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. 2006 Mar;117(3):402–408. doi: 10.1111/j.1365-2567.2005.02314.x

Blockade of OX40-ligand after initial triggering of the T helper 2 response inhibits mercuric chloride-induced autoimmunity

Iain A M MacPhee 1, Hideo Yagita 2, David B G Oliveira 1
PMCID: PMC1782235  PMID: 16476060

Abstract

Mercuric chloride (HgCl2)-induced autoimmunity in Brown Norway rats is a spontaneously resolving autoimmune response driven by the activation of T helper type 2 lymphocytes (Th2 cells). Treatment with antibody to OX40-ligand (OX40-L) from the time of the first HgCl2 injection for 12 days had little effect. Delayed treatment commenced 8 days after the first HgCl2 injection significantly suppressed immunoglobulin E production, splenomegaly, weight loss and mortality. This makes OX40/OX40-L signalling an attractive therapeutic target for Th2-driven autoimmune diseases. Intravenous administration of the murine antibody to OX-40-L elicited a vigorous anti-mouse immunoglobulin antibody response that was significantly enhanced compared to the response to control immunoglobulin. It is likely that this response significantly reduced the plasma half-life of the anti-OX40-L antibody and this observation has clear implications for the interpretation of data from experiments where anti-OX40-L is used in vivo.

Keywords: OX40-ligand, mercuric chloride, autoimmunity, costimulation, Th2

Introduction

Mercuric chloride (HgCl2)-induced autoimmunity in Brown Norway (BN) rats is a spontaneously resolving autoimmune response driven by the activation of autoreactive interleukin (IL)-4 secreting T helper type 2 lymphocytes (Th2 cells). There are a number of manifestations of this process, including increased serum concentrations of immunoglobulin E (IgE) and a number of IgG autoantibodies, generalized lymphoproliferation, mucosal vasculitis affecting primarily the caecum, and arthritis (reviewed in 1). These responses peak after 15–20 days followed by spontaneous resolution.

T lymphocytes require at least two signals for activation, the first being delivered through the antigen receptor and the second via a number of costimulatory pathways. Cross-linking of CD28 probably delivers the most important costimulatory signal early in the immune response. We have shown that HgCl2-induced autoimmunity was completely suppressed by a combination of antibodies to the ligands for CD28 (CD80 and CD86) given from the time of the first HgCl2 injection, but that the suppression was less complete when the antibody treatment was delayed until day 4 or day 8.2,3 OX40 (CD134) is a member of the tumor necrosis factor receptor family that is expressed on activated T-lymphocytes. OX40 signalling plays a key role in sustaining primary CD4+ T-lymphocyte responses, increases the number of cells entering the memory cell pool4,5 and is involved in the reactivation of Th2 memory cells.6 The ligand for OX40 (OX40-L), a member of the tumour necrosis factor family, is expressed on B-lymphocytes,7,8 dendritic cells,8,9 mast cells10 and activated endothelium.11 Antibody to OX40 was found to augment in vitro T-lymphocyte proliferation12 and OX40 ligation favours the development of Th2 responses.13–16 OX40-L deficient mice sensitized with ovalbumin had an attenuated IgE response to pulmonary challenge with ovalbumin.17,18 Constitutive expression of OX40-L in transgenic mice resulted in spontaneous autoimmunity, which was strain specific.19 Fundamental to the action of OX40 signalling is sustained phosphoinositol-3-kinase (PI3k) : protein kinase B activity20 leading to the production of survivin, a protein involved in cell cycle progression and the inhibition of apoptosis.21 In common with CD28, OX40 activates nuclear factor (NF)-κB22,23 with up-regulation of the antiapoptotic genes Bcl-xL and Bcl-2.24 Signalling through the PI3 kinase and P38MAP kinase pathways following OX40 ligation has been demonstrated to prolong the half lives of several cytokine mRNAs.25 There is evidence to suggest that in addition to acting as a ligand for OX40, signals may be delivered to the B-lymphocyte by OX40-L mediating germinal centre formation26 and the differentiation of B lymphocytes into antibody-secreting cells.27

The observation that blockade of CD28 signalling becomes less effective at inhibiting HgCl2-induced autoimmunity when commenced after the initiation of the Th2 response and the concept that OX40 signalling follows sequentially from CD28 in maintaining the activation of T lymphocytes led to the hypothesis that blockade of OX40 signalling would be an effective strategy for suppressing HgCl2-induced autoimmunity late in its course. Here we demonstrate that treatment with a monoclonal antibody to OX40-L early in the course of HgCl2-induced autoimmunity was ineffective but later treatment was suppressive.

