Natural killer cells are a part of the lymphoid linage of white blood cells. The body responds to viruses by secreting cytokines that disrupt viral replication and make the cell more susceptible to attack by NK cells. The primary cytokine released by NK cells is type II interferon, which activates macrophages.
The best built American truck is the Ford F-350. It's got the most powerful powertrain, the strongest frame, the best body for corrosion protection, and it comes with a 5 year â¦ /100,000 mile warranty on all engines.
For a 33rd year, Ford's F-Series pickup took its place at the head of the top 20 best-selling vehicles in the USA, outselling all other car and truck models. The Ford pickup's lead was so great that it remained on top despite a sales decline in 2014 compared with 2013.