Study of CD19 t-haNK and NAI With Rituximab in Participants With Indolent Non-Hodgkin Lymphoma

Participants will receive treatment for a maximum of 12 cycles( 36 weeks) or until they have PD, unacceptable toxicity, withdrawal consent, or if the investigator feels it is no longer their best interest to continue treatment. Subjects first receive CD19t-haNK, N-803 and Rituximab for a 4-week induction cycle. If subjects respond to treatment they will receive maintenance therapy from cycle 2 to 12 (repeated 3 week cycles). All participants should be followed for collection of survival statis, disease status, and posttreatment therapies every 12 weeks (+/- 2 weeks). The follow up visits may occur in-person or via phone contact. The cycles have visits on the following days: Cycle 1 (Day 1, 8, and 15), Cycles 2-6 (Day 1, 8) and Cycles 7-12 (Day 1). On each of these days, the following will be conducted: Concomitant Medication, Physical Exam, Vitals, ECOG and Labs.