Donor killer immunoglobulin-like receptor (KIR) genotype-patient cognate KIR ligand combination and antithymocyte globulin preadministration are critical factors in outcome of HLA-C-KIR ligand-mismatched T cell-replete unrelated bone marrow transplantation.

We previously reported the potent adverse effects of killer immunoglobulin-like receptor (KIR) ligand mismatch (KIR-L-MM) on the outcome of T cell-replete unrelated hematopoietic stem cell transplantation (UR-HSCT) through the Japan Marrow Donor Program. Other UR-HSCT studies have yielded inconsistent results. To address this discrepancy, we evaluated candidate factors contributing to the effects of KIR-L-MM on transplantation outcomes in retrospectively selected hematologic malignancy cases with uniform graft-versus-host disease (GVHD) prophylaxis (n = 1489). KIR-L-MM in the graft-versus-host direction (KIR-L-MM-G) was associated with a higher incidence of acute GVHD (aGVHD; P < .002) and a lower overall survival (OS; P < .0001) only without the preadministration of antithymocyte globulin (ATG). Furthermore, in KIR-L-MM-G, the donor KIR2DS2 gene with the patient cognate C1 ligand was associated with a higher incidence of aGVHD (P = .012). Multivariate analysis by Cox proportional hazard models suggested that donor 2DS2 and ATG preadministration were critical factors in grade III-IV aGVHD (hazard ratio = 1.96; 95% confidence interval = 1.01-3.80; P = .045, and hazard ratio = 0.56; 95% confidence interval = 0.31-0.99; P = .047, respectively). These results indicate that the adverse effects of KIR-L-MM-G depend on combination of donor-activating KIR genotype-patient cognate KIR ligand type and no ATG preadministration, thereby suggesting the importance of these factors in UR-HSCT and in leukemia treatment using natural killer (NK) cell alloreactivity.

High-risk HLA allele mismatch combinations responsible for severe acute graft-versus-host disease and implication for its molecular mechanism.

In allogenic hematopoietic stem-cell transplantation, an effect of HLA locus mismatch in allele level on clinical outcome has been clarified. However, the effect of each HLA allele mismatch combination is little known, and its molecular mechanism to induce acute graft-versus-host disease (aGVHD) remains to be elucidated. A total of 5210 donor-patient pairs who underwent transplantation through Japan Marrow Donor Program were analyzed. All HLA-A, -B, -C, -DRB1, -DQB1, and -DPB1 alleles were retrospectively typed in all pairs. The impacts of the HLA allele mismatch combinations and amino acid substitution positions in 6 HLA loci on severe aGVHD were analyzed. A total of 15 significant high-risk HLA allele mismatch combinations and 1 HLA-DRB1-DQB1 linked mismatch combinations (high-risk mismatch) for severe aGVHD were identified, and the number of high-risk mismatches was highly associated with the occurrence of severe aGVHD regardless of the presence of mismatch combinations other than high-risk mismatch. Furthermore, 6 specific amino acid substitution positions in HLA class I were identified as those responsible for severe aGVHD. These findings provide evidence to elucidate the mechanism of aGVHD on the basis of HLA molecule. Furthermore, the identification of high-risk mismatch, that is, nonpermissive mismatch, would be beneficial for the selection of a suitable donor.

Effects of HLA allele and killer immunoglobulin-like receptor ligand matching on clinical outcome in leukemia patients undergoing transplantation with T-cell-replete marrow from an unrelated donor.

The responsible human leukocyte antigen (HLA) locus and the role of killer immunoglobulin-like receptor (KIR) ligand matching on transplantation outcome were simultaneously identified by multivariate analysis in 1790 patients with leukemia who underwent transplantation with T-cell-replete marrow from an unrelated donor (UR-BMT) through the Japan Marrow Donor Program. The graft-versus-leukemia (GVL) effect depended on leukemia cell type. HLA-C mismatch reduced the relapse rate in acute lymphoblastic leukemia (ALL) (hazard ratio [HR] = 0.47; P = .003), and HLA-DPB1 mismatch reduced it in chronic myeloid leukemia (CML) (HR = 0.35; P < .001). In contrast, KIR2DL ligand mismatch in the graft-versus-host (GVH) direction (KIR-L-MM-G) increased in ALL (HR = 2.55; P = .017). An increased rejection rate was observed in KIR2DL ligand mismatch in the host-versus-graft direction (HR = 4.39; P = .012). Acute GVH disease (GVHD) was increased not only in the mismatch of HLA-A, -B, -C, and -DPB1, but also in KIR-L-MM-G. As a whole, the mismatch of HLA-A, -B, and -DQB1 locus and KIR-L-MM-G resulted in increased mortality. In conclusion, not only the mismatch of HLA-C and -DPB1, but also KIR-L-MM-G affected leukemia relapse, which should be considered based on leukemia cell type. Furthermore, KIR-L-MM induced adverse effects on acute GVHD (aGVHD) and rejection, and brought no survival benefits to patients with T-cell-replete UR-BMT.

