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.
Non-refundable American Express service fee of $39 (per ticket) applies to each purchase and itinerary change for Platinum and Business Platinum Card Members. *** Ticket refunds require cancellation of reservation prior to scheduled departure.