Loss of IL-7Ra is Associated With CD4+ T Cell Depletion, High IL-7 Levels and CD28 Down-regulation in HIV Infected Patients

BioMed Cen al Page 1 o 1 (page numbe no o ci a ion pu poses) Re o i ology Open Access Pos e p esen a ion Loss o IL-7Ra is Associa ed Wi h CD4+ T Cell Deple ion, High IL-7 Le els and CD28 Down- egula ion in HIV In ec ed Pa ien s Bence Re hi*‡1, Ca oline Fluu 1, Ann A las2, S en G ü zmeie 3, Angelo De Mili o1, É a Rajna ölgyi4 and F ancesca Chiodi1 Add ess: 1Mic obiology and Tumo Biology Cen e , Ka olinska Ins i u e , S ockholm, Sweden, 2In ec ious Diseases Uni , Ka olinska Uni e si y Hospi al, Solna, Sweden, 3Gay Men's Heal h Clinic, The Sode Hospi al, S ockholm, Sweden and 4Ins i u e o Immunology, Uni e si y o Deb ecen, Hunga y Email: Bence Re hi* - [email p o ec ed] * Co esponding au ho ‡P esen ing au ho In e leukin-7 (IL-7) is a su i al ac o o naï e and mem- o y T lymphocy es and i also inc eases T cell p oli e a ion du ing lymphopenic condi ions. Ele a ed le els o IL-7 ha e been ound in he blood o HIV+ pa ien s, which was conside ed as a homeos a ic esponse o pe iphe al T cell deple ion. We showed ha HIV in ec ion is associa ed wi h an inc eased p opo ion o IL-7Ra low/nega i e pe iphe al T lymphocy es. Down- egula ion o IL-7Rα on T cells was co ela ed wi h he deple ion o CD4+ T cells and also wi h he inc eased concen a ion o se um IL-7. The dec eased IL-7Rα exp ession esul ed in he educed su - i al capaci y o T cells in p esence o IL-7 and was associ- a ed wi h low Bcl-2 exp ession. Mos ly he memo y T cells down- egula ed he IL-7Rα and we ound a s ong associ- a ion be ween CD28 and IL-7Rα down- egula ion. Acco dingly, only CD28+ T cells esponded o IL-7 wi h s ong Bcl-2 up egula ion. The posi i e e ec s o IL-7 on su i al and homeos a ic p oli e a ion o T cells migh be se e ely impai ed in HIV- in ec ed indi iduals due o he dec eased IL-7Rα exp es- sion. Ch onic T cell ac i a ion may lead o an o e all dec ease o IL-7 media ed su i al signals in HIV-in ec ed indi iduals. om 2005 In e na ional Mee ing o The Ins i u e o Human Vi ology Bal imo e, USA, 29 Augus – 2 Sep embe 2005 Published: 8 Decembe 2005 Re o i ology 2005, 2(Suppl 1):P84 doi:10.1186/1742-4690-2-S1-P84 <supplemen > < i le> <p>2005 In e na ional Mee ing o The Ins i u e o Human Vi ology</p> </ i le> <no e>Mee ing abs ac s – A single PDF con aining all abs ac s in his Supplemen is a ailable he e. [link 'he e' using 'a h e ' o: <u l>h p://www.biomedcen al.com/con en /pd /1742-4690-2-S1- ull.pd </u l>]</no e> </supplemen >