By
From the * Division of Molecular Genetics, Center for Biological Science, Chiba University School of
Medicine, Chiba 260, Japan; and the Department of Immunology, Juntendo University School of
Medicine, Tokyo 113, Japan
Natural killer (NK) cells exhibit cytotoxicity against variety of tumor cells and virus-infected cells
without prior sensitization and represent unique lymphocytes involved in primary host defense. NKR-P1 is thought to be one of NK receptors mediating activation signals because cross-linking of NKR-P1 activates NK cells to exhibit cytotoxicity and IFN- production. However,
molecular mechanism of NK cell activation via NKR-P1 is not well elucidated. In this study,
we analyzed the cell surface complex associated with NKR-P1 on NK cells and found that
NKR-P1 associates with the FcR
chain which is an essential component of Fc receptors for IgG
and IgE. The association between FcR
and NKR-P1 is independent of Fc receptor complexes. Furthermore, NK cells from FcR
-deficient mice did not show cytotoxicity or IFN-
production upon NKR-P1 cross-linking. Similarly, NK1.1+ T cells from FcR
-deficient mice
did not produce IFN-
upon NKR-P1 crosslinking. These findings demonstrate that the
FcR
chain plays an important role in activation of NK cells via the NKR-P1 molecule.
NK cells play a pivotal role in protective immunity. Especially, NK cells are involved in the earliest stage of
immune response because they can exhibit cytotoxicity or
cytokine production without prior sensitization (1). Therefore, it is important to elucidate the mechanism of antigen
recognition by NK cells to understand innate immunity.
Recent analyses have revealed that various types of receptors are involved in the regulation of NK cell activation (2,
3). Among these, the NKR-P1 molecule is thought to be one of NK receptors which mediates NK cell activation
because cross-linking of NKR-P1 induces various activation signals such as, Ca2+ flux, PI turnover and lymphokine
production (4, 5). The NKR-P1 was originally cloned from
rat NK cells (4, 5), and subsequently cloned from mouse
and human (6, 7). In mouse NK cells, NK1.1, a specific
marker of mouse NK cells, is one of NKR-P1 family molecules, NKR-P1C (8).
NK cells exhibit cytotoxicity and IFN- In respect to the signaling pathway for NKR-P1, it has
been shown that NKR-P1 crosslinking stimulates PI turnover and raises intracellular Ca2+ concentration (13). In addition, NKR-P1 possesses a p56lck-binding motif which is
represented by YxxL sequence and indeed the association
of p56lck to NKR-P1 was recently reported (14). However,
essential components for NK cell activation via the NKR-P1
molecule have not been elucidated. In the present study,
we analyzed the cell surface complex associated with the
NKR-P1 molecule and found that the FcR Mice.
FcR NK Cell Preparation.
NK cells were purified as previously described (18). In brief, NK cells were purified from spleen of 6-8-wk-old C57BL/6 mice. Splenocytes were mixed with anti-CD4
mAb (GK1.5) and anti-CD8 mAb (53.6.7), and incubated with
magnetic beads (Advanced Magnetics, Inc., Cambridge, MA)
coupled with goat anti-mouse IgG Ab and goat anti-rat IgG Ab
(Cappel, Organon Teknika Co., West Chester, PA) to remove
surface Ig (sIg)+ B cells and CD4+ and CD8+ T cells. The residual cells were then stained with PE-anti-NK1.1 (PK136) mAb
and FITC-anti-CD3 Flow Cytometric Analysis of NK Cells.
CD4 NK1.1+ T Cell Preparation.
Basically, NK1.1+ T cells were
prepared as previously described (10). Thymocytes were treated
with anti-HSA mAb (J11d) followed by complement treatment.
The resultant cells were incubated with anti-CD8 and anti-MEL-14 mAb. Thereafter, CD8+ MEL-14+ cells were removed by use
of magnetic beads coupled with goat anti-rat IgG Ab. The residual cells were cultured for 3 d in the presence of 1,000 U/ml IL-2.
Thereafter, cells were stained with PE-anti-NK1.1 mAb and
FITC-anti-CD3 Surface Biotinylation, Immunoprecipitation and Western Blotting.
