Quantitative analysis of T helper 1, T helper 2, and inflammatory cytokine expression in patients after allogeneic bone marrow transplantation: relationship with the occurrence of acute graft-versus-host disease

Combination of IL-10 and IL-2 induces oligoclonal human CD4 T cell expansion during xenogeneic and allogeneic GVHD in humanized mice

IL-10 is a crucial anti-inflammatory cytokine which can also exert a seemingly divergent immunostimulatory effects under certain conditions. We found high levels of the cytokine in a xenogeneic GVHD model where NOD-scid IL2rγcnull (NSG) mice were transplanted with human PBMCs in presence of IL-2. Presence of exogenous IL-10 altered the kinetics of IL-2 induced human T cell reconstitution in vivo, showing an initial delay, followed by rapid expansion. Further, compared to IL-2 alone, treatment with IL-2 in combination with IL-10 increased survival in most animals and completely protected ∼20% of mice from GVHD. Additionally, IL-2 induced expansion of both CD4⁺ and CD8⁺ xenoreactive T cells whereas a combination of IL-2 and IL-10 resulted in selective expansion of CD4⁺ T cells only. TCR Vβ repertoire analysis of CD4⁺ T cells showed that in contrast to IL-2 alone, simultaneous presence of both cytokines drastically reduced the Vβ repertoire of the expanded CD4⁺ T cells. Highly restricted Vβ usage was also observed when the cytokine combination was tested in an allogeneic GVHD model where NOD-scid IL2rγc^null mice expressing HLA-DR4 (NSG-DR4) were transplanted with purified CD4⁺ T cells from HLA-DR4 negative donors. Taken together, our results demonstrate that IL-10 can profoundly modulate the subset composition and repertoire of responding T cells during GVHD.

Circulating Levels of Adipokines Predict the Occurrence of Acute Graft-versus-host Disease

Currently, detecting biochemical differences before and after allogeneic stem cell transplantation (SCT) for improved prediction of acute graft-versus-host disease (aGVHD) is a major clinical challenge. In this pilot study, we analyzed the kinetics of circulating adipokine levels in patients with or without aGVHD before and after allogeneic SCT. Serum samples were obtained and stored at -80℃ within 3 hours after collection, prior to conditioning and at engraftment after transplantation. A protein array system was used to measure the levels of 7 adipokines of patients with aGVHD (n=20) and without aGVHD (n=20). The resistin level at engraftment was significantly increased (p<0.001) after transplantation, regardless of aGVHD occurrence. In the non-aGVHD group, the concentrations of the hepatocyte growth factor (HGF) (mean values±SD; 206.6±34.3 vs. 432.3±108.9 pg/ml, p=0.040) and angiopoietin-2 (ANG-2) (mean values±SD; 3,197.2±328.3 vs. 4,471.8±568.4 pg/ml, p=0.037) at engraftment were significantly higher than those of the pre-transplant period, whereas in the aGVHD group, the levels of adipokines did not change after transplantation. Our study suggests that changes in serum HGF and ANG-2 levels could be considered helpful markers for the subsequent occurrence of aGVHD.

Monocyte-induced development of Th17 cells and the release of S100 proteins are involved in the pathogenesis of graft-versus-host disease

Graft-versus-host disease (GvHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. However, the pathophysiology of GvHD remains poorly understood. In this study, we analyzed the induction of Th17 cells by monocytes of patients with GvHD in vitro, demonstrating that monocytes isolated from patients with acute skin and intestinal GvHD stage I-IV and chronic GvHD induce significantly increased levels of Th17 cells compared with patients without GvHD. S100 proteins are known to act as innate amplifier of inflammation. We therefore investigated the presence of S100 proteins in the stool, serum, and bowel tissue of patients with GvHD and the influence of S100 proteins on the induction of Th17 cells. Elevated levels of S100 proteins could be detected in patients with acute GvHD, demonstrating the release of these phagocyte-specific proteins during GvHD. Furthermore, stimulation of monocytes with S100 proteins was found to promote Th17 development, emphasizing the role of S100 proteins in Th17-triggered inflammation. Altogether, our results indicate that induction of Th17 cells by activated monocytes and the stimulatory effects of proinflammatory S100 proteins might play a relevant role in the pathogenesis of acute GvHD. Regarding our data, S100 proteins might be novel markers for the diagnosis and follow-up of GvHD.

