Maintenance Olaparib for Germline BRCA-Mutated Metastatic Pancreatic Cancer.

BACKGROUND: Patients with a germline BRCA1 or BRCA2 mutation make up a small subgroup of those with metastatic pancreatic cancer. The poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor olaparib has had antitumor activity in this population. METHODS: We conducted a randomized, double-blind, placebo-controlled, phase 3 trial to evaluate the efficacy of olaparib as maintenance therapy in patients who had a germline BRCA1 or BRCA2 mutation and metastatic pancreatic cancer and disease that had not progressed during first-line platinum-based chemotherapy. Patients were randomly assigned, in a 3:2 ratio, to receive maintenance olaparib tablets (300 mg twice daily) or placebo. The primary end point was progression-free survival, which was assessed by blinded independent central review. RESULTS: Of the 3315 patients who underwent screening, 154 underwent randomization and were assigned to a trial intervention (92 to receive olaparib and 62 to receive placebo). The median progression-free survival was significantly longer in the olaparib group than in the placebo group (7.4 months vs. 3.8 months; hazard ratio for disease progression or death, 0.53; 95% confidence interval [CI], 0.35 to 0.82; P = 0.004). An interim analysis of overall survival, at a data maturity of 46%, showed no difference between the olaparib and placebo groups (median, 18.9 months vs. 18.1 months; hazard ratio for death, 0.91; 95% CI, 0.56 to 1.46; P = 0.68). There was no significant between-group difference in health-related quality of life, as indicated by the overall change from baseline in the global quality-of-life score (on a 100-point scale, with higher scores indicating better quality of life) based on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (between-group difference, -2.47 points; 95% CI, -7.27 to 2.33). The incidence of grade 3 or higher adverse events was 40% in the olaparib group and 23% in the placebo group (between-group difference, 16 percentage points; 95% CI, -0.02 to 31); 5% and 2% of the patients, respectively, discontinued the trial intervention because of an adverse event. CONCLUSIONS: Among patients with a germline BRCA mutation and metastatic pancreatic cancer, progression-free survival was longer with maintenance olaparib than with placebo. (Funded by AstraZeneca and others; POLO ClinicalTrials.gov number, NCT02184195.).

Adoptive transfer of costimulated CD4+ T cells induces expansion of peripheral T cells and decreased CCR5 expression in HIV infection.

To study the safety and feasibility of T-cell reconstitution in HIV-infected individuals, we adoptively transferred activated autologous CD4+ T cells. Polyclonal peripheral blood CD4+ cells were costimulated ex vivo and subjects were given infusions of up to 3 x 1010 activated CD4+ cells. Dose-dependent increases in CD4+ cell counts and in the CD4:CD8 ratio were observed. Sustained increases in the fraction of cytokine-secreting T cells and decreases in the percentage of CD4+CCR5+ cells were noted in vivo, suggesting enhanced function and resistance to HIV infection. The frequency of CD4+Ki-67+ cells increased whereas CD4+ T cells containing T cell-receptor rearrangement excision circles (TRECs) decreased. These findings indicate that expansion of the peripheral T-cell pool mediated the increase in CD4 counts and suggest that approaches to reconstitute CD4 helper cell activity and decrease CCR5 expression may augment natural immunity to HIV infection.

Development and Characterization of a Novel Non-Lytic Cancer Immunotherapy Using a Recombinant Arenavirus Vector Platform.

