Like oTher viruses, HIV needs a hosT cell To mulTiply. IT aTTacks helperT cells and can infecT oTher cells.
像其它的病毒一样，HIV病毒也需要一个主体细胞来繁殖。它攻击辅助T细胞并感染其它的细胞。
2
The CD4 + test directly measures the abundance of the helpertcell, an of immune cell in the bloodstream distinguishable because they are the only ones that carry the CD4 marker.
CD 4 +试验直接检测辅助型T细胞数量。辅助型T细胞是血流中可分辨的免疫细胞中的一种，因为只有他们才具有CD 4标志物。
3
Before a helpertcell can trigger a response to a pathogen or parasite, it has to "feel" these molecular bits of an invader displayed on the surface of an antigen-presenting cell (APC).