Helper T-cell differentiation in graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective therapeutic option for many malignant diseases. However, the efficacy of allo-HSCT is limited by the occurrence of destructive graft-versus-host disease (GVHD). Since allogeneic T cells are the driving force in the development of GVHD, their activation, proliferation, and differentiation are key factors to understanding GVHD pathogenesis. This review focuses on one critical aspect: the differentiation and function of helper T (Th) cells in acute GVHD. We first summarize well-established subsets including Th1, Th2, Th17, and T-regulatory cells; their flexibility, plasticity, and epigenetic modification; and newly identified subsets including Th9, Th22, and T follicular helper cells. Next, we extensively discuss preclinical findings of Th-cell lineages in GVHD: the networks of transcription factors involved in differentiation, the cytokine and signaling requirements for development, the reciprocal differentiation features, and the regulation of microRNAs on T-cell differentiation. Finally, we briefly summarize the recent findings on the roles of T-cell subsets in clinical GVHD and ongoing strategies to modify T-cell differentiation for controlling GVHD in patients. We believe further exploration and understanding of the immunobiology of T-cell differentiation in GVHD will expand therapeutic options for the continuing success of allo-HSCT.

Antagonistic effect of Candida albicans and IFNγ on E-cadherin expression and production by human primary gingival epithelial cells

Caused mainly by Candida albicans, oropharyngeal candidiasis is the most common oral complication associated with HIV disease worldwide. Host defenses against C. albicans essentially fall into two categories: specific immune mechanisms and local oral mucosal epithelial cell defenses. Since oral mucosa is the first line of defense in the form of a physical barrier against C. albicans invasion, and since epithelial cells are involved in anti-Candida innate immunity through different cytokines, we wanted to determine whether C. albicans alters E-cadherin expression and production, and whether interferon-γ (INFγ), a TH1 cytokine, is involved in the anti-Candida defense. Using primary human gingival epithelial cells, we demonstrated that C. albicans significantly decreased E-cadherin mRNA expression and protein production. This effect was basically obtained at later infective periods (24 and 48h). Interestingly, when IFNγ was added to C. albicans infected epithelial cell cultures, it prevented the side effect of C. albicans on E-cadherin mRNA expression and protein production and deposition. All together, these results suggested concomitant interactions between oral epithelial cells and IFNγ against C. albicans infection.

Attenuation of acute graft-versus-host disease in the absence of the transcription factor RORγt

Graft-versus-host disease (GVHD) remains the most significant complication after allogeneic stem cell transplantation. Previously, acute GVHD had been considered to be mediated predominantly by Th1-polarized T cells. Recently, investigators have identified a second proinflammatory lineage of T cells termed Th17 that is critically dependent on the transcription factor retinoic acid-related orphan receptor (ROR)γt. In this study, we have evaluated the role of Th17 cells in murine acute GVHD by infusing donor T cells lacking RORC and as a consequence the isoform RORγt. Recipients given donor CD4(+) and CD8(+) T cells lacking RORC had significantly attenuated acute GVHD and markedly decreased tissue pathology in the colon, liver, and lung. Using a clinically relevant haploidentical murine transplantation model, we showed that RORC(-/-) CD4(+) T cells alone diminished the severity and lethality of acute GVHD. This was not found when CD4(+) T cells from RORC(-/-) mice were given to completely mismatched BALB/c mice, and it was correlated with absolute differences in the generation of TNF in the colon after transplant. Thus, CD4(+) T cell expression of RORC is important in the pathogenesis of acute GVHD.

Effector CD4+ T cells, the cytokines they generate, and GVHD: something old and something new

GVHD is a syndrome that results from minor and major histocompatibility complex incompatibilities between the donor and recipient. More than 50 years after its initial description, the pathophysiology of GVHD remains poorly understood. Nonetheless, donor T cells have been shown to be critical to the pathophysiology of acute and chronic GVHD, yet precisely how they function remains unclear. The effector mechanisms by which donor T cells mediate tissue inflammation is even less well understood. Identification of several new lineages of CD4(+) T cells made in the past decade and their roles in the pathophysiology of T cell-mediated diseases has shed new light on these effector mechanisms. In this review, we summarize the recent descriptions of these T-cell lineages and the current data supporting their role in acute and to a lesser extent chronic GVHD. Investigations into the activity of these new T-cell lineages may provide more rationale approaches to the treatment or prevention of GVHD.