Engineered viral vectors represent a promising strategy to trigger antigen-specific antitumor T cell responses. Arenaviruses have been widely studied because of their ability to elicit potent and protective T cell responses. Here, we provide an overview of a novel intravenously administered, replication-competent, non-lytic arenavirus-based vector technology that delivers tumor antigens to induce antigen-specific anti-cancer T cell responses. Preclinical studies in mice and cell culture experiments with human peripheral blood mononuclear cells demonstrate that arenavirus vectors preferentially infect antigen-presenting cells. This, in conjunction with a non-lytic functional activation of the infected antigen-presenting cells, leads to a robust antigen-specific CD8+ T cell response. T cell migration to, and infiltration of, the tumor microenvironment has been demonstrated in various preclinical tumor models with vectors encoding self- and non-self-antigens. The available data also suggest that arenavirus-based vector therapy can induce immunological memory protecting from tumor rechallenge. Based on promising preclinical data, a phase 1/2 clinical trial was initiated and is currently ongoing to test the activity and safety of arenavirus vectors, HB-201 and HB-202, created using lymphocytic choriomeningitis virus and Pichinde virus, respectively. Both vectors have been engineered to deliver non-oncogenic versions of the human papilloma virus 16 (HPV16) antigens E7 and E6 and will be injected intravenously with or without an initial intratumoral dose. This dose escalation/expansion study is being conducted in patients with recurrent or metastatic HPV16+ cancers. Promising preliminary data from this ongoing clinical study have been reported. Immunogenicity data from several patients demonstrate that a single injection of HB-201 or HB-202 monotherapy is highly immunogenic, as evidenced by an increase in inflammatory cytokines/chemokines and the expansion of antigen-specific CD8+ T cell responses. This response can be further enhanced by alternating injections of HB-202 and HB-201, which has resulted in frequencies of circulating HPV16 E7/E6-specific CD8+ T cells of up to 40% of the total CD8+ T cell compartment in peripheral blood in analyses to date. Treatment with intravenous administration also resulted in a disease control rate of 73% among 11 evaluable patients with head and neck cancer dosed every three weeks, including 2 patients with a partial response.

Intratumoral T cells, recurrence, and survival in epithelial ovarian cancer.

BACKGROUND: Although tumor-infiltrating T cells have been documented in ovarian carcinoma, a clear association with clinical outcome has not been established. METHODS: We performed immunohistochemical analysis of 186 frozen specimens from advanced-stage ovarian carcinomas to assess the distribution of tumor-infiltrating T cells and conducted outcome analyses. Molecular analyses were performed in some tumors by real-time polymerase chain reaction. RESULTS: CD3+ tumor-infiltrating T cells were detected within tumor-cell islets (intratumoral T cells) in 102 of the 186 tumors (54.8 percent); they were undetectable in 72 tumors (38.7 percent); the remaining 12 tumors (6.5 percent) could not be evaluated. There were significant differences in the distributions of progression-free survival and overall survival according to the presence or absence of intratumoral T cells (P<0.001 for both comparisons). The five-year overall survival rate was 38.0 percent among patients whose tumors contained T cells and 4.5 percent among patients whose tumors contained no T cells in islets. Significant differences in the distributions of progression-free survival and overall survival according to the presence or absence of intratumoral T cells (P<0.001 for both comparisons) were also seen among 74 patients with a complete clinical response after debulking and platinum-based chemotherapy: the five-year overall survival rate was 73.9 percent among patients whose tumors contained T cells and 11.9 percent among patients whose tumors contained no T cells in islets. The presence of intratumoral T cells independently correlated with delayed recurrence or delayed death in multivariate analysis and was associated with increased expression of interferon-gamma, interleukin-2, and lymphocyte-attracting chemokines within the tumor. The absence of intratumoral T cells was associated with increased levels of vascular endothelial growth factor. CONCLUSIONS: The presence of intratumoral T cells correlates with improved clinical outcome in advanced ovarian carcinoma.

Safety and immunogenicity profile of the concomitant administration of ZOSTAVAX and inactivated influenza vaccine in adults aged 50 and older.

