Primary analysis of a prospective, randomized, single-blinded phase II trial evaluating the HER2 peptide AE37 vaccine in breast cancer patients to prevent recurrence

BACKGROUND

AE37 is the Ii-Key hybrid of the MHC class II peptide, AE36 (HER2 aa:776-790). Phase I studies showed AE37 administered with granulocyte macrophage colony-stimulating factor (GM-CSF) to be safe and highly immunogenic. A prospective, randomized, multicenter phase II adjuvant trial was conducted to evaluate the vaccine's efficacy.

METHODS

Clinically disease-free node-positive and high-risk node-negative breast cancer patients with tumors expressing any degree of HER2 [immunohistochemistry (IHC) 1-3+] were enrolled. Patients were randomized to AE37 + GM-CSF versus GM-CSF alone. Toxicity was monitored. Clinical recurrences were documented and disease-free survival (DFS) analyzed.

RESULTS

The trial enrolled 298 patients; 153 received AE37 + GM-CSF and 145 received GM-CSF alone. The groups were well matched for clinicopathologic characteristics. Toxicities have been minimal. At the time of the primary analysis, the recurrence rate in the vaccinated group was 12.4% versus 13.8% in the control group [relative risk reduction 12%, HR 0.885, 95% confidence interval (CI) 0.472-1.659, P = 0.70]. The Kaplan-Meier estimated 5-year DFS rate was 80.8% in vaccinated versus 79.5% in control patients. In planned subset analyses of patients with IHC 1+/2+ HER2-expressing tumors, 5-year DFS was 77.2% in vaccinated patients (n = 76) versus 65.7% in control patients (n = 78) (P = 0.21). In patients with triple-negative breast cancer (HER2 IHC 1+/2+ and hormone receptor negative) DFS was 77.7% in vaccinated patients (n = 25) versus 49.0% in control patients (n = 25) (P = 0.12).

CONCLUSION

The overall intention-to-treat analysis demonstrates no benefit to vaccination. However, the results confirm that the vaccine is safe and suggest that vaccination may have clinical benefit in patients with low HER2-expressing tumors, specifically TNBC. Further evaluation in a randomized trial enrolling TNBC patients is warranted.

Final report of the phase I/II clinical trial of the E75 (nelipepimut-S) vaccine with booster inoculations to prevent disease recurrence in high-risk breast cancer patients

BACKGROUND

E75 (nelipepimut-S) is a human leukocyte antigen (HLA)-A2/A3-restricted immunogenic peptide derived from the HER2 protein. We have conducted phase I/II clinical trials vaccinating breast cancer patients with nelipepimut-S and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the adjuvant setting to prevent disease recurrence. All patients have completed 60 months follow-up, and here, we report the final analyses.

PATIENTS AND METHODS

The studies were conducted as dose escalation/schedule optimization trials enrolling node-positive and high-risk node-negative patients with tumors expressing any degree of HER2 (immunohistochemistry 1-3+). HLA-A2/3+ patients were vaccinated; others were followed prospectively as controls. Local and systemic toxicity was monitored. Clinical recurrences were documented, and disease-free survival (DFS) was analyzed by Kaplan-Meier curves; groups were compared using log-rank tests.

RESULTS

Of 195 enrolled patients, 187 were assessable: 108 (57.8%) in the vaccinated group (VG) and 79 (42.2%) in the control group (CG). The groups were well matched for clinicopathologic characteristics. Toxicities were minimal. Five-year DFS was 89.7% in the VG versus 80.2% in the CG (P = 0.08). Due to trial design, 65% of patients received less than the optimal vaccine dose. Five-year DFS was 94.6% in optimally dosed patients (P = 0.05 versus the CG) and 87.1% in suboptimally dosed patients. A voluntary booster program was initiated, and among the 21 patients that were optimally boosted, there was only one recurrence (DFS = 95.2%).

CONCLUSION

The E75 vaccine is safe and appears to have clinical efficacy. A phase III trial evaluating the optimal dose and including booster inoculations has been initiated.

CLINICAL TRIALS

NCT00841399, NCT00584789.

Abstract P4-13-02: Preliminary results for the phase 1 trial of a dual HER2 peptide cancer vaccine in breast and ovarian cancer patients

BACKGROUND: HER2 is a commonly expressed tumor-associated antigen in breast (BrCa) and ovarian cancer (OvCa) and, therefore, an attractive target for immunotherapy. We have investigated HER2-derived peptides as vaccines mixed with GM-CSF to include GP2 (a HLA-A2 and HLA-A3 restricted, CD8+ eliciting epitope) and AE37 (a HLA unrestricted, MHC class II, CD4+ eliciting epitope). Both peptide vaccines (PV) have shown clinical promise individually. There is clear rationale for combining GP2 and AE37 to elicit a more robust immune response (IR) of both CD4+ and CD8+ T cells. Here, we summarize initial toxicity (tox) and in vivo IR data from a phase 1 trial of the combined PV.

METHODS: The trial is being performed as a five cohort, 3+3 dose-escalation, safety trial. Clinically disease-free, HLA-A2+ and A3+, BrCa and OvCa patients with tumors expressing any level of HER2 (IHC 1-3+) and who have completed standard-of-care therapy are accrued. In the first cohort, three patients received six, monthly intradermal inoculations (R1-R6) of 100mcg of AE37, 100mcg of GP2, and 125mcg of GM-CSF or 100:100:125. The second cohort received 250mcg of AE37, 100mcg of GP2, and 125mcg of GM-CSF or 250:100:125. Three additional cohorts were vaccinated: 250:250:125, 500:250:125, and 500:500:125. Toxicity was graded 48-72 hours post vaccination using NCI Toxicity Criteria v4.0. After each inoculation, local reactions (LR) are measured via the sensitive ballpoint pen method and reported as the orthogonal mean (OM). IR is assessed in vivo by delayed type hypersensitivity (DTH) reactions with separate intradermal inoculations of AE37, AE36, and GP2 antigens, measured both pre-vaccination (R0) and after the vaccine series (R6) via the sensitive ballpoint pen method, and reported as the OM. Means were compared using paired t-tests.

RESULTS: 28 patients enrolled; 8 withdrew consent, 1 recurred prior to completing R6, 3 had an intercurrent illness, 14 patients completed R1-R6, and the vaccine series is ongoing in 2 patients. Six patients did not receive any inoculations and, therefore, are not included in this safety analysis. In 22 patients, the vaccine was well tolerated (max local tox: 23% Grade (Gr) 1, 73% Gr 2, 4% Gr 3; max systemic tox: 14% Gr 0, 50% Gr 1, 36% Gr 2). No dose-limiting toxicity was observed. For the 14 patients who completed the VS, the median age was 51(35-83). Breast tumor size was 3.3±1.1cm and ovarian tumor size was 10.0±2.3cm. Compared to GP2 LR at R1 (15.5±4.1mm), LR increased at R2 (31.7±5.9mm), R3 (42.9±7.4mm), R4 (35.3±7.3mm), R5 (45.0±9.9mm), and R6 (25.9±6.7mm, p = 0.17). Compared to the AE37 LR at R1 (18.5±3.8mm), LR increased at R2 (37.3±6.7mm), R3 (36.4±4.6mm), R4 (42.2±5.9mm), R5 (46.0±8.9mm), and R6 (36.2±6.6mm). Unless stated, all LR p-values < 0.05. After the VS, AE37 DTH increased from 0.0±0.0mm to 19.6±6.7mm (p<0.01), AE36 DTH increased from 0.0±0.0mm to 10.3±3.9mm (p<0.01), and GP2 DTH reactions increased from 0.3±0.2mm to 4.1±2.0mm (p = 0.056).

CONCLUSIONS: Initial results from a phase I trial of a vaccine combining GP2 and AE37 peptides show that dual administration of the peptides is well tolerated at all tested dosing levels. Additionally, the combination is capable of stimulating strong peptide-specific in vivo immune responses. Continued testing of this vaccination strategy is underway.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-13-02.

Abstract P4-13-05: HLA-A2 is not a prognostic indicator in breast cancer: Implications for cancer vaccine trials

Introduction

Peptide-based cancer vaccines require presentation by a specific HLA molecule. HLA-A2 is the most common class I allele in the US (40-50% of the population) and, therefore, the most commonly targeted. Our group has been investigating HER2-derived peptide vaccines administered in the adjuvant setting to high risk breast cancer patients in order to prevent disease recurrence. This study was undertaken to compare known prognostic factors and disease-free survival (DFS) in control HLA-A2+ and HLA-A2- patients in order to better define these populations for future trial design.

