CD59, a broadly expressed GPI-anchored molecule, regulates formation of the membrane attack complex of the complement cascade. We previously demonstrated that mouse CD59 also down-modulates CD4+ T cell activity in vivo. In this study, we explored the role of CD59 on human CD4+ T cells. Our data demonstrate that CD59 is up-regulated on activated CD4+ T cells and serves to down-modulate their activity in response to polyclonal and Ag- specific stimulation. The therapeutic potential of this finding was explored using T cells isolated from colorectal cancer patients. The findings were striking and indicated that blockade of CD59 significantly enhanced the CD4+ T cell response to two different tumor Ags. These data highlight the potential for manipulating CD59 expression on T cells for boosting weak immune responses, such as those found in individuals with cancer.

CD59 is a GPI-anchored glycoprotein expressed on all human tissues that inhibits the formation of the membrane attack complex in the complement (C)5 cascade (1). As well as regulating complement, CD59 influences the activity of CD4+ T cells. In vitro analyses of human T cells have shown that Ab cross-linking of CD59 promotes T cell activation, implying a costimulatory effect of CD59 on T cells (2). Our recent studies using CD59a-deficient mice (CD59a−/− mice) question the relevance of these findings because virus-specific CD4+ T cells from CD59a−/− mice exhibited enhanced proliferation and cytokine production compared with wild-type animals. This implies that, under physiological conditions, CD59 down-modulates CD4+ T cell responses (3), perhaps serving to limit T cell mediated immunopathology (4). With this in mind, we reasoned that blockade of CD59 would boost Ag-specific T cell responses thereby serving as a target for immunotherapeutic intervention for diseases characterized by weak immune responses such as cancer. To address whether this is indeed the case, this study sought to explore how CD59 impacts on human CD4+ T cells and to determine whether its blockade boosts immune responses in patients with colorectal cancer.

Mapping studies have been described previously for various human CD59-specific Abs (5). MEM-43 and HC-1 were selected based on their epitope binding regions. The CD59-specific Abs, MEM-43 and HC-1 (both IgG2a), were incubated in digestion buffer (20 mM sodium phosphate, 10 mM EDTA, 20 mM Cysteine HCl (pH 7.0)) and immobilized papain (Pierce) at an enzyme to substrate ratio of 1/50 (w/w) for 5 h at 37°C with constant mixing. Post incubation, the papain was separated from the Abs by centrifugation. The Fc fragments were purified using a Hi-Trap protein A-Sepharose column leading to a pure population of Fab. This process was conducted using endotoxin free reagents under sterile conditions. The molecular mass and purity of the Fab were evaluated using a 10% SDS-PAGE gel. Endotoxin levels (<5 EU/ml) were assessed using the Limulus amebocyte lysate (Cambrex) as described by the manufacturer.

PBMC and CD4+ T cells were purified from healthy donors and patients with colorectal cancer (CRC) as described earlier (6). The study on CRC patients has been reviewed and approved by a local ethical committee.

Samples were stained with fluorescently labeled Abs to CD4 (clone RPA-T4), CD25 (clone M-A251), CD45RA, CD45RO (clone UCHL1), and CTLA4 (clone BNI3) (BD Pharmingen), CD4 (clone S3.5) (Caltag), CD25 (clone 4E3) (Miltenyi Biotec), and CD69 (clone FN50) (eBioscience). All staining was performed in PBS, 2.5% FCS, 5 mM EDTA, and intracellular staining was performed using the cytofix, cytoperm kit (BD Pharmingen). FOXP3 staining was performed using the FITC anti-human FOXP3 staining kit (clone PCH101) (71-5776 eBioscience). CD59 expression was detected using a biotinylated Ab (MEM-43) followed by SA-PerCPCy5.5. Lymphocytes were gated on forward and side scatter profiles. The Fab of MEM-43 and HC-1 were tested for their ability to bind to CD59 by incubating both CD59+ and CD59 U937 cells (U937CD59+ and U937CD59 cells respectively) with the Fab followed by fluorescently labeled secondary Ab (PE conjugated anti-IgG2a). All flow cytometric analysis was performed on a FACSCalibur (BD Biosciences).