Cells were surface biotinylated as previously described (19). Biotinylated cells were lysed with a lysis buffer containing 1% digitonin, 50 mM Tris-HCl (pH 7.6), 150 mM NaCl, 10 µg/ml aprotinin, 10 µg/ml leupeptin, 1 mM PMSF, 10 mM iodoacetamide,
at a concentration of 1 × 107 cell/ml. Immunoprecipitation was
performed with anti-CD3 NKR-P1 and TCR Stimulation.
(Fab) Measurement of IFN- Redirected Cytotoxicity of NK Cells.
Cytotoxic assay was done
basically as previously described (20). Briefly, freshly isolated
CD4 To elucidate signaling pathways for NK cell activation
through NKR-P1, we analyzed the NKR-P1-associated
complex on the cell surface using an NK1.1-expressing T
cell line CTLL-2. CTLL-2 cells were surface-biotinylated
and the cell lysate was immunoprecipitated with anti-NK1.1 or anti-CD3 As shown in Fig. 1 A, immunoprecipitation with anti-NK1.1 mAb revealed that a 9-kD homodimer was coprecipitated with NK1.1 molecule. In contrast, when the TCR
complex was precipitated with anti-CD3
To elucidate the physiological role of the association between FcR
Recently, we have shown that cross-linking of NKR-P1
on NK cells with anti-NK1.1 mAb induced not only cytotoxicity but also IFN-
Because NK1.1+ T cells also produce IFN-
We also investigated the involvement of FcR
The failure of NK cell activation through NKR-P1 in
FcR Fc Recent analysis revealed that activation of NK cells is
negatively regulated by several killer inhibitory receptors
(KIR) possessing immunoreceptor tyrosine-based inhibition
motif (ITIM) (28, 29). These receptors such as p58,
NKG2, and Ly49 recognize specific MHC class I molecule
and deliver inhibitory signal for the cytotoxicity by NK
cells (30). Furthermore, association of SHP-1 phosphatase with ITIM is important for the inhibition of NK cell
activation (28, 29). Although the coprecipitation of CD3 Although the NKR-P1 molecule belongs to the C-type
lectin superfamily and has been shown to have affinity to
specific carbohydrates (12), the exact function of NKR-P1
has remained unclear. This is partly because antibodies
against mouse or rat NKR-P1 do not block cytotoxicity of
NK cells against YAC-1, a NK-sensitive target cell line. In
addition, NK cells from production
upon cross-linking of NKR-P1 molecule with specific
mAb (4, 5, 9, 10). Indeed, introduction of NKR-P1 into a
NKR-P1-deficient NK cell line restored cytotoxicity against
certain tumor cell targets (11). Furthermore, anti-NKR-P1
mAb blocked the cytotoxicity by the NKR-P1-transfected
NK cells (11). Therefore, NKR-P1 seems to be involved
in the antigen recognition by NK cells. Although the exact
ligand for NKR-P1 remains to be determined, NKR-P1
belongs to the C-type lectin superfamily and certain carbohydrates expressed on target cells are postulated to be recognized by the NKR-P1 molecule (12).
chain is associated with NKR-P1. Furthermore, the analysis of NK
cells from FcR
-deficient mice revealed that the FcR
chain is essential for mediating activation signals via NKR-P1.
-deficient (
/
)1 mice with C57BL/6 background
were established by gene targeting using a C57BL/6 origin ES cell
line BL6/III (15) in our laboratory (Park, S.Y. et al., manuscript submitted, 16, 17) and maintained in our animal facility in SPF condition.
(145-2C11) mAb (Pharmingen, San Diego, CA) and NK1.1+ CD3
cells were sorted by FACStarplus®
(Becton Dickinson, Mountain View, CA). The purified NK cells were cultured in RPMI-1640 supplemented with 10% FCS, kanamycin (100 µg/ml) and 5 × 10
5 M 2-ME in the presence of
1,000 U/ml human recombinant IL-2 (kindly provided by Dr.
Junji Hamuro, Ajinomoto Co. Inc., Kawasaki, Japan) for 5 d.
