Inclusion Criteria

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)