Noun. 1. interleukin-any of several lymphokines that promote macrophages and killer T cells and B cells and other components of the immune system. lymphokine-a cytokine secreted by helper T cells in response to stimulation by antigens and that acts on other cells of the immune system (as by activating macrophages).
Now, passengers must pay a flat fee of $5.60 in each direction, no matter how many plane transfers are made to get from one city to another. For passengers flying a nonstop round trip, that means the fee will increase from $5 to $11.20.Passengers flying round-trip with a connection each way will see their fees increase $1.20 to $11.20 per round trip, versus $10 before the fee increase.ost of the new revenue will go to pay down the federal deficit. Until Monday, a passenger was charged $2.50 for each leg of a journey. For a nonstop round trip, the cost was $5. For a round trip with a connection each way, the cost was $10. The fee was capped at two flights each way.
Passengers, then as now, were charged $2.50 per enplanement with a maximum one-way-trip fee of $5.00. In other words, a passenger taking a non-stop flight would pay a total of $2.50, while a passenger with at least one connecting flight would pay $5.00.t would also eliminate the ASIF fee charged to air carriers. The higher passenger fee collections would allow TSA to ultimately offset about 43 percent of aviation-security costs. [1] Air carriers are charged an Aviation Security Infrastructure Fee (ASIF), which accounts for about 20 percent of total fees collected.