OBJECTIVES: To evaluate the safety and immunogenicity of ZOSTAVAX administered concomitantly with inactivated influenza vaccine or sequentially in adults aged 50 and older. DESIGN: Randomized, blinded, placebo-controlled study. SETTING: Thirteen U.S. and seven European study sites. PARTICIPANTS: Three hundred eighty-two concomitantly, 380 sequentially vaccinated subjects. INTERVENTION: The concomitant vaccination group received influenza vaccine and ZOSTAVAX at separate injection sites on Day 1 and placebo at Week 4. The nonconcomitant vaccination group received influenza vaccine and placebo at separate injection sites on Day 1 and ZOSTAVAX at Week 4. MEASUREMENTS: Primary safety endpoints: vaccine-related serious adverse experiences (AEs) within 28 days postvaccination (PV); and diary card-prompted local and systemic AEs. Primary immunogenicity endpoints: geometric mean titer (GMT) and geometric mean fold rise (GMFR) from baseline of varicella-zoster virus (VZV) antibody (Ab) at 4 weeks PV according to glycoprotein enzyme-linked immunosorbent assay (gpELISA) and GMT of influenza Ab for the three vaccine strains (2005-2006 influenza season) at 4 weeks PV according to hemagglutination inhibition assay. Secondary immunogenicity endpoint: influenza seroconversion rates (SCRs). RESULTS: No serious AEs related to ZOSTAVAX were observed during the study. VZV Ab GMTs 4 weeks PV for the concomitant and sequential groups were 554 and 597 gpELISA U/mL, respectively. The estimated VZV Ab GMT ratio was 0.9 (95% confidence interval (CI)=0.8-1.0), indicating noninferior (P<.001 for the null hypothesis of GMT ratio <0.67) responses. Estimated VZV Ab GMFR from baseline in the concomitant group was 2.1 (95% CI=2.0-2.3), indicating acceptable fold rise. Estimated GMT ratios (concomitant/sequential) for influenza strains A(H1N1), A(H3N2), and B were 0.9 (95% CI=0.8-1.1), 1.1 (95% CI=0.9-1.3), and 0.9 (95% CI=0.8-1.1), respectively, and SCRs were comparable across both groups, with more than 85% achieving titers of 1:40 or greater, meeting regulatory criteria. CONCLUSION: ZOSTAVAX and influenza vaccine given concomitantly are generally well tolerated in adults aged 50 and older. Ab responses were similar whether ZOSTAVAX and influenza vaccine were given concomitantly or sequentially.

Ex vivo expansion of polyclonal and antigen-specific cytotoxic T lymphocytes by artificial APCs expressing ligands for the T-cell receptor, CD28 and 4-1BB.

The ex vivo priming and expansion of human cytotoxic T lymphocytes (CTLs) has potential for use in immunotherapy applications for cancer and infectious diseases. To overcome the difficulty in obtaining sufficient numbers of CTLs, we have developed artificial antigen-presenting cells (aAPCs) expressing ligands for the T-cell receptor (TCR) and the CD28 and 4-1BB co-stimulatory surface molecules. These aAPCs reproducibly activate and rapidly expand polyclonal or antigen-specific CD8(+) T cells. The starting repertoire of CD8+ T cells was preserved during culture. Furthermore, apoptosis of cultured CD8(+) T cells was diminished by this approach. This approach may have important therapeutic implications for adoptive immunotherapy.

Expression of endocrine gland-derived vascular endothelial growth factor in ovarian carcinoma.

The first tissue-specific angiogenic molecule, endocrine gland-derived vascular endothelial growth factor (EG-VEGF), was identified recently in human ovary, raising hopes of developing tumor type-specific angiogenesis inhibitors. In the present study, we analyzed the expression of EG-VEGF mRNA in normal human tissues and ovarian neoplasms by quantitative real-time reverse transcription-PCR. EG-VEGF mRNA was expressed in all ovarian neoplasms examined. No significant difference was identified among benign, low malignant potential neoplasms or stage I ovarian cancer, all of which exhibited 2-fold lower mRNA levels compared with normal premenopausal ovaries. EG-VEGF mRNA levels further decreased in late stage compared with early stage carcinomas (P < 0.05) and were consistently lower in laser capture microdissected tumor islets compared with surrounding stroma. EG-VEGF was undetectable by reverse transcription-PCR in 17 established epithelial ovarian cancer cell lines or in cultured human ovarian surface epithelial cells, whereas it was detected in peripheral blood as well as tumor-infiltrating T lymphocytes. Finally, in contrast to VEGF, EG-VEGF mRNA levels did not correlate with clinical outcome in advanced ovarian carcinoma. These results suggest that EG-VEGF is most likely derived from nonepithelial components of ovarian carcinomas and may play a marginal role in promoting angiogenesis in advanced ovarian carcinoma. We postulate that EG-VEGF-targeted antiangiogenic therapy may prove useful in early stage but not in advanced stage ovarian carcinoma.