The C inhibitory activity of intact MEM-43 and HC-1 Abs and their Fab was assessed in a C-mediated lysis assay. Human erythrocytes, washed and resuspended at 1% in PBS, were sensitized with CD55-specific Abs (100 μg/ml) for 40 min at 37°C. After extensive washing with C fixation diluent (Oxoid) the erythrocytes were incubated with either MEM-43 or HC-1 Abs or Fab at 10 μg/ml per 2 × 107 cells for 20 min on ice. Erythrocytes were washed by centrifugation and aliquoted at 2 × 106 cells per well in a 96-well plate. The erythrocytes were then incubated with various dilutions of normal human serum for 30 min at 37°C. Zero and 100% lysis controls were included in the assay. Plates were centrifuged and hemoglobin levels in the supernatants were measured (by absorbance at 412 nm) and values used as an index of lysis. Percent lysis was calculated as described earlier (7).

PBMCs at 2 × 106 cells/ml were activated using beads coated with both anti-CD3 and anti-CD28 Abs (Dynal Biotech) at a bead to cell ratio of 1:4, or purified protein derivative (PPD) from tuberculin at 2 μg/ml (Statens Serum Institut). In some experiments PBMCs were CFSE (2 μM) labeled before activation (3).

Purified CD4+ T cells or PBMCs, either CFSE labeled or unlabelled, were incubated with Fab of anti-CD59 Abs HC-1 and MEM-43 or control mouse IgG2a at 1 or 3 μg/ml for 20 min on ice. After washing, cells were stimulated with anti-CD3 Abs in the presence of irradiated PBMCs (depleted of CD4+ T cells) as APCs and proliferation assessed by thymidine incorporation or dilution of CFSE. In some experiments, instead of PBMCs, irradiated U937 cells that lack CD59 were used as APCs. To assess the response to recall Ags, PBMCs were stimulated with tetanus toxoid or PPD and proliferation assessed as above. Mitotic divisions, assessed by dilution of CFSE, were calculated as described by Yamazaki et al. (8).

Purified CD4+ T cells were incubated with anti-CD59 Abs (HC-1 or MEM-43 at 1 μg/ml). After washing cells twice, 100 μl of polyclonal rabbit anti-mouse IgG at 5 μg/ml was added. Cells were further stimulated with anti-CD3 Abs at 1 μg/ml for 3 days and proliferation was assessed by pulsing cell cultures with 1 μCi/well of thymidine for 16 h before harvesting.

PBMC were incubated with Fab of anti-CD59 Abs HC-1 or MEM-43 and the frequency of T cells specific for recall and tumor-associated Ags, carcinoembryogenic Ag (CEA) (9) and 5T4 (10) was determined by IFN-γ ELISPOT assay as described earlier (6). In some experiments, the effect of regulatory T cell (Treg) depletion on Ag-specific IFN-γ production was assessed in parallel assays. CD25high cells were depleted by magnetic separation using CD25-specific microbeads as described previously (Miltenyi Biotec) (6).

To understand how CD59 impacts on human CD4+ T cells, we first analyzed the pattern of CD59 expression among different populations of CD4+ T lymphocytes. For this purpose, PBMCs from healthy donors were phenotypically characterized using Abs specific for T cell activation, regulation, and memory markers. CD59 expression was found to be higher on freshly isolated CD4+ T cells expressing CD25 and Foxp3 as compared with CD4+ T cells negative for these markers (Table I). In accordance with a previous report, we also found that CD59 is expressed at a higher level on memory CD4+ T cells (CD45RO+) compared with naive T cells (CD45RA+) (Ref. 11 and data not shown). These findings imply that CD59 expression is up-regulated on activated T cells and is most pronounced on highly differentiated T cells. To confirm this, CD59 expression was compared on PBMCs, either unstimulated or activated with anti-CD3 Abs or recall Ags. Expression of CD59 increased upon stimulation in association with activation markers, CD69, CD25, CTLA4, and Foxp3 (Table I). The ratio of CD59 expression on activated vs unactivated cells was calculated and the increase was found to be statistically significant (Fig. 1,A). When CD59 expression was monitored on actively dividing CD4+ T cells using CFSE, its expression increased with successive cell divisions (Fig. 1 B).