Cytokine Gene Expression in Peripheral Blood Mononuclear Cells and Alloreactivity in Hematopoietic Cell Transplantation with Nonmyeloablative Conditioning

Cytokines are thought to play an important role in the pathophysiology of graft-versus-host disease (GVHD). To study the relationship between cytokines and GVHD, we obtained peripheral blood mononuclear cells (MNCs) from 21 patients with hematologic malignancies and their HLA-identical sibling donors before and sequentially after hematopoietic cell transplantation (HCT) with nonmyeloablative conditioning. The MNCs were cultured for 72 hours either alone or in mixed lymphocyte cultures with irradiated MNCs of recipient, donor, or HLA-mismatched third-party origin. The gene expression of interleukin (IL)-2, IL-4, IL-10, IL-18, tumor necrosis factor alpha, and transforming growth factor beta in each culture was then measured by real-time quantitative reverse transcriptase-polymerase chain reaction. The composition of the responder MNCs differed between patients and donors and changed after HCT, with a possible influence on the results. Early after transplantation (day +14), the IL-10 messenger RNA (mRNA) level in response to recipient or donor antigens was higher in patients who did not develop clinically significant acute GVHD when compared with the level in patients who subsequently developed acute GVHD grades II to IV (P = .005 and P = .004, respectively). The IL-10 mRNA level on day +14 was highly correlated with the pretransplantation mRNA level of the recipient MNCs but not with the level of the donor MNCs; this suggests that the IL-10 mRNA detected on day +14 originated from responder cells of recipient origin. A higher IL-10 mRNA level was found in MNCs obtained before transplantation from recipients whose disease progressed or relapsed after the transplantation when compared with the level in patients whose disease did not progress or relapse (P = .03). In conclusion, a high IL-10 gene expression in the recipient MNCs may be related to a reduced incidence of acute GVHD grades II to IV and a reduced graft-versus-tumor effect after HCT with nonmyeloablative conditioning.

Cytokine expression during acute graft-versus-host disease after allogeneic peripheral stem cell transplantation

Acute graft-versus-host disease (aGVHD) is one of the major problems following allogeneic peripheral blood stem cell transplantation (allo-PBSCT). In order to investigate the pathogenesis of human aGVHD, we analyzed cytokine gene expression and cytokine secretion by peripheral blood mononuclear cells (PBMC) in 30 patients who underwent allo-PBSCT. In this study, reverse transcription-polymerase chain reaction (RT-PCR) was used to explore the mRNA expression of interleukin (IL)-2, interferon (IFN)-gamma, IL-4, IL-10 and IL-12 in the PBMC of allo-PBSCT patients with aGVHD and in controls. The concentrations of these cytokines and of IL-18 were also measured by means of ELISA in medium obtained from cultured leukocytes after stimulation with PHA or LPS. Compared with the normal allo-PBSCT group (n=14), IL-2 and IFN-gamma were detected more frequently in aGVHD group (n=16). IL-12 and IL-18 were elevated, while IL-10 level decreased in the same group. There is no difference in IL-4 gene expression between patients with or without aGVHD, but the concentration of IL-4 for patients with grade II-IV aGVHD decreased. These data suggest that IL-2, IFN-gamma, IL-12 and IL-18 play important roles in the development of aGVHD in humans.

[Development of the method for analysis of the cytokine balance shift associated with diseases]

A dual-color enzyme-linked immunospot (ELISPOT) assay enabled us to analyze three types of cytokine-secreting cells simultaneously. T helper (Th) cells can be subdivided into at least two distinct functional subsets based on their cytokine secretion profiles. The first type of clones (Th1) produces interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), but not IL-4 or IL-5. The second type of clones (Th2) produces IL-4 and IL-5, but not IL-2 or IFN-gamma. Furthermore, the presence of the third type (Th0) of cell, which is a precursor of Th1 or Th2 cells, has been demonstrated to produce both Th1- and Th2-type cytokines. The dual-color ELISPOT assay was developed to differentiate these three subtypes of Th cells in an identical well. In the system, the red spots corresponding to IL-2-secreting cells (Th1) were developed with horseradish peroxidase and aminoethylcarbazole/H(2)O(2). The light-blue spots corresponding to IL-4-secreting cells (Th2) were developed with alkaline phosphatase and Vector blue (chromogenic substrate for alkaline phosphatase). The mixed-colored (indigo) spots corresponding to both types of cytokine-secreting cells (Th0-cells) were developed with both chromogenic substrates. With this system, we could detect the IL-2- and/or IL-4-secreting cells simultaneously in a murine spleen cell or human peripheral mononuclear cell preparation.