Materials and methods

Animals

Male BN rats weighing 250–350 g were purchased from Harlan Olac (Bicester, UK). Male rats were used because of their greater susceptibility to HgCl2-induced autoimmunity.28 All procedures were performed under halothane anaesthesia and were approved by the UK Home Office.

Treatment with mercuric chloride

HgCl2 (Sigma, Poole, UK) was dissolved at a concentration of 1 mg/ml in saline and was injected subcutaneously at a dose of 1 mg/kg for a total of five doses given on alternate days29. Humane end-points required killing of any animal with weight loss of more than 25%, severe ocular or oral mucositis, or arthritis affecting gait.

Monoclonal antibodies

ATM-2, a murine IgG1 antibody to rat OX40-L was prepared as described previously.8 Anti-CD80 (3H5) and anti-CD86 (24F) antibodies30 were prepared from tissue culture supernatant by ammonium sulphate precipitation and passage through a protein-A column. Both antibodies are murine IgG1. An isotype-matched control MOPC 21 (Sigma, St. Louis, MO) was prepared from clarified ascites by passage through a protein-A column. BN rats were injected intravenously with 100 µg anti-OX40-L (0·33 mg/kg), 100 µg each of anti-CD80 and anti-CD86 (0·33 mg/kg), or 100 µg of MOPC 21 as an isotype control, in 1 ml 0·9% NaCl, initially daily for 3 days and then on alternate days until day 12 after the first HgCl2 injection (early treatment). Late treatment was by the same regimen, but commencing on day 8 after the first HgCl2 injection with the last dose on day 20. These doses were derived from preliminary dose-finding experiments.

IgE enzyme-linked immunosorbent assay (ELISA)

Serum was prepared from blood collected from a cut in the tail vein and stored at −20° until assayed. Total IgE was measured by ELISA as described.28 Briefly, 96 well plates (Dynex Technologies Ltd, Billingshurst, UK) were coated with monoclonal anti-rat IgE heavy chain (Serotec Ltd, Oxford, UK) in carbonate buffer. Unoccupied binding sites were blocked with 5% skimmed milk in phosphate-buffered saline (PBS). Known concentrations of rat IgEκ myeloma protein (Serotec) or serum samples were added in duplicate to coated wells and singly to anti-IgE-free wells. Binding was detected with alkaline phosphatase-conjugated monoclonal anti-rat κ and λ light chain antibodies (Sigma) followed by p-nitrophenyl phosphate substrate. The optical density (OD) at 405 nm was read after 20 min using a Dynatech multiplate reader (Dynex Technologies). A standard curve created from the OD of the known concentrations of IgE on each plate was used to calculate the IgE concentration from the mean OD of the test samples.

Assay for antibody to murine IgG1

An ELISA assay was performed essentially as described above but the plates were coated with MOPC 21 immunoglobulin. The sera were incubated for 12 hr at 4° and the alkaline phosphatase-conjugated monoclonal anti-rat κ and λ light chain antibodies were incubated for 2 hr at 4°. Sera were titrated against serum from a rat with a high titre of anti-mouse immunoglobulin which was given a value of 1. Results for test sera are presented as relative values. Serum from a rat treated with HgCl2 but not murine immunoglobulin was used as a negative control.2

Results

Early treatment with anti-OX40-L antibody

Previously, we demonstrated that treatment with antibodies to CD80 and CD86 gave optimal inhibition in this model when treatment was commenced from the time of the first HgCl2 injection.3 The optimal protocol for disease inhibition using antibodies to CD80 and CD86 was 100 µg of antibody given intravenously on days 0, 1, 2, 4, 6, 8, 10 and 12. This regimen was used for treatment with ATM-2, a murine anti-rat OX40-L antibody.8 MOPC 21 was given as an isotype control immunoglobulin. Use of this protocol with antibody to OX40-L had no significant effect on total serum IgE concentrations measured by ELISA (repeated measures anova, Fig. 1). This result has been repeated for the early part of the time-course (up to day 14 in two further experiments). Median spleen weight (interquartile range) on day 14 was 1·13 g (1·10–1·22, n = 12) for MOPC-treated animals and 1·01 g (0·96–1·08, n = 12) for anti-OX40-L treated animals, Mann–Whitney U P < 0·015. Normal BN rat spleens for animals weighing 250–350 g weighed 0·58 ± 0·1 g (mean ± SD).3 There was no difference in the severity of caecal vasculitis on day 14 (data not shown). In a preliminary experiment an increase in the dose of anti-OX40-L to 500 µg using the same protocol gave similar results.