Methods

Our group is currently enrolling patients in a phase II trial evaluating the HER2-derived peptide vaccines, AE37 (MHC Class II, HLA-non-restricted epitope) and GP2 (MHC Class I, HLA-A2+ restricted epitope). The studies are enrolling high-risk, disease-free breast cancer patients with any level of HER2 expression (IHC 1+, 2+ or 3+) after completion of standard of care therapy. Patients are HLA-typed. HLA-A2+ patients are randomized to GP2+GM-CSF or GM-CSF alone. HLA-A2- patients are randomized to AE37+GM-CSF or GM-CSF alone. Demographics between groups are compared using chi squared or fisher exact as appropriate. DFS is compared using log rank.

Results

Thus far, 407 patients have been enrolled to the study (181 HLA-A2+ and 226 HLA-A2-). Demographics are shown in Table 1.

Table 1. Demographics (all) A2+A2-pn181226 Age (median)51500.47Node Positive62%66%0.46Grade 354%54%0.99Tumor >/ = 2 cm59%64%0.23ER/PR Negative36%38%0.59HER2 Overexpression55%51%0.39Triple Negative13%15%0.52

There are no differences between groups with respect to age, node positivity, grade, tumor size, ER/PR status, HER2 over-expression, or triple negative breast cancer. Of those enrolled, 83 HLA-A2+ patients and 109 HLA-A2- patients have been randomized to the control groups. Within the control group, there are no differences between the HLA-A2+ and HLA-A2- patients regarding age, node positivity, grade, tumor size, ER/PR status, HER2 over-expression, or triple negative breast cancer (Table 2).

With a median follow-up of 30 months, DFS is similar between A2+ and A2- control patients (83% v. 80%, p = 0.93).

Conclusions

Baseline clinico-pathologic factors are similar between HLA-A2+ and HLA-A2- breast cancer patients with no correlations to known prognostic factors. Well-matched blinded control patients treated only with GM-CSF demonstrate no differences in DFS between HLA-A2+ and HLA-A2- patients. Therefore, it does not appear that HLA-A2 status is a prognostic factor in breast cancer, and HLA-A2+ and HLA-A2- patients should be comparable in peptide-based breast cancer vaccine trials.

Table 2. Demographics (Control Group Only) A2+A2-pn83109 Age (median)51510.75Node Positive65%64%0.99Grade 359%57%0.76Tumor >/ =59%71%0.08ER/PR Negative36%38%0.84HER2 Overexpression55%46%0.19Triple Negative11%16%0.34

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-13-05.

Abstract P2-14-01: Breast cancer patients with HER2 low-expression: An under-recognized group at significant risk for recurrence

Background:

HER2 over-expression is associated with more aggressive malignant disease. The introduction of trastuzumab and other HER2-directed therapies, however, has led to improved prognosis for patients (pts) with HER2 over-expressing (OE) tumors. Currently, no HER2-targeted therapies are available for patients with HER2 low-expressing (LE) (1+, 2+ by IHC) tumors. We are conducting a randomized, controlled Phase II trial of multiple peptide vaccines enrolling patients with any level of HER2 expression (1+, 2+ and 3+). Here, we report survival data based on levels of HER2 expression in our unvaccinated, control pts.

Methods:

After standard of care therapy, disease-free, high-risk BCa pts were randomized to receive either peptide+GM-CSF (Vaccine Group, VG) or GM-CSF alone (Control Group, CG) in six, monthly doses followed by four boosters every six months. Pts were prospectively followed for recurrence. Demographic information was available for all pts and was compared between groups using chi square or fisher exact tests. Disease-Free Survival (DFS) was compared using log rank.

Results:

To date, we have enrolled 196 pts in the CG. 96 pts had HER2 OE tumors, 100 had LE tumors. The only significant demographic difference between the CG OE and LE groups was more ER/PR positive patients in LE (LE 72% vs OE 51%, p = 0.008). 83% of CG OE pts received trastuzumab, 3% of CG LE pts received trastuzumab. At a median f/u of 30 mo, DFS was significantly higher for CG OE vs CG LE (92.5% v 65.5%, p = 0.001).

Conclusions:

In the cohort of control pts from our ongoing vaccine trial, conducted in an era when Tz has been standard of care therapy for patients with HER2 OE tumors, we have shown that HER2 LE pts are at higher risk of recurrence than OE pts, despite having more ER/PR positive. This calls for increased efforts to develop novel therapies for patients with HER2 LE disease. We have previously shown a trend towards increased DFS with the HER2 vaccines, AE37 (p = 0.13, median f/u 22 mo) and E75 (p = 0.16, median f/u 60mo) in HER2 LE pts, suggesting that these vaccines may represent one such novel therapeutic approach.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-14-01.

Abstract P5-16-05: The combination of trastuzumab and HER2-directed peptide vaccines is safe in HER2-expressing breast cancer patients

Background: Cardiotoxicity is the most concerning toxicity associated with the commonly used HER2-directed immunotherapy, trastuzumab (Tz). In general, a significant decline of left ventricular ejection fraction (EF) in asymptomatic patients is accepted as a decrease of at least 10% or an absolute value of below 50%. We are currently conducting multiple trials of HER2-directed peptide vaccines, often given either concurrently or in close temporal proximity to Tz. This has raised the issue that combining therapies could increase the risk of cardio-toxicity. Here, we present safety data from multiple trials in which the combination of these HER2-directed therapies was administered.

Methods: Phase I and II trials were conducted in disease-free breast cancer patients after completion of chemotherapy when indicated. Patients (pts) who were determined by treating oncologists to qualify for Tz received this therapy per standard-of-care. These pts were enrolled onto HER2-directed peptide vaccine trials per each trial's inclusion criteria, with vaccinated (VG) pts receiving peptide + GM-CSF and control (CG) pts receiving GM-CSF alone. All patients were monitored for local and systemic toxicity to peptide inoculations (graded by the NCI's Common Terminology Criteria for Adverse Events). In addition, patients who received Tz had EF tracked through either echocardiogram or MUGA according to local standard of practice. Our database was queried for patients who received Tz and peptide, and had documented measures of EF pre-vaccine (Pre), during vaccine (D) and post-vaccine (Post). These pts were then placed in two groups based on the timing of Tz and vaccine therapy: concurrent(C) group and sequential(S) group. Mean EF at each time point was compared using a t-test.

Results: Overall, the peptide vaccines were well tolerated (max local tox: 1% Grade 0, 65% Gr 1, 33% Gr 2, 1% Gr 3; max systemic tox: 19% Gr 0, 63% Gr 1, 18% Gr 2, 0% Gr 3). These toxicities are likely secondary to the GM-CSF immunoadjuvant as control pts receiving GM-CSF alone have similar toxicity profiles (max local tox: 0% Gr 0, 76% Gr 1, 23% Gr 2, 1% Gr 3; max systemic tox: 20% Gr 0, 65% Gr 1, 15% Gr 2, 0% Gr 3). There have been no serious or non-serious cardiac-related adverse events in our trials. In total, 71 pts treated with Tz and enrolled in a vaccine trial had EF measurements available for analysis; 54 in the S group (35 VG, 19 CG) and 17 in the C group (10 VG, 7 CG). Overall, neither VG nor CG pts had significant changes in EF (VG Pre: 65±0.8%, D: 63±0.9%, Post: 64±0.3%; CG Pre: 63±1.2%, D: 64±1.8%, Post: 63±1.1%). Separating VG pts into C and S pts, there were again no significant changes in EF, (C Pre: 65±1.0%, D: 63±1.0%, Post: 63±1.4%; S Pre: 65±1.7%, D: 61±1.3%, Post: 65±1.8%).

Conclusions: HER2-directed peptide vaccines are safe and well tolerated. Initial data indicate that the combination of Tz and HER2-directed peptide vaccines, whether concurrent or sequential, does not cause significant cardiac toxicities as measured by changes in the EF during and after therapy. We will continue to track this safety data to confirm early findings as we pursue additional combination trials.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-16-05.

OT3-01-18: Combination Immunotherapy with Trastuzumab and the HER2 Vaccine E75 in Low and Intermediate HER2−Expressing Breast Cancer Patients To Prevent Recurrence

Background

In a phase II trial, the HER2−derived E75 vaccine administered with the immunoadjuvant GM-CSF has been shown to reduce breast cancer recurrence in the adjuvant setting, with a greater benefit seen in patients with low levels of HER2 expression (IHC 1+ or 2+). There has also been recent suggestion that patients with low HER2 expression may also benefit from trastuzumab. Preclinical testing of the combination of trastuzumab and the E75 vaccine has shown a synergism with combinational therapy. Finally, from our phase II trials of cytotoxic T cell-eliciting peptide vaccines, sequential treatment with trastuzumab and HER2 vaccination has resulted in no recurrences in 30 patients with a median follow-up of 48 months. Based on these results, we have designed a trial to evaluate the ability of the combination of trastuzumab and the E75 vaccine to prevent breast cancer recurrence.