A preliminary analysis of the balance between Th1 and Th2 cells after CD34+ cell-selected autologous PBSC transplantation

BACKGROUND

CD34+ cell-selected autologous PBSC transplantation (CD34+ APBSCT) is a procedure used for the treatment of patients with malignant disease that is intended to eliminate residual tumor cells from autologous grafts. However, frequent infectious complications after CD34+ APBSCT can occur. A delay of recovery of the absolute number of CD4+ T cells after transplantation was reported to be one disadvantageous factor. As data on T-cell function after CD34+ APBSCT are scanty, we analyzed changes in T-helper cell 1 (Th1) and T-helper cell 2 (Th2) after CD34+ APBSCT to evaluate immune reconstitution.

METHODS

Twelve patients underwent APBSCT (CD34+APBSCT group, n=4, and unselected APBSCT, n=8). Peripheral blood (PB) samples were obtained at 2, 4, 8, 12 and 16 weeks after the transplantation. The dynamics of the Th1 and Th2 were analyzed at a single-cell level, using flow cytometry.

RESULTS

In the CD34+ APBSCT group, not only the absolute count of CD4+ T cells but also the proportion of Th1 cells in CD4+ T cells and the ratio of Th1 to Th2 after transplantation were significantly decreased at 2 and 4 weeks after transplantation compared with findings in the unselected APBSCT group.

DISCUSSION

We suggest that higher rates of infectious complications after CD34+ APBSCT may be due to the inability of residual T cells from the CD34+ cell selection to generate mature T cells that function adequately against infection. Although further study would be required, our preliminary data provide some information on the immune reconstitution after CD34+ APBSCT and differentiation of T lymphocytes into Th1 and Th2 in vivo.

Elevated serum interleukin-15 level in acute graft-versus-host disease after hematopoietic cell transplantation

OBJECTIVE

To correlate serum cytokine levels and the development of acute graft-versus-host disease (GVHD), the authors conducted a prospective study on serial measurements of interferon (IFN)-gamma and interleukin (IL)-10, IL-12 and IL-15.

METHODS

The cytokines were measured in 27 subjects by enzyme-linked immunosorbent assay serially for the first 2 months after hematopoietic cell transplantation.

RESULTS

Nineteen subjects with acute GVHD had significantly higher mean peak serum levels of IFN-gamma and IL-15 than the baseline levels at the start of conditioning. The peak level occurred soon after stem cell infusion and returned to the pretransplantation state in the second month. In contrast, there was lesser difference between the mean peak serum levels of IFN-gamma, IL-10, and IL-15 and the baseline level in the eight subjects without GVHD. The peak serum level for IL-15 was, in addition, significantly higher among GVHD subjects than those without GVHD in the first month posttransplantation. However, the level of IL-15 showed no correlation with the severity of GVHD.

CONCLUSIONS

These changes point to a possible role of systemic cytokine secretion in the development of acute GVHD. Elevated levels of IL-15 early in the posttransplant period could be a helpful laboratory predictor of acute GVHD.

Interleukin-1 blockade does not prevent acute graft-versus-host disease: results of a randomized, double-blind, placebo-controlled trial of interleukin-1 receptor antagonist in allogeneic bone marrow transplantation

