CD86 (B7-2) antigen on B cells from atopic patients shows selective, antigen-specific upregulation

Characterization of allergen-specific monocyte-derived dendritic cells generated from monocytes by a single-step procedure: effect on naïve and memory T cells

BACKGROUND

Dendritic cells are one of the most potent antigen-presenting cells and when pulsed with allergen can modulate allergen-specific T-cell responses. We sought to establish a single-step method by which to generate allergen-specific monocyte-derived dendritic cells (MoDCs).

METHODS

Dermatophagoides farinae (Df)-prepulsed MoDCs were generated from monocytes by culturing with Df in the presence interleukin (IL)-4, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumour necrosis factor (TNF)-alpha simultaneously. Df-prepulsed MoDC were incubated with autologous naive and memory T cells in the absence of recall antigen, then proliferation and cytokine production by T cells was determined.

RESULTS

Generation of allergen-prepulsed MoDCs was confirmed by examining expression of surface molecules. Df-prepulsed MoDC selectively induced proliferation of Df-specific T cells in the absence of recall antigen. Under these conditions, Df-prepulsed MoDCs augmented but did not alter the cytokine production profile. In addition, Df-prepulsed MoDCs activated naive T cells leading to proliferation and selective production of IFN-gamma in allergic patients but not in healthy subjects.

CONCLUSIONS

These results suggest that Df-prepulsed MoDC generated from monocytes by a simple single-step manipulation can induce Df-specific cellular responses from both naive and memory T cells in the absence of recall antigen, and these cells potentially can be utilized as immune adjuvants in allergen-specific immunotherapy.

Enhanced expression of B7.2 (CD86) by percutaneous sensitization with house dust mite antigen

House dust mite antigen is a well-known allergen in the pathogenesis of atopic dermatitis (AD), a chronic relapsing inflammatory skin disease. We evaluated the AD model mice sensitized with house dust mite antigen and observed a Th2-dominant immune response. In this experiment, BALB/c mice were sensitized percutaneously with house dust mite antigen three times with 7 days interval after skin barrier disruption. A remarkable infiltration of polymorphonuclear granulocytes and monocytes in the cutis was observed in mice treated with this antigen, high serum IgE levels and IL-4 mRNA expression in local lymph node cells was also observed. CD19(+) B cell numbers overturned to CD4(+) helper T cells. In these mice, there was significant increase of B7.2 (CD86) expression on CD19(+) B cells. These results indicate that house dust mite antigen sensitizes BALB/c mice and skews their Th1/Th2 balance toward Th2.

Inhibitory action of a macrolide antibiotic, roxithromycin, on co-stimulatory molecule expressions in vitro and in vivo

OBJECTIVE

The influence of a macrolide antibiotic, roxithromycin (RXM), on co-stimulatory molecule expression was examined in vitro and in vivo.

MATERIALS AND METHODS

Spleen cells obtained from BALB/c mice 10 days after immunization with 8.0 microg of hemocyanin absorbed to 4.0 mg of aluminum hydroxide were cultured in the presence of 100.0 microg/ml of hemocyanin and various concentrations of RXM. We first examined the influence of RXM on cell activation by examining the proliferative response of cells and cytokine production. We also examined the influence of RXM on co-stimulatory molecule (CD40, CD80 and CD86) expressions on cultured splenic B-lymphocytes induced by in vitro antigenic stimulation using flow cytometry. In the second part of experiments, non-immunized and immunized mice were treated orally with 2.5 mg/kg of RXM once a day for 4 or 8 weeks. Splenic B lymphocytes were obtained from these mice 24 h after antigenic challenge, and co-stimulatory molecule expressions were examined by flow cytometer.

