogen-treated group. An analysis of CMI that used stimulation indices underrepresented the immunogenicity of the Immunogen. Further examination revealed that the lymphocytes of the HIV-1 Immunogen-treated patients were proliferating in vitro without exogenous antigen. Although the clinical significance of this phenomenon currently is unknown, it may be a relevant prognostic marker for assessment of HIV-1 therapy. The data presented here support the concept that immunotherapy with the HIV-1 Immunogen may slow disease progression.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS Vaccines↗
PubMed1993

Development and validation of a polymerase chain reaction method for the precise quantitation of HIV-1 DNA in blood cells from subjects undergoing a 1-year immunotherapeutic treatment.

OBJECTIVE: To validate a quantitative polymerase chain reaction method developed to measure HIV-1 DNA in peripheral blood mononuclear cells. DESIGN: The assay was used to measure HIV-1 DNA in 15 consecutive blood samples taken from subjects enrolled in a multicenter, randomly allocated, double-blind, placebo-controlled trial using an HIV-1 immunogen. The assay was validated following the United States Pharmacopeia guidelines. The analytical parameters assessed were sensitivity, specificity, linearity and precision. METHODS: The quantitative analysis was obtained by (1) co-amplifying HIV-1 DNA targets with an endogenous control (globin); (2) extrapolating the target values using HIV-1 and globin standard curves; and (3) normalizing the HIV-1 copy numbers to the globin copy numbers (genomic DNA load). RESULTS: With United States Pharmacopeia assay validation methodology, the HIV-1 DNA polymerase chain reaction assay proved to be sensitive, specific, linear and precise and the evaluation of the relative difference between two consecutive blood samples was reproducible. The intra-assay variability, which examines the reproducibility of replicates, was determined using a conservative assessment (tolerance intervals). We established that an increase of 60% or more in the number of DNA copies or a decrease of 38% or more was significantly greater than the variation due to random or experimental error and therefore attributed this variability to a significant change in the HIV-1 DNA copy number. CONCLUSION: We developed and validated a polymerase chain reaction method for the precise quantitation of HIV-1 DNA in peripheral blood mononuclear cells. This assay was able to detect changes in viral loads in HIV-1-infected asymptomatic subjects enrolled in a double-blind placebo-controlled trial using an HIV-1 immunogen.

Biomarkers↗
PubMed1993

T cell receptor V beta repertoire in HIV-infection individuals: lack of evidence for selective V beta deletion.

The gradual decline of CD4+ T lymphocytes in HIV-infected individuals culminates in the lethal immunosuppression of AIDS. The mechanism of CD4+ T cell loss is currently unknown, but has recently been suggested to occur as a result of an HIV-encoded superantigen which facilitates a selective deletion of T cells expressing specific V beta genes. To verify and extend such observations, peripheral blood leucocytes (PBL) from 15 HIV+ individuals, 10 of which had very low CD4 T cell counts (< 200/mm3), were analysed for T cell receptor (TCR) V beta gene expression. In contrast to a recent study, the results presented here fail to provide evidence that selective loss of V beta-bearing T cells occurs in HIV+ individuals. Furthermore, when PBL from HIV+ individuals were stimulated with Staphylococcal enterotoxin B (SEB), T cells expressing V beta subfamilies known to engage this superantigen were expanded, indicating that such cells were not deleted and were responsive to stimulation by a bacterial superantigen. Collectively, these data suggest that CD4 loss in HIV patients does not occur in a V beta-selective, superantigen-mediated fashion.

Base Sequence↗
PubMed1993

Cell-mediated immunity to HIV-1 in Walter Reed stages 1-6 individuals: correlation with virus burden.