Trial Design: This study will be a multi-center, prospective, randomized, single-blinded, phase II trial evaluating trastuzumab + E75+GM-CSF (immunoadjuvant) vs. trastuzumab + GM-CSF alone (no E75) in the adjuvant setting in breast cancer patients. Eligible patients include node positive (or node negative if negative for both ER and PR) disease-free breast cancer patients with low or intermediate levels of HER2 expression (IHC 1+ or 2+) and adequate cardiac function (LVEF >50%). Patients must be HLA-A2/A3+ (E75 is HLA-A2/A3-restricted). Patients will be enrolled after completing standard of care multi-modal therapy and randomized between the two treatment arms with stratification by HER2 expression (1+ or 2+) and nodal status (N0, N1, N2, or N3). Vaccinations (E75+GM-CSF or GM-CSF alone) will be administered as six monthly intradermal inoculations concurrently with trastuzumab therapy. The primary efficacy endpoint is to compare disease-free survival (DFS) between treatment arms at 24 months. Secondary objectives will include evaluation of cardiac toxicity from combination therapy (periodic cardiac assessment with MUGA or ECHO), DFS at 36 months, and immunologic responses to vaccination. From previously published experience with trastuzumab, we expect a recurrence rate of 15% in trastuzumab (plus GM-CSF) treated patients and anticipate that the combination of trastuzumab with E75+GM-CSF will reduce this recurrence rate to 5%. In order to show a statistical difference between these recurrence rates, we plan to enroll 150 patients per treatment arm (300 total) with a type I error rate of 5% and 80% power to detect the primary endpoint. Trial accrual is anticipated to begin in January 2012, with a two year period of enrollment followed by a three year follow-up period.

Conclusion: We hypothesize that combination adjuvant immunotherapy with trastuzumab and E75 vaccination will result in a greater reduction in breast cancer recurrence than trastuzumab therapy alone and have designed a multi-center, prospective, randomized, single-blinded, phase II trial evaluating the efficacy of this immunotherapy combination.

Contact Information: This trial is sponsored by Genentech and RXi Pharmaceuticals through the Henry M. Jackson Foundation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-01-18.

Abstract P2-20-02: Increased Prevalence of HLA-DR3 among Breast Cancer Patients: Implications for Adjuvant Her2/neu Peptide Vaccine Trials

BACKGROUND: HER2/neu is overexpressed in approximately 25% of breast cancer (Bca) patients (pts) and the source of a number of immunogenic HLA class I and II peptides. HLA class II molecules are generally promiscuous in their peptide affinity. Previous studies have shown that HLA-DR3, which has a prevalence of 13% in the population, has a lower binding affinity to multiple HER2/neu peptides. This suggests that pts who are HLA-DR3 positive (DR3+) may respond more poorly to HER2/neu peptide vaccines than HLA-DR3 negative (DR3-). We are conducting clinical trials evaluating HER2/neu-derived peptides GP2, E75, and AE37 administered in the adjuvant setting to prevent disease recurrence in high risk pts. GP2 and E75 are class I peptides. AE37 is the Ii-Key hybrid of HER2/neu:776-790 (AE36), an HLA class II peptide. Here, we report an analysis of DR3 status and response to AE37 vaccination in our trials. METHODS: We enrolled Bca pts rendered disease-free after receiving standard adjuvant therapy. HLA-DR3 status was determined via flow cytometry performed on peripheral blood mononuclear cells. In our phase II trial, pts were randomized to six monthly inoculations of either AE37 with granulocyte-macrophage colony-stimulating factor (GM-CSF) or GM-CSF alone. In vivo immune responses were measured using a delayed-type hypersensitivity immune response (DTH). Ex vivo immune response was measured by vaccine specific proliferative activity of T-lymphocytes using standard 3H-thymidine incorporation proliferation assay and a standard ELISPOT assay measuring peptide specific interferon-γ secreting T-cells.

RESULTS: DR3 status has been determined in 131 pts; 34 (26%) are DR3+, twice the expected (13%). Demographics (age, nodal status, tumor size, HER2 expression) were similar when comparing DR3+ pts to DR3-pts, with the exception that DR3 + pts were less likely to have high grade disease (n=11, 33%) compared to DR3-pts (n=58, 60%, p=0.035). 77 pts (56 DR3-, 21 DR3+) received AE37 ± GM-CSF. Post-vaccination DTH responses were significantly larger in AE37 pts compared to their respective GM-CSF controls (DR3-pts: AE37 40 ± 7 mm, GM-CSF 1 ± 0.5 mm, P<0.00001; DR3+ pts: AE37 39 ± 8 mm, GM-CSF 6 ± 3mm, p=0.002). DTH were similar comparing DR3-and DR3+ pts in both the GM (DR3+ 6 ± 3mm vs DR3-1 ± 0.5 mm, p=NS) and in the AE37 pts (DR3+ 39 ± 8 mm vs DR3-39 ± 7 mm, p =NS). There was a non-statistically significant trend toward increased post vaccination peptide-specific T-cells measured by proliferation and ELISPOT assay when comparing AE37 pts to GM-CSF pts; however, there was no difference in assays comparing DR3+ and DR3-pts.

CONCLUSIONS: We have observed DR3 phenotype in our BCa pts at twice the expected prevalence. DR3+ pts were less likely to have high grade tumors compared to DR3-pts. Despite in vitro studies demonstrating limited binding affinity of DR3 for numerous Her2/neu-derived peptides, our pts demonstrated no statistical difference in the in vivo or ex vivo immunogenic response between DR3+ and DR3-pts to vaccination with AE37 + GM-CSF, suggesting the Ii-key hybrid peptide AE37 may overcome weakly binding MHC II phenotypes. The increased prevalence of DR3 among BCa pts warrants further study.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-20-02.

Interim Analysis of a Randomized Phase II Study of the Novel Ii-Key Hybrid HER2/Neu Peptide (AE37) Vaccine To Prevent Breast Cancer Recurrence: United States Military Cancer Institute Clinical Trials Group Study I-05

BACKGROUND: CD4+ T helper peptides from HER2/neu have been evaluated in vaccine trials. The Ii-Key addition, a 4-amino-acid (LRMK) modification, increases vaccine potency when compared to unmodified class II epitopes. We present results of a prospective, randomized, single-blinded phase II clinical trial of the Ii-Key hybrid HER2/neu peptide (AE37) + GM-CSF immunoadjuvant vaccine versus GM-CSF alone in the adjuvant setting in disease-free, high risk breast cancer (BCa) patients to prevent recurrence.METHODS: Disease-free, high risk BCa patients who have completed standard adjuvant therapy were enrolled and randomized to receive six monthly inoculations of either 500 mcg of AE37 with 62.5 or 125 mcg of GM-CSF (Peptide group; PG) or 62.5 or 125 mcg of GM-CSF alone (adjuvant group; AG). Toxicity was assessed after each inoculation using National Cancer Institute Common Terminology Criteria for Adverse Events v3.0 (CTCAE). Immunologic response was monitored using delayed type hypersensitivity reactions (DTH) and 3H-thymidine proliferative assays for both hybrid AE37 (LRMK+HER2/neu:776-790) and AE36 (unmodified HER2/neu:776-790) peptides. Patients were clinically, radiographically, and pathologically monitored for recurrence of BCa.RESULTS: Thus far, 120 (49 PG, 71 AG) of the planned 200 patients have completed the primary series. The PG and AG have similar demographic/prognostic characteristics (Table 1). Toxicity profiles in the PG and AG were almost identical with no grade 4-5 local toxicities and no grade 3-5 systemic toxicities in either arm. Median DTH reaction to AE36 and AE37 increased significantly from baseline at 1 month after completion of the primary series in the PG group (AE36: 0.0±0.8 cm to 15.3 ±2.1 cm; AE37: 0.0±0.7 cm to 24.5±2.6 cm; p<0.0001) and did not change in the AG group (AE36: 0.0±0.5 cm to 0.0±1.4 cm; AE37: 0.0±0.7 cm to 0.0±1.6 cm; p>0.05). Median proliferation response to AE36 and AE37 increased significantly from baseline at 3, 6, and 12 months after the start of the vaccine series in the PG (p<0.015) and did not change significantly in the AG. At a median follow up of 13 months, there have been no (0.0%) recurrences in the PG (0/49) compared to 7.0% (5/71) in the AG (p=0.08).CONCLUSIONS: The modified peptide AE37 is safe with mild toxicities observed primarily due to the GM-CSF immunoadjuvant. AE37 elicits a strong HER2/neu-specific in-vivo and ex-vivo immune response to the modified and unmodified peptides. Importantly, the AE37 peptide vaccine may protect against BCa recurrences. peptideadjuvantp valueN=4971 Age (median)49520.06Node Positive75.5%62.1%0,16Grade 348.9%57.8%0.44Tumor ≥2 cm55.1%56.1%1ER/PR negative38.8%40.9%0.84HER2 over-expressor59.2%60.6%1 

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3183.

