Limits...
p46, a novel natural killer cell-specific surface molecule that mediates cell activation.

Sivori S, Vitale M, Morelli L, Sanseverino L, Augugliaro R, Bottino C, Moretta L, Moretta A - J. Exp. Med. (1997)

Bottom Line: Upon mAb-mediated cross-linking, p46 molecules induced strong cell triggering leading to [Ca2+]i increases, lymphokine production, and cytolytic activity both in resting NK cells and NK cell clones.The p46-mediated induction of Ca2+ increases or triggering of cytolytic activity was downregulated by the simultaneous engagement of inhibitory receptors including p58, p70, and CD94/NKG2A.Both the unique cellular distribution and functional capability of p46 molecules suggest a possible role in the mechanisms of non-major histocompatibility complex-restricted cytolysis mediated by human NK cells.

View Article: PubMed Central - PubMed

Affiliation: Istituto di Istologia ed Embriologia Generale, Università di Genova, Genova, Italy.

ABSTRACT
Limited information is available on the surface molecules that are involved in natural killer (NK) cell triggering. In this study, we selected the BAB281 monoclonal antibody (mAb) on the basis of its ability to trigger NK-mediated target cell lysis. BAB281 identified a novel NK cell-specific surface molecule of 46 kD (p46) that is expressed by all resting or activated NK cells. Importantly, unlike the NK cell antigens identified so far, the expression of p46 was strictly confined to NK cells. Upon mAb-mediated cross-linking, p46 molecules induced strong cell triggering leading to [Ca2+]i increases, lymphokine production, and cytolytic activity both in resting NK cells and NK cell clones. The p46-mediated induction of Ca2+ increases or triggering of cytolytic activity was downregulated by the simultaneous engagement of inhibitory receptors including p58, p70, and CD94/NKG2A. Both the unique cellular distribution and functional capability of p46 molecules suggest a possible role in the mechanisms of non-major histocompatibility complex-restricted cytolysis mediated by human NK cells.

Show MeSH

Related in: MedlinePlus

p46-mediated triggering  of cytolytic activity in fresh peripheral  blood NK cells. (a) Freshly isolated  peripheral blood NK cells were analyzed for their ability to kill the indicated FcγR+ target cells in the absence of mAb (□) or presence of anti-CD16 (▨ ), BAB281 (▪), or anti-CD56 mAb (▤ ). The effector target  ratio was 20:1 against P815 target cells  and 10:1 against K562 target cells. (b)  Freshly isolated PBL were sorted according to the lack of expression of  p46 (○) or CD3 (▴) or both p46 and  CD3 (*) and compared to unfractionated cells (•) for cytolytic activity  against 51Cr-labeled K562 target cells  in the absence of added mAbs.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2211712&req=5

Figure 6: p46-mediated triggering of cytolytic activity in fresh peripheral blood NK cells. (a) Freshly isolated peripheral blood NK cells were analyzed for their ability to kill the indicated FcγR+ target cells in the absence of mAb (□) or presence of anti-CD16 (▨ ), BAB281 (▪), or anti-CD56 mAb (▤ ). The effector target ratio was 20:1 against P815 target cells and 10:1 against K562 target cells. (b) Freshly isolated PBL were sorted according to the lack of expression of p46 (○) or CD3 (▴) or both p46 and CD3 (*) and compared to unfractionated cells (•) for cytolytic activity against 51Cr-labeled K562 target cells in the absence of added mAbs.

Mentions: To obtain an NK cell–enriched lymphocyte population, PBMCs were depleted of plastic-adherent cells and subsequently incubated with anti-CD3 (JT3A) mAb for 30 min at 4°C followed by treatment with goat anti–mouse–coated Dynabeads (Dynal, Oslo, Norway) for 30 min at 4°C. The resulting CD3− lymphocyte populations contained ∼1% CD3+ cells, 20% HLA-DR+ cells, and 80% CD56+ cells. These cells were used for FACS® analysis of CD3-depleted populations (see Fig. 3) and for cytolytic activity against K562 and P815 target cells (see Fig. 6 a). In another set of experiments, PBMCs were stained for both anti-CD3 and anti-p46 mAb and subsequently cells lacking the expression of p46 or CD3 or both markers (CD3−, p46−) were sorted and analyzed for cytolytic activity against K562 target cells (see Fig. 6 b).


p46, a novel natural killer cell-specific surface molecule that mediates cell activation.

