Predictors of HIV-specific lymphocyte proliferative immune responses induced by therapeutic vaccination.

We treated a cohort of 38 HIV-infected individuals with a therapeutic vaccine (REMUNE, HIV-1 Immunogen) in an open label study. We then determined whether baseline parameters, such as CD4 cell count, viral load and IgG levels, were predictive of the magnitude of the HIV-specific lymphocyte proliferative responses (LPRs). We demonstrate herein that there is a significant enhancement from baseline for both HIV and p24 antigen-stimulated LPRs after immunization. Using a responder definition of a stimulation index of >5 on at least two post-immunization time-points, 29/38 (76%) responded to HIV-1 antigen while 27/38 (71%) responded to native p24 antigen. Viral load and total IgG were negatively correlated, while CD4 cell counts were positively associated with the magnitude of the HIV antigen LPR. In a multivariable analysis, baseline CD4 was the best predictor of HIV antigen LPR post-immunization.

Vaccination with a CDR2 BV6S2/6S5 peptide in adjuvant induces peptide-specific T-cell responses in patients with multiple sclerosis.

Earlier studies from several groups including ours have documented that patients with multiple sclerosis (MS) have over-expression of activated T-cells from specific TCR V beta families, including BV6S2/S5 (Kotzin et al. [1991] Proc. Natl. Acad. Sci. USA 88:9161--9165; Gold et al. [1997] J. Neuroimmunol. 76:29--38). It has also been established in the rat EAE model that peptide vaccines to the over-expressed V beta 8.2 TCR can prevent MBP induced disease (Vandenbark et al. [1989] Nature 341:541--544). In the current clinical study, 10 patients were vaccinated with 300 microg of BV6S2/6S5 peptide emulsified in incomplete Freund's adjuvant (IFA) and monitored for safety and immunogenicity in a 48-week multicenter, open-label trial. The peptide vaccine was well tolerated and no serious adverse events were observed. Vaccinations induced cell-mediated immunity to the immunizing peptide in eight of 10 patients as demonstrated by lymphocyte proliferation assay (LPA) and delayed-type hypersensitivity (DTH) skin test responses. In summary, these results demonstrate that immunization with TCR BV6S2/6S5 peptide vaccine in MS patients is safe and immunogenic, and supports a larger double-blind placebo controlled trial to determine the clinical efficacy of this approach.

Human immunodeficiency virus (HIV)-specific immune responses are generated with the simultaneous vaccination of a gp120-depleted, whole-killed HIV-1 immunogen with cytosine-phosphorothioate-guanine dinucleotide immunostimulatory sequences of DNA.

OBJECTIVES: We compared the effect of priming with a synthetic oligodeoxynucleotide (ODN) immunostimulatory DNA sequence followed by vaccination with human immunodeficiency virus type 1 (HIV-1) in incomplete Freund's adjuvant (IFA) or HIV-1 antigen alone to the simultaneous administration of immunostimulatory sequences (ISS) with HIV-1 in IFA. METHODS: We examined immune function involving interferon-gamma (IFN-gamma) production, RANTES (regulated upon activation, normal T cell expressed and secreted) production, and lymphocyte proliferation, all of which appear to be augmented in HIV-1-exposed, but uninfected, individuals. RESULTS: We demonstrate that similar levels of antigen-specific IFN-gamma were produced from lymph node cells of the animals immunized with HIV-1 antigen in IFA containing the CpG ODN 1826 (ISS; mean +/- SE = 450.8 +/- 224.3 pg/mL) and the group of animals primed with the ODN before injection with the HIV-1 in IFA (mean +/- SE = 377.7 +/- 294.8 pg/mL) or HIV-1 antigen alone (IFN-gamma = 0 pg/mL). However, the group that received the HIV-1 in IFA plus ISS mounted a stronger lymphocyte proliferation (mean net +/- SE = 29,180 +/- 1,932 cpm) compared to the group primed with the ODN before injection with HIV-1 in IFA (mean net +/- SE = 8,575 +/- 2,978 cpm). Furthermore, the group that received the HIV-1 in IFA plus ISS also mounted stronger beta-chemokine production measured as RANTES (mean +/- SE = 1,217 +/- 267.4 pg/mL) compared to the group that received the ODN before injection with HIV-1 in IFA (mean +/- SE = 129.1 +/- 48.5 pg/mL). Antibody responses from the group that received the HIV-1 in IFA plus ISS also showed a higher p24-specific response that was predominantly of the immunoglobulin G IgG2b isotype. CONCLUSION: These results suggest that the simultaneous administration of the ISS in the HIV-1 in IFA emulsion may be a condidate for testing in non-human primates and in human studies as a therapeutic and preventative vaccine.

