CD4 and infection: To study the characteristics of CD3+γδTCR+ cells after infection, single lung cells from both normal naïve and infected mice were stained with different fluorescence labeled factors: CD3, γδ TCR, CD4, CD8, Vγ2, CD25, CD69, CD127, CD62L, MHCII, CD80, PDL1, PDL2, CXCR3, CXCR4, CXCR6, and CX3CR1.