TRANCE- and CD40 ligand-matured dendritic cells reveal MHC class I-restricted T cells specific for autologous tumor in late-stage ovarian cancer patients.

PURPOSE: The use of mature dendritic cells (DCs) presenting tumor-associated antigens (TAAs) to trigger tumor-specific T cells in vivo or in vitro represents a promising approach for cancer immunotherapy. We hypothesized that tumor antigens, mostly unidentified, are present on ovarian tumor cells and that mature DCs could be used to generate tumor-specific responses in unprimed patients. We also sought to measure preexisting antitumor immunity in patients with advanced ovarian cancer. EXPERIMENTAL DESIGN: Autologous DCs from 10 patients with ovarian cancer were pulsed with killed autologous primary tumors as a source of TAAs. DCs were then cultured in the presence of tumor necrosis factor alpha + TRANCE (tumor necrosis factor-related activation-induced cytokine) to induce maturation. Mature TAA-pulsed DCs were used in vitro to stimulate tumor-specific peripheral blood T cells. RESULTS: TRANCE and CD40 ligand were effective at maturing DCs. T-cell lines were generated in vitro that were capable of secreting IFN-gamma in response to autologous tumor. These tumor-specific T cells were MHC class I restricted. The frequency of tumor-specific T cells in uncultured cells from malignant ascites fluid and peripheral blood was measured in the same patients. CONCLUSIONS: IFN-gamma-secreting tumor-specific T cells were demonstrated at baseline in uncultured T cells from some unvaccinated ovarian cancer patients; however, the T cells could not kill autologous tumor. These data demonstrate that mature DCs presenting tumor antigens from engulfed autologous tumors can be used to augment antitumor immunity in vitro in patients with epithelial ovarian cancer. The results support the feasibility of therapeutic vaccination of ovarian cancer patients.

Safety, tolerability, and immunogenicity of zoster vaccine in subjects on chronic/maintenance corticosteroids.

BACKGROUND: This randomized, placebo-controlled study assessed the safety, tolerability, and immunogenicity of live virus zoster vaccine (ZV) in individuals receiving chronic/maintenance systemic corticosteroid therapy (daily dose equivalent of 5-20mg prednisone) for ≥2 weeks prior to vaccination and ≥6 weeks postvaccination. METHODS: Subjects were followed for adverse experiences (AEs), exposure to varicella or herpes zoster (HZ), or development of varicella/varicella-like or HZ/HZ-like rashes for 42 days postvaccination (primary safety follow-up period) and for serious AEs (SAEs) through Day 182 postvaccination (secondary follow-up period). Varicella-zoster virus (VZV) antibody titers by glycoprotein enzyme-linked immunosorbent assay (gpELISA) were measured at baseline and at Week 6 postvaccination. RESULTS: The proportions of subjects reporting systemic AEs and SAEs were similar in both groups. A higher percentage of subjects reported injection-site AEs in the ZV group (21.5%) than in the placebo group (12.1%). One SAE of ophthalmic HZ (onset Day 16 postvaccination) was reported in the ZV group and deemed vaccine-related by the study investigator; however, PCR testing confirmed the presence of wild-type (not vaccine strain) VZV. Geometric mean titer (GMT) at 6 weeks postvaccination was higher for ZV recipients than placebo recipients, with estimated geometric mean fold rises (GMFR) of 2.3 (CI: 2.0, 2.7) and 1.1 (CI: 1.0, 1.2) respectfully. CONCLUSIONS: In adults ≥60 years old on chronic/maintenance corticosteroids, ZV was generally well tolerated and immunogenic. The VZV-specific gpELISA antibody GMT at 6 weeks postvaccination and the GMFR from baseline to 6 weeks postvaccination were higher in the ZV group than in the placebo group.