CD8
sIg
splenocytes prepared as described above were cultured for 4 d in the
presence of 1,000 U/ml IL-2. The cultured cells were first stained
with FITC-anti-Fc
RIII (2.4G2) mAb. Then, the cells were mixed
with Biotin-anti-CD3
and PE-anti-NK1.1 mAbs followed by
Quantum-red streptavidin (Sigma Chem. Co., St. Louis, MO).
mAb. The stained cells were sorted into
NK1.1+CD3+ cells. The sorted cells were further cultured for 2 d
in the presence of 1,000 U/ml IL-2 and used for functional analysis.
or anti-NK1.1 mAbs. Immunoprecipitates were separated on two-dimensional nonreducing and reducing SDS-PAGE and transferred onto a polyvinylidene difluoride (PVDF) membrane (Immobilon-P; Millipore Corporation, Bedford, MA). The biotinylated proteins were detected using streptavidin-peroxidase (VECSTAIN Elite ABC kit; Vector Laboratories Incorporated, Burlingame, CA), the ECL system (Amersham
International, Buckinghamshire, England), and autoradiography.
After termination of chemiluminescence, the membrane was blotted with anti-FcR
Ab followed by peroxidase-labeled anti-rabbit Ab (Amersham) and detected by the ECL system.
2 fragment of anti-NK1.1 mAb was immobilized on a 96-well flat-bottomed culture
plate (Coaster, Cambridge, MA) by incubating for 2 h at 37°C at
a concentration of 50 µg/ml in PBS. Similarly, anti-TCR-
mAb (H57-597) was immobilized at a concentration of 100 µg/ml.
1 × 105 NK cells cultured for four days in the presence of IL-2
were stimulated with the immobilized anti-NK1.1 mAb, or with
recombinant mouse IL-12 (4.9 × 106 U/mg, generously supplied
from Genetics Institute, Inc., Cambridge, MA) for 2 d.
and IL-4.
IFN-
and IL-4 in the culture supernatant was measured by ELISA with standard protocol.
Anti-IFN-
(R4-6A2) and anti-IL-4 (BVD4-1D11) mAb was
coated to capture IFN-
and IL-4 and the captured IFN-
and
IL-4 were detected with biotinylated anti-IFN-
(XMG1.2) and
anti-IL-4 (BVD6-24G2) mAbs. These antibodies were purchased from Pharmingen. Concentrations of IFN-
and IL-4 were determined with recombinant IFN-
and IL-4 as a standard.
CD8
HSA
sIg
population was used as NK cell enriched population. About 50% of this population expressed the
NK1.1 molecule. These NK cells were incubated at 4°C for 30 min in the presence or absence of anti-NK1.1 mAb. Thereafter,
51Cr-labeled FcR-expressing P815 cells were added and cultured
at 37°C for 4 h and analyzed the amount of Cr51 released in the
culture supernatant. Specific cytotoxicity was calculated as previously described (20).
mAbs, followed by analysis on two dimensional nonreducing and reducing SDS-PAGE.
mAb, CD3
homodimers, CD3
-FcR
heterodimers and a small amount
of FcR
homodimers were observed as previously reported (21). Interestingly, the 9-kD homodimers coprecipitated with NK1.1 appeared to be identical to FcR
within the TCR
complex. Indeed, the homodimers coprecipitated with NK1.1
were blotted with anti-FcR
Ab similarly to FcR
observed in the CD3
-immunoprecipitates (Fig. 1 B). The association of the FcR
chain with the NKR-P1 molecule
was also observed in a rat NK cell line, RNK-16 (data not
shown). We next analyzed normal NK cells to generalize
the physical association between FcR
and NKR-P1 in
normal NK cell population. Similar to CTLL-2, when
NK1.1 was immunoprecipitated from IL-2 activated NK
cells, the FcR
homodimer was coprecipitated with
NK1.1 (Fig. 2). Collectively, these data indicate that the association of FcR
with NKR-P1 is generally observed for
NK cells in vivo.
Fig. 1.
Association of the FcR chain with the NKR-P1 molecule
on the cell surface of CTLL-2 cell line. (A) CTLL-2 cells were surface-biotinylated and the cell lysate was immunoprecipitated with anti-NK1.1
mAb or anti-CD3
mAb and analyzed on two-dimensional nonreducing
(NR) and reducing (R) SDS-PAGE. Biotinylated proteins were detected by an ECL. (B) FcR
chain was detected by blotting the membrane with
anti-FcR
Ab after immunoprecipitation with anti-NK1.1 or anti-CD3
mAbs. FcR
homodimer (
-
) and CD3
-FcR
heterodimers (
-
)
were indicated.
[View Larger Version of this Image (71K GIF file)]
Fig. 2.