Acute graft-versus-host disease (GVHD) is thought to derive from direct T-cell injury of target tissues through perforin/granzyme, Fas/FasL interactions, and the effects of inflammatory cytokines. Animal models and some clinical trials support the notion that inhibition of inflammatory mediators such as interleukin-1 (IL-1), tumor necrosis factor alpha, and interferon gamma may ameliorate or prevent GVHD. We hypothesized that blockade of IL-1 during the period of initial T-cell activation would reduce the risk of severe GVHD. We tested this hypothesis in a double-blind, placebo-controlled randomized trial of recombinant human IL-1 receptor antagonist (IL-1Ra) in 186 patients undergoing allogeneic stem cell transplantation. Randomization was stratified by degree of histocompatibility and stem cell source. All patients were conditioned with cyclophosphamide and total body irradiation. GVHD prevention consisted of cyclosporine and methotrexate in all patients. Recombinant human IL-1Ra or saline placebo was given from day -4 to day +10. Randomization was stratified according to GVHD risk. The 2 groups were well-matched for pretreatment characteristics. Moderate to severe GVHD (grades B-D) developed in 57 (61%) of 94 patients receiving IL-1Ra and in 51 (59%) of 86 patients on placebo (P =.88). There was no difference in hematologic recovery, transplantation-related toxicity, event-free survival, or overall survival. We conclude that blockade of IL-1 using IL-1Ra during conditioning and 10 days immediately after transplantation is not sufficient to reduce GVHD or toxicity or to improve survival.

Tacrolimus and cyclosporine A inhibit allostimulatory capacity and cytokine production of human myeloid dendritic cells

Myeloid dendritic cells (DCs) are pivotal in the recognition of alloantigens and, therefore, in the induction of allograft rejection. Induction of alloreactive T cell proliferation by myeloid DCs depends on the maturation of DCs, the expression of costimulatory molecules, and the cytokine environment. This study investigated the effects of tacrolimus and cyclosporine A (CsA) on DC maturation and allostimulatory capacity. Myeloid DCs were propagated from normal blood monocytes with interleukin (IL) 4 and GM-CSF for 7 days in the presence or absence of tacrolimus (FK506; 10 nM) or CsA (1 microg/mL). Exposure of DCs during maturation to tacrolimus or CsA resulted in no significant change in the expression of DC phenotypic markers, including CD80, CD86, and HLA Class I and II antigens determined by flow cytometry. T cell proliferation in one-way, mixed-leukocyte reaction experiments revealed a decreased allostimulatory capacity of DCs that matured in the presence of tacrolimus or CsA compared with untreated controls (P<0.02). Production of inflammatory cytokines, tumor necrosis factor alpha (P<0.04) and IL-12 (P<0.04) in response to lipopolysaccharide (1 microg/mL) or staphylococcal enterotoxin B (1 microg/mL) induction was significantly reduced in DCs exposed to tacrolimus or CsA during maturation. In contrast, production of the immuninhibitory cytokine IL-10 was not decreased in tacrolimus- or CsA-treated DCs. These results suggest that tacrolimus and CsA inhibit the allostimulatory capacity of in vitro-generated myeloid DCs without significant effects on DC phenotypic maturation. Decreased production of IL-12 and tumor necrosis factor alpha, but not of IL-10, is likely to contribute to the impaired accessory-cell function of tacrolimus- and CsA-treated DCs. Thus, tacrolimus and CsA can inhibit recognition of alloantigens by decreasing the accessory-cell capacity of monocyte-derived myeloid DCs.

Interferon-gamma and interleukin-6 gene polymorphisms associate with graft-versus-host disease in HLA-matched sibling bone marrow transplantation

Proinflammatory cytokines including interferon-gamma (IFNgamma), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNFalpha) are implicated in the pathogenesis of acute graft-versus-host disease (aGVHD). Cytokine gene polymorphism is associated with functional differences in cytokine regulation and altered clinical performance in a variety of diseases. Polymorphism in the IFNgammaIntron1 microsatellite (CA)n repeat has been linked with in vitro IFNgamma production and renal transplant rejection. The IL-6(-174)(G/C) single nucleotide polymorphism has been linked to in vitro and in vivo IL-6 production, juvenile chronic arthritis, and renal transplant rejection. This study examined the potential association of GVHD with IFNgamma and IL-6 polymorphisms in 80 sibling bone marrow transplant (BMT) donor/recipient pairs. Patients homozygous for the IFNgammaIntron1 allele 3 had more severe (grade III-IV) aGVHD. Patients possessing the IL-6(-174)G allele had a trend toward higher grades of aGVHD, and those homozygous for the IL-6(-174)G allele were more likely to develop chronic GVHD (cGVHD). The associations of previously identified aGVHD severity-associated cytokine gene polymorphisms (TNFd and IL-10(-1064)) with severe aGVHD were reconfirmed. Logistic regression analysis confirmed the association of severe aGVHD with recipient genotype at IFNgammaIntron1 (odds ratio [OR] 3.92; P =.02), IL-10(-1064) (OR 4.61; P =.026) and TNFd (OR 3.29; P =.039), and that of cGVHD with recipient IL-6(-174) genotype (OR 4.25; P =.007), in addition to age, gender mismatch, and underlying disease. Assessment of cytokine genotype may potentially allow more accurate prediction of GVHD and appropriate adjustment of GVHD prophylaxis, as well as indicating novel areas for future studies of GVHD pathogenesis.

