Oral aCD3 MAb will be administered at a dosage level of 0.2 or 1.0 or 5.0 mg per day for 30 days. Up of 9 subjects will be treated at each dosage level, and up to 9 subjects will receive placebo buffered in normal saline that is used as diluents for the MAb. One 20mg tablet of Omeprazole (a proton pump inhibitor) will be taken orally as part of the study drug cocktail in order to neutralize stomach pH for enhancing stability of the MAb. During the treatment period, subjects will ingest the study drug/s every day for 30 days, and will be followed for clinical and laboratory effects. Subjects will be followed up to Day 60 (30 days after termination of treatment)