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.
1 One-way Alaska cruises in and out of San Francisco, Seattle or Vancouver allow travelers to spend additional land time in the northern state and cost about $430-$6,000 per person, double occupancy, for an interior room, depending on sailing date, cruise line and choice of stateroom.2  Onshore lodging is not included. One-way airfare to Alaska costs about $475-$650 from Seattle, $600-$750 from Los Angeles, or $375-$650 from New York, depending on airline and travel date. 2  Alcoholic beverages are typically not included and cost about $5-$7 per beer, $6-$11 wine or $4-$10 cocktails.