Both genetic and clinical factors predict the development of graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Graft-versus-host disease is the main complication of hematopoietic stem cell transplantation. Recently, pro- and anti-inflammatory cytokines and mismatches of minor histocompatibility antigens between HLA-identical sibling donor/recipient pairs have been implicated in the development of acute graft-versus-host disease. It is not known, however, whether these factors are independent of other clinically recognized risk factors such as age and disease stage.

METHODS

In this study, we searched for risk factors of acute graft-versus-host disease using multivariate Cox regression analysis in 100 consecutive patients who underwent allogeneic stem cell transplantation from an HLA-identical sibling donor. Eight polymorphisms from five different cytokine genes were studied (tumor necrosis factor alpha, tumor necrosis factor beta, interleukin (IL) 6, IL-10, and interferon gamma). Mismatches for the minor histocompatibility antigen HA-1 were searched in HLA-A*0201 individuals. In addition to these new risk factors, patient, donor, disease, and transplant risk factors were analyzed by multivariate analysis using the Cox proportional hazards model.

RESULTS

Acute graft-versus-host disease was independently associated with IL-10 gene polymorphisms both from the recipient (relative risk=7.9, P<0.0001) and the donor (relative risk=3.5, P=0.02), a donor's positive serology for cytomegalovirus, and HA-1 mismatches in HLA-A*0201 individuals (relative risk=2.8, P=0.05). Chronic graft-versus-host disease was independently associated with IL-6 gene polymorphism from the recipient (relative risk=4.2, P=0.02), older age (relative risk=2.5, P=0.0009), and previous acute graft-versus-host disease (relative risk=9.7, P=0.003).

CONCLUSION

In addition to previously described clinical risk factors, genetic risk factors are independently associated with the risk of developing graft-versus-host disease and may, thus, be considered for the selection of the donor.

Defective antifungal T-helper 1 (TH1) immunity in a murine model of allogeneic T-cell-depleted bone marrow transplantation and its restoration by treatment with TH2 cytokine antagonists

Patients undergoing full haplotype-mismatched hematopoietic transplantations may experience severe intractable invasive fungal infections. To verify whether an imbalanced production of T-helper 1 (TH1) and TH2 cytokines may be responsible for susceptibility to fungal infections, C3H/HeJ (H-2(k)) recipient mice were lethally irradiated, received transplantations with T-cell-depleted allogeneic bone marrow (BM) cells from mice of H-2(d) haplotype, and were infected with Candida albicans. At different time-points after transplantation, mice were assessed for pattern of TH cytokine production and susceptibility to infection. The results show that a long-term, donor-type chimerism was achieved as early as 2 weeks after BM transplantation (BMT), at the time when high-level production of TH2 cytokines (interleukin-4 [IL-4] and IL-10) and impaired production of TH1 cytokines (interferon-gamma [IFN-gamma] and IL-12] were observed. At this time, mice were highly susceptible to both disseminated and mucosal infections, as indicated by decreased survival, uncontrolled fungal growth, and failure to develop protective TH1 immunity. However, a predominant production of TH1 cytokines was observed by week 5 after BMT, at the time when mice developed donor-type protective TH1 responses and were resistant to infections. Therapeutic ablation of IL-4 or IL-10 greatly increased resistance to candidiasis. These results indicate that a dysregulated production of TH cytokines occurs in mice undergoing T-cell-depleted allogeneic BMT. The transient predominant production of TH2 cytokines over that of IL-12 impaired the ability of mice to develop antifungal TH1 resistance, an activity that could be efficiently restored upon treatment with TH2 cytokine antagonists.