Table I.

CD59 expression on CD4+ T cellsa

UnstimulatedAnti-CD3 plus CD28PPD
% of cellsCD59 (MFI)% of cellsCD59 (MFI)% of cellsCD59 (MFI)
CD4+CD69 98.44 225 63.88 229 92.4 222 
CD4+CD69+ 1.31 336 35.05 346 7.03 386 
CD4+CD25 73.73 225 50.24 209 72.20 217 
CD4+CD25med 22.55 290 21.14 279 18.28 296 
CD4+CD25high 1.24 330 26.89 406 6.69 309 
CD4+FoxP3 93.29 223 75.25 235 87.01 226 
CD4+FoxP3+ 6.69 285 24.74 382 12.38 296 
CD4+CTLA4 98.1 225 78.98 241 94.85 222 
CD4+CTLA4+ 1.02 330 18.69 362 3.97 342 
UnstimulatedAnti-CD3 plus CD28PPD
% of cellsCD59 (MFI)% of cellsCD59 (MFI)% of cellsCD59 (MFI)
CD4+CD69 98.44 225 63.88 229 92.4 222 
CD4+CD69+ 1.31 336 35.05 346 7.03 386 
CD4+CD25 73.73 225 50.24 209 72.20 217 
CD4+CD25med 22.55 290 21.14 279 18.28 296 
CD4+CD25high 1.24 330 26.89 406 6.69 309 
CD4+FoxP3 93.29 223 75.25 235 87.01 226 
CD4+FoxP3+ 6.69 285 24.74 382 12.38 296 
CD4+CTLA4 98.1 225 78.98 241 94.85 222 
CD4+CTLA4+ 1.02 330 18.69 362 3.97 342 
a

PBMCs were either left unstimulated or stimulated with anti-CD3 plus CD28 beads or PPD. The percentage of cells within each subset is shown as well as the mean fluorescence intensity of CD59 on each subset. Values are representative of four independent experiments performed using blood obtained from different individuals.

FIGURE 1.

CD59 expression is significantly increased on activated cells. A, The average ratio of CD59 expression on activated vs unactivated cells from four different individuals. The statistical significance indicated on the bar was calculated using a one sample t test. B, Proliferation of CFSE labeled CD4+ T cells unstimulated (open histogram) or stimulated with anti-CD3 plus CD28 Ab-coated beads (filled histogram). Values on the histogram indicate mean fluorescence intensity for CD59 expression on cells gated as indicated. The results are representative of four independent experiments performed using blood obtained from different individuals.

FIGURE 1.

CD59 expression is significantly increased on activated cells. A, The average ratio of CD59 expression on activated vs unactivated cells from four different individuals. The statistical significance indicated on the bar was calculated using a one sample t test. B, Proliferation of CFSE labeled CD4+ T cells unstimulated (open histogram) or stimulated with anti-CD3 plus CD28 Ab-coated beads (filled histogram). Values on the histogram indicate mean fluorescence intensity for CD59 expression on cells gated as indicated. The results are representative of four independent experiments performed using blood obtained from different individuals.

Close modal

The functional significance of CD59 expression on CD4+ T cells was evaluated. As mentioned previously, we had previously found that CD59 down-modulates the activity of mouse T cells. To address whether CD59 impacts similarly on human CD4+ T cell activity, we reasoned that use of Fab of CD59-specific Abs, which would not induce cross-linking, would enable us to compare the activity of CD4+ T cells expressing CD59 and those where CD59 is obscured by Ab binding. Two CD59-specific mAbs, named MEM-43 and HC-1, were selected. These were selected due to their CD59-binding characteristics (5). MEM-43 binding causes significant inhibition of complement regulation by CD59 whereas HC-1 does not. Fab of these Abs, generated as described in Materials and Methods, were assessed for their ability to bind CD59 and to inhibit its complement regulating activity (Fig. 2, A and B). As expected, both Fab bound CD59 (Fig. 2,A). To functionally test the Fab, complement-mediated lysis of human erythrocytes was analyzed in the presence of the intact Abs or the Fab. As shown in Fig. 2 B, the Fab behaved in a similar manner to the intact Abs in that MEM-43-Fab inhibited the complement regulating activity of CD59 whereas HC-1-Fab did not. Overall therefore, the Fab were deemed useful for use in experiments designed to address how CD59 impacts on CD4+ T cell activity.