Efficient transduction of human monocyte-derived dendritic cells by chimpanzee-derived adenoviral vector.

Using recombinant adenoviruses (Ads) to target host dendritic cells (DCs) presents an attractive prospect for immunization. The efficacy of commonly used human Ad-derived gene transfer vectors for antigen delivery in humans is often compromised by preexisting anti-Ad immunity, acquired by the majority of human population as a result of frequent naturally occurring virus infections. As an alternative vector we propose chimpanzee-derived recombinant adenoviruses, which are poorly neutralized by human sera. In the present study we examine the ability of one such vector, AdC68, to transduce and activate human monocyte-derived DCs in culture. We found that AdC68 could efficiently transduce both immature and mature DCs at levels similar to those by the human serotype 5 Ad recombinant. Exposure of immature DCs to AdC68 did not alter the expression of activation and maturation marker molecules on the cell surface. Nevertheless, the transduction induced DCs to secrete interferon alpha and interleukin (IL)-6, but not IL-12 or tumor necrosis factor alpha. In addition, AdC68-transduced immature DCs could stimulate proliferation of autologous T lymphocytes. This is the first report describing a chimpanzee-derived recombinant Ad as a vector for transduction of human DCs.

Safety, tolerability, and immunogenicity after 1 and 2 doses of zoster vaccine in healthy adults ≥60 years of age.

BACKGROUND: Incidence and severity of herpes zoster (HZ) and postherpetic neuralgia increase with age, associated with age-related decrease in immunity to varicella-zoster virus (VZV). One dose of zoster vaccine (ZV) has demonstrated substantial protection against HZ; this study examined impact of a second dose of ZV. METHODS: Randomized, double-blind, multicenter study with 210 subjects ≥60 years old compared immunity and safety profiles after one and two doses of ZV, separated by 6 weeks, vs. placebo. Immunogenicity was evaluated using VZV interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay and VZV glycoprotein enzyme-linked immunosorbent antibody (gpELISA) assay. Adverse experiences (AEs) were recorded on a standardized Vaccination Report Card. RESULTS: No serious vaccine-related AEs occurred. VZV IFN-γ ELISPOT geometric mean count (GMC) of spot-forming cells per 10(6) peripheral blood mononuclear cells increased in the ZV group from 16.9 prevaccination to 49.5 and 32.8 at 2 and 6 weeks postdose 1, respectively. Two weeks, 6 weeks and 6 months postdose 2, GMC was 44.3, 42.9, and 36.5, respectively. GMC in the placebo group did not change during the study. The peak ELISPOT response occurred ∼2 weeks after each ZV dose. The gpELISA geometric mean titers (GMTs) in the ZV group were higher than in the placebo group at 6 weeks after each dose. Correlation between the IFN-γ ELISPOT and gpELISA assays was poor. CONCLUSIONS: ZV was generally well-tolerated and immunogenic in adults ≥60 years old. A second dose of ZV was generally safe, but did not boost VZV-specific immunity beyond levels achieved postdose 1.

Safety, tolerability, and immunogenicity of zoster vaccine in subjects with a history of herpes zoster.