Association of the FcR chain with the NKR-P1 molecule
in IL-2-expanded NK cells. NK cells from normal mice expanded for 1 wk
in the presence of IL-2 and were surface-biotinylated. The cell lysate of
them was immunoprecipitated with anti-NK1.1 mAb ((Fab)
2 fragment)
and analyzed on two-dimensional nonreducing (NR) and reducing (R)
SDS-PAGE. Biotinylated proteins were detected as Fig. 1 A. FcR
homodimer (
-
) was indicated.
[View Larger Version of this Image (44K GIF file)]
and NKR-P1 particularly on signal transduction in NK cells, NK cells were prepared from
/
mice
and analyzed for NKR-P1 expression and NKR-P1-mediated NK cell activation. When CD4
CD8
sIg
splenocytes from
/
mice were stained with anti-NK1.1 and
anti-CD3
mAbs, normal development of NK cells
(NK1.1+CD3
) was observed (data not shown). When expression of Fc
RIII on IL-2-expanded NK cells was analyzed, NK cells from
/
mice did not express Fc
RIII
(Fig. 3). In addition, the expression level of NK1.1 on the
cell surface of IL-2-expanded NK cells from
/
mice
was significantly lower than that of NK cells from
+/+ and
+/
mice. However, the difference of NK1.1 expression
between
/
and
+/
mice was marginal when freshly
isolated NK cells were analyzed (data not shown). This
suggested that FcR
is not absolutely required for but affects the surface expression of the NKR-P1 molecule.
Fig. 3.
Loss of the cell surface expression of FcRIII on NK cells
from
/
mice. CD4
CD8
HSA
sIg
splenocytes from
+/+,
+/
and
/
mice were cultured for 4 d in the presence of 1,000 U/ml IL-2. The
cultured cells were stained with FITC-anti-Fc
RIII, PE-anti-NK1.1 and
Quantum red-anti-CD3
mAbs and the expression of Fc
RIII and NK1.1 on the CD3
population was illustrated. Representative data from
five independent experiments are shown.
[View Larger Version of this Image (14K GIF file)]
production (10). Thus, we stimulated purified NK cells from
/
mice with immobilized
F(ab)
2 fragment of anti-NK1.1 mAb in order to avoid the
binding of the Ab to Fc receptors, and measured the amount of IFN-
produced in the culture supernatant. Surprisingly, NK cells from
/
mice did not produce IFN-
at all upon NKR-P1 cross-linking, whereas NK cells from
+/+ mice produced a large amount (Fig. 4). In contrast,
NK cells from both
/
and
+/+ mice produced almost
equal amount of IFN-
upon IL-12 stimulation. This suggests that the defect of IFN-
production upon NKR-P1 cross-linking by NK cells from
/
mice is not due to the
inability of IFN-
production but the signaling defect via
NKR-P1.
Fig. 4.
Defect of IFN- production by NK cells from
/
mice
upon stimulation with NK1.1 cross-linking. NK cells from
+/+ (closed
bar) and
/
(open bar) mice were stimulated with immobilized (Fab)
2
fragment of anti-NK1.1 mAb or 1 ng/ml IL-12 and IFN-
produced in
the culture supernatant was measured. Data are presented as mean ± SD
of triplicate culture.
[View Larger Version of this Image (12K GIF file)]
but not IL-4
upon NKR-P1 cross-linking (10), we also analyzed the
function of NK1.1+ T cells in
/
mice. As we have previously reported (22), NK1.1+ T cells develop normally in
/
mice. NK1.1+ T cells were prepared from
+/+ and
/
mice and stimulated with immobilized anti-NK1.1
mAb (Fig. 5). Similar to NK cells, NK1.1+ T cells from
/
mice did not produce IFN-
upon NKR-P1 cross-linking whereas these cells from
+/+ mice produced a significant amount of IFN-
. In contrast to the stimulation
through NKR-P1, NK1.1+ T cells from both
+/+ and
/
mice produced IFN-
and IL-4 upon TCR crosslinking. These observations demonstrate that the FcR
chain is required for IFN-
production via NKR-P1 cross-linking both in NK cells and NK1.1+ T cells.
Fig. 5.