Figure 1.

Figure 1

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Early treatment with anti-OX40-L antibody had no effect on serum IgE concentrations. Serum IgE concentrations are shown for groups of nine animals pooled from two identical experiments treated with MOPC (isotype control immunoglobulin, closed circles) or anti-OX40-L (open circles) 100 µg intravenously on days 0, 1, 2, 4, 6, 8, 10 and 12. There was no statistically significant difference between the groups.

Late treatment with anti-OX40-L antibody

In the late treatment protocol 100 µg of anti-OX40-L or MOPC was given intravenously on days 8, 9, 10, 12, 14, 16, 18 and 20. Late treatment resulted in significant inhibition of IgE production (repeated measures anova on log-transformed data: P = 0·006, Fig. 2). Late treatment with anti-OX40-L resulted in a significant reduction in lymphoproliferation as indicated by spleen weight on day 24/day 25 (Kruskall–Wallis P = 0·008) which was not significant for late (CD80+CD86)-treated animals (Fig. 3). However, late treatment with CD80 and CD86 did suppress IgE production (data in Fig. 7). Weight loss was significantly inhibited (repeated measures anova: P = 0·036, Fig. 4). The data shown are from two pooled identical experiments and have been reproduced in two further experiments.

Figure 2.

Figure 2

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Late treatment with anti-OX40-L antibody suppressed IgE production. Serum IgE concentrations are shown for groups of 10 animals pooled from two identical experiments treated with MOPC (isotype control immunoglobulin, closed circles) or anti-OX40-L (open circles) 100 µg intravenously on days 8, 9, 10, 12, 14, 16, 18, 20. Difference between the groups was tested by repeated measures anova on log-transformed data: P = 0·006.

Figure 3.

Figure 3

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Late treatment with anti-OX40-L antibody suppressed lymphoproliferation. Spleen weights are shown for animals pooled from three separate experiments with similar design where animals were treated with MOPC, anti-OX40-L 100 µg intravenously or anti-CD80+CD86 (100 µg of each antibody) on days 8, 9, 10, 12, 14, 16, 18 and 20. Median values are indicated. The only statistically significant difference by Kruskall–Wallis anova was between the MOPC and anti-OX40-L-treated groups (P = 0·008).

Figure 7.

Figure 7

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Absence of synergy between late blockade of OX40-L and CD80/CD86. Serum IgE concentrations are shown for groups of five animals from a single experiment treated with antibodies from day 8: MOPC (closed circles), anti-OX40-L (open circles), CD80 plus CD86 (closed triangles) or anti-OX40-L plus CD80 plus CD86 (open triangles). Repeated measures anova on log-transformed data: anti-OX40-L versus MOPC (P = 0·003). There was no difference between anti-OX40-L-treated animals with or without CD80 and CD86 antibodies.

Figure 4.

Figure 4

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Late treatment with anti-OX40-L antibody reduced weight loss. The percentage weight on day 8 after the first HgCl2 injection (mean ± SEM) are shown for groups of 10 animals pooled from two identical experiments treated with MOPC (closed circles) or anti-OX40-L (open circles) from day 8. Difference between the groups was tested by repeated measures anova: P = 0·036.

Anti-mouse immunoglobulin antibody production

Anti-mouse immunoglobulin antibody production measured by ELISA had developed to a significant degree in animals treated early with anti-OX40-L by day 10. This response developed later in animals treated from day 8 but appeared to be of greater magnitude. In both cases the response was significantly greater than that elicited by treatment with the isotype control antibody. Data from a single experiment which has been repeated once with similar results are shown in Fig. 5.

Figure 5.

Figure 5

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Enhanced anti-mouse immunoglobulin antibody response to anti-OX40-LRepresentative raw data are presented in (a). Titres were related to a standard serum from mercuric chloride-treated animals injected intravenously with murine immunoglobulin (closed triangles) with serum from a non-immunized rat as a negative control (open triangles). Calculated values are shown for serum from animals treated with MOPC from day 8 (open squares), anti-OX40-L from day 0 (open circles) and anti-OX40-L from day 8 (closed squares) collected on day 20 and assayed on a single ELISA plate. Data for groups of five animals from a single experiment which has been repeated with similar results are shown in (b). All animals were injected with HgCl2. Antibody treatment groups are shown by: MOPC from day 0 (closed circles), MOPC from day 8 (open squares), anti-OX40-L from day 0 (open circles), anti-OX40-L from day 8 (closed squares).

