*2.7. Flow Cytometry Analysis of PBMCs*

For the flow cytometry analysis blood from two healthy volunteers was collected after informed consent and PBMCs were isolated separately using density gradient centrifugation (Polymorphprep; Cosmo Bio, Tokyo, Japan) and washed with PBS (1% FBS). After treating PBMCs (106 cells/mL) with varying concentrations of LUMS1, MVN, and cyanovirin-N (CVN) for 72 h at 37 ◦C and 5% CO2, cells were washed with PBS (2% FBS) and incubated with APC-conjugated anti-cluster of differentiation-4 (CD4), PE-conjugated anti-CD25, and percp cy5.5-conjugated anti-CD20 antibodies for 30 min at 4 ◦C. Respective isotype controls were used for compensation of backgrounds. Finally, cells were washed with PBS (2% FBS), fixed with 1% formaldehyde, and analyzed by FACS (Calibur; BD Biosciences, Franklin lakes, NJ, USA), using CellQuest software for data acquisition [18].

#### *2.8. MTT Assay*

TZM-bl cells and PBMCs were seeded in 96-well plates at optimized concentrations of 8 <sup>×</sup> 104 and 7 <sup>×</sup> 10<sup>5</sup> cells per 100 <sup>μ</sup>L, respectively, with various concentrations of the LUMS1 protein (1.25, 2.5, 5, and 10 μM), and incubated for 48 h. MTT reagent was added at a final concentration of 0.5 mg/mL and incubated for 4 h as reported previously [24]. The plate containing PBMCs was centrifuged for 5 min at 300× *g*. After completely removing the media, 100 μL DMSO was added and thoroughly mixed to dissolve the crystals, and finally absorbance was measured at 570 nm.

#### **3. Results**