BACKGROUND: Prior clinical studies of zoster vaccine enrolled subjects without a history of herpes zoster (HZ), so there are limited data on safety and immunogenicity in vaccinees with a prior history of HZ. This study was conducted to evaluate the safety and immunogenicity of zoster vaccine recipients who had a prior episode of HZ. METHODS: A total of 101 subjects > or = 50 years of age with a prior history of HZ were enrolled. They were stratified by number of years since their HZ (5 to 9 years and > or = 10 years, in an approximate 2:1 ratio), and randomized 1:1 to one of two vaccination groups. On day 1, Group I was administered zoster vaccine and Group II received placebo. At week 4, Group I received placebo and Group II received zoster vaccine. Subjects were followed for adverse experiences (AEs), exposure to varicella or HZ, and development of any varicella/varicella-like or HZ/HZ-like rashes, for 28 days after each injection. Blood samples were obtained prior to study injection on day 1 and week 4, and at week 8. Serum was assessed for varicella-zoster virus (VZV) antibody concentration by glycoprotein enzyme-linked immunosorbent assay. RESULTS: No serious AEs were reported within the 28-day safety follow-up period following any vaccination. Although a higher percentage of subjects reported injection-site AEs after receiving zoster vaccine than did placebo recipients, the proportion of subjects reporting systemic clinical AEs was similar in both groups. Zoster vaccine induced a VZV antibody response at 4 weeks post-vaccination. The estimated geometric mean titer (GMT) ratio (vaccine/placebo) was 2.07 (95% CI: 1.48, 2.88). The geometric mean fold-rise (GMFR) from prevaccination to week 4 post-vaccination was 2.1 in zoster vaccine recipients, versus 1.0 in placebo recipients. CONCLUSIONS: In HZ history-positive adults > or = 50 years of age, zoster vaccine: (1) was well tolerated; and (2) significantly boosted the level of VZV antibody from baseline to 4 weeks post-vaccination as measured by GMT and GMFR. These data support the Advisory Committee on Immunization Practices' recommendation for routine zoster vaccination for all immunocompetent persons >/=60 years of age irrespective of HZ history.

Comparison of the levels of immunogenicity and safety of Zostavax in adults 50 to 59 years old and in adults 60 years old or older.

Zostavax has been shown to be efficacious in the prevention of herpes zoster and generally well tolerated in clinical trials among subjects 60 years old or older. This prespecified combined analysis from two studies compares the levels of immunogenicity and safety of Zostavax in subjects 50 to 59 years old versus those in subjects >or=60 years old. Varicella-zoster virus (VZV) antibody (Ab) titers were measured by glycoprotein enzyme-linked immunosorbent assay at baseline and 4 weeks postvaccination. Noninferiority was evaluated by estimated geometric mean severalfold rise (GMFR) ratio (50 to 59 years old/>or=60 years old) and two-sided 95% confidence interval (CI). Success was defined by a lower bound (LB) of the 95% CI of the GMFR ratio of >0.67. Acceptability of postvaccination VZV Ab was defined by an LB of the 95% CI of the GMFR of >1.4. Safety data were recorded for 28 days postvaccination by standardized vaccination report card. The estimated GMFRs from baseline to 4 weeks postvaccination were 2.6 (95% CI, 2.4, 2.9) in subjects 50 to 59 years old and 2.3 (95% CI, 2.1, 2.4) in subjects >or=60 years old. The estimated GMFR ratio (50 to 59 years old/>or=60 years old) was 1.13 (95% CI, 1.02, 1.25). No serious Zostavax-related adverse experiences were reported. After a dose of Zostavax, the GMFR of the VZV Ab response in subjects 50 to 59 years old was noninferior to that in subjects >or=60 years old. The VZV Ab response was acceptable in both age groups. Zostavax was generally well tolerated in both age groups.

A double-blind, randomized, controlled, multicenter safety and immunogenicity study of a refrigerator-stable formulation of Zostavax.