Cell-mediated immunity (CMI) to human immunodeficiency virus-1 (HIV-1) was assessed in a blinded fashion for a patient group (n = 79) representing Walter Reed (WR) stages 1-6. At the same time, viral load was quantitatively measured by two different methods, specifically, virus isolation and HIV viral DNA copy number as measured by the polymerase chain reaction (PCR). After unblinding it was determined that the ability to generate a lymphoproliferative response to an inactivated gp120-depleted HIV (HIV-ag) and tetanus toxoid diminished with advancing WR staging, with complete anergy to HIV-ag and tetanus at stage 6. As a group, individuals whose peripheral blood mononuclear cells (PBMC) proliferated to HIV-ag were either virus isolation negative or produced low levels of virus as measured by p24 antigen (< 250 pg p24) on day 7. Similarly, HIV DNA copy number in the HIV-ag responders was low (< 200 copies/4 x 10(5) PBMC). In contrast, antigen proliferation to tetanus toxoid did not correlate with virus load. Thus, clinical progression as defined by the WR staging system appears to coincide with a loss of CMI to HIV. More importantly, the low viral load measured in HIV-ag responders suggests a link between viral burden and CMI to HIV which might be exploited in the design of immunotherapies for HIV-infected individuals.

Cell Division↗
PubMed1992

Quantitation of HIV viral burden by PCR in HIV seropositive Navy personnel representing Walter Reed stages 1 to 6.

To quantitate the amount of human immunodeficiency virus type 1 (HIV-1) DNA in peripheral blood mononuclear cells (PBMC) of 78 infected individuals, we have developed a polymerase chain reaction (PCR) assay that is both quantitative and sensitive. Quantitation was based on incorporation of a 32P end-labelled primer (SK39) in the PCR reaction and on comparison after electrophoresis with known amounts of HIV DNA. A linear relationship was obtained between the natural logarithms of the radioactive counts detected and the number of HIV-1 DNA copies (10-1000 copies) from the standard DNA. HIV copy numbers from patient samples were then extrapolated from the standard curves. This sensitive and reproducible method was compared with virus isolation which is a semiquantitative evaluation of viral burden. HIV DNA levels correlated with virus isolation, i.e., high viral burden (100-1000 HIV copies) were found in most samples from which virus was isolated after only 7 days in culture; low viral burden (less than 100 HIV copies) was observed in samples from which virus was isolated after 14 to 21 days in culture. These estimates of viral burden were then compared with the clinical stage of the individuals.

DNA, Viral↗
PubMed1991

Limited T-cell receptor beta-chain heterogeneity among interleukin 2 receptor-positive synovial T cells suggests a role for superantigen in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a disease affecting the synovial membranes of articulating joints that is thought to result from T-cell-mediated autoimmune phenomena. T cells responsible for the pathogenesis of RA are likely present in that fraction of synovial T cells that expresses the interleukin 2 receptor (IL-2R), one marker of T-cell activation. We report herein an analysis of T-cell receptor (TCR) beta-chain gene expression by IL-2R-positive synovial T cells. These T cells were isolated from uncultured synovial tissue specimens by using IL-2R-specific monoclonal antibodies and magnetic beads, and TCR beta-chain transcription was analyzed by PCR-catalyzed amplification using a panel of primers specific for the human TCR beta-chain variable region (V beta). Multiple V beta gene families were found to be transcribed in these patients samples; however, three gene families, V beta 3, V beta 14, and V beta 17, were found in a majority of the five synovial samples analyzed, suggesting that T cells bearing these V beta s had been selectively retained in the synovial microenvironment. In many instances, the V beta 3, V beta 14, or V beta 17 repertoires amplified from an individual patient were dominated by a single rearrangement, indicative of clonal expansion in the synovium and supportive of a role for these T cells in RA. Of note is a high sequence similarity between V beta 3, V beta 14, and V beta 17 polypeptides, particularly in the fourth complementarity-determining region (CDR). Given that binding sites for superantigens have been mapped to the CDR4s of TCR beta chains, the synovial localization of T cells bearing V beta s with significant CDR4 homology indicates that V beta-specific T-cell activation by superantigen may play a role in RA.

Alleles↗