Survival

Treatment with anti-OX40-L antibody commenced on day 8 after the first HgCl2-injection significantly improved survival when compared to isotype control treated animals (Fig. 6, log-rank P < 0·02). There was no difference in outcome for animals where treatment with MOPC was commenced on day 0 (n = 9) or day 8 (n = 18) so these groups were pooled for analysis. There was no statistically significant difference for animals treated with anti-OX40-L from day 0. There were four deaths, and 10 animals were killed after reaching humane end-points (nine had >25% weight loss and one severe ocular mucositis) in the MOPC group. In the late OX40-L-treated group there was one death and two animals were killed for >25% weight loss, and in the early treated OX40-L group there was one death and one animal was killed for weight loss.

Figure 6.

Figure 6

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Treatment with anti-OX40-L improved survival. Kaplan–Meier survival data are shown for animals injected with HgCl2 and MOPC (solid line, n = 27), anti-OX40-L from day 0 (dotted line, n = 9) or anti-OX40-L from day 8 (dashed line, n = 19). Treatment with anti-OX40-L from day 8 was significantly different from control (log-rank P < 0·02). The data shown were pooled from six independent experiments with identical experimental design.

Comparison with blockade of CD80 and CD86

From our previously published data, treatment with CD80 plus CD86 antibody from day 8 partially blocked the disease.3 We performed an experiment comparing blockade of OX40-L and CD80/CD86 separately and together. Addition of CD80 and CD86 antibodies to anti-OX40-L did not result in further inhibition of IgE production (Fig. 7).

Discussion

The observation that OX-40 signalling is not essential for the initial triggering of HgCl2-induced autoimmunity but is required for the optimal evolution of the Th2-response is compatible with previously published data on the role of OX40. Th2 cytokine production in ovalbumin-primed mice was inhibited by the administration of a neutralizing antibody to OX40-L from the time of first immunization with ovalbumin but no significant reduction in serum IgE or IgG1 was found.18 Our findings of a slight reduction in lymphoproliferation as measured by spleen weight but no change in serum IgE concentrations with early anti-OX40-L treatment is in agreement with these observations. Our data contrast with the observation that optimal enhancement of T-lymphocyte proliferative responses by an agonist OX40 antibody required administration within 48 hr of immunization. However, while enhancement of both Th1 and Th2 driven antibody responses was observed in this study, no data on the optimal time for administration of the OX40 signal for the antibody responses were provided.31

An increase in the proportion of T lymphocytes expressing OX40 was noted in lymph nodes of BN rats 4 days after starting mercuric chloride injections32 and subsequently shown to be inducible by IL4 in vitro.33 Interestingly, this work noted significant labelling in the resting state which we have confirmed (unpublished observations). In other rats strains OX40 expression has been found only on activated T lymphocytes.12 It could be hypothesized that expression of OX40 in the resting state in BN rats predisposes them to Th2-driven autoimmunity.

The published literature on the impact of absence of OX40 signalling in OX40 knockout mice on antibody production presents a complex picture. OX40 deficient mice were found to have normal immunoglobulin concentrations and antibody responses for all antibody isotypes tested34. However, while IgG1 was measured as a Th2-dependent isotype IgE was not. Similarly, OX40 deficient mice had apparently normal class-switched antibody responses in response to LCMV infection,35 but again, no data were provided for IgE. In studies where the IgE response to infection was measured the IgE response to Nippostrongylus brasiliensis was normal.36,37 However, when Heligmosomoides polygyrus was used as the antigen near normal IgG1 responses but markedly depressed IgE production were observed.37

The observations of reduced weight loss and mortality with anti-OX40-L treatment is similar to the reduced weight loss and reduced severity of illness described in influenza-infected mice treated with an OX40 fusion protein either from the time of first infection or delayed until day 3 after inoculation.38

The observation that early treatment with anti-OX40-L had no effect when given from days 0–12 but did have a significant effect when treatment was delayed until day 8 was surprising given the serum half-life of murine IgG. We would have expected significant concentrations of anti-OX40-L antibody to be present during the late treatment period in the plasma of rats treated by the early treatment protocol. A marked antibody response to the murine immunoglobulin was elicited which may have neutralized the antibody during the period when OX40-signalling was critical. We have observed an enhanced anti-mouse immunoglobulin response previously in rats treated with murine antibodies to CD80 and CD862 and a similar observation has been made in mice treated with rat antibodies to CD80 and CD86.39 These molecules are all expressed on B lymphocytes and antigen-presenting cells suggesting the hypothesis that selective compartmentalization of the antigen resulted in enhanced presentation with an accelerated antibody response. An alternative explanation could be that the anti-OX40-L antibody delivered a positive signal to the B-lymphocytes producing anti-mouse immunoglobulin. Support for this comes from the observation that OX40-signalling in vitro enhanced both the proliferation and immunoglobulin secretion of human40,41 and murine42 B lymphocytes stimulated by mitogen or CD40 cross-linking in vitro. Mercuric chloride polyclonally activates B lymphocytes and may have been a cofactor in enhancing the antibody response to a foreign protein.