NOTE: This abstract was accepted for presentation at the Symposium after the Abstract Book went to press.

Circulating regulatory (CD4+CD25+FOXP3+) T cells decrease in breast cancer patients after vaccination with an Ii-Key-modified class II HER2/neu peptide (AE37)

Abstract #3134

Background: CD4+CD25+FOXP3+ regulatory T cells (Tregs) have been implicated in the suppression of immune responses against various tumors. To monitor the potential induction of Tregs in breast cancer (BrCa) patients receiving a modified HLA Class II HER2/neu peptide (AE37) vaccine in a clinical trial, we have analyzed peripheral blood lymphocytes (PBL) from vaccinated patients for the presence of Tregs and correlated our findings with ex vivo immune assays and in vivo delayed type hypersensitivity (DTH) responses to the vaccine. Methods: Fifteen BrCa patients have completed 6 monthly injections of the AE37+GM-CSF vaccine in a dose escalation safety study. The AE37 peptide consists of a HER2/neu peptide (776-790) linked to the Ii-Key moiety of the HLA Class II-associated invariant chain, which enhances epitope interaction with the Class II molecule. PBL obtained pre- and post-vaccination were stained with anti-CD4/CD25 (n=15) and FOXP3 (n=9) antibodies (PCH101 and 236A/E7) and analyzed by flow cytometry. Cells were also stimulated ex vivo with AE37 peptide to measure IFN-γ ELISPOT, proliferation (3H-thymidine-cpm) and cytokine secretion (TGF-β). DTH responses to the AE37 peptide pre- and post-vaccination were also recorded. Results: The mean CD4+ and CD4+CD25+ T cell populations for all patients (n=15) did not change from pre- to post-vaccination (CD4+ = 52.3+3.3% vs. 50.5+3.9%, p=0.6; CD4+CD25+ = 1.9+0.2% vs. 2.4+0.5%, p=0.2). Tregs (CD4+CD25+FOXP3+) were reduced in all 9 patients tested pre- to post-vaccination for both FOXP3 antibodies (Ab) (FOXP3 Ab1 = 2.1+0.2% vs. 1.1+0.1%, p=0.002; FOXP3 Ab2 = 2.0+0.2% vs. 1.0+0.2%, p=0.0009). There was no difference in pre- to post-vaccination levels of TGF-β (2720+582 pg/ml vs. 3387+848 pg/ml; p=0.9). AE37-specific proliferative responses increased from pre- to post-vaccination (34+23cpm vs. 6427+1431 cpm; p<0.001). ELISPOT demonstrated an increased response from pre- to long term (6-12mo.) post-vaccination (Median – 2 vs. 34 spots/106 cells; p=0.003). DTH responses increased in all patients from pre- to post-vaccination (3.6+1.4 mm vs. 56.0+9.4 mm; p<0.0001), and there appeared to be an inverse relationship between the degree of Treg reduction and the size of DTH response to AE37 (R2=0.83).
 Discussion: The novel AE37 HER2/neu peptide vaccine does not result in increased levels of Tregs. Furthermore, the reduced levels of Tregs in vaccinated patients appear to be associated with more robust responses in ex vivo immune assays and in vivo DTH reactions suggesting that the AE37 vaccine may be clinically useful.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3134.

Optimal method of dosing HER2/neu peptide vaccines: U.S. Military Cancer Institute Clinical Trials Group Study 1-01, 1-02, 1-03, and 1-04

Abstract #3139

Background: Our Cancer Vaccine Development Program has performed phase I and II clinical trials using immunogenic peptides from the HER2/neu protein. AE37 (aa:776-790+Ii-Key) is HLA promiscuous whereas E75 (aa:369-377) and GP2 (aa:654-662) are HLA-A2/A3+ restricted. The peptides are located on the intracellular, extracellular, and transmembrane portions of the HER2/neu protein. We evaluate patients who required dose reductions and compare them to those who did not in our three peptide vaccine trials to determine the immunologic and clinical relevance of different responses to the peptide vaccines. Methods: Three vaccine trials were performed separately with similar dose escalation design by varying the amount of AE37, GP2 or E75 peptide and GM-CSF adjuvant. Dose reductions (DR) were made in event of significant toxicity (>100mm local or ≥grade 2 systemic) by decreasing GM-CSF (or peptide if no GM-CSF) by 50% for subsequent inoculations. We compared patients necessitating DR and those who did not. Immune response was measured ex vivo via 3H-thymidine proliferative assays or HLA-A2:Ig dimer assays and in vivo via DTH reactions pre- and post-vaccine. Recurrence and mortality data were available for E75 treated patients at 30-month median follow-up. Results: 132 patients underwent peptide vaccination and 39 patients required DR (Table 1).
 
 No patient had grade 3-5 local or systemic toxicities. DR patients, particularly those reduced for robust local reactions (DR-L), had greater immune responses ex vivo and in vivo. The post-vaccine DTH in DR-L patients compared to all other vaccinated patients was significantly larger in E75 (24.5±4.1mm vs. 12.7±1.3mm; p=0.001) and trended towards significant in AE37 (69.4±10.3mm vs. 35.8±14.9mm; p=0.08) and GP2 (48.9±14.1mm vs. 24.1±3.3mm; p=0.08). No recurrences or deaths were noted in the E75 DR patients; but for patients not requiring dose reductions there were 10 (12.5%) recurrences and 1 (1.25%) death.Discussion: All three peptide vaccines are safe and well-tolerated with minimal toxicity. The safety was partly due to reducing GM-CSF (or peptide if no GM-CSF) by 50% for patients with >100mm local reactions or >grade 2 systemic toxicity. DR patients, particularly DR-L patients, immunological responses were larger. This increased immune response (noted by DTH) suggests improved clinical response as there have been no recurrences or deaths among DR patients. Our analysis indicates that the optimal method of dosing HER2/neu peptide vaccines consists of constant peptide dose with a large enough dose of adjuvant to generate robust local reactions and that when local reactions are >100mm performing DR of adjuvant by 50% for subsequent inoculations.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3139.

Monitoring circulating tumor cells in cancer vaccine trials

The presence of circulating tumor cells (CTC) from various cancers has provided a wealth of information and possibilities. As the role of CTC detection in the treatment assessment of metastatic breast cancer becomes standard, there is interest in applying this tool in cancer vaccine development and clinical trial monitoring. Since we lack a proven immunologic assay that correlates with clinical response, CTC detection, quantification and phenotypic characterization may be a useful surrogate for clinical outcome. The Cancer Vaccine Development Program is involved in the development of HER2/neu peptide based vaccine development for the prevention of recurrence in HER2/neu expressing cancers like breast cancer. The CellSearch System (Veridex, LLC Warren, NJ) has been used by our lab in conjunction with in vivo and/or in vitro immunologic measurements to define a monitoring tool that could predict clinical response. Once validated, this assay could significantly shorten clinical trials and lead to more efficient assessment of potentially promising cancer vaccines.

Assessment of circulating tumor cell (CTC) patterns among disease-free breast cancer patients vaccinated with a preventive HER2/neu E75-peptide vaccine

3059

Background: The quantity of CTC and post-treatment reduction predict outcome in medically treated metastatic breast cancer patients (BCa); however, the impact on survival of CTC in patients at risk for recurrence rendered free of disease after multimodality treatment is unknown. We conducted a pilot study to assess CTC in clinically disease-free node-positive (NP) BCa patients, and to determine the effect on CTC of vaccination with the immunogenic HER2/neu peptide E75. Methods: The CellSearch System (Veridex, LLC Warren, NJ) was used to enumerate total CTC and HER2/neu+ CTC in 20 ml of blood from selected samples obtained from patients (n=16) throughout and after the E75 vaccination series. Standard prognostic factors were collected on these patients as were measures of their immunologic response to the vaccine. Results: 14/16 patients (88%) had at least 1 CTC and 10/16 (63%) had 2 or more CTC identified. Standard clinical prognostic factors (tumor size, grade, lymph nodes and HER2/neu overexpression) did not correlate with number of CTC. Thus far, 9 patients have had multiple samples collected prior to, during and/or after the vaccine series. Early levels of CTC were significantly higher (mean±SE=5.2±0.5) vs. post-vaccination levels (0.3±0.1, p=0.005). Levels of HER2/neu+ CTC were also significantly different (early 3.4±0.3 vs. post 0.4±0.1, p=0.01). All patients showed a decline in CTC from early to post levels while demonstrating HER2/neu immunity as measured by DTH to the E75 peptide post- vaccination (22.9±1.8 mm vs. control 4±0.9 mm, p=0.006). Conclusions: CTCs are readily demonstrated in clinically disease-free NP BCa patients. Prognostic indicators do not seem to correlate with the number of CTCs. CTCs decline during the course of vaccination. These data suggest a potential role for the CTC assay in assessing response to preventive vaccine-based immunotherapy. The views expressed in this abstract are those of the authors and do not necessarily reflect the official policy or position of the Departments of Army or Navy, Department of Defense or the U.S. Government.