CXCR4 and CCR5 expression on CD4+ T cells in vivo and HIV-1 antigen beta-chemokine production in vitro after treatment with HIV-1 immunogen (REMUNE).

BACKGROUND: The chemokine receptors CXCR4 and CCR5 have been identified as the major coreceptors for HIV-1 on CD4+ cells and macrophages. The natural ligands for these receptors are SDF-1 and the beta-chemokines (MIP-1alpha, MIP-1beta, RANTES), respectively, and are the products of a variety of immune cells, including CD8+ T lymphocytes. STUDY DESIGN/METHODS: We hypothesized that the ability to stimulate the natural ligands for these receptors using an immune based therapy might influence in vivo chemokine receptor expression. RESULTS: In vivo CXCR4 expression remained stable after treatment with an HIV-1 Immunogen (REMUNE), whereas CCR5 expression on CD4+ T cells decreased (p < .05). Furthermore, HIV-1 antigen-specific production of beta-chemokines in vitro was also augmented (P < .05). CONCLUSIONS: These preliminary results suggest that this HIV-1-specific immune-based therapy can stimulate antigen-specific beta-chemokine production in vitro and downregulate CCR5 receptor expression on CD4 cells in vivo.

HIV-Specific CD4(+) and CD8(+) immune responses are generated with a gp120-depleted, whole-killed HIV-1 immunogen with CpG immunostimulatory sequences of DNA.

We examined the adjuvant effects of a synthetic CpG oligodeoxynucleotide immunostimulatory sequence (ISS) using a whole-killed, gp120-depleted HIV antigen (HIV-1 antigen) in a Lewis rat model. We hypothesized that HIV-1-specific CD4(+) T helper (Th) immune responses could be enhanced when an ISS was combined with an HIV-1 antigen in incomplete Freund's adjuvant (IFA). We also reasoned that if such Th responses were sufficient, such a combination might also induce HIV-specific CD8(+) T cell immune responses. Here we demonstrate that the HIV-1 antigen in IFA combined with ISS stimulates both CD4(+) and CD8(+) HIV-specific immune responses as measured by interferon-gamma (IFN-gamma) in the ELISPOT assay. A strong correlation between these CD4(+) and CD8(+) responses was demonstrated. Furthermore, we found that the HIV-1 antigen in IFA with ISS as an adjuvant stimulated strong antibody responses to core antigen (p24). These studies suggest that the combination of the whole-killed, gp120-depleted HIV-1 antigen in IFA with ISS may be an ideal candidate to test in nonhuman primates and in human studies as a preventive HIV-1 vaccine.

In vitro immune function after vaccination with an inactivated, gp120-depleted HIV-1 antigen with immunostimulatory oligodeoxynucleotides.

We examined the effect of a synthetic oligodeoxynucleotide containing unmethylated CpG immunostimulatory sequences (ISS) as an adjuvant for an HIV-1 immunogen (inactivated, gp120-depleted HIV-1 virus particles). The addition of the ISS to HIV-1 in incomplete Freund's adjuvant (IFA) was the optimal combination for the production of HIV-1-specific immune responses as measured by IFN-gamma (p=0.002) and IgG antibody production. Furthermore, the group that was immunized with HIV/IFA/ISS, as well as the group that received HIV-1 in complete Freund's adjuvant (CFA), stimulated significantly more RANTES (a beta-chemokine) (p=0.002) production from lymph node cells. These results suggest that the addition of CpG immunostimulatory sequences to HIV antigens in IFA may optimize HIV-1-specific immune responses and provides further rationale for the testing of ISS in combination with gp120-depleted whole-killed HIV-1 in IFA as a potential preventive or therapeutic HIV-1 vaccine.