An interesting paradox is the inhibition of IgE production occurring concurrently with enhancement of IgG production. This would be compatible with the concept that IgE production is more dependent on OX40 than IgG. None of the above studies on the impact of OX40-L cross-linking on immunoglobulin production measured IgE. Clearly, the potential for enhanced anti-immunoglobulin responses is an important issue for the interpretation of in vivo experiments using xenogeneic antibodies specific for markers on B-lymphocytes or other antigen presenting cells. However, this seems not to have been a universal problem as treatment of mice with a rat antibody to OX40-L from the time of infection with Leishmania major resulted in significant inhibition of serum IgE concentrations 30 and 40 days after infection.13 Totsuka et al.43 performed an analogous experiment in Th1-driven chronic colitis induced in BALB/c severe combined immunodeficent mice by the adoptive transfer of CD4+ CD45RBhigh cells. In this model clinical manifestations of the disease become evident 3–5 weeks after cell transfer. Treatment with rat anti-OX40-L intraperitoneally either continuously from the time of cell transfer or commenced after 3 weeks was effective in the suppression of disease. No data on anti-rat IgG responses were provided but would not appear to have caused problems.

It has been suggested that OX40 signalling is involved in the generation of regulatory T cells (Treg) and that the delivery of OX40 signals can override Treg activity.44 We saw no delay in the kinetics of recovery in anti-OX40-L treated animals suggesting that the autoregulatory mechanism is OX40-independent.

The failure of blockade of signalling through CD28 using antibodies to CD80 and CD86 to synergize with anti-OX40-L treatment in the suppression of HgCl2-induced autoimmunity would fit with the concept that CD28 signalling is essential early with OX40 signalling being more important later in the immune response.4

It is well-established that it is easier to suppress immune responses during the activation stage than after they have become established. In treating autoimmune disease therapeutic strategies must have an effect on an established immune response. These data suggest that OX40-L is an attractive therapeutic target for Th2-mediated autoimmune disease. Our observations are analogous to findings in non-obese diabetic mice where treatment with antibody to OX40-L markedly reduced the onset of diabetes mellitus when given on week 12 of life but was relatively ineffective if given earlier. This is the reverse to the pattern found for blockade of CD28 which was effective early but not late, similar to observations with HgCl2-induced autoimmunity.45

In conclusion, treatment with anti-OX40-L antibody after initial triggering significantly inhibited this Th2-driven autoimmune response. This suggests the OX40 pathway as an attractive therapeutic target for putative Th2-mediated autoimmune diseases such as membranous nephropathy, systemic lupus erythematosus or systemic sclerosis.1 An important caveat is the impact of intravenous administration of anti-OX40-L on the anti-mouse immunoglobulin response. In interpreting data with this experimental design it is important not to confuse pharmacokinetic problems with the blocking antibodies used with real biological effects.

