A Basket Study of CTA313 in Participants With Active Autoimmune Diseases

Key Inclusion Criteria: * Male or female, ≥ 18 and ≤ 75 years of age * Adequate organ function * Diagnosed with one of the following in addition to meeting disease-specific criteria: 1. Refractory Systemic Lupus Erythematosus (SLE) defined as an inadequate response to at least two immunomodulatory agents and one biologic agent 2. Primary progressive multiple sclerosis (PPMS) or non-active secondary progressive multiple sclerosis (SPMS) 3. Autoimmune Encephalitis (AIE) Key Exclusion Criteria: * Coexisting autoimmune diseases that could interfere with the attribution of disease activity or pose an increased safety risk * Participants with the following cardiac conditions are excluded: 1. History of heart failure New York Heart Association (NYHA) class III or IV; 2. History of myocardial infarction, cardiovascular angioplasty or stenting, unstable angina, or other serious heart diseases within 12 months of enrollment. * History of severe central nervous system (CNS) disorders that could compromise the participant's ability to comply with protocol requirements or interfere with the accuracy of study assessments * Current or prior malignancy unless the malignancy was treated with curative intent and the subject has no known active malignant disease present for ≥ 5 years before enrollment * Primary immune deficiency * Presence of uncontrolled infections * History of untreated hepatitis C virus, or syphilis * History of HIV infection, or active or latent hepatitis B virus (HBV) infection. * Evidence of active Epstein-Barr virus (EBV), cytomegalovirus (CMV) or tuberculosis (TB) * History of prior CAR-T cell therapy or any other genetically modified immune cell therapy * Having received live/attenuated vaccine within 4 weeks prior to enrollment * Participants with a history of hypersensitivity to tacrolimus * Those who have participated in other interventional clinical trials within 30 days before enrollment * Participants who meet disease-specific exclusionary criteria as specified