Defect of IFN- production by
NK1.1+ T cells from
/
mice upon stimulation with NK1.1 cross-linking. NK1.1+
T cells from
+/+ (closed bar) and
/
(open
bar) mice were stimulated with immobilized
anti-NK1.1 mAb or anti-TCR
mAb and
IFN-
and IL-4 produced in the culture supernatant was measured. Data are presented
as mean ± SD of triplicate culture.
[View Larger Version of this Image (12K GIF file)]
in the
NKR-P1-mediated cytotoxicity of NK cells. Since NKR-P1
is known to induce redirected cytotoxicity against FcR-expressing cells, we analyzed cytotoxicity of NK cells against
FcR-expressing P815 cells in the presence of anti-NK1.1
mAb (Fig. 6). NK cells from
+/+ and
+/
mice showed
increased cytotoxicity against P815 cells in the presence of
anti-NK1.1 mAb, whereas NK cells from
/
mice failed
to enhance cytotoxicity. These results demonstrate that
FcR
is involved in both IFN-
production and cytotoxicity upon stimulation through the NKR-P1 molecule.
Fig. 6.
Defect of NK1.1
mediated cytotoxicity by NK
cells from /
mice. Cytotoxicity of NK cells from
+/+,
+/
,
and
/
mice against P815 cell
line was analyzed in the presence
(open circles) or absence (closed circles) of anti-NK1.1 mAb. Data
are presented as mean ± SD of
triplicate assay.
[View Larger Version of this Image (11K GIF file)]
/
mice is likely due to a defect in signaling pathway of
the NKR-P1 molecule. However, since the NK1.1 expression on the cell surface of NK cells from
/
mice is
slightly lower than that of
+/
and
+/+ mice, it might be
attributed to the low expression of the cell surface NKR-P1.
To clarify these possibilities, we prepared two populations
of NK cells from normal mice expressing low or high level
of NKR-P1 (NKR-P1lo and NKR-P1hi, respectively) by cell
sorting. The expression level of NKR-P1 on the NKR-P1lo population was almost identical to that of NK cells from
/
mice. (Fig. 7, A and B). Then, we stimulated these
NK cell populations with immobilized anti-NK1.1 mAb.
NKR-P1lo NK cells from
+/+ mice produced significant
amount of IFN-
upon NKR-P1 cross-linking, although
the amount of IFN-
was lower than that by NKR-P1hi
NK cells (Fig. 7 C). In contrast, NK cells from
/
mice did
not produce any detectable level of IFN-
upon NKR-P1 cross-linking. These observations confirm the crucial role
of FcR
in signaling pathway through NKR-P1 for NK
activation and also demonstrate that FcR
is partly involved in the expression of the cell surface NKR-P1.
Fig. 7.
Activation defect of NK cells from FcR-deficient mice
upon NKR-P1 crosslinking is not due to the low level of NKR-P1 expression. (A) NK1.1 expression on NK cells from
+/+ and
/
mice.
NK cells from
+/+ or
/
mice were stained with anti-NK1.1 mAb
(solid line) or control Ab (dotted line). (B) Preparation of NK cell population expressing high (hi) and low (lo) level of NKR-P1 from wild-type
mice. (C) Production of IFN-
by NK cell population expressing low
NKR-P1 upon stimulation with immobilized anti-NK1.1 mAb. Two
NK cell populations expressing high (NK1.1hi) and low (NK1.1lo) level of
NK1.1 as shown in B from
+/+ mice and NK cells from
/
mice were
stimulated with immobilized (Fab)
2 fragment anti-NK1.1 mAb and IFN-
production was measured.
[View Larger Version of this Image (22K GIF file)]
was originally identified in the Fc
RI complex
and found to play an essential role in the expression and
signaling of Fc
RI (23). FcR
was also found to be required for the expression and function of Fc
RI, Fc
RIII
and Fc
R (24, 25). On the other hand, we found that
FcR
also associates with the TCR complexes in two types
of T cells. One is T cells in epithelia such as CD8
+
TCR-
/
+ intestinal intraepitherial lymphocytes and TCR
/
+ dendritic epidermal cells and the association with
FcR
in these cells was shown in vivo from the analysis of
CD3
-deficient mice (26). The second population is
NK1.1+ TCR-
/
+ T cells. (22). However, these T cells
obtained from
/
mice showed no clear defect in function upon TCR activation, although the expression level of
the TCR complex was slightly decreased (27). Accordingly, it is striking that NK cells and NK1.1+ T cells from
/
mice show no response upon NKR-P1 cross-linking
in spite of normal development. This finding suggests that
CD3
expressed in NK cells and NK1.1+ T cells can not
be replaced for FcR
in signaling through NKR-P1, because NKR-P1 bind only to FcR
dimers but not to
CD3
homodimers or CD3
-FcR
heterodimers. In contrast, T cells show no functional defect in
/
mice probably because the TCR complexes can utilize both CD3
and FcR
and CD3
can replace for FcR
in the TCR
complexes of
/
mice.