Sivori S, Vitale M, Morelli L, Sanseverino L, Augugliaro R, Bottino C, Moretta L, Moretta A - J. Exp. Med. (1997)

p46-mediated triggering  of cytolytic activity in fresh peripheral  blood NK cells. (a) Freshly isolated  peripheral blood NK cells were analyzed for their ability to kill the indicated FcγR+ target cells in the absence of mAb (□) or presence of anti-CD16 (▨ ), BAB281 (▪), or anti-CD56 mAb (▤ ). The effector target  ratio was 20:1 against P815 target cells  and 10:1 against K562 target cells. (b)  Freshly isolated PBL were sorted according to the lack of expression of  p46 (○) or CD3 (▴) or both p46 and  CD3 (*) and compared to unfractionated cells (•) for cytolytic activity  against 51Cr-labeled K562 target cells  in the absence of added mAbs.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211712&req=5

Figure 6: p46-mediated triggering of cytolytic activity in fresh peripheral blood NK cells. (a) Freshly isolated peripheral blood NK cells were analyzed for their ability to kill the indicated FcγR+ target cells in the absence of mAb (□) or presence of anti-CD16 (▨ ), BAB281 (▪), or anti-CD56 mAb (▤ ). The effector target ratio was 20:1 against P815 target cells and 10:1 against K562 target cells. (b) Freshly isolated PBL were sorted according to the lack of expression of p46 (○) or CD3 (▴) or both p46 and CD3 (*) and compared to unfractionated cells (•) for cytolytic activity against 51Cr-labeled K562 target cells in the absence of added mAbs.
Mentions: To obtain an NK cell–enriched lymphocyte population, PBMCs were depleted of plastic-adherent cells and subsequently incubated with anti-CD3 (JT3A) mAb for 30 min at 4°C followed by treatment with goat anti–mouse–coated Dynabeads (Dynal, Oslo, Norway) for 30 min at 4°C. The resulting CD3− lymphocyte populations contained ∼1% CD3+ cells, 20% HLA-DR+ cells, and 80% CD56+ cells. These cells were used for FACS® analysis of CD3-depleted populations (see Fig. 3) and for cytolytic activity against K562 and P815 target cells (see Fig. 6 a). In another set of experiments, PBMCs were stained for both anti-CD3 and anti-p46 mAb and subsequently cells lacking the expression of p46 or CD3 or both markers (CD3−, p46−) were sorted and analyzed for cytolytic activity against K562 target cells (see Fig. 6 b).

Bottom Line: Upon mAb-mediated cross-linking, p46 molecules induced strong cell triggering leading to [Ca2+]i increases, lymphokine production, and cytolytic activity both in resting NK cells and NK cell clones.The p46-mediated induction of Ca2+ increases or triggering of cytolytic activity was downregulated by the simultaneous engagement of inhibitory receptors including p58, p70, and CD94/NKG2A.Both the unique cellular distribution and functional capability of p46 molecules suggest a possible role in the mechanisms of non-major histocompatibility complex-restricted cytolysis mediated by human NK cells.

View Article: PubMed Central - PubMed

Affiliation: Istituto di Istologia ed Embriologia Generale, Università di Genova, Genova, Italy.

ABSTRACT
Limited information is available on the surface molecules that are involved in natural killer (NK) cell triggering. In this study, we selected the BAB281 monoclonal antibody (mAb) on the basis of its ability to trigger NK-mediated target cell lysis. BAB281 identified a novel NK cell-specific surface molecule of 46 kD (p46) that is expressed by all resting or activated NK cells. Importantly, unlike the NK cell antigens identified so far, the expression of p46 was strictly confined to NK cells. Upon mAb-mediated cross-linking, p46 molecules induced strong cell triggering leading to [Ca2+]i increases, lymphokine production, and cytolytic activity both in resting NK cells and NK cell clones. The p46-mediated induction of Ca2+ increases or triggering of cytolytic activity was downregulated by the simultaneous engagement of inhibitory receptors including p58, p70, and CD94/NKG2A. Both the unique cellular distribution and functional capability of p46 molecules suggest a possible role in the mechanisms of non-major histocompatibility complex-restricted cytolysis mediated by human NK cells.

Show MeSH
Related in: MedlinePlus