The vaccine Zostavax has been shown to prevent herpes zoster (HZ) and postherpetic neuralgia and is recommended for individuals > or =60 years of age. This study compared the safety and the immunogenicity of a refrigerator-stable formulation (Zostavax refrigerated) with those of the current formulation (Zostavax frozen) in subjects > or =50 years of age. Subjects with a negative history for HZ were randomized 1:1 to receive one dose of either formulation. Enrollment was stratified 1:2 by age (50 to 59 years and > or =60 years). Safety was evaluated for 28 days postvaccination. Varicella-zoster virus (VZV) antibody responses were measured by a glycoprotein enzyme-linked immunosorbent assay (gpELISA). The primary endpoints were the VZV antibody geometric mean titer (GMT; day 28), the VZV antibody geometric mean rise (GMR; days 1 to 28), and the incidence of vaccine-related serious adverse experiences (AEs) over 28 days. The refrigerated (n = 182) and frozen (n = 185) formulations induced similar GMTs (727.4 and 834.4 gpELISA units/ml, respectively); the estimated GMT ratio (refrigerated formulation/frozen formulation) was 0.87 (95% confidence interval, 0.71 to 1.07). The GMRs were 2.6- and 2.9-fold, respectively. No vaccine-related serious AEs were reported in either group, and the safety profiles of the formulations were generally similar. The frequencies of injection-site AEs during follow-up were 35.6% and 46.4% in the refrigerated and the frozen formulation groups, respectively, and were generally mild. The frequencies of systemic AEs were similar in the two groups, and those of vaccine-related AEs were approximately 6% in both groups. The refrigerator-stable formulation of Zostavax has an acceptable safety profile and is as immunogenic as the frozen formulation; thus, the vaccine may be used in clinical settings where freezer availability is limited.

Safety, tolerability, and immunogenicity of a two-dose regimen of high-titer varicella vaccine in subjects > or =13 years of age.

A new manufacturing process, known as process upgrade varicella vaccine (PUVV) was developed for a refrigerated formulation of varicella vaccine and for an investigational zoster vaccine. Safety and tolerability of a two-dose regimen of high-titered (approximately 50,000 PFU) PUVV were compared to a lower-titer formulation (approximately 5400 PFU) of VARIVAX; in 1366 healthy subjects > or =13 years old. Only one vaccine-related clinical serious adverse experience (pruritus; no hospitalization) was reported, in the VARIVAX group. Injection-site adverse experiences following any dose were higher in the PUVV group, 70.0%, than in the VARIVAX group, 56.2%, but generally were mild. Immunogenicity were similar in both groups in seronegative subjects. PUVV was generally well tolerated, and elicited an immune response similar to that induced by the marketed formulation of VARIVAX.

Cutting edge: Regulatory T cells from lung cancer patients directly inhibit autologous T cell proliferation.

Active suppression by T regulatory cells plays an important role in the down-regulation of T cell responses to foreign and self-Ags. Thus far, the potential role of CD4(+)CD25(+) T cells in human tumors has not been reported. In this work we show that lung tumors contain large numbers of these cells and that they have constitutive high-level expression of CD152 (CTLA-4). Furthermore, the CD4(+)CD25(+) T cells mediate potent inhibition of autologous T cell proliferation. Finally, regulatory T cells from patient tumors failed to inhibit the proliferation of allogeneic T cells. Together these results suggest that the CD4(+)CD25(+) T cells found in lung tumors selectively inhibit the host immune response and therefore could contribute to the progression of lung cancer.

Tumor-associated macrophages as a source of functional dendritic cells in ovarian cancer patients.

We have generated dendritic cells (DCs) from tumor-associated macrophages (TAMs) obtained from ascites fluid or tumor specimens of ovarian cancer patients, and compared them phenotypically and functionally to DCs derived from the patients' peripheral blood mononuclear cells (PBMCs). Both immature and mature DCs could be generated from TAMs. However, TAM-derived DCs underwent maturation to a lesser degree than PBMC-derived DCs, as measured by DC receptor surface expression. Nonetheless, in allogeneic mixed lymphocyte reactions, TAM-derived DCs stimulated T cell proliferation as efficiently as PBMC-derived DCs. In addition, TAM-derived DCs presenting tumor Ags were capable of stimulating IFN-gamma secretion by tumor-specific T cell lines. Thus, TAMs isolated from ovarian cancer patients can be used to generate significant numbers of DCs. Therefore, TAMs have potential use for either ex vivo or in vivo DC-based immunotherapy, particularly in individuals in which more conventional sources of DCs have been depleted.

Extensive replicative capacity of human central memory T cells.