Abbreviations

OX40-L

OX40-ligand

References

  • 1.Wu Z, MacPhee IA, Oliveira DB. Reactive oxygen species in the initiation of IL-4 driven autoimmunity as a potential therapeutic target. Curr Pharm Des. 2004;10:899–913. doi: 10.2174/1381612043452875. [DOI] [PubMed] [Google Scholar]
  • 2.MacPhee IAM, Turner DR, Yagita H, Oliveira DBG. CD80 (B7.1) and CD86 (B7.2) do not have distinct roles in setting the Th1/Th2 balance in autoimmunity in rats. Scand J Immunol. 2001;54:486–94. doi: 10.1046/j.1365-3083.2001.00998.x. [DOI] [PubMed] [Google Scholar]
  • 3.MacPhee IAM, Turner DR, Yagita H, Oliveira DBG. The Th2-response in mercuric chloride-induced autoimmunity requires continuing costimulation via CD28. Clin Exp Immunol. 2002;129:405–10. doi: 10.1046/j.1365-2249.2002.01928.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4.Gramaglia I, Weinberg AD, Lemon M, Croft M. Ox-40 ligand: a potent costimulatory molecule for sustaining primary CD4 T cell responses. J Immunol. 1998;161:6510–7. [PubMed] [Google Scholar]
  • 5.Gramaglia I, Jember A, Pippig SD, Weinberg AD, Killeen N, Croft M. The OX40 costimulatory receptor determines the development of CD4 memory by regulating primary clonal expansion. J Immunol. 2000;165:3043–50. doi: 10.4049/jimmunol.165.6.3043. [DOI] [PubMed] [Google Scholar]
  • 6.Salek-Ardakani S, Song J, Halteman BS, Jember AG, Akiba H, Yagita H, Croft M. OX40 (CD134) controls memory T helper 2 cells that drive lung inflammation. J Exp Med. 2003;198:315–24. doi: 10.1084/jem.20021937. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7.Akiba H, Oshima H, Takeda K, et al. CD28-independent costimulation of T cells by OX40 ligand and CD70 on activated B cells. J Immunol. 1999;162:7058–66. [PubMed] [Google Scholar]
  • 8.Satake Y, Akiba H, Takeda K, Atsuta M, Yagita H, Okumura K. Characterization of rat OX40 ligand by monoclonal antibody. Biochem Biophys Res Commun. 2000;270:1041–8. doi: 10.1006/bbrc.2000.2560. [DOI] [PubMed] [Google Scholar]
  • 9.Ohshima Y, Tanaka Y, Tozawa H, Takahashi Y, Maliszewski C, Delespesse G. Expression and function of OX40 ligand on human dendritic cells. J Immunol. 1997;159:3838–48. [PubMed] [Google Scholar]
  • 10.Kashiwakura J, Yokoi H, Saito H, Okayama Y. T cell proliferation by direct cross-talk between OX40 ligand on human mast cells and OX40 on human T cells: comparison of gene expression profiles between human tonsillar and lung-cultured mast cells. J Immunol. 2004;173:5247–57. doi: 10.4049/jimmunol.173.8.5247. [DOI] [PubMed] [Google Scholar]
  • 11.Imura A, Hori T, Imada K, et al. The human OX40/gp34 system directly mediates adhesion of activated T cells to vascular endothelial cells. J Exp Med. 1996;183:2185–95. doi: 10.1084/jem.183.5.2185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12.Paterson DJ, Jefferies WA, Green JR, Brandon MR, Corthesy P, Puklavec M, Williams AF. Antigens of activated rat T lymphocytes including a molecule of 50 000 Mr detected only on CD4 positive T blasts. Mol Immunol. 1987;24:1281–90. doi: 10.1016/0161-5890(87)90122-2. [DOI] [PubMed] [Google Scholar]
  • 13.Akiba H, Miyahira Y, Atsuta M, et al. Critical contribution of OX40 ligand to T helper cell type 2 differentiation in experimental leishmaniasis. J Exp Med. 2000;191:375–80. doi: 10.1084/jem.191.2.375. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Flynn S, Toellner KM, Raykundalia C, Goodall M, Lane P. CD4 T cell cytokine differentiation: the B cell activation molecule, OX40 ligand, instructs CD4 T cells to express interleukin 4 and upregulates expression of the chemokine receptor, Blr-1. J Exp Med. 1998;188:297–304. doi: 10.1084/jem.188.2.297. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Ohshima Y, Yang LP, Uchiyama T, et al. OX40 costimulation enhances interleukin-4 (IL-4) expression at priming and promotes the differentiation of naive human CD4 (+) T cells into high IL-4-producing effectors. Blood. 1998;92:3338–45. [PubMed] [Google Scholar]
