Inclusion Criteria:

- Diagnosis of Prostate Cancer

- Castrate Resistant Disease

- Progressive disease despite androgen deprivation therapy as defined by rising PSA
levels or progressive soft tissue or bony disease

- Normal organ function per laboratory tests

- Life expectancy of at least 6 months

Exclusion Criteria:

- History of life-threatening autoimmune disease

- Small cell or other variant prostate cancer histology

- Serum testosterone at screening < 50 ng/dL

- Prior cytotoxic chemotherapy within 6 months of registration

- Patients who have undergone splenectomy

- Radiation therapy within 4 weeks of registration is prohibited, or anticipated need
for radiation therapy (e.g. imminent pathological fracture or spinal cord
compression) within 3 months of registration.

- Another malignancy other than non-melanoma skin cancer or carcinoma in situ of the
bladder. Subjects with a history of other curatively treated cancers are eligible.

- Known brain metastases

- Any antibiotic therapy or evidence of infection within 1 week of registration