Abstract: Objective To track peptide E7-specific CD4⁺ T cells in peripheral bloods(PBL) from pulmonary tuberculosis(PTB) patients during the untreated and 6-months treatment.Methods Two types of E7/HLA-DR8(E7/HLA-DRB1*08032 and E7/HLA-DRB1*0818) tetramers were prepared by using biotinylated monomers expressed and purified from constructed stable Drosophila Schneider 2 cell(S2 cell) lines,and then respectively used to detect tetramer-positive(peptide E7-specific) CD4⁺ T cells and total CD4⁺ T cells in the PBL of PTB patients about at days 0,15,30,45,60,90,120,150 and 180 during their regular anti-tuberculosis(TB) therapy by anti-human CD4-FITC staining and flow cytometric analysis.The PBL of non-TB patients with pulmonary infection and healthy adults,and umbilicalcord blood were used as controls.Results The percentage of total CD4⁺ T cells in the PBL of most untreated PTB patients was slightly lower than normal level;along with treatment,it got to increase rapidly and reach almost normal level in a short period;but statistical difference was only found between the PBL of untreated PTB patients and umbilicalcord blood(P<0.05),and statistical differences were not seen between other groups(P>0.05).High levels of tetramer-positive CD4⁺ T cells in the PBL of PTB patients could be detected about at days 0,15,30,45 and 60 during their regular anti-TB therapy,respectively,and statistical differences were found between the PBL of these time-points and both of subsequent time-points and 3 control groups(P<0.01 or P<0.05).In contrast,there was no statistical difference between 2 tetramer staining(P>0.05).The results suggested that relatively high and the highest levels of tetramer-positive CD4⁺ T cells appeared in the PBL of untreated PTB patients and treated cases at days 15-60,respectively.Subsequently,although some small rise and fall in some patients,the percentages of tetramer-positive CD4⁺ T cells began to decrease,and gradually reached and kept at a relatively low even normal level.Conclusion Peptide/HLA-DR tetramers could be used to track peptide-specific CD4⁺ T cells in the PBL of TB patients during the untreatment and treatment,which combined with the detection of total CD4⁺ T cells is significant for monitoring TB development and recovery.

Key words: Tuberculosis,pulmonary/immunology, CD4-positive T-lymphocytes, HLA-DR antigens