  • 16.Linton PJ, Bautista B, Biederman E, et al. Costimulation via OX40L expressed by B cells is sufficient to determine the extent of primary CD4 cell expansion and Th2 cytokine secretion in vivo. J Exp Med. 2003;197:875–83. doi: 10.1084/jem.20021290. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17.Arestides RS, He H, Westlake RM, Chen AI, Sharpe AH, Perkins DL, Finn PW. Costimulatory molecule OX40L is critical for both Th1 and Th2 responses in allergic inflammation. Eur J Immunol. 2002;32:2874–80. doi: 10.1002/1521-4141(2002010)32:10<2874::AID-IMMU2874>3.0.CO;2-4. [DOI] [PubMed] [Google Scholar]
  • 18.Hoshino A, Tanaka Y, Akiba H, et al. Critical role for OX40 ligand in the development of pathogenic Th2 cells in a murine model of asthma. Eur J Immunol. 2003;33:861–9. doi: 10.1002/eji.200323455. [DOI] [PubMed] [Google Scholar]
  • 19.Murata K, Nose M, Ndhlovu LC, Sato T, Sugamura K, Ishii N. Constitutive OX40/OX40 ligand interaction induces autoimmune-like diseases. J Immunol. 2002;169:4628–36. doi: 10.4049/jimmunol.169.8.4628. [DOI] [PubMed] [Google Scholar]
  • 20.Song J, Salek-Ardakani S, Rogers PR, Cheng M, Van Parijs L, Croft M. The costimulation-regulated duration of PKB activation controls T cell longevity. Nat Immunol. 2004;5:150–8. doi: 10.1038/ni1030. [DOI] [PubMed] [Google Scholar]
  • 21.Song J, So T, Cheng M, Tang X, Croft M. Sustained survivin expression from OX40 costimulatory signals drives T cell clonal expansion. Immunity. 2005;22:621–31. doi: 10.1016/j.immuni.2005.03.012. [DOI] [PubMed] [Google Scholar]
  • 22.Kawamata S, Hori T, Imura A, Takaori-Kondo A, Uchiyama T. Activation of OX40 signal transduction pathways leads to tumor necrosis factor receptor-associated factor (TRAF) 2- and TRAF5-mediated NF-kappaB activation. J Biol Chem. 1998;273:5808–14. doi: 10.1074/jbc.273.10.5808. [DOI] [PubMed] [Google Scholar]
  • 23.Arch RH, Thompson CB. 4-1BB and OX40 are members of a tumor necrosis factor (TNF)–nerve growth factor receptor subfamily that bind TNF receptor-associated factors and activate nuclear factor kappa B. Mol Cell Biol. 1998;18:558–65. doi: 10.1128/mcb.18.1.558. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24.Rogers PR, Song J, Gramaglia I, Killeen N, Croft M. OX40 promotes Bcl-xL and Bcl-2 expression and is essential for long-term survival of CD4 T cells. Immunity. 2001;15:445–55. doi: 10.1016/s1074-7613(01)00191-1. [DOI] [PubMed] [Google Scholar]
  • 25.Mestas J, Crampton SP, Hori T, Hughes CC. Endothelial cell co-stimulation through OX40 augments and prolongs T cell cytokine synthesis by stabilization of cytokine mRNA. Int Immunol. 2005;17:737–47. doi: 10.1093/intimm/dxh255. [DOI] [PubMed] [Google Scholar]
  • 26.Walker LS, Gulbranson-Judge A, Flynn S, et al. Compromised OX40 function in CD28-deficient mice is linked with failure to develop CXC chemokine receptor 5-positive CD4 cells and germinal centers. J Exp Med. 1999;190:1115–22. doi: 10.1084/jem.190.8.1115. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 27.Stuber E, Strober W. The T cell–B cell interaction via OX40–OX40L is necessary for the T cell-dependent humoral immune response. J Exp Med. 1996;183:979–89. doi: 10.1084/jem.183.3.979. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28.Kiely PDW, Thiru S, Oliveira DBG. Inflammatory polyarthritis induced by mercuric chloride in the Brown Norway rat. Lab Invest. 1995;73:284–93. [PubMed] [Google Scholar]
  • 29.Bowman C, Mason DW, Pusey CD, Lockwood CM. Autoregulation of autoantibody synthesis in mercuric chloride nephritis in the Brown Norway rat. I. A role for T suppressor cells. Eur J Immunol. 1984;14:464–70. doi: 10.1002/eji.1830140515. [DOI] [PubMed] [Google Scholar]
  • 30.Maeda K, Sato T, Azuma M, Yagita H, Okumura K. Characterization of rat CD80 and CD86 by molecular cloning and mAb. Int Immunol. 1997;9:993–1000. doi: 10.1093/intimm/9.7.993. [DOI] [PubMed] [Google Scholar]
