Objective     To explore the activation effect of tuberculin pure protein derivative (PPD) on γδT cells of human peripheral blood.     Methods     Human peripheral blood mononu

clear cells were separated with Ficoll density gradient centrifugation method

and T cells were separated with a nylon fiber column. After separately stimulated with bacillus calmette-guerin (BCG) and PPD

the γδT cells were sorted and purified with a flow cytometer

and their antigen-presenting cell phenotypes were detected. According to culture medium components of T cells

four experimental groups were established

i.e.

(1) blank group:

Mycobacterium tuberculosis

 (Mtb) secretory antigen (Mtb-Sag) 25 μg/ml+CFSE-labeled T cells

(2) BCG group: BCG-stimulated γδT cells + Mtb-Sag 25 μg/ml+CFSE-labeled T cells

(3) PPD group: PPD-stimulated γδT cells+Mtb-Sag 25 μg/ml+CFSE-labeled T cells

and (4) dendritic cell (DC) group: mature DC+Mtb-Sag 25 μg/ml+CFSE-labeled T cells. The proliferation of T cells and CD4-positive T cells was detected.      Results     Compared with the resting phase

PPD could stimulate the expression of CD80

CD86 and HLA-DR of γδT cells to reach levels of 39.07±1.26%

51.93±1.85% and 45.74±1.58% (

P

<

0.05)

respectively

demonstrating effects comparable to BCG stimulation [(42.12±1.72)%

(54.67±2.01)% and (49.79±1.61)%

P

>0.05

respectively

]

. The T cell number [(5.14±0.68)×10

6

]

and the CD4-positive T cell ratio (35.01%) in the PPD group were remarkably higher than those in the blank group [(1.22±0.02)×10

6

8.28%

P

<

0.05

]

similar to those in the BCG group [(4.6±0.77)×10

6

32.00%

]

and remarkably lower than those in the DC group [(7.50±0.35)×10

6

58.94%

P<

0.05

]

.     Conclusion     PPD can stimulate the expression of CD80

CD86 and HLA-DR of γδT cells

indicating its activation effects on human peripheral blood γδT cells.