RESULTS

Cell activation induced by in vitro antigenic stimulation was suppressed by RXM when cells were cultured in the presence of more than 5.0 microg/ml of the agent. Addition of RXM at a concentration of 5.0 microg/ml into cell cultures also suppressed co-stimulatory molecule (CD40, CD80 and CD86) expressions on splenic B lymphocytes, which was enhanced by antigenic stimulation in vitro. Oral RXM administration for 4 weeks clearly suppressed the enhancement of CD40 and CD86 (but not CD80) expressions on splenic B lymphocytes induced by antigenic stimulation in vivo. This suppressive activity of RXM on co-stimulatory molecule (CD40 and CD86) expressions was further strengthened by the treatment of mice for 8 weeks. Long-term treatment with oral RXM also suppressed CD80 expressions, which was not suppressed by 4-week treatment.

CONCLUSION

The present results suggest that RXM exerts its immunomodulating effects through suppression of both cell activation and co-stimulatory molecule expressions induced by antigenic stimulation. These suppressive activities of RXM might contribute, in part, to the therapeutic mode of action of RXM on inflammatory diseases.

Suppressive effects of anti-allergic agent suplatast tosilate (IPD-1151T) on the expression of co-stimulatory molecules on mouse splenocytes in vivo

The effects of IPD-1151T on the expression of co-stimulatory molecules, CD40, CD80 and CD86, were investigated in vivo using mice with allergic disorders. BALB/c mice were immunized intraperitoneally with two doses of dinitrophenylated ovalbumin (DNP-OVA) at 1-week intervals. These mice then were treated intraperitoneally with 100 microg/kg of IPD-1151T once a day for 14 days, starting 7 days after the first immunization. On day 21, some mice were challenged intraperitoneally with DNP-OVA and the other mice were not challenged. All mice were autopsied on day 22 and assayed for immunoglobulin E, interleuken (IL)-4 and IL-5 productions following DNP-OVA immunization. The intraperitoneal treatment with IPD-1151T strongly suppressed immunoglobulin E contents in serum, which were enhanced by DNA-OVA immunization. IPD-1151T also caused a decrease in both IL-4 and IL-5 levels in splenic lymphocytes. We next examined the influence of IPD-1151T on co-stimulatory molecule expression on splenic lymphocytes. IPD-1151T caused suppression of CD40 and CD86 expression; however, the treatments did not affect CD80 expression.

Differential role of CD80 and CD86 molecules in the induction and the effector phases of allergic rhinitis in mice

Selective involvement of CD80 and/or CD86 in the differentiation of T-helper (Th)1 and Th2 was seen in several diseases. In this study, we sought to determine the differential roles of CD80 and CD86 in the induction and effector phase of allergic rhinitis using Schistosoma mansoni egg antigen (SEA) as a specific Ag. Intranasal sensitization with SEA in BALB/c mice elicited a strong Th2 response including SEA-specific IgE production, nasal eosinophilia, and IL-4 and IL-5 production by nasal lymphocytes after Ag challenge. Blockade of CD80 at the induction phase significantly inhibited these manifestations, whereas no effect was observed by CD86 blockade. In contrast, the simultaneous blockade of both CD80 and CD86 during the effector phase partially inhibited IgE and IgG(1) production and nasal eosinophilia, although either blockade of CD80 or CD86 during the phase failed to inhibit these responses. Flow cytometric analysis on nasal mononuclear cells showed that CD80 but not CD86 was preferentially expressed on non-B cells by in vitro SEA stimulation in unsensitized mice. However, both CD80 and CD86 expression were significantly augmented by in vitro SEA stimulation in sensitized mice. Our results suggest the differential roles and expression of CD80 and CD86 in the development of allergic rhinitis.

Langerhans' cells in vernal keratoconjunctivitis express the costimulatory molecule B7-2 (CD86), but not B7-1 (CD80)

PURPOSE

Vernal keratoconjunctivitis (VKC) is associated with T-helper 2 (TH2)-like cell response and increased immunoglobulin (Ig) E production. Recent studies have suggested that interactions between costimulatory molecules B7 on antigen-presenting cells and CD28 on T cells are critical for successful antigen presentation and the development of the TH2 immune response. The objective of this study was to examine the expression of costimulatory molecules CD28, B7-1 (CD80) and B7-2 (CD86) in conjunctival biopsies from patients with active VKC and normal controls.

