Peripheral Blood Mononuclear Cells (PBMC) are a mixed population of cells with a single nucleus found in peripheral blood (i.e., blood outside the bone marrow), including natural killer cells (NK), T lymphocytes (70% - 90%), and B lymphocytes. They can be further isolated and purified and are the main source of immune cells. This study will be conducted at our hospital, with a planned recruitment of 200 subjects. Subjects who meet the inclusion criteria and do not meet the exclusion criteria will have their peripheral blood mononuclear cells collected via apheresis. Each subject will need to provide an apheresis sample containing approximately 8×10^9 mononuclear cells (with a sample volume of about 150 mL).

Inclusion Criteria:

• Aged between 18 and 40 (inclusive), male or non-pregnant female, regardless of nationality.

Weight: Male ≥ 50kg; Female ≥ 45kg, and 19kg/m2 ≤ BMI ≤ 30kg/m2 (BMI, Body Mass Index = weight (kg) ÷ height (m)2).

Blood pressure: Measurement results are either normal or abnormal, but without clinical significance.

Pulse rate: Measurement of normal or abnormal pulse rate has no clinical significance.

Temperature (ear temperature): 35.4-37.2℃. The patient's general condition is good: there is no damage to vital organs such as the heart, lungs, liver, and kidneys, no severe or uncontrolled infections, and no history of severe mental disorders.

Clinical examination must meet the following criteria: • Hemoglobin (Hb) measurement is normal or abnormal without clinical significance • White blood cell count (WBC) measurement is normal or abnormal without clinical significance • Platelet count (PLT) measurement is normal or abnormal without clinical significance • Neutrophil count (NEU) measurement is normal or abnormal without clinical significance • Liver function test indicators <1.5ULN • Coagulation function is normal or abnormal without clinical significance • 12-lead electrocardiogram results are normal or abnormal without clinical significance • Hepatitis A virus antibody (HAV) is negative.

Hepatitis B virus surface antigen (HBsAg) negative Hepatitis C virus antibody (HCV antibody) negative.

Human immunodeficiency virus antibody (HIV-1 and HIV-2 antibody) negative. Treponema pallidum antibody test is negative. The test result for CMV IgM antibody is negative.

Exclusion Criteria:

• Previously had adverse reactions to blood donation. The following diseases are considered clinically significant by researchers: autoimmune diseases, severe endocrine and metabolic diseases, malignant tumors, neuropsychiatric diseases; Creutzfeldt-Jakob disease and those with a family history, or those who have received treatment with tissues or tissue derivatives that may have been infected with the Creutzfeldt-Jakob pathogen; chronic skin diseases, especially infectious, allergic, or inflammatory systemic skin diseases; those with allergic diseases or recurrent allergies; those who have undergone surgical operations in the past three months.

Women who are in their menstrual period, pregnancy, less than 6 months after abortion, or less than 1 year since the end of childbirth and lactation period.

Individuals who have recovered from an upper respiratory infection within the past week, or those who have recovered from pneumonia within the past three months.

Individuals with urinary system infections less than 3 months old, or those experiencing an acute episode of urinary system stones.

Equipment contaminated by blood or tissue fluid causing injury or contaminating wounds, or individuals who have undergone tattooing less than one year ago.

Long-term uninterrupted use of hormone drugs or immunosuppressants exceeding physiological replacement doses is required, including but not limited to glucocorticoids and steroids, hydroxyurea, and immunomodulatory drugs (such as alpha or gamma interferon, GM-CSF, mTOR inhibitors, cyclosporine, thymosin, etc.) in doses exceeding physiological replacement levels.

Those who have received whole blood and blood component transfusions within 1 year.

Those who have received their last dose of antitoxin or immune serum within 1 year, or those who have received their last dose of hepatitis B immunoglobulin injection within 1 year.

Individuals who have received the last dose of live attenuated vaccines such as measles, mumps, or polio vaccines within 2 weeks, or the last dose of live rubella vaccines or live attenuated Japanese encephalitis vaccines within 4 weeks.

Individuals who have received the final immunization dose of rabies vaccine within one year after being bitten by an animal.

Poor conditions for vascular puncture, unable to tolerate venipuncture, or history of fainting at the sight or touch of blood. Upon inquiry, individuals with a history of drug use, drug abuse, or positive drug abuse screening (morphine, methamphetamine, ketamine, tetrahydrocannabinolic acid, MDMA) within the previous 12 months prior to screening. Healthy volunteers who have participated in intervention drug clinical studies and have used study drugs within 7 days prior to screening.

Other situations where the researcher believes participation in this study is not appropriate.

healthy individuals