FIGURE 2.

Generation and characterization of Fab. A, Binding of Fab of CD59-specifc Abs (MEM-43 and HC-1) was detected on CD4+ T cells by flow cytometry. B, Hemolytic assay using intact and Fab of CD59 specific Abs MEM-43 and HC-1. Values shown are the mean ± SD in triplicates.

FIGURE 2.

Generation and characterization of Fab. A, Binding of Fab of CD59-specifc Abs (MEM-43 and HC-1) was detected on CD4+ T cells by flow cytometry. B, Hemolytic assay using intact and Fab of CD59 specific Abs MEM-43 and HC-1. Values shown are the mean ± SD in triplicates.

Close modal

As mentioned above, we reasoned that use of Fab, which would not induce cross-linking of CD59, would enable us to evaluate the impact of blocking CD59 on activity of CD4+ T cells. When CD4+ T cells were incubated with the Fab and subsequently stimulated with CD3-specific Abs and APCs, those incubated with HC-1-Fab exhibited a significant and dose-dependent increase in proliferation in comparison with CD4+ T cells stimulated with anti-CD3 alone (Fig. 3,A). No effect was observed with MEM-43-Fab or the control Fab (Fig. 3,A). When proliferation was assessed by CFSE dilution, more cell division was observed following incubation of the CD4+ T cells with HC-1-Fab whereas again, no effect of incubation with MEM-43-Fab was observed (Fig. 3,B). In experiments using CD59 U937 cells as APCs, the HC-1 Fab increased the proliferation of CD4+ T cells in comparison to control cultures (Fig. 3 C). This experiment indicates that the modulatory effect of the HC-1-Fab is due to CD59 expressed on the responding CD4+ T cell.

FIGURE 3.

Blocking CD59 on CD4+ T cells increases the immune response. A, Proliferation of CD4+ T cells stimulated with anti-CD3 Abs in the presence of irradiated PBMCs as APCs and Fab of Abs to CD59 (HC-1 or MEM-43) or control Fab. B, Proliferation of CFSE-labeled CD4+ T cells when stimulated with anti-CD3 Abs in the presence of irradiated PBMCs as APC and either HC-1 or MEM-43 Fab. Values (mean of triplicates) in the histograms indicate the mitotic divisions under the respective conditions. C, Proliferation of CD4+ T cells stimulated with anti-CD3 Abs in the presence of irradiated CD59 U937 cells and either HC-1 or MEM-43 Fab. D, Proliferation of CD4+ T cells stimulated with anti-CD3 Abs and cross-linked anti-CD59 Abs. Statistical significance (∗, p < 0.05) was evaluated using the Student’s t test. The results are representative of four independent experiments performed using blood obtained from different individuals.

FIGURE 3.

Blocking CD59 on CD4+ T cells increases the immune response. A, Proliferation of CD4+ T cells stimulated with anti-CD3 Abs in the presence of irradiated PBMCs as APCs and Fab of Abs to CD59 (HC-1 or MEM-43) or control Fab. B, Proliferation of CFSE-labeled CD4+ T cells when stimulated with anti-CD3 Abs in the presence of irradiated PBMCs as APC and either HC-1 or MEM-43 Fab. Values (mean of triplicates) in the histograms indicate the mitotic divisions under the respective conditions. C, Proliferation of CD4+ T cells stimulated with anti-CD3 Abs in the presence of irradiated CD59 U937 cells and either HC-1 or MEM-43 Fab. D, Proliferation of CD4+ T cells stimulated with anti-CD3 Abs and cross-linked anti-CD59 Abs. Statistical significance (∗, p < 0.05) was evaluated using the Student’s t test. The results are representative of four independent experiments performed using blood obtained from different individuals.

