Vaccine Therapy in Treating Patients With Metastatic Prostate Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed metastatic adenocarcinoma of the prostate * Stage D1-3 * Regional lymph node, bone, visceral, or soft tissue metastases * No transitional cell or small cell carcinoma * Testosterone less than 50 mg/L if prior treatment with luteinizing hormone releasing hormone (LHRH) analogues or estrogens * Evidence of androgen refractory disease after surgical castration and discontinuation of LHRH analogue therapy * No previously irradiated or new CNS metastases PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 70-100% Life expectancy: * More than 6 months Hematopoietic: * WBC at least 3,000/mm\^3 * Hemoglobin at least 9 g/dL * Platelet count at least 100,000/mm\^3 Hepatic: * Bilirubin less than 2.0 mg/dL * PT at least 11.3 seconds but no greater than 13.3 seconds * PTT at least 20.1 seconds but no greater than 32.9 seconds * No hepatic disease * No viral hepatitis Renal: * Creatinine less than 2.5 mg/dL Cardiovascular: * No New York Heart Association class III or IV heart disease Pulmonary: * No asthma * No chronic obstructive pulmonary disease * No severe lung disease Other: * No other medical illness or psychological impediment that would preclude study * No other concurrent malignancy except nonmelanoma skin cancer or controlled superficial bladder cancer * No active acute or chronic infection including symptomatic urinary tract infection * No autoimmune disease (e.g., inflammatory bowel disease, systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, scleroderma, or multiple sclerosis) * HIV negative * Adequate peripheral vein access PRIOR CONCURRENT THERAPY: Biologic therapy: * Prior biologic therapy allowed * No other concurrent immunotherapy Chemotherapy: * Prior chemotherapy allowed * No concurrent chemotherapy Endocrine therapy: * See Disease Characteristics * At least 4 weeks since prior non-steroidal hormonal therapy if increase in PSA while receiving non-steroidal hormonal therapy * At least 6 weeks since prior steroids * Concurrent LHRH analogues for gonadal androgen suppression allowed * No concurrent steroid therapy * No concurrent corticosteroids Radiotherapy: * See Disease Characteristics * Prior palliative radiotherapy for bone metastases allowed * Prior prostatic radiotherapy allowed * At least 4 weeks since prior radiotherapy * At least 12 weeks since prior strontium chloride Sr 89 * No concurrent radiotherapy Surgery: * See Disease Characteristics Other: * Recovered from prior therapy * No concurrent immunosuppressive agents (e.g., azathioprine or cyclosporine)