No significant financial relationships to disclose.

Clinical and immunologic effects of a HER2/neu (E75) peptide vaccine booster in previously vaccinated breast cancer patients

3014

Background: We are conducting clinical trials of the HER2/neu E75-peptide vaccine in clinically disease-free breast cancer (BCa) patients. Our Phase I/II trials have shown that the E75+GM-CSF vaccine is safe and effective in stimulating clonal expansion of E75-specific CD8+ T-cells. Since peptide vaccines may not lead to long term immunity, we have assessed the need for and response to a vaccine booster for patients after completion of their primary vaccination series. Methods: BCa patients enrolled in our E75 vaccine trials who were >6 months from the completion of their primary vaccination series were offered a single 1000 mcg dose of E75 peptide with 250 mcg of GM-CSF. Patients were monitored for local and systemic toxicity. E75-specific CD8+ T-cells were quantified using the HLA-A2:IgG dimer before and after booster administration. Results: 19 patients have received the vaccine booster. Median time from primary vaccine series was 12 months (range 6–25) and median residual E75-specific immunity was 0.61% (range 0- 3.43%). Significant residual immunity (SRI=CD8+ E75-specific T-cells >0.5%) was seen in 71% of patients <12 months from primary vaccination vs. 33% of patients ≥12 months. Graded local toxicities were as follows: 18/19 (94.7%) grade 1; 1/19 (5.3%) grade 2. Only 6/19 (31.6%) experienced even grade 1 systemic toxicity. Local reactions were more robust in patients receiving the booster <12 months from primary vaccine compared to those ≥12 months (99±2.8 mm vs. 75±1 mm, p=0.01). In patients lacking SRI, 80% showed increased specific immunity post-vaccination. In these patients, the average CD8+ E75-specific T-cells pre-booster vs. post-booster was 0.37±0.03% vs. 1.06 ± 0.14% (p=0.07). Conclusions: The HER2/neu peptide vaccine E75 stimulates specific immunity in disease-free BCa patients. However, only about half of patients show SRI at median follow-up of 12 months. A vaccine booster is safe and highly effective in stimulating E75-specific immunity especially in those patients without SRI. Initial results suggest that the booster should be given within a year of completion of the initial vaccine series.

No significant financial relationships to disclose.

Early results of a phase I clinical trial of an Ii-Key/Her2/neu MHC class II peptide-based vaccine in breast cancer patients

2532

Background: HER2/neu is over-expressed in breast cancer (BCa) and is the source of immunogenic peptides currently being evaluated in clinical trials as cancer vaccines. Ii-Key is a 4-amino-acid modification of peptides that has been reported to increase their occupancy of MHC class II molecules and enhance CD4 T cell responses. We are currently conducting a phase I clinical trial with an Ii-Key/HER2/neu MHC class II peptide (AE37) in BCa patients. Methods: The dose escalation safety trial design is for 3 groups of 3 patients to receive either 100, 500, or 1,000 μg of AE37 with 250 μg of GM-CSF in 6 monthly inoculations. Six additional patients will then be vaccinated at the optimal dose. Local and systemic toxicity is monitored and graded by the Common Toxicity Criteria. Immunologic response is monitored by peptide-stimulated proliferation (3H-thymidine incorporation) and ELISPOT (IFN-γ) assays for both AE37 and AE36 [the unmodified peptide HER2 776–790 (GVGSPYVSRLLGICL)]. Thus far 6 BCa patients have been vaccinated. Results: The 100μg dose group has completed all 6 vaccinations with maximum local and systemic toxicities of grade 2 and 1, respectively. All 3 patients developed increasing peptide-specific proliferation post-vaccination to both AE37 and AE36. ELISPOT responses were more variable with 1 minimal responder (30 IFN-γ spot-forming cells (SFC)/106 cells), 1 moderate responder (600 IFN-γ SFC/106 cells), and 1 good responder (1500 IFN-γ SFC/106 cells) post-vaccination. The 500μg dose group has thus far experienced earlier and larger local reactions but limited systemic toxicity. All 3 patients have demonstrated >1500 IFN-γ SFC /106 cells after just 2 inoculations. Peptide-specific proliferation after 2 inoculations has ranged between 3200–11500 cpm for the 500μg patients compared with 1200–2000 cpm after 6 inoculations for the 100μg dose group. Conclusions: AE37 appears to be safe and well-tolerated. A dose-dependent immunologic response has been demonstrated to the Ii-Key modified peptide as well as the naturally occurring sequence. These encouraging early results suggest that AE37 may prove to be useful as a CD4-specific vaccine either alone or in combination with CD8-specific HER2/neu peptides for improved cancer immunotherapy.

[Table: see text]

Differential expression of the 150-kd oxygen-regulated protein (ORP150) in benign, pre-malignant and malignant breast tissue

10770

Background: Heat shock protein, ORP150, plays a role in hypoxia/ischemia and angiogenesis. Preliminary studies demonstrate increased ORP 150 expression in human cancer, and associate its over expression with aggressive tumor biology. This study further evaluates ORP150 expression in different stages of breast cancer, such as benign, pre-malignant and malignant breast lesions and correlates it with clinical-pathological data. Methods: Sixty-six prospectively collected paraffin-embedded breast tissue sections were reviewed for diagnostic confirmation (normal, n=25; DCIS, n=20; invasive breast cancer (Ca), n=21) and stained using ORP150 antibody immunohistochemistry (IHC). Antibody-staining levels in the benign, DCIS and invasive component of each lesion were reviewed independently by two pathologists and scored: 0 (lowest) to 3+ (highest). Clinical-pathological data was compared with ORP150 staining using ANOVA or T-Test as appropriate with significance determined by p<0.05. Results: Significant differential ORP150 staining was detected in benign-normal versus benign adjacent to invasive cancer, as well as in benign adjacent to DCIS versus benign adjacent to invasive cancer. ORP150 expression in the invasive portion of the breast cancer correlated significantly with tumor grade and absence of hormone receptor expression, presence of lymphovascular invasion and lymph node metastasis. Conclusions: ORP150 expression in breast cancer is associated with poor prognostic histological factors. As ORP150 is differentially expressed in benign tissue adjacent to invasive cancer, further study is warranted to determine its utility in detecting occult invasive cancer within benign biopsy specimens, as well as its putative role in tumor-stromal cell interactions.

[Table: see text]

No significant financial relationships to disclose.

Developing a predictive model for disease status in breast cancer patients using Th1 and Th2 serum cytokine profiles

10078

Background: Using the Luminex multiplex assay, we have reported significant correlations between serum levels of MCP-1, eotaxin, and IL-6 and disease characteristics in breast cancer (BCa) patients. We now examine the potential of utilizing a general cytokine profile to develop a statistical model to predict certain disease states in these patients. Methods: Sera from 36 BCa patients (24 node-negative, 12 node-positive, 12 normals) were analyzed using the Luminex assay for levels of 21 cytokines (IL-1α, 1b, 2, 4, 5, 6, 8, 10, 12, 13, 15, 17, IFN-γ, G-CSF, GM-CSF, TNF-α, IP-10, MIP-1α, RANTES, MCP-1, eotaxin). Logistic regression models were used to assess if a binary outcome variable (Y) can be predicted by using serum cytokine levels (X). The area under a receiver operating characteristic (ROC) curve (c) was used to assess the potential utility of a biomarker. The larger the value of c, the better the biomarker. Results: MCP-1 was found to be a possible predictor of the presence of BCa while other potential biomarkers were IL-13, MIP-1α and eotaxin. The higher the MCP-1 level, the greater the likelihood that the patient would have BCa. Similar relationships applied to the other potential biomarkers. Among BCa patients, GM-CSF seemed to be a good predictor of nodal status with lower levels of GM-CSF predicting positive nodes. Other potential biomarkers with a similar expression pattern for nodal status were MCP-1, IL-6 and IL-5. Due to small sample sizes, we were unable to examine a potential “panel” of cytokines to develop a prognostic algorithm based on serum analysis. Conclusions: MCP-1, which was previously shown to be elevated in BCa, may also have some predictive value linking the presence of disease and disease severity as measured by nodal status. Other prominent cytokines from earlier studies (MIP-1α, eotaxin, IL-6) also displayed some possible predictive value. Our results warrant studying a larger population in order to establish a unified prognostic formula for BCa based on serum cytokine levels.

[Table: see text]

No significant financial relationships to disclose.