Close modal

To understand how the intact MEM-43 and HC-1 Abs function when used for cross-linking CD59 on CD4+ T cells, we examined the CD4+ T cell response when CD59 was cross-linked using these intact Abs. In accordance with previous publications, cells incubated with CD3-specific Abs and either cross-linked MEM-43 or HC-1, showed enhanced proliferation as compared with cells incubated with CD3-specific Abs alone (Fig. 3 D).

We next sought to understand how blocking CD59 affects proliferation and cytokine production following Ag-specific stimulation of CD4+ T cells. Using the Fab described above, we found that T cells incubated with titrated amounts of HC-1-Fab, proliferated significantly more than cells stimulated in the presence or absence of MEM-43 Fab (Fig. 4,A). Incubation with HC-1-Fab in the absence of Ag had no effect on T cell proliferation ruling out a nonspecific effect of the Fab. ELISPOT assays were subsequently performed to assess the impact of CD59 on IFN-γ production. The results of these experiments paralleled those observed in the proliferation assays because blocking CD59 with HC-1-Fab (but not MEM-43-Fab or control Fabs) increased the number of IFN-γ producing cells in an Ag-dependent manner (Fig. 4 B). Collectively these data, which show that blocking CD59 on T cells can enhance both Ag-specific proliferation and cytokine production, imply that CD59 normally serves to down modulate Ag-specific CD4+ T cell responses.

FIGURE 4.

Blocking CD59 increases the CD4+ T cell response to recall Ags. A, Proliferation of T cells in response to recall Ags tetanus toxoid and PPD in the presence of Fab of MEM-43 and HC-1. B, IFN-γ response to recall Ags in the presence or absence of Fab of MEM-43 and HC-1. The bars indicate the number of spot forming cells enumerated in an ELISPOT assay for IFN-γ. Statistical significance (∗, p < 0.05) was evaluated using the Student’s t test. The results are representative of four independent experiments performed using blood obtained from different individuals.

FIGURE 4.

Blocking CD59 increases the CD4+ T cell response to recall Ags. A, Proliferation of T cells in response to recall Ags tetanus toxoid and PPD in the presence of Fab of MEM-43 and HC-1. B, IFN-γ response to recall Ags in the presence or absence of Fab of MEM-43 and HC-1. The bars indicate the number of spot forming cells enumerated in an ELISPOT assay for IFN-γ. Statistical significance (∗, p < 0.05) was evaluated using the Student’s t test. The results are representative of four independent experiments performed using blood obtained from different individuals.

Close modal

We next examined whether blockade of CD59 could be used to enhance CD4+ T cell responses generally found to be weak in nature, such as those measured in patients with CRC. For this purpose, we examined responses to two tumor-associated Ags (CEA and 5T4) using PBMC from the CRC patients in ELISPOT assays. In the presence of HC-1 Fab, there was a significant and Ag-specific increase in the frequency of Ag-specific IFN-γ producing cells compared with cells incubated with MEM-43-Fab or medium alone (Fig. 5, A and B). Thus, blockade of CD59 can boost the CD4+ T cell response to tumor Ags in these patients.

FIGURE 5.

Blocking CD59 increases the IFN-γ response to tumor Ags in CRC patients. IFN-γ production in response to tumor Ags CEA (A) and 5T4 (B) in the presence and absence of Fab of Abs to CD59. The results are representative of three independent experiments with blood obtained from different individuals. C, IFN-γ response to tumor Ags in PBMCs depleted and undepleted for CD4+CD25high cells in the presence and absence of Fab of Abs to CD59. Statistical significance (∗, p < 0.05; ∗∗, p < 0.01) was evaluated using the Student’s t test.

FIGURE 5.

Blocking CD59 increases the IFN-γ response to tumor Ags in CRC patients. IFN-γ production in response to tumor Ags CEA (A) and 5T4 (B) in the presence and absence of Fab of Abs to CD59. The results are representative of three independent experiments with blood obtained from different individuals. C, IFN-γ response to tumor Ags in PBMCs depleted and undepleted for CD4+CD25high cells in the presence and absence of Fab of Abs to CD59. Statistical significance (∗, p < 0.05; ∗∗, p < 0.01) was evaluated using the Student’s t test.