RIII which is associated with FcR
is known to activate NK cells upon cross-linking. Therefore, there is a
possibility that NKR-P1 associates with Fc
RIII on the cell
surface and delivers activating signal through FcR
which
is coupled with Fc
RIII. However, this is unlikely because
of two reasons. One is that Fc
RIII was not expressed on
the cell surface of CTLL-2 (data not shown), whereas the
association between FcR
and NKR-P1 was readily detected in the CTLL-2 (Fig. 1). Second, we used the (Fab)
2 fragment of anti-NK1.1 mAb for cross-linking of NKR-P1
and thus it is unlikely that immobilized anti-NK1.1 mAb
activated Fc
RIII. Taken together, the association of FcR
with NKR-P1 is essentially independent of Fc
RIII.
or FcR
with p58 was suggested, functional significance remained unclear (33). On the other hand, only a few receptors which deliver positive signal for NK cell activation
have been identified such as NKR-P1 and CD94/NKG2-C
(34) and the molecular mechanism of NK cell activation
through these receptors remains unclear. Under these circumstances, it is noteworthy that FcR
, a signal transducing chain possessing immunoreceptor tyrosine-based activation motif (ITAM), is involved in signal transduction
through NKR-P1. Because Syk tyrosine kinase interacts with
the phosphorylated ITAM of FcR
and is involved in NK
cell activation through FcR (35, 36), it is likely that Syk
also mediates the activating signal through NKR-P1 in NK
cells. Furthermore, it has been shown that Lck directly associates with NKR-P1 (14). Taken together, both Syk and
Lck seem to play an important role in mediating activation signals through NKR-P1 in NK cells.
/
mice showed normal cytotoxicity against representative NK targets (data not shown).
However, the failure of blocking with anti-NKR-P1 mAb
can be explained by the possible redundancy of NKR-P1
family molecules on NK cells. Indeed, recent observation
that introduction of NKR-P1 into a NKR-P1-deficient
NK cell line restored cytotoxicity against specific tumor cell
targets and the restored cytotoxicity was blocked by anti-
NKR-P1 mAb (11) strongly suggested that NKR-P1 is involved in the recognition of specific target molecules on NK
cells. A couple of reports demonstrating that anti-NK1.1 mAb blocked cytotoxicity of NK cells against specific targets also support this idea (37, 38). Further analysis of NK
cells in
/
mice may elucidate novel function of NKR-P1 molecule in the host defence.
Address correspondence to Takashi Saito, Division of Molecular Genetics, Center for Biological Science, Chiba University School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260, Japan. Phone: 81 43 226-2197; FAX: 81 43 222-1791; E-mail: saito{at}med.m.chiba-u.ac.jp
Received for publication 28 July 1997 and in revised form 3 October 1997.
The first two authors contributed equally to this work.We would like to thank Dr. J. Hamuro for providing IL-2, Ms. C. Sakuma and Ms. R. Siina for technical assistance, and Ms. H. Yamaguchi for secretarial assistance.
This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education to H. Arase and T. Saito.
1. | Scott, P., and G. Trinchieri. 1995. The role of natural killer cells in host-parasite interactions. Curr. Opin. Immunol. 7: 34-40 [Medline]. |
2. | Yokoyama, W.M.. 1995. Natural killer cell receptors. Curr. Opin. Immunol. 7: 110-120 [Medline]. |
3. | Raulet, D.H., and W. Held. 1995. Natural killer cell receptors: the offs and ons of NK cell recognition. Cell. 82: 697-700 [Medline]. |
4. | Chambers, W.H., N.L. Vujanovic, A.B. DeLeo, M.W. Olszowy, R.B. Herberman, and J.C. Hiserodt. 1989. Monoclonal antibody to a triggering structure expressed on rat natural killer cells and adherent lymphokine-activated killer cells. J. Exp. Med. 169: 1373-1389 [Abstract]. |
5. | Giorda, R., W.A. Rudert, C. Vavassori, W.H. Chambers, J.C. Hiserodt, and M. Trucco. 1990. NKR-P1, a signal transduction molecule on natural killer cells. Science. 249: 1298-1300 [Medline]. |
6. |
Giorda, R., and
M. Trucco.
1991.