METHODS

Conjunctival biopsy specimens from 15 subjects with active VKC, and 8 control subjects, were studied by immunohistochemical techniques using a panel of monoclonal and polyclonal antibodies directed against CD28, B7-1 and B7-2 molecules. The phenotype of inflammatory cells expressing costimulatory molecules was examined by sequential double immunohistochemistry.

RESULTS

In the normal conjunctiva, B7-2 was expressed on a few mononuclear cells in the epithelium and substantia propria in 5 of 8 specimens. There was no immunoreactivity for CD28 or B7-1. In VKC specimens, few B7-1+ mononuclear cells were noted in the substantia propria in 7 of 15 specimens. B7-2 was expressed on mononuclear cells in the epithelium and substantia propria in all specimens. Compared with normal controls, VKC specimens showed significantly more mononuclear cells expressing B7-2 (30.5+/-14.1 vs 1.88+/-2.5; p < 0.001). In VKC specimens, the numbers of mononuclear cells expressing B7-2 were significantly higher than the numbers of mononuclear cells expressing B7-1 (30.5+/-14.1 vs 2.3+/-3.1; p < 0.001). CD28 was expressed on mononuclear cells in the epithelium and substantia propria in 14 specimens. Colocalisation studies revealed that the majority of mononuclear cells expressing B7-2 were CD1a+ Langerhans' cells, and that the mononuclear cells expressing CD28 were CD3+ T lymphocytes.

CONCLUSIONS

B7-2 is more widely and prominently expressed by Langerhans' cells compared with B7-1. The interaction of B7-2 with CD28 may mediate the development of the TH2 immune response in VKC. Thus the manipulation of this pathway could be an important target for the development of future therapies in VKC.

Expression of costimulatory CD80/CD86-CD28/CD152 molecules in nasal mucosa of patients with perennial allergic rhinitis

BACKGROUND

B7 molecules (CD80, CD86) and their counter-receptors, CD28 and CD152 (CTLA-4), play an important role in T cell-mediated immune responses. We previously demonstrated that B7 molecules are selectively up-regulated not only on B cells but also on T cells from the peripheral blood mononuclear cells of patients with perennial rhinitis cultured with allergen. However, the expression of CD80/CD86 molecules and their counter-receptors in nasal mucosa, the actual inflammatory site of allergic rhinitis, has not yet been clarified.

PATIENTS AND METHODS

Inferior turbinates from patients with either allergy to house dust or non-allergic rhinitis were excised and immunohistologically stained. In addition, the inferior turbinates were challenged with paper discs containing extracts of house dust and subsequently excised. Samples were double stained with immunofluorescent-labelled antibody to identify cells bearing CD86.

RESULTS

Without the nasal provocation, only the expression of CD86 was increased in nasal mucosa of patients with allergic rhinitis compared with those with non-allergic rhinitis. However, following the nasal provocation with house dust, not only CD86, but also CD80, CD28, and CD152 were significantly expressed in allergic patients. Immunofluorescent double staining revealed CD86 expression in CD19, CD1a, CD14 and CD3 lymphocytes.

CONCLUSION

These results indicate that the expression of CD80/CD86 molecules and their counter-receptors is induced in allergic patients following nasal provocation with allergen, suggesting a local amplification of allergen-specific immune responses in perennial rhinitis.

Lacto-N-fucopentaose III found on Schistosoma mansoni egg antigens functions as adjuvant for proteins by inducing Th2-type response