Close modal

Because we previously found that the expression of CD59 is higher on CD4+ T cells expressing high levels of Foxp3, we examined whether the effects of CD59-blockade by the HC-1-Fab were mediated by inhibiting the activity of Tregs. This was also of interest in light of our previous findings that Tregs inhibit 5T4- and CEA-specific CD4+ T cell responses in CRC patients (Ref. 6 and data not shown). Should HC-1-Fab act by blocking the inhibitory effects of Tregs, incubation with the Fab would be expected to have no effect on the frequency of CD4+ T cells producing IFN-γ in cultures depleted of Tregs. However, as shown in Fig. 5,C, we found that, although depletion of CD4+ CD25high cells did enhance responses, incubation with HC-1-Fab increased the number of Ag-specific IFN-γ producing cells even in cultures depleted of these Tregs. Collectively, these data indicate that CD59 limits Ag-specific T cell responses in a manner that is independent of Tregs (Fig. 5 C).

Following our previous studies in the mouse (3, 4), we set out to investigate whether CD59 impacts on the activity of human CD4+ T cells. These investigations revealed that CD59 expression is increased on activated and memory CD4+ T cells and that its expression influences both CD4+ T cell proliferation and cytokine production in response to stimulation with cognate Ag. These findings indicate that the responsiveness of both central memory cells (measured in proliferation assays) and effector memory cells (measured in ELISPOT assays) is increased following blockade of CD59.

The latter point was elucidated using both intact Abs and Fab of CD59-specific Abs. Intact Abs and their corresponding Fab affect their target cells in distinct ways. Although CD59-specific Fab simply block access to a portion of the target molecule, cross-linked intact Abs facilitate clustering of molecules that may not normally occur under physiological activation conditions. Hence, while cross-linking by both CD59-specific Abs, HC-1 and MEM-43, resulted in enhanced CD4+ T cell proliferation, only one of the Fab (HC-1) enhanced proliferation. Overall this implies that cross-linking induces proliferation regardless of the Ab binding site whereas increased proliferation by CD59 blockade depends on the binding site of the Ab. The difference when CD59 is blocked with two different Fab (HC-1 and MEM-43) could be explained by the fact that these Abs bind to nonidentical epitopes on CD59 (5), suggesting that HC-1 but not MEM-43 binds to the active site of CD59 responsible for modulation of CD4+ T cell activity. Use of the HC-1-Fab enhanced T cell proliferation even when CD59 cells were used as APCs thereby indicating that the modulatory effect of CD59 is due to its expression on CD4+ T cells. It is also noteworthy that our findings in both mouse and human indicate that the down-modulatory effect of CD59 is observed only when APCs are present in proliferation assays implying the presence of an as yet unidentified ligand expressed on the surface of APCs that binds CD59 on CD4+ T cells resulting in delivery of a negative signal to the responding T cells. With this in mind, it is possible that HC-1-Fab but not MEM-43-Fab inhibits this interaction.

In summary, this study demonstrates that CD59 expression is up-regulated on activated CD4+ T cells and that blockade of CD59 enhances CD4+ T cell responses. These data support the hypothesis that, as in the mouse, CD59 influences human CD4+ T cell activity by exerting a down-modulatory effect. Although the mechanism through which CD59 mediates this effect remains to be elucidated, the data presented in this study highlight the potential utility of inhibiting CD59. Currently, there is a great deal of interest in adoptive cell transfer as a method of treating patients with cancer (12). In vitro expanded autologous CD4+ T cell clones specific for the tumor-associated Ag NY-ESO-1 when adoptively transferred, showed durable clinical remission (13), supporting an anti-tumor role for CD4+ T cells. Manipulation of these cells through blockade or silencing of CD59 expression may represent a novel means of refining the responsiveness of Ag-specific CD4+ T cell responses for the purpose of improving the efficacy of adoptive immunotherapy.

