Inclusion Criteria:
1. Aged 18-65 years, both male and female are eligible;
2. Diagnosis of autoimmune encephalitis within 3 months of onset (meeting the 2016 Graus and Dalmau diagnostic criteria), with positive serum/cerebrospinal fluid anti-NMDAR antibodies or anti-LGI1 antibodies;
3. Modified Rankin Scale (mRS) score ≥ 2 at enrollment;
4. The subject or legally authorized representative is able to sign the informed consent form;
5. Subjects of childbearing potential must agree to practice strict contraception during the study period.
Exclusion Criteria:
1. Pre-morbid modified Rankin Scale (mRS) score ≥ 2;
2. Known allergy to any component of the investigational product or history of severe allergic reactions;
3. Presence of neurological or psychiatric disorders (e.g., cerebrovascular disease, Parkinson's disease, severe depression) deemed by the investigator to potentially impair trial participation or study assessments;
4. Current or history of any clinically significant systemic diseases judged by the investigator as unsuitable for inclusion, including but not limited to:
* Severe cardiovascular diseases (e.g., congestive heart failure, severe arrhythmia, myocardial infarction)
* Hepatic diseases (e.g., cirrhosis)
* Renal diseases (e.g., requiring hemodialysis or peritoneal dialysis)
* Hematological diseases (e.g., hemophilia with bleeding tendency)
* Endocrine disorders (e.g., poorly controlled diabetes with blood glucose \>16.8 mmol/L or \<2.8 mmol/L, or with severe complications)
* Immune system disorders (active or uncontrolled systemic autoimmune diseases, primary/secondary immunodeficiency)
* Malignancies;
5. Anatomical nasal abnormalities, nasal mucosal damage, severe rhinitis, or other nasal conditions affecting drug administration;
6. Requiring nasogastric tube placement;
7. Organ function meeting any of the following criteria:
1. Absolute neutrophil count (ANC) \<1.5×10⁹/L, platelets (PLT) \<100×10⁹/L, hemoglobin (Hb) \<90 g/L
2. Aspartate aminotransferase (AST) \>2.5×ULN and/or alanine aminotransferase (ALT) \>2.5×ULN, total bilirubin (TBIL) \>1.5×ULN
3. Creatinine \>1.5×ULN
4. Without anticoagulant/antiplatelet therapy: International normalized ratio (INR) \>1.7 or activated partial thromboplastin time (APTT) \>1.25×ULN With anticoagulant/antiplatelet therapy: INR \>3.0 or APTT \>1.5×ULN;
8. Positive hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb) with detectable HBV-DNA; or positive for hepatitis C antibody (HCVAb), Treponema pallidum antibody (TPAb/RPR), or human immunodeficiency virus antibody (HIV);
9. Pregnant or lactating patients;
10. Contraindications for MRI (e.g., metal implants such as pacemakers, claustrophobia);
11. Participation in any clinical trial involving investigational drugs within 3 months prior to dosing (or within 5 half-lives of last dose, whichever is longer);
12. Major trauma or surgery within 3 months prior to dosing, or planned surgery during the trial (excluding laparoscopy or minor procedures \>4 weeks before baseline; excluding thymoma/teratoma surgery);
13. History of drug abuse or alcoholism within 1 year prior to dosing;
14. Previous treatment with stem cells or derivatives;
15. Any other condition that may increase patient risk or interfere with result interpretation, as determined by the investigator.