To characterize the replicative capacity of human central memory (T(CM)) CD4 T cells, we have developed a defined culture system optimized for the ex vivo expansion of Ag-specific CD4(+) T cells. Artificial APCs (aAPCs) consisting of magnetic beads coated with Abs to HLA class II and a costimulatory Ab to CD28 were prepared; peptide-charged HLA class II tetramers were then loaded on the beads to provide Ag specificity. Influenza-specific DR*0401 CD4 T(CM) were isolated from the peripheral blood of normal donors by flow cytometry. Peptide-loaded aAPC were not sufficient to induce resting CD4 T(CM) to proliferate. In contrast, we found that the beads efficiently promoted the growth of previously activated CD4 T(CM) cells, yielding cultures with >80% Ag-specific CD4 cells after two stimulations. Further stimulation with peptide-loaded aAPC increased purity to >99% Ag-specific T cells. After in vitro culture for 3-12 wk, the flu-specific CD4 T(CM) had surface markers that were generally consistent with an effector phenotype described for CD8 T cells, except for the maintenance of CD28 expression. The T(CM) were capable of 20-40 mean population doublings in vitro, and the expanded cells produced IFN-gamma, IL-2, and TNF-alpha in response to Ag, and a subset of cells also secreted IL-4 with PMA/ionomycin treatment. In conclusion, aAPCs expand T(CM) that have extensive replicative capacity, and have potential applications in adoptive immunotherapy as well as for studying the biology of human MHC class II-restricted T cells.

A tumor-associated glycoprotein that blocks MHC class II-dependent antigen presentation by dendritic cells.

Tumors evade immune surveillance despite the frequent expression of tumor-associated Ags (TAA). Tumor cells escape recognition by CD8(+) T cells through several mechanisms, including down-regulation of MHC class I molecules and associated Ag-processing machinery. However, although it is well accepted that optimal anti-tumor immune responses require tumor-reactive CD4(+) T cells, few studies have addressed how tumor cells evade CD4(+) T cell recognition. In this study, we show that a common TAA, GA733-2, and its murine orthologue, mouse epithelial glycoprotein (mEGP), function in blocking MHC class II-restricted Ag presentation by dendritic cells. GA733-2 is a common TAA that is expressed normally at low levels by some epithelial tissues and a subset of dendritic cells, but at high levels on colon, breast, lung, and some nonepithelial tumors. We show that ectopic expression of mEGP or GA733-2, respectively, in dendritic cells derived from murine bone marrow or human monocytes results in a dose-dependent inability to stimulate proliferation of Ag-specific or alloreactive CD4(+) T cells. Dendritic cells exposed to cell debris from tumors expressing mEGP are similarly compromised. Furthermore, mice immunized with dendritic cells expressing mEGP from a recombinant adenovirus vector exhibited a muted anti-adenovirus immune response. The inhibitory effect of mEGP was not due to down-regulation of functional MHC class II molecules or active suppression of T cells, and did not extend to T cell responses to superantigen. These results demonstrate a novel mechanism by which tumors may evade CD4(+) T cell-dependent immune responses through expression of a TAA.

Immune reconstitution following autologous transfers of CD3/CD28 stimulated CD4(+) T cells to HIV-infected persons.

We have previously shown that adoptive transfer of in vitro CD3/CD28 activated autologous CD4(+) T cells results in increased CD4 counts and CD4/CD8 ratios in HIV+ subjects. In this report, analysis of variable beta (Vbeta) chain T cell receptor (TCR) repertoire showed that CD3/CD28 stimulation was able to increase polyclonality within skewed spectra types in vitro. In vivo, two of eight subjects showed increase in TCR diversity and importantly, in no subject did a highly skewed in vivo repertoire emerge. Measurement of proliferative response to alloantigen showed increases following infusions. Response to pharmacological stimulus and lectin via Interferon-gamma ELISpot assay showed increases in a subset of subjects following infusions. However, interferon-gamma response to HIV antigens and peptides declined concurrent with stable or diminishing latent infectious viral load in CD4(+) T cells. These data provide further evidence that adoptive transfer of activated autologous CD4(+) T cells can augment the immune system.