We have recently demonstrated that induction of Th2 responses by Schistosoma mansoni egg Ag is largely due to carbohydrates on the Ag functioning as adjuvants. Lacto-N-fucopentaose III (LNFPIII), a polylactosamine sugar, is the predominant carbohydrate found in S. mansoni egg Ag. Therefore, using neoglycoprotein, we investigated whether LNFPIII induces in vivo Th2 response and functions as an adjuvant. Following intranasal immunization with LNFPIII linked to human serum albumin (HSA) (HSA-LNFPIII), BALB/c mice mounted a strong Th2 response and produced significantly higher levels of total IgE as well as HSA-specific IgG, IgG1, and IgE. HSA-LNFPIII was over 1000-fold more potent in inducing Ab production as compared with HSA alone. Although LNFPIII itself did not function as an epitope for either IgG or IgE, its conjugation with protein was essential for the adjuvant activity. Moreover, fucose residue on LNFPIII was crucial for induction of Ab production. Nasal lymphocytes from mice immunized with HSA-LNFPIII produced IL-4, IL-5, and IL-10, but not IFN-gamma following in vitro stimulation with HSA or HSA-LNFPIII. In addition, these activated nasal lymphocytes also showed a significant increase of B7-2 expression on B220-positive cells. Furthermore, not only intranasal but also both i.p. and s.c. immunization with HSA-LNFPIII induced significant production of HSA-specific Abs compared with the immunization with HSA alone, suggesting that the activity of LNFPIII was not restricted on particular route of immunization. These results demonstrate that Lewis type carbohydrate LNFPIII can function as an adjuvant by their ability to induce a Th2 response.

Suppression of co-stimulatory molecule expressions on splenic B lymphocytes by a macrolide antibiotic, roxithromycin in vitro

The influence of a macrolide antibiotic, roxithromycin (RXM), on co-stimulatory molecule expression was examined using in vitro cell culture technique. Spleen cells obtained from BALB/c mice 10 days after immunization with 8.0 micrograms of haemocyanin absorbed to 4.0 mg aluminum hydroxide were cultured in the presence of 100.0 micrograms/ml haemocyanin and various concentrations of RXM for 72 h. Low concentrations (1.0 and 2.5 micrograms/ml) of RXM did not influence cell activation induced by antigenic stimulation, whereas RXM showed a suppressive effect on blastic activity of the cells when the agent was added to the cultures at more than 5.0 micrograms/ml. RXM did not affect blastic activity of splenic T cells by anti-CD3 monoclonal antibody stimulation even when the cells were cultured in the presence of 10.0 micrograms/ml RXM. Addition of anti-CD80 and anti-CD86 monoclonal antibody to cell cultures caused significant suppression of cell activation by antigenic stimulation. We next examined the influence of RXM on co-stimulatory molecule expressions on splenic B cells in response to antigenic stimulation. Addition of RXM at a concentration of 5.0 micrograms/ml into cell cultures remarkably suppressed co-stimulatory molecule, CD40, CD80 and CD86, expressions, which enhanced by antigenic stimulation in vitro.

The modulation of B7.2 and B7.1 on B cells by immunosuppressive agents

Several recent studies demonstrate that B7.2, but not B7.1, play an important role in allergic inflammation and IgE production. Agents that down-regulate B7.2 may therefore be of benefit for the treatment of Th2-driven allergic diseases. Our current study was carried out to investigate the effect of immunosuppressive agents, cyclosporin A (CsA) and dexamethasone, on B7.2 and B7.1 expression on B cells stimulated with the superantigen, toxic shock syndrome toxin-1 (TSST-1). The analysis of B7.2 and B7.1 on the same cells by flow cytometry demonstrated that TSST-1 up-regulated B7.2+B7.1- but not B7.1+B7.2- on B cells in a dose-dependent fashion. CsA and dexamethasone significantly down-regulated B7.2+B7.1- but up-regulated B7.2-B7.1+ B cells in the presence or absence of TSST-1 (100 ng/ml). Interestingly, the combination of CsA and dexamethasone was much more potent in the inhibition of B7.2 expression than either of these agents alone. As CD40 is known to up-regulate B7.2 expression on B cells, the mechanism of B7.2 down-regulation by CsA and dexamethasone was further studied by investigating the effect of these agents on CD40 expression on B cells. TSST-1 significantly increased CD40 expression on B cells. However, the addition of CsA or dexamethasone significantly down-regulated CD40 expression. Anti-CD40 MoAb significantly reversed the effects of CsA or dexamethasone on B7.2 and B7.1 expression, suggesting that T cell engagement of CD40 plays a role in the mechanisms by which CsA and dexamethasone acts on B cells. These data demonstrate the modulatory effect of CsA and dexamethasone on B7.2 and B7.1 expression on B cells and the potential role of CD40 in mediating this effect.