Therapeutic activation of Valpha24+Vbeta11+ NKT cells in human subjects results in highly coordinated secondary activation of acquired and innate immunity.

Human Valpha24+Vbeta11+ natural killer T (NKT) cells are a distinct CD1d-restricted lymphoid subset specifically and potently activated by alpha-galactosylceramide (alpha-GalCer) (KRN7000) presented by CD1d on antigen-presenting cells. Preclinical models show that activation of Valpha24+Vbeta11+ NKT cells induces effective antitumor immune responses and potentially important secondary immune effects, including activation of conventional T cells and NK cells. We describe the first clinical trial of cancer immune therapy with alpha-GalCer-pulsed CD1d-expressing dendritic cells. The results show that this therapy has substantial, rapid, and highly reproducible specific effects on Valpha24+Vbeta11+ NKT cells and provide the first human in vivo evidence that Valpha24+Vbeta11+ NKT cell stimulation leads to activation of both innate and acquired immunity, resulting in modulation of NK, T-, and B-cell numbers and increased serum interferon-gamma. We present the first clinical evidence that Valpha24+Vbeta11+ NKT cell memory produces faster, more vigorous secondary immune responses by innate and acquired immunity upon restimulation.

Dendritic cell vaccination for patients with chronic myelogenous leukemia.

In this pilot study, we investigated the ability of autologous dendritic cells (DCs) pulsed ex vivo with leukemia-specific peptide to stimulate host antitumor immunity when administrated as a vaccine. Three patients with chronic myelogenous leukemia (CML) received three series of four administration of bcr-abl peptide-pulsed (1) blood DCs injected intravenously, (2) immature monocyte-derived DCs injected intradermally or (3) mature monocyte-derived DCs injected intradermally. Vaccination was well tolerated. No major toxicity occurred in any of the patients. In method (1), one patient developed peptide-specific cellular immune response with no clinical response. In method (2), one patient developed peptide-specific cellular immune response with no clinical response. In method (3), all patients developed peptide-specific cellular immune response with no clinical response. The clinical benefits of bcr-abl peptide-specific vaccination in CML remain to be determined. Further vaccine development is necessary to increase the clinical effect.

The CD1d natural killer T-cell antigen presentation pathway is highly conserved between humans and rhesus macaques.

Natural killer T (NKT) cells play an important role in controlling cancers, infectious diseases and autoimmune diseases. Although the rhesus macaque is a useful primate model for many human diseases such as infectious and autoimmune diseases, little is known about their NKT cells. We analyzed V alpha 24TCR+ T cells from rhesus macaque peripheral blood mononuclear cells stimulated with alpha-galactosylceramide (alpha-GalCer) and interleukin-2. We found that rhesus macaques possess V alpha 24TCR+ T cells, suggesting that recognition of alpha-GalCer is highly conserved between rhesus macaques and humans. The amino acid sequences of the V-J junction for the V alpha 24TCR of rhesus macaque and human NKT cells are highly conserved (93% similarity), and the CD1d alpha1-alpha2 domains of both species are highly homologous (95.6%). These findings indicate that the rhesus macaque is a useful primate model for understanding the contribution of NKT cells to the control of human diseases.

A subject with a novel type I bare lymphocyte syndrome has tapasin deficiency due to deletion of 4 exons by Alu-mediated recombination.