PSA is a candidate self-antigen in autoimmune chronic prostatitis/chronic pelvic pain syndrome

BACKGROUND

Previous studies demonstrated that recognition of seminal plasma antigens can occur in patients with chronic prostatitis/chronic pelvic pain syndrome. This suggests that an autoimmune component may contribute to symptoms in some men. To determine if any of the principal secretory proteins of the prostate could be candidate antigens in autoimmune prostatitis, we examined the recall proliferative response of purified CD4 T cells in patients with chronic prostatitis and in normal volunteers using purified seminal plasma antigens and autologous dendritic cells.

METHODS

Peripheral blood mononuclear cells were harvested from 14 patients with chronic prostatitis and 12 normal volunteers by density gradient centrifugation. The stimulating cells were irradiated autologous dendritic cells produced by culture of monocyte-enriched fractions with IL-4 and Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF). Purified CD4 T cells were the responding population. Recall proliferation assays were performed, using purified seminal plasma proteins as antigens.

RESULTS

In 14 patients with chronic prostatitis, we detected a greater than 2-fold increase in proliferative response to PSA compared to control in 5 patients (36%). No response to Prostatic Acid Phosphatase (PAP) or beta-microseminoprotein was observed in these 14 patients. In 12 normal volunteer donors with no history of genitourinary disease or symptoms, no proliferative response above background was observed for any prostatic antigen.

CONCLUSIONS

The data suggest that some men with symptoms of chronic prostatitis have evidence of a proliferative CD4 T-cell response to PSA. PSA is a candidate antigen in chronic prostatitis/chronic pelvic pain syndrome and may be an appropriate target for immunotherapy for prostatic cancer.

B cell development and activation defects resulting in xid-like immunodeficiency in BLNK/SLP-65-deficient mice

Engagement of the B cell receptor (BCR) leads to the activation of tyrosine kinases and other signaling molecules that ultimately determine the type and magnitude of the B lymphocyte's cellular response. The adaptor protein BLNK/SLP-65 plays a pivotal role in BCR signal transduction by coupling Syk activation to downstream elements such as Grb2, phospholipase C-gamma, Vav and Nck. We have generated BLNK(-/-) mice to determine the physiological role of this protein in B cell development and activation. BLNK(-/-) mice exhibit an incomplete block in B cell development with a severe inhibition of pro-B to pre-B cell differentiation. BLNK(-/-) sIgM(+) cells can develop, seed the peripheral lymphoid tissues and accumulate in numbers overtime. However, these mutant B cells failed to mature and are non-responsive to BCR cross-linking in terms of proliferation and up-regulation of activation markers such as CD69 and CD86 (B7-2). In addition, the CD5(+) subset of B cells is absent. The immune response to T cell-independent antigen but not T cell-dependent antigen is also impaired. Overall, the phenotype of BLNK(-/-) mice bears a striking resemblance to that of xid mice which is the murine model of human XLA that has a mutation in Bruton's tyrosine kinase. This raises the interesting possibility that mutation in BLNK/SLP-65 may be responsible for certain human immunodeficiencies.

Developing dendritic cell polynucleotide vaccination for prostate cancer immunotherapy

Immunotherapy has been successfully used to treat some human malignancies, principally melanoma and renal cell carcinoma. Genetic-based cancer immunotherapies were proposed which prime T lymphocyte recognition of unique neo-antigens arising from specific mutations. Genetic immunization (polynucleotide vaccination, DNA vaccines) is a process whereby gene therapy methods are used to create vaccines and immunotherapies. Recent findings indicate that genetic immunization works indirectly via a bone marrow derived cell, probably a type of dendritic antigen presenting cell (APC). Direct targeting of genetic vaccines to these cells may provide an efficient method for stimulating cellular and humoral immune responses to infectious agents and tumor antigens. Initial studies have provided monocytic-derived dendritic cell (DC) isolation and culture techniques, simple methods for delivering genes into these cells, and have also uncovered potential obstacles to effective cancer immunotherapy which may restrict the utility of this paradigm to a subset of patients.

Targeted disruption of the tyrosine phosphatase PTPalpha leads to constitutive downregulation of the kinases Src and Fyn

A role for the receptor-like protein tyrosine phosphatase alpha (PTPalpha) in regulating the kinase activity of Src family members has been proposed because ectopic expression of PTPalpha enhances the dephosphorylation and activation of Src and Fyn [1] [2] [3]. We have generated mice lacking catalytically active PTPalpha to address the question of whether PTPalpha is a physiological activator of Src and Fyn, and to investigate its other potential functions in the context of the whole animal. Mice homozygous for the targeted PTPalpha allele (PTPalpha-/-) and lacking detectable PTPalpha protein exhibited no gross phenotypic defects. The kinase activities of Src and Fyn were significantly reduced in PTPalpha-/- mouse brain and primary embryonic fibroblasts, and this correlated with enhanced phosphorylation of the carboxy-terminal regulatory Tyr527 of Src in PTPalpha-/- mice. Thus, PTPalpha is a physiological positive regulator of the tyrosine kinases Src and Fyn. Increased tyrosine phosphorylation of several unidentified proteins was also apparent in PTPalpha-/- mouse brain lysates. These may be PTPalpha substrates or downstream signaling proteins. Taken together, the results indicate that PTPalpha has a dual function as a positive and negative regulator of tyrosine phosphorylation events, increasing phosphotyrosyl proteins through activation of Src and Fyn, and directly or indirectly removing tyrosine phosphate from other unidentified proteins.

Elevated levels of proinflammatory cytokines in the semen of patients with chronic prostatitis/chronic pelvic pain syndrome

OBJECTIVES

Chronic prostatitis/chronic pelvic pain syndrome is a common diagnosis, but the disease is poorly understood. The diagnosis is based only on symptoms, and no measurable parameter can help in defining the presence of the disease, its severity, or its cause. Cytokines are soluble proteins secreted by cells of the immune system that principally regulate inflammatory and immune responses. To provide an objective measure of inflammation in the genital tract, we measured levels of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) in the semen of men with chronic prostatitis/chronic pelvic pain syndrome and compared these with levels in normal men.

METHODS

We obtained semen samples from 18 men with chronic prostatitis/chronic pelvic pain syndrome and from 8 normal male volunteers. Cytokine levels were measured in the seminal plasma by two-antibody enzyme-linked immunosorbent assay.

RESULTS

Men with prostatitis had higher mean levels of IL-1 beta and TNF-alpha in seminal plasma (mean +/-SEM) than normal men: TNF-alpha 98+/-39 versus 17+/-8; IL-1 beta 246+/-63 versus 27+/-10, respectively; P <0.05. There was a strong correlation between the levels of TNF-alpha and IL-1 beta in the semen of men with chronic prostatitis/chronic pelvic pain syndrome. There was no correlation between either TNF-alpha or IL-1 beta levels and the number of leukocytes per high power field in expressed prostatic secretions in patients.

CONCLUSIONS

Some men with chronic prostatitis/chronic pelvic pain syndrome have elevated levels of TNF-alpha and IL-1 beta in the semen. This suggests that inflammation of the genital tract is a feature of this disease, irrespective of the presence or absence of leukocytes in the expressed prostatic secretions. Seminal cytokine levels may provide an objective measure of disease in these patients and suggest specific therapeutic strategies to treat chronic prostatitis/chronic pelvic pain syndrome in such patients.

In vitro and in vivo promoter analyses of the mouse phospholamban gene

To determine the mechanisms responsible for regulation of the phospholamban (PLB) gene expression, a critical regulatory phosphoprotein in cardiac muscle, the mouse PLB gene was isolated and promoter analysis was performed in vitro and in vivo. The PLB gene consists of two exons separated by a single large intron. Deletion analysis revealed that a 7-kb 5' flanking fragment (including exon 1, the entire intron and part of exon 2) was necessary for maximal transcriptional activity in H9c2 and L6 cell lines. Interestingly, deletion of a 2.4-kb intronic region, which contained repetitive elements, caused a dramatic increase in CAT activity in both these cell lines. In vivo analysis indicated that the PLB fusion gene containing 7 kb of the 5'-flanking region was capable of cardiac specific gene expression in transgenic mice. Furthermore, these mice exhibited 3-fold higher levels of CAT activity in the ventricles compared with the atria, mimicking endogenous PLB mRNA expression. Our findings suggest that: (a) PLB gene expression may be regulated by the interplay of cis-acting regulatory elements located within the 5' flanking and intronic regions; and (b) the 7-kb upstream region is capable of directing cardiac-specific and compartment-specific expression in vivo.

Autoimmune prostatitis: evidence of T cell reactivity with normal prostatic proteins

OBJECTIVES

To determine whether men with chronic prostatitis/chronic pelvic pain syndrome have evidence of an autoimmune response to prostatic proteins. We examined men with a history of chronic prostatitis/ chronic pelvic pain syndrome for evidence of T lymphocyte reactivity to seminal plasma.