The authors have no financial conflict of interest.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

1

The work was funded by a Wellcome trust project grant awarded to A.M.G. and B.P.M. that supports B.S. (ref. no: 079115). A.M.G. is a Medical Research Council senior research fellow (ref. no. G117/488). M.P.L. is a recipient of Wellcome trust prize studentship (ref. no. 073055). B.P.M. is funded by Wellcome trust program grant (ref. no. 068590).

5

Abbreviations used in this paper: C, complement; CRC, colorectal cancer; PPD, purified protein derivative; CEA, carcinoembryogenic Ag; Treg, regulatory T cell.

1
Kimberley, F. C., B. Sivasankar, B. Paul Morgan.
2007
. Alternative roles for CD59.
Mol. Immunol.
44
:
73
-81.
2
Korty, P. E., C. Brando, E. M. Shevach.
1991
. CD59 functions as a signal-transducing molecule for human T cell activation.
J. Immunol.
146
:
4092
-4098.
3
Longhi, M. P., B. Sivasankar, N. Omidvar, B. P. Morgan, A. Gallimore.
2005
. Cutting edge: murine CD59a modulates antiviral CD4+ T cell activity in a complement-independent manner.
J. Immunol.
175
:
7098
-7102.
4
Longhi, M. P., A. Williams, M. Wise, B. P. Morgan, A. Gallimore.
2007
. CD59a deficiency exacerbates influenza-induced lung inflammation through complement-dependent and -independent mechanisms.
Eur. J. Immunol.
37
:
1266
-1274.
5
Bodian, D. L., S. J. Davis, B. P. Morgan, N. K. Rushmere.
1997
. Mutational analysis of the active site and antibody epitopes of the complement-inhibitory glycoprotein, CD59.
J. Exp. Med.
185
:
507
-516.
6
Clarke, S. L., G. J. Betts, A. Plant, K. L. Wright, T. M. El-Shanawany, R. Harrop, J. Torkington, B. I. Rees, G. T. Williams, A. M. Gallimore, A. J. Godkin.
2006
. CD4+CD25+FOXP3+ regulatory T cells suppress anti-tumor immune responses in patients with colorectal cancer.
PLoS ONE
1
:
e129
7
Baalasubramanian, S., C. L. Harris, R. M. Donev, M. Mizuno, N. Omidvar, W. C. Song, B. P. Morgan.
2004
. CD59a is the primary regulator of membrane attack complex assembly in the mouse.
J. Immunol.
173
:
3684
-3692.
8
Yamazaki, S., T. Iyoda, K. Tarbell, K. Olson, K. Velinzon, K. Inaba, R. M. Steinman.
2003
. Direct expansion of functional CD25+ CD4+ regulatory T cells by antigen-processing dendritic cells.
J. Exp. Med.
198
:
235
-247.
9
Thompson, J. A., F. Grunert, W. Zimmermann.
1991
. Carcinoembryonic antigen gene family: molecular biology and clinical perspectives.
J. Clin. Lab. Anal.
5
:
344
-366.
10
Woods, A. M., W. W. Wang, D. M. Shaw, C. M. Ward, M. W. Carroll, B. R. Rees, P. L. Stern.
2002
. Characterization of the murine 5T4 oncofoetal antigen: a target for immunotherapy in cancer.
Biochem. J.
366
:
353
-365.
11
Christmas, S., C. de la Mata Espinosa, D. Halliday, C. Buxton, J. Cummerson, P. Johnson.
2006
. Levels of expression of complement regulatory proteins CD46, CD55 and CD59 on resting and activated human peripheral blood leucocytes.
Immunology
119
:
522
-528.
12
Rosenberg, S. A., N. P. Restifo, J. C. Yang, R. A. Morgan, M. E. Dudley.
2008
. Adoptive cell transfer: a clinical path to effective cancer immunotherapy.
Nat. Rev. Cancer
8
:
299
-308.
13
Hunder, N. N., H. Wallen, J. Cao, D. W. Hendricks, J. Z. Reilly, R. Rodmyre, A. Jungbluth, S. Gnjatic, J. A. Thompson, C. Yee.
2008
. Treatment of metastatic melanoma with autologous CD4+ T cells against NY-ESO-1.
N. Engl. J. Med.
358
:
2698
-2703.