Mouse NKR-P1: a family
of genes selectively coexpressed in adherent lymphokine-activated killer cells.
J. Immunol.
147:
1701-1708
|
7. |
Lanier, L.L.,
C. Chang, and
J.H. Phillips.
1994.
Human
NKR-P1A. A disulfide-linked homodimer of the C-type
lectin superfamily expressed by a subset of NK and T lymphocytes.
J. Immunol.
153:
2417-2428
|
8. |
Ryan, J.C.,
J. Turck,
E.C. Niemi,
W.M. Yokoyama, and
W.E. Seaman.
1992.
Molecular cloning of the NK1.1 antigen, a member of the NKR-P1 family of natural killer cell
activation molecules.
J. Immunol.
149:
1631-1635
|
9. |
Karlhofer, F.M., and
W.M. Yokoyama.
1991.
Stimulation of
murine natural killer (NK) cells by a monoclonal antibody
specific for the NK1.1 antigen. IL-2 activated NK cells possess additional specific stimulation pathways.
J. Immunol.
146:
3662-3673
|
10. |
Arase, H.,
N. Arase, and
T. Saito.
1996.
Interferon-![]() |
11. | Ryan, J.C., E.C. Niemi, M.C. Nakamura, and W.E. Seaman. 1995. NKR-P1A is a target-specific receptor that activates natural killer cell cytotoxicity. J. Exp. Med. 181: 1911-1915 [Abstract]. |
12. | Bezouska, K., C.-T. Yuen, J. O'Brien, R.A. Childs, W. Chai, A.M. Lawson, K. Drbal, A. Fiserova, M. Pospisil, and T. Feizi. 1994. High affinity oligosaccharide ligands for NKR-P1 protein that elicits natural killer cell activation and cytotoxicity. Nature. 372: 150-157 [Medline]. |
13. |
Ryan, J.C.,
E.C. Niemi,
R.D. Goldfien,
J.C. Hiserodt, and
W.E. Seaman.
1991.
NKR-P1, an activating molecule on rat
natural killer cells, stimulates phosphoinositide turnover and a
rise in intracellular calcium.
J. Immunol.
147:
3244-3250
|
14. | Campbell, K.S., and R. Giorda. 1997. The cytoplasmic domain of rat NKR-P1 receptor interacts with the N-terminal domain of p56(lck) via cysteine residues. Eur. J. Immunol. 27: 72-77 [Medline]. |
15. | Ledermann, B., and K. Burki. 1991. Establishment of a germ-line competent C57BL/6 embryonic stem cell line. Exp. Cell. Res. 197: 254-258 [Medline]. |
16. |
van Vugt, M.J.,
A.F. Heijnen,
P.J. Capel,
S.Y. Park,
C. Ra,
T. Saito,
J.S. Verbeek, and
J.G. van de Winkel.
1996.
FcR![]() ![]() |
17. |
Poole, A.,
J.M. Gibbins,
M. Turner,
M.J. van Vugt,
J.G.J. van de Winkel,
T. Saito,
V.L.J. Tybulewicz, and
S.P. Watson.
1997.
The Fc receptor ![]() |
18. | Arase, H., N. Arase, and T. Saito. 1995. Fas-mediated cytotoxicity by freshly isolated natural killer cells. J. Exp. Med. 181: 1235-1238 [Abstract]. |
19. |
Ono, S.,
H. Ohno, and
T. Saito.
1995.
Rapid turnover of the
CD3![]() |
20. |
Arase, H.,
N. Arase-Fukushi,
R.A. Good, and
K. Onoé.
1993.
Lymphokine-activated killer cell activity of CD4![]() ![]() ![]() ![]() |
21. |
Orloff, D.G.,
C. Ra,
S.J. Frank,
R.D. Klausner, and
J.P. Kinet.
1990.
Family of disulfide-linked dimers containing the ![]() ![]() ![]() |
22. |
Arase, H.,
S. Ono,
N. Arase,
S.Y. Park,
K. Wakizaka,
H. Watanabe,
H. Ohno, and
T. Saito.
1995.