T cell receptor peptide vaccination in rheumatoid arthritis: a placebo-controlled trial using a combination of Vbeta3, Vbeta14, and Vbeta17 peptides.

OBJECTIVE: Restricted T cell receptor (TCR) gene usage has been demonstrated in animal models of autoimmune disease and has resulted in the successful use of TCR peptide therapy in animal studies. This clinical trial was undertaken to determine the safety and efficacy of a combination of Vbeta3, Vbeta14, and Vbeta17 TCR peptides in Freund's incomplete adjuvant (IFA) in patients with rheumatoid arthritis (RA). METHODS: A double-blind, placebo-controlled, multicenter, phase II clinical trial was undertaken using IR501 therapeutic vaccine, which consists of a combination of 3 peptides derived from TCRs (Vbeta3, Vbeta14, and Vbeta17) in IFA. A total of 99 patients with active RA received either 90 microg (n = 31) or 300 microg (n = 35) of IR501 or IFA alone (n = 33) as a control. The study medication and placebo were administered as a single intramuscular injection (1 ml) at weeks 0, 4, 8, and 20. RESULTS: Treatment with IR501 was safe and well tolerated. None of the patients discontinued the trial because of treatment-related adverse events. Efficacy was measured according to the American College of Rheumatology 20% improvement criteria. Using these criteria, patients in both IR501 dosage groups showed improvement in disease activity. In the most conservative analysis used to evaluate efficacy, an intent-to-treat analysis including all patients who enrolled, the 90-microg dosage group showed a statistically significant improvement compared with control patients at the 20-week time point after the third injection. Trends toward improvement were shown in both the 90-microg and the 300-microg dosage groups at week 24 after the fourth injection. CONCLUSION: IR501 therapeutic vaccine therapy was safe and well tolerated, immunogenic, and demonstrated clinical improvement in RA patients. Additional clinical trials are planned to confirm and extend these observations.

Results of a phase I clinical trial of a T-cell receptor vaccine in patients with multiple sclerosis. II. Comparative analysis of TCR utilization in CSF T-cell populations before and after vaccination with a TCRV beta 6 CDR2 peptide.

We report here the results of a phase I trial of a T-cell receptor (TCR) V beta 6 CDR2 region peptide vaccine in 10 patients with multiple sclerosis who showed biased over-representations of V beta 6 mRNA among T-cells in their cerebrospinal fluids (CSF). One group of 5 patients was immunized twice during a four week period with 100 micrograms of the TCRV beta 6 peptide 39-LGQGPEF LTYFQNEAQLEKS-58 emulsified in incomplete Freund's adjuvant (IFA); the second group of 5 MS patients received 300 micrograms of the same peptide in IFA over a similar time period. Patients were monitored for adverse events, immunogenicity of the peptide and changes in their CSF T-cell populations. The results indicate that this peptide was immunogenic (T-cell proliferation assays and recall DTH responses) in some of the patients, although none of the immunized patients produced detectable anti-peptide antibodies. More importantly, we show that the 5 patients treated with higher doses of the vaccine displayed a slight decrease in CSF cellularity, a lack of growth of CSF cells in cytokine supplemented expansion cultures that implies a significant absence of a subset of activated CD4 T-cells and a marked diminution in V beta 6 mRNA levels among T-cells in these cultures. By comparison, in 5 patients receiving the lower dosage of the vaccine, CSF cellularity was the same or slightly increased over pre-vaccination levels, CSF cells from 1 patient failed to grow in expansion cultures and cultured CSF cells from 2 patients underwent a change from an oligoclonal V beta 6 pattern to one that was more polyclonal. These results justify a more through exploration of the use of TCR peptide vaccines as a possible therapeutic treatment for MS.

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.

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.