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i2.;iw@:r:;vi. known as IgE. The reaction involves several steps. When an allergen enters the body, so-called helper T cells sig- nal danger bv releasing a chemical called 11-4. That alarm prompts a second class of immune cells-the B cells-to churn out i¢E antibodies. When these antibod- ies dock with receptors on still other immune cells (the mast cells and baso- philsl, they trigger a flood of histamine and other chemicals. These "allergic me- diators" cause different kinds of misery depending on the tissues they infiltrate. How could science reverse such a process? One approach, pioneered by researchers at Genentech of South San Could now research render ragweed - pollen / harmless? highlight 11-4's role in IgE sytttcesis. But 'vs resu3ts suggest that dummy 11-4 covid maioevotetrt ..,r«.j,,e Even if these methodicai endeavuuus Sindtreya5fim, ize allergy treatment, trial andertnrjust raight. Consut er what happened when researchers at Chicrago's Northwestern University Medial Schnni started studying a natural hormone rza;W sahstanre p As expected, a single dose made atumaLss mme sensisive to a common allergen. But several months later, Dc Roy Patterson discovered that the treated animals were producing fewer aller gic antibodies. Suspecting he was onto somethh'tg, Pat- terson treated three coi- leagues with substance P Francisco and Tanox Biosystems of Houston, is to knock out IgE d small doses of ragweed or rye gtasa with genetically engineered antibodies. Both firms have designed I an dBefore they got the treatment. all three molecules that fit onto IgE as a lock fits around a key. By binding ~ were producing IgE antibodies to those with IgE before it can connect with the receptors on mast cells, these agents should prevent the release of histamine. Both compa- nies have completed initial safety studies and are now giving patients injections to gauge the therapeutic effects. If all went well, a drug could reach the market within seven years. Meanwhile, scientists at Palo Alto's DNAX Research Institute are learning to defuse allergic reactions at an even earlier stage. Reasoning that errant B cells would make less IgE if they weren't always being goaded by 11-4, the DNAX researchers have created an impotent version of the ll-4 molecule. Given to mice, the mole- cule sticks to the receptors on B cells, shutting out true 11-4 and foiling IgE production. The mouse study was intended merely to OENN[5 KUNKEL-CNpI-PIIOTprNl6 1= irritants, though not enough to rause symptoms. After their shots, two of the three experienced a sharp drop in Ig$ and the effect has persisted. iarger studies are now in the works. Don't toss your Kleenexjustyet; spar kling preliminary findings rarely turn out to he gold. But if these new ap- proaches pan out, they could yield a mother lode of relief. -Geoffrey Cowley with Robina Riccitiello t`i~TIC~O'I`I\-E GL, ALP 8.d naw toe agsheads-Zll. 60millloa Lrriryatesi5gthe:fadrsean'tlbsirto dN~irrreR.t U~- jehn's Nntaitls ofhen tails to gro.r moch S..r. tluv. p.ah fas Vis.l..wwro5n. 31 pueant l..t trar. Trus. Maek is igraas- hK Its praa.t.• sbkdd55adev{ PSa~s- csab s h.i-zrerlh prod55et. But.torth. nett few years, tr7 shavingyourhsad. IA S I~n lh.~ DocToR ~~oL~ Irr:' It's called NICOAETTE' inicotme polactilexl. And it's "-~ ~TTE a serious medicine that's only available through your doctor. -~ My doctor and I discussed whether NICORETTE was right for me. Shouldn't you find out whether it's right for you? NICORETTE® (nicotine polacrilex) AskYour Healthcare Professional About It Tbdav So SmrthXlm. L.dum 01994. smNhKlino &edum Cunwmcr HnlNhwrt I