METHODS

Patients underwent automated leukopheresis to obtain peripheral blood mononuclear cells. We performed a recall antigen proliferation assay to detect specific proliferation of peripheral helper T lymphocytes in men. with chronic prostatitis/chronic pelvic pain syndrome and compared the results with those of normal men. The antigen for these studies consisted of seminal plasma from normal donors and men with seminal vesicle atresia.

RESULTS

A specific recall proliferative response to seminal plasma was observed in 3 of 10 men with a history of chronic prostatitis/chronic pelvic pain syndrome compared with none of 15 normal men. The CD4 T cell proliferative response to seminal plasma was statistically significant when compared with medium alone in men with a history of chronic prostatitis/chronic pelvic pain syndrome but it was not statistically significant in normal men. The recall responses of both the chronic prostatitis/chronic pelvic pain syndrome group and normal subjects to the recall antigens tetanus toxoid and Candida extract were equivalent.

CONCLUSIONS

The data represent the first direct evidence that some men with chronic prostatitis/chronic pelvic pain syndrome have an autoimmune component to their disease. Autoimmunity is a potential etiology for chronic nonbacterial prostatitis.

Cryosurgical ablation of the normal ventral prostate plus adjuvant does not protect Copenhagen rats from Dunning prostatic adenocarcinoma challenge

PURPOSE

We wished to determine if cryosurgical ablation of the normal ventral prostate of Copenhagen rats confers protective immunity against a subsequent challenge with Dunning R3327 MatLyLu prostatic adenocarcinoma. In human melanoma, tumor antigens have been characterized as normal cellular proteins. We reasoned that cryosurgical ablation of the normal prostate along with immunostimulatory adjuvants might release prostatic antigens to the immune system engendering an immune response and rendering rats immune to prostatic cancer cells.

MATERIALS AND METHODS

On day 0, Copenhagen rats underwent cryosurgical ablation of the normal ventral prostate, cryosurgery and intraprostatic injection of Complete Freund's Adjuvant (CFA), CFA injection alone, or laparotomy alone. On day 21, animals received a subcutaneous challenge of MatLyLu tumor cells. Tumor dimensions were recorded at regular intervals by a single blinded investigator.

RESULTS

Animals receiving cryosurgical ablation of the normal ventral prostate or intraprostatic CFA developed tumors more frequently than animals receiving laparotomy alone and the effect was statistically significant if animals received both cryosurgical ablation of the prostate and intraprostatic CFA (3 experiments, 1 x 10(4) MatLyLu cells), total number with tumors/total number challenged: laparotomy alone 3/17, cryosurgical ablation 7/17, cryosurgery plus CFA 10/16 (p = 0.013 versus laparotomy, Fisher's exact test), CFA alone 9/17.

CONCLUSIONS

Cryosurgical ablation of the normal rat ventral prostate and intraprostatic CFA does not protect against and can enhance the tumorigenicity of MatLyLu prostatic cancer cells at distant sites. This could be occurring through specific immunologic effects or non-specific mechanisms induced by cryosurgery and CFA.

Cardiac-specific overexpression of phospholamban alters calcium kinetics and resultant cardiomyocyte mechanics in transgenic mice

Phospholamban is the regulator of the cardiac sarcoplasmic reticulum (SR) Ca(2+)-ATPase activity and an important modulator of basal contractility in the heart. To determine whether all the SR Ca(2+)-ATPase enzymes are subject to regulation by phospholamban in vivo, transgenic mice were generated which overexpressed phospholamban in the heart, driven by the cardiac-specific alpha-myosin heavy chain promoter. Quantitative immunoblotting revealed a twofold increase in the phospholamban protein levels in transgenic hearts compared to wild type littermate hearts. The transgenic mice showed no phenotypic alterations and no changes in heart/body weight, heart/lung weight, and cardiomyocyte size. Isolated unloaded cardiac myocytes from transgenic mice exhibited diminished shortening fraction (63%) and decreased rates of shortening (64%) and relengthening (55%) compared to wild type (100%) cardiomyocytes. The decreases in contractile parameters of transgenic cardiomyocytes reflected decreases in the amplitude (83%) of the Ca2+ signal and prolongation (131%) in the time for decay of the Ca2+ signal, which was associated with a decrease in the apparent affinity of the SR Ca(2+)-ATPase for Ca2+ (56%), compared to wild type (100%) cardiomyocytes. In vivo analysis of left ventricular systolic function using M mode and pulsed-wave Doppler echocardiography revealed decreases in fractional shortening (79%) and the normalized mean velocity of circumferential shortening (67%) in transgenic mice compared to wild type (100%) mice. The differences in contractile parameters and Ca2+ kinetics in transgenic cardiomyocytes and the depressed left ventricular systolic function in transgenic mice were abolished upon isoproterenol stimulation. These findings indicate that a fraction of the Ca(2+)-ATPases in native SR is not under regulation by phospholamban. Expression of additional phospholamban molecules results in: (a) inhibition of SR Ca2+ transport; (b) decreases in systolic Ca2+ levels and contractile parameters in ventricular myocytes; and (c) depression of basal left ventricular systolic function in vivo.

Selective response of gamma delta T-cell hybridomas to orthomyxovirus-infected cells

A gamma delta T-cell hybridoma established from influenza virus-infected mice responded to a reproducible way when cultured with influenza virus-infected stimulators. Subclones of this line responded to cells infected with influenza viruses A/PR/8/34 (H1N1), X-31 (H3N2), and B/HK/8/73 but not to cells infected with vaccinia virus or Sendai virus. This spectrum of response to both type A and type B orthomyxoviruses has never been recognized for the alpha beta T-cell receptor-positive subsets. There was no response to cells infected with a panel of recombinant vaccinia viruses expressing all individual influenza virus proteins, and so it is unlikely that the stimulating antigen is of viral origin. The alternative is that the antigen is a cellular molecule induced in influenza virus-infected cells. Infectious virus was required for stimulation, and immunofluorescence studies showed increased expression of heat shock protein 60 (Hsp60) in influenza virus- but not Sendai virus- or vaccinia virus-infected cells. Both the hybridoma generated from influenza virus-infected mice and an established hybridoma which uses the same gamma delta T-cell receptor combination responded to recombinant Hsp60. Furthermore, the Hsp60-reactive hybridoma, which was obtained from an uninfected mouse, also responded to influenza virus-infected cells, indicating that Hsp60 may indeed be the target antigen.

Differential phospholamban gene expression in murine cardiac compartments. Molecular and physiological analyses

Phospholamban, the regulator of the Ca2+ pump in cardiac sarcoplasmic reticulum, is differentially expressed between murine atrial and ventricular muscles. Quantitative analyses of RNA isolated from atrial flaps and ventricular apices indicated that the phospholamban gene transcript copy number is 2.5-fold higher in the ventricle compared with the atrium of the FVB/N mouse and 6-fold higher in the ventricle compared with the atrium of the B6D2/F1 mouse strain. These findings were corroborated by in situ hybridization studies of cardiopulmonary sections from both murine strains, and phospholamban transcripts were also observed in pulmonary myocardia of both strains. Analyses of phospholamban transcript levels relative to alpha-myosin heavy chain (alpha-MHC) revealed a 3-fold higher phospholamban abundance in the ventricle compared with the atrium of the FVB/N murine strain. However, the relative mRNA level of Ca(2+)-ATPase (ratio of sarcoplasmic reticulum Ca(2+)-ATPase [SERCA2] to alpha-MHC) in the ventricle was 80% of that in the atrium. Consequently, the relative ratio of phospholamban to SERCA2 mRNA was 4.2-fold lower in the atrium than in the ventricle. The lower transcript ratio of phospholamban to SERCA2 in the atrium was associated with significantly shortened times to half-relaxation (17.40 +/- 0.71 milliseconds for atrium versus 30.58 +/- 2.04 milliseconds for ventricle), assessed in isolated superfused cardiac tissue preparations recorded at maximum length tension. Contraction times, measured as times to peak tension, were also significantly shortened in atrial muscle (27.36 +/- 0.82 milliseconds) compared with ventricular muscle (44.60 +/- 2.55 milliseconds), assessed in the same tissue preparations. These findings suggest that phospholamban gene expression is differentially regulated in murine atrial and ventricular muscles and that this differential expression may be associated with differences in the contractile parameters of these cardiac compartments.