Kinetic analysis of cytokine gene expression in patients with GVHD after donor lymphocyte infusion

Patients who receive a donor lymphocyte infusion (DLI) for the treatment of relapsed leukemia after allogeneic BMT (alloBMT) often developed GVHD. To determine whether cytokines might have a role in GVHD, an intensive kinetic analysis of in vivo cytokine gene expression was performed on PBMC from three such patients. Expression of IL-1beta, IL-2, IFN-gamma, IL-4, IL-5, IL-8, IL-10, IL-12, TNF-alpha, and IL-2Ralpha was examined using a sensitive semi-quantitative reverse transcription (RT)-PCR assay system. Six normal controls were also analyzed for comparison. Expression of type 1 T helper (Th1) cytokines, IL-2 and IFN-gamma was greatly increased in all three patients. In particular, the changes in IL-2 gene expression correlated well with disease progression, suggesting that IL-2 has a critical role in the development of GVHD. Although the pattern of type 2 T helper (Th2) cytokine gene expression differed in each patient, the expression of IL-4 was inversely related to expression of Th1 cytokines. These results suggest that Th1 dominates in the development of human clinical GVHD.

Determination of helper T-cell precursor frequencies against non-haemopoietic cells: comparison of co-stimulation provided by anti-CD28 antibody versus the cellular ligand B7-1

Helper T-cell precursor frequency assays (HTLp-assays) are commonly used in transplantation to examine the frequency of T cells reactive against donor or host alloantigens. In these assays, peripheral blood mononuclear cells (PBMCs) are most often used as stimulator cells. However, cells targeted after transplantation do not always belong to the haematopoietic lineage and may express different alloantigens, especially minor histocompatibility antigens (mHags). Non-haematopoietic cells lack expression of the B7 co-stimulatory molecules needed to activate primary T cells that can be supplied by anti-CD28 (alphaCD28) antibodies or transfection with B7-1 coding sequences. At present, it is not known how these two ways of supplied co-stimulation compare in HTLp assays. B7-1-transfected A431 keratinocytes (A431B7-1) induced higher proliferative responses in allogeneic primary T cells and more interleukin (IL) 2 production than that induced by A431 cells plus alphaCD28, whereas the kinetics of proliferation and IL-2 production were similar. Neither cross-linking of alphaCD28 bound to T cells nor prevention of IL-2 resorption by the anti-IL-2 receptor resulted in improved proliferation or IL-2 production. Results of HTLp assays indicated that A431B7-1 activated on average 7.5 times more alloreactive IL-2-producing T cells than A431 cells plus alphaCD28. We conclude that primary T-cell alloresponses against major histocompatibility complexes (MHCs) and mHags expressed on non-haematopoietic cells can be measured in HTLp assays using supplied co-stimulation, although alphaCD28 yields an intrinsic underestimation of actual frequencies.

Cutaneous T cell lymphoma reactive CD4+ cytotoxic T lymphocyte clones display a Th1 cytokine profile and use a fas-independent pathway for specific tumor cell lysis

We have previously described two cytotoxic T lymphocyte clones isolated from lymphocytes infiltrating a human major histocompatibility complex class II-/class I+, CD4+ cutaneous T cell lymphoma. These clones displayed a CD4+CD8dim+ (TC5) and CD4+ CD8- (TC7) phenotype and mediated a specific major histocompatibility complex class I-restricted cytotoxic activity toward Cou-LB autologous tumor cell line. Our studies were performed to elucidate the mechanism involved in T-cell-clone-mediated cytotoxicity and to determine the cytokine profile of both the lymphoma cell line and specific cytotoxic T lymphocyte clones. The results indicate that, despite surface expression of Fas receptor on Cou-LB and Fas ligand induction on TC5 and TC7 cell membranes, the CD4+ cytotoxic T lymphocyte clones do not use this cytotoxic mechanism to lyse their specific target. The TC7 clone uses instead a granzyme-perforin-dependent pathway. Furthermore, quantitative analysis of Th1 and Th2 cytokine mRNA expression in the cutaneous T cell lymphoma cell line as well as in TC5 and TC7 clones indicated that, whereas the tumor cells display a Th2-type profile (interleukin-4, interleukin-6, and interleukin-10), the cytotoxic T lymphocyte clones express Th1-type cytokines (interferon-gamma, granulocyte macrophage colony stimulating factor, and interleukin-2). In addition, preincubation of the tumor-infiltrating lymphocyte clones with autologous tumor cells induced their activation and subsequent amplification of the Th1-type response. These results indicate a direct contribution of the malignant cells in the Th1/Th2 imbalance observed frequently in cutaneous T cell lymphoma patients and suggest their potential role in depressed cell-mediated immunity. Identification of CD4+ Th1-type cytotoxic T lymphocyte clones, the tumor antigen they recognize, and optimization of their cytokine expression profile should be useful for the design of new immunotherapy protocols in cutaneous T cell lymphoma.