Developmental arrest of NK1.1+ T cell receptor (TCR)-![]() ![]() ![]() ![]() ![]() |
23. | Blank, U., C. Ra, L. Miller, K. White, H. Metzger, and J.P. Kinet. 1989. Complete structure and expression in transfected cells of high affinity IgE receptor. Nature. 337: 187-189 [Medline]. |
24. |
Ra, C.,
M.-H. Jouvin,
U. Blank, and
J.P. Kinet.
1989.
A
macrophage Fc![]() |
25. | Ravetch, J.V., and J.P. Kinet. 1991. Fc receptors. Ann. Rev. Immunol. 9: 457-492 [Medline]. |
26. |
Ohno, H.,
S. Ono,
N. Hirayama,
S. Shimada, and
T. Saito.
1994.
Preferential usage of the Fc receptor ![]() ![]() ![]() |
27. |
Park, S.Y.,
H. Arase,
K. Wakizaka,
N. Hirayama,
S. Masaki,
S. Sato,
J.V. Ravetch, and
T. Saito.
1995.
Differential contribution of the FcR-![]() ![]() |
28. |
Olcese, L.,
P. Lang,
F. Vely,
A. Cambiaggi,
D. Marguet,
M. Blery,
K.L. Hippen,
R. Biassoni,
A. Moretta, et al
.
1996.
Human and mouse killer-cell inhibitory receptors recruit
PTP1C and PTP1D protein tyrosine phosphatases.
J. Immunol.
156:
4531-4534
|
29. | Burshtyn, D.N., A.M. Scharenberg, N. Wagtmann, S. Rajagopalan, K. Berrada, T. Yi, J.P. Kinet, and E.O. Long. 1996. Recruitment of tyrosine phosphatase HCP by the killer cell inhibitory receptor. Immunity. 4: 77-85 [Medline]. |
30. | Colonna, M., and J. Samaridis. 1995. Cloning of immunoglobulin-superfamily members associated with HLA-C and HLA-B recognition by human natural killer cells. Science. 268: 405-408 [Medline]. |
31. | Phillips, J.H., J.E. Gumperz, P. Parham, and L.L. Lanier. 1995. Superantigen-dependent, cell-mediated cytotoxicity inhibited by MHC class I receptors on T lymphocytes. Science. 268: 403-405 [Medline]. |
32. | Karlhofer, F.M., R.K. Ribaudo, and W.M. Yokoyama. 1992. MHC class I alloantigen specificity of Ly-49+ IL-2 activated natural killer cells. Nature. 358: 66-70 [Medline]. |
33. |
Bottino, C.,
M. Vitale,
L. Olcese,
S. Sivori,
L. Morelli,
A. Augugliaro,
E. Ciccone,
L. Moretta, and
A. Moretta.
1994.
The human natural killer cell receptor for major histocompatibility complex class I molecules. Surface modulation of
p58 molecules and their linkage to CD3![]() ![]() ![]() |
34. |
Mason, L.H.,
S.K. Anderson,
W.M. Yokoyama,
H.R. Smith,
R. Winkler-Pickett, and
J.R. Ortaldo.
1996.
The Ly-49D receptor activates murine natural killer cells.
J. Exp. Med.
184:
2119-2128
|
35. |
Ting, A.T.,
C.J. Dick,
R.A. Schoon,
L.M. Karnitz,
R.T. Abraham, and
P.J. Leibson.
1997.
Interaction between lck
and syk family tyrosine kinases in Fc![]() |
36. |
Shiue, L.,
M.J. Zoller, and
J.S. Brugge.
1995.
Syk is activated
by phosphotyrosine-containing peptides representing the tyrosine-based activation motifs of the high affinity receptor for
IgE.
J. Biol. Chem.
270:
10498-10502
|
37. |
Kung, S.K.P., and
R.G. Miller.
1995.
The NK1.1 antigen in
NK-mediated F1 antiparent killing in vitro.
J. Immunol.
154:
1624-1633
|
38. | Takeda, K., and G. Dennert. 1994. Demonstration of MHC class I-specific cytolytic activity in IL-2-activated NK1+CD3+ cells and evidence of usage of T and NK cell receptors. Transplantation. 58: 496-504 [Medline]. |