  • 31.Evans DE, Prell RA, Thalhofer CJ, Hurwitz AA, Weinberg AD. Engagement of OX40 enhances antigen-specific CD4 (+) T cell mobilization/memory development and humoral immunity: comparison of alphaOX-40 with alphaCTLA-4. J Immunol. 2001;167:6804–11. doi: 10.4049/jimmunol.167.12.6804. [DOI] [PubMed] [Google Scholar]
  • 32.Roos A, Claessen N, Weening JJ, Aten J. Enhanced T lymphocyte expression of LFA-1, ICAM-1, and the TNF receptor family member OX40 in HgCl2-induced systemic autoimmunity. Scand J Immunol. 1996;43:507–18. doi: 10.1046/j.1365-3083.1996.d01-66.x. [DOI] [PubMed] [Google Scholar]
  • 33.Roos A, Schilder-Tol EJ, Weening JJ, Aten J. Strong expression of CD134 (OX40), a member of the TNF receptor family, in a T helper 2-type cytokine environment. J Leukoc Biol. 1998;64:503–10. doi: 10.1002/jlb.64.4.503. [DOI] [PubMed] [Google Scholar]
  • 34.Chen AI, McAdam AJ, Buhlmann JE, et al. Ox40-ligand has a critical costimulatory role in dendritic cell: T cell interactions. Immunity. 1999;11:689–98. doi: 10.1016/s1074-7613(00)80143-0. [DOI] [PubMed] [Google Scholar]
  • 35.Kopf M, Ruedl C, Schmitz N, et al. OX40-deficient mice are defective in Th cell proliferation but are competent in generating B cell and CTL Responses after virus infection. Immunity. 1999;11:699–708. doi: 10.1016/s1074-7613(00)80144-2. [DOI] [PubMed] [Google Scholar]
  • 36.Pippig SD, Pena-Rossi C, Long J, et al. Robust B cell immunity but impaired T cell proliferation in the absence of CD134 (OX40) J Immunol. 1999;163:6520–9. [PubMed] [Google Scholar]
  • 37.Ekkens MJ, Liu Z, Liu Q, Whitmire J, Xiao S, Foster A, et al. The role of OX40 ligand interactions in the development of the Th2 response to the gastrointestinal nematode parasite Heligmosomoides polygyrus. J Immunol. 2003;170:384–93. doi: 10.4049/jimmunol.170.1.384. [DOI] [PubMed] [Google Scholar]
  • 38.Humphreys IR, Walzl G, Edwards L, Rae A, Hill S, Hussell T. A critical role for OX40 in T cell-mediated immunopathology during lung viral infection. J Exp Med. 2003;198:1237–42. doi: 10.1084/jem.20030351. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 39.Daikh DI, Wofsy D. Effects of anti-B7 monoclonal antibodies on humoral immune responses. J Autoimmunity. 1999;12:101–8. doi: 10.1006/jaut.1998.0258. [DOI] [PubMed] [Google Scholar]
  • 40.Morimoto S, Kanno Y, Tanaka Y, et al. CD134L engagement enhances human B cell Ig production: CD154/CD40, CD70/CD27, and CD134/CD134L interactions coordinately regulate T cell-dependent B cell responses. J Immunol. 2000;164:4097–104. doi: 10.4049/jimmunol.164.8.4097. [DOI] [PubMed] [Google Scholar]
  • 41.Wang Q, Chen Y, Ge Y, et al. Characterization and functional study of five novel monoclonal antibodies against human OX40L highlight reverse signalling: enhancement of IgG production of B cells and promotion of maturation of DCs. Tissue Antigens. 2004;64:566–74. doi: 10.1111/j.1399-0039.2004.00300.x. [DOI] [PubMed] [Google Scholar]
  • 42.Stuber E, Neurath M, Calderhead D, Fell HP, Strober W. Cross-linking of OX40 ligand, a member of the TNF/NGF cytokine family, induces proliferation and differentiation in murine splenic B cells. Immunity. 1995;2:507–21. doi: 10.1016/1074-7613(95)90031-4. [DOI] [PubMed] [Google Scholar]
  • 43.Totsuka T, Kanai T, Uraushihara K, et al. Therapeutic effect of anti-OX40L and anti-TNF-alpha MAbs in a murine model of chronic colitis. Am J Physiol Gastrointest Liver Physiol. 2003;284:G595–G603. doi: 10.1152/ajpgi.00450.2002. [DOI] [PubMed] [Google Scholar]
  • 44.Takeda I, Ine S, Killeen N, et al. Distinct roles for the OX40–OX40 ligand interaction in regulatory and nonregulatory T cells. J Immunol. 2004;172:3580–9. doi: 10.4049/jimmunol.172.6.3580. [DOI] [PubMed] [Google Scholar]
  • 45.Pakala SV, Bansal-Pakala P, Halteman BS, Croft M. Prevention of diabetes in NOD mice at a late stage by targeting OX40/OX40 ligand interactions. Eur J Immunol. 2004;34:3039–46. doi: 10.1002/eji.200425141. [DOI] [PubMed] [Google Scholar]

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