Expression of phospholamban in C2C12 cells and regulation of endogenous SERCA1 activity

Phospholamban (PLB) is a regulator of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2) expressed in cardiac, slow-twitch skeletal, and smooth muscles. Phospholamban is not expressed in the sarcoplasmic reticulum of fast-twitch skeletal muscle, but it can regulate the sarcoplasmic reticulum Ca(2+)-ATPase activity (SERCA1) expressed in this muscle, in vitro. To determine whether phospholamban can regulate SERCA1 activity in its native membrane environment, phospholamban was stably transfected into a cell line (C2C12) derived from murine fast-twitch skeletal muscle. Differentiation of C2C12 myoblasts to myotubes was associated with induction of SERCA1 expression, assessed by Western blotting analysis using Ca(2+)-ATPase isoform specific antibodies. The expressed phospholamban protein was localized in the microsomal fraction isolated from C2C12 myotubes. To determine the effect of phospholamban expression on SERCA1 activity, microsomes were isolated from transfected and nontransfected C2C12 cell myotubes, and the initial rates of 45Ca(2+)-uptake were determined over a wide range of Ca2+ concentrations (0.1-10 microM). Expression of phospholamban was associated with inhibition of the initial rates of Ca(2+)-uptake at low [Ca2+] and this resulted in a decrease in the affinity of SERCA1 for Ca2+ (0.27 +/- 0.02 microM in nontransfected vs. 0.41 +/- 0.03 microM in PLB transfected C2C12 cells). These findings indicate that phospholamban expression in C2C12 cells is associated with inhibition of the endogenous SERCA1 activity and provide evidence that phospholamban is capable of regulating this Ca(2+)-ATPase isoform in its native membrane environment.

Targeted ablation of the phospholamban gene is associated with markedly enhanced myocardial contractility and loss of beta-agonist stimulation

Phospholamban is the regulator of the Ca(2+)-ATPase in cardiac sarcoplasmic reticulum (SR), and it has been suggested to be an important determinant in the inotropic responses of the heart to beta-adrenergic stimulation. To determine the role of phospholamban in vivo, the gene coding for this protein was targeted in murine embryonic stem cells, and mice deficient in phospholamban were generated. The phospholamban-deficient mice showed no gross developmental abnormalities but exhibited enhanced myocardial performance without changes in heart rate. The time to peak pressure and the time to half-relaxation were significantly shorter in phospholamban-deficient mice compared with their wild-type homozygous littermates as assessed in work-performing mouse heart preparations under identical venous returns, afterloads, and heart rates. The first derivatives of intraventricular pressure (+/- dP/dt) were also significantly elevated, and this was associated with an increase in the affinity of the SR Ca(2+)-ATPase for Ca2+ in the phospholamban-deficient hearts. Baseline levels of these parameters in the phospholamban-deficient hearts were equal to those observed in hearts of wild-type littermates maximally stimulated with the beta-agonist isoproterenol. These findings indicate that phospholamban acts as a critical repressor of basal myocardial contractility and may be the key phosphoprotein in mediating the heart's contractile responses to beta-adrenergic agonists.

T-cell-independent stimulation of immunoglobulin secretion in resting human B lymphocytes by the mannose-specific adhesin of Escherichia coli type 1 fimbriae

Purified Escherichia coli type 1 fimbriae have been shown previously to stimulate T-cell-independent proliferation of human B lymphocytes. The response is mediated by the mannose-specific, lectin-like adhesin protein FimH. Here we show that type 1 fimbriae also stimulate immunoglobulin (Ig) secretion by B cells. The response was maximal at three days of culture and consisted predominantly of the IgM isotype. It was independent of serum components, T lymphocytes, monocytes, and natural killer cells. Highly purified resting B cells were induced to proliferate and secrete Ig in response to the fimbriae. The role of FimH in the response was shown by the failure of FimH- type 1 fimbriae to stimulate and by inhibition of the response with alpha-methyl mannoside. In light of the fact that carbohydrate-binding adhesins have been found on a wide variety of microorganisms, these studies suggest the possibility that responses of other cell types to other microbial adhesins will be discovered.

Mouse phospholamban gene expression during development in vivo and in vitro

To establish a murine model that may allow for definition of the precise role of phospholamban in myocardial contractility through selective perturbations in the phospholamban gene, we initiated studies on the role of phospholamban in the murine heart. Intact beating hearts were perfused in the absence or presence of isoproterenol, and quantitative measurements of cardiac performance were obtained. Isoproterenol stimulation was associated with increases in the affinity of the sarcoplasmic reticulum Ca2+ pump for Ca2+ that were due to phospholamban phosphorylation. To assess the regulation of phospholamban gene expression during murine development, Northern blot and polymerase chain reaction analyses were used. Phospholamban mRNA was first detected in murine embryos on the ninth day of development (the time when the cardiac tube begins to contract). In murine embryoid bodies, which have been shown to recapitulate several aspects of cardiogenesis, phospholamban mRNA was detected on the seventh day (the time when spontaneous contractions are first observed). Only those embryoid bodies that exhibited contractions expressed phospholamban transcripts, and these were accompanied by expression of the protein, as revealed by immunofluorescence microscopy. Sequence analysis of the cDNA encoding phospholamban in embryoid bodies indicated complete homology to that in adult hearts. The deduced amino acid sequence of murine phospholamban was identical to rabbit cardiac phospholamban but different from dog cardiac and human cardiac phospholamban by one amino acid. These data suggest that phospholamban, the regulator of the Ca(2+)-ATPase in cardiac sarcoplasmic reticulum, is present very early in murine cardiogenesis in utero and in vitro, and this may constitute an important determinant for proper development of myocardial contractility.

Intensive care experience in Guillain-Barre syndrome

In a retrospective study of 34 patients with acute Guillain-Barre syndrome admitted to an intensive care unit (ICU) during a six year period from January 1984 to December 1989, for bulbar paresis or impending respiratory failure, 4 required endotracheal intubation to protect the airway, and 27 required mechanical ventilation. A high incidence of respiratory complications was noted. Two patients died of cardiovascular instability. Close monitoring of respiratory and cardiovascular status is essential to ensure survival.

Glycerol-induced unraveling of the tight helical conformation of Escherichia coli type 1 fimbriae

Glycerol was found to unravel the helical conformation of Escherichia coli type 1 fimbriae without appreciable depolymerization. The linearized fimbrial polymers have a diameter of 2 nm, react strongly with a monoclonal antibody directed at an inaccessible epitope on native fimbriae, and display greater mannose-binding activity and trypsin sensitivity than native fimbriae. Removal of glycerol by dialysis results in spontaneous reassembly of the linear polymers into structures morphologically, antigenically, and functionally indistinguishable from native fimbriae.

Fragmentation of Escherichia coli type 1 fimbriae exposes cryptic D-mannose-binding sites

Cells of the gram-negative bacterium Escherichia coli are able to attach to various host cells by means of a mannose-specific adhesin associated with type 1 fimbriae. Here we show that fragmentation of type 1 fimbriae by freezing and thawing results in increased mannose-binding activity as demonstrated by increased hemagglutination, increased stimulation of human lymphocyte proliferation, and increased binding of the mannose-containing enzyme horseradish peroxidase. Increased activity in all three assays was mannose sensitive and was not exhibited by FimH- mutant type 1 fimbriae lacking the adhesin. Scatchard analysis of the data from peroxidase binding assays showed that unfrozen and frozen fimbriae contain binding sites displaying two classes of affinity. Frozen and thawed fimbriae expressed an increase in the number of high-affinity binding sites. These results show that fragmentation of the fimbrial structure exposes cryptic mannose-binding activity associated with type 1 fimbriae, presumably that of internally located adhesin molecules. Our data support earlier observations that adhesin moieties of type 1 fimbriae are located both at the tips and at intervals along the length of the fimbriae. In addition, our data suggest that only the adhesin moieties that are located at the fimbrial tips are functional in binding mannose. Adhesins located along the length of the fimbriae have their mannose-binding activity buried within the fimbrial structure and hence are not functional. We propose an updated model for the structure of type 1 fimbriae that is in agreement with the above observations.

Mouse transgenes in human cells detect specific base substitutions

We describe a system of transgenic human cell lines that detects and identifies specific point mutations at defined positions within a gene. The target transgenome is a mouse adenine phosphoribosyltransferase (APRT) gene rendered nonfunctional by introduction of a substitution at either of two bases that comprise a splice acceptor site. Reversion at a mutated site results in the expression of wild-type mouse APRT and consequent growth of APRT+ transgenic cell colonies. Site-specific reversion to wild-type sequence is confirmed by regeneration of a previously destroyed diagnostic Pst I site. Two independent cell clones, each with mutant transgenomes bearing an A----G transition, exhibited an up to 7500-fold, dose-dependent induction of reversion following treatment with ethyl methanesulfonate. Treatment of these clones with 2-aminopurine resulted in no induction of revertants. In contrast, another transgenic cell clone, bearing a G----A transition, reverted as a consequence of 2-aminopurine, but not ethyl methanesulfonate, treatment. These data confirm for human cells the proposed mechanisms of action of these mutagens and provide evidence for the utility of our site-specific reversion method for mutagenesis studies.