Naslov
Expression of activating and inhibiting NK receptors on natural killer cell subsets in infants

Autori
Vojvoda, Valerija ; Bendelja, Krešo ; Turkalj, Mirjana ; Aberle, Neda ; Jonjić, Stipan ; Rabatić, Sabina

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
NK2010 / - , 2010

Skup
12th Meeting of the Society for Natural Immunity & NK2010

Mjesto i datum
Cavtat, Hrvatska, 11.09.2010. - 15.09.2010

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
NK cells; NK receptors; infants; RSV

Sažetak
Infants are more prone to infections than adults since their immune system is still not completely developed. Natural killer (NK) cells play an important role in the first line of defense against viral infection. NK cells can be immunophenotyped regarding specific CD56 and CD16 (FcγRII) expression that can be variably present at their surface. Regarding the expression of these two molecules NK cells can be divided into two subsets ; major CD56+CD16+ and minor CD56- CD16+ NK cells with diminished cytotoxic activity. Although, NK cell cytotoxicity is dependent on the interaction between different NK receptors (NKR) and target cell ligands, the balance between engagement of activating and inhibiting NKR determines outcome. Our goal was to analyze NK subsets panel and distribution of activating and inhibiting NK receptors in infants and adults. PBMC were isolated from healthy adults, healthy infants and RSV infected hospitalized infants. NK cell subsets were distinguished based on CD3, CD56 and CD16 antibody staining. Gated CD3- lyphocytes were further analyzed regarding CD56 and CD16 expression. Thus total NK population comprises CD56+CD16-, CD56+CD16+, CD56-CD16+ subsets. NK cells were additionally stained with noncommercial antibodies for NK receptors (LIR1, KIR2DL2, NKp46, NKp80, NKG2D or CMRF) followed by secondary staining with goat anti-mouse immunoglobulin. Different proportion of NK cell subsets were noticed in infants compared to adults. CD56+CD16+ cells were predominant in all tested groups, while CD56-CD16+ cells, although scarce in adults, represented one third of total NK cells in infants. Those two subsets of NK cells revealed also some differences regarding NKR expression in both infants and adults. In adults CD56+CD16+ cells had higher percentages of activating receptors (NKp46, NKp80, NKG2D and CMRF) compared to CD56-CD16+ cells. In healthy and RSV infected infants, inhibiting receptors (LIR1 and KIR2DL2) tended to be lower on CD56+CD16+ cells compared to healthy adults. Comparison of NKR between two examined NK cell subsets showed lower expression of NK activating receptors on CD56-CD16+ NK cells. The fact that CD56-CD16+ cells represent significant proportion of total NK cells in infants might be the reason for lower overall NK activity observed in this group. Lower CMRF and NKG2D expression on NK cells in healthy and RSV- infected infants impose lower activating potential. Misbalance in ratio of CD56+CD16+ cells versus CD56-CD16+ cells, together with different NKR expression, can contribute to the weaker antiviral response in infants.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti, Kliničke medicinske znanosti

Napomena
Dodijeljena stipendija za pohađanje sastanka

POVEZANOST RADA