Quantitative analysis of Th1, Th2 and TGF-beta1 cytokine expression in tumor, TIL and PBL of non-small cell lung cancer patients

For understanding the local immune response in human non-small cell lung cancer (NSCLC), we investigated both Th1 and Th2-type as well as TGF-beta1 cytokine mRNA expression in 10 fresh tumor biopsies, the corresponding tumor and short term TIL cell lines as well as patient PBMC. A methodology based on a highly sensitive quantitative RT-PCR was used. We found that IL-6 mRNA was highly expressed in all tumor biopsy samples analyzed (4 LLC, 3 ADC and 3 SCC). IL-10 mRNA was expressed in 7 of 10 biopsies whereas IL-4 mRNA expression was moderate. Analysis of type I cytokines revealed a low expression level of IL-2 mRNA, while IFNgamma and GM-CSF expression was high in the majority of the tumor lesions studied. Quantitatively, high amounts of Th2-type cytokine mRNA were detected at the tumor site with IL-6 as the predominant lymphokine. A high mRNA expression level of the immunosuppressive cytokine TGF-beta1 was observed in all NSCLC. To identify the cell types responsible for the production of TGF-beta1, IL-6, IL-10 and GM-CSF at the tumor site, tumor and TIL cell lines were derived from the corresponding biopsies. All the 3 tumor cell lines analysed were found to express high amount of TGF-beta1 but not IL-10 mRNA, 2 expressing IL-6 and GM-CSF. Five short term TIL cell lines established in the presence of IL-2 expressed high level of IL-10, IL-4 and IFNgamma but not IL-2 mRNA. Strikingly, high expression of IL-10 mRNA was also observed in all 6 patient PBMC analyzed as compared to controls. Together, our results indicate the existence of a local and peripheral Th-2-type cytokine pattern in patients bearing NSCLC.

NK cells differentiated from bone marrow, cord blood and peripheral blood stem cells exhibit similar phenotype and functions

In the present study, we investigated the differentiation of human NK cells from bone marrow, cord blood and mobilized peripheral blood purified CD34+ stem cells using a potent culture system. Elutriated CD34+ stem cells were grown for several weeks in medium supplemented with stem cell factor (SCF) and IL-15 in the presence or absence of a murine stromal cell line (MS-5). Our data indicate that IL-15 induced the proliferation and maturation of highly positive CD56+ NK cells in both types of culture, although murine stromal cells slightly increased the proliferation of NK cells. NK cells differentiated in the presence of MS-5 were mostly CD56+ CD7 and a small subset expressed CD16. These in vitro differentiated CD56+ NK cells displayed cytolytic activity against the HLA class I- target K562. The CD56+ CD16+ subset also lysed NK-resistant Daudi cells. Neither of these NK subsets were shown to express Fas ligand. Total CD56+ cells expressed high amounts of transforming growth factor-beta and granulocyte-macrophage colony-stimulating factor, but no IFN-gamma. Investigation of NK receptor expression showed that most CD56+ cells expressed membrane CD94 and NKG2-A mRNA. PCR analysis revealed that p58 was also expressed in these cells. The role of CD94 in NK cell-mediated cytotoxicity was assessed on human HLA-B7-transfected murine L cells. While a low cytotoxic activity towards HLA-B7 cells was observed, the HLA-DR4 control cells were killed with high efficiency. These studies demonstrate that cytolytic and cytokine-producing NK cells may be derived from adult and fetal precursors by IL-15 and that these cells express a CD94 receptor which may influence their lytic potential.