HLA class I expression depends on the formation of a peptide-loading complex composed of class I heavy chain; beta(2)-microglobulin; the transporter associated with antigen processing (TAP); and tapasin, which links TAP to the heavy chain. Defects in TAP result in a class I deficiency called the type I bare lymphocyte syndrome (BLS). In the present study, we examined a subject with a novel type I BLS who does not exhibit apparent TAP abnormalities but who has a tapasin defect. The subject's TAPASIN gene has a 7.4-kilobase deletion between introns 3 and 7; an Alu repeat-mediated unequal homologous recombination may be the cause of the deletion. No tapasin polypeptide was detected in the subject's cells. The cell surface class I expression level in tapasin-deficient cells was markedly reduced but the reduction was not as profound as in TAP-deficient cells. These results suggest that tapasin deficiency is another cause of type I BLS.

Anaphylactic transfusion reactions in haptoglobin-deficient patients with IgE and IgG haptoglobin antibodies.

BACKGROUND: Patients with haptoglobin deficiency associated with haptoglobin IgG antibodies, who experienced severe nonhemolytic transfusion reactions (NHTRs), have been identified in Japan. Haptoglobin deficiency therefore might be a risk factor for NHTRs. STUDY DESIGN AND METHODS: A total of 4138 cases of voluntarily reported NHTRs in Japan, including 367 cases of immediate-onset anaphylactic NHTRs, were examined to identify haptoglobin deficiency. Serum haptoglobin IgG and IgE antibodies were determined in haptoglobin-deficient patients to elucidate the mechanism underlying the transfusion reactions. RESULTS: Seven patients with haptoglobin deficiency were identified. Six of them experienced severe and acute NHTRs. Six of them were identified to be homozygous for the Hpdel allele of the haptoglobin gene. Both haptoglobin IgG and IgE antibodies were detected in serum samples of all the patients. The stimulative effects of blood transfusion on the production of hap- toglobin antibodies in the patients and the relation- ship between the presence of the antibodies and the occurrence of the transfusion reactions were observed. CONCLUSION: Anaphylactic NHTRs in these patients with haptoglobin deficiency associated with serum haptoglobin antibodies were suggested to be prevalent in Japan. In addition to IgG antibodies, IgE haptoglobin antibodies detected in the sera of such patients were suggested to play a role in the occurrence of the reactions.

Activation and suppression of renin-angiotensin system in human dendritic cells.

We previously identified the gene expression of renin-angiotensin system in human monocyte-derived dendritic cells (DCs). This study was conducted to examine the mechanisms by which angiotensin II and captopril, the inhibitor of the angiotensin-converting enzyme (ACE), affect human DCs. In DCs, lipopolysaccharide (LPS)-induced production of tumor necrosis factor-alpha (TNF-alpha), interleukin-(IL)-1alpha, IL-10, IL-12, and IL-18 was significantly inhibited by captopril. In contrast, angiotensin II treatment resulted in a significant increase in TNF-alpha and IL-6 protein biosynthesis by DCs. In addition, we have studied the global expression of 2400 genes in DCs from two donors. Here, we demonstrated the specific down-regulation of the ACE gene expression in captopril-treated DCs. Our finding indicates the possible activation of NF-kappaB through the up-regulation of expressions of MEFV gene (encoding PYRIN protein) and heterogeneous nuclear ribonucleoprotein R in DCs. This is the first study on the modulation of cytokine and gene expression by angiotensin II and captopril in DCs.

The clinical significance of human leukocyte antigen (HLA) allele compatibility in patients receiving a marrow transplant from serologically HLA-A, HLA-B, and HLA-DR matched unrelated donors.

To improve the clinical outcome of allogeneic hematopoietic stem cell transplantation from an unrelated donor, the identification of human leukocyte antigen (HLA) alleles responsible for immunologic events such as graft-versus-host disease (GVHD), engraftment failure, and graft-versus-leukemia effect is essential. Genomic typing of HLA-A, -B, -C, -DRB1, and -DQB1 was retrospectively performed in 1298 donor-patient pairs in cases where marrow was donated from serologically HLA-A, -B, and -DR compatible donors. Single disparities of the HLA-A, -B, -C, or -DRB1 allele were independent risk factors for acute GVHD, and the synergistic effect of the HLA-C allele mismatch with other HLA allele mismatches on acute GVHD was remarkable. HLA-A and/or HLA-B allele mismatch was found to be a significant factor for the occurrence of chronic GVHD. HLA class I (A, B, and/or C) allele mismatch caused a significantly higher incidence of engraftment failure than HLA match. Significant association of HLA-C allele mismatch with leukemia relapse was not observed. As the result of these events, HLA-A and/or HLA-B allele mismatch reduced overall survival remarkably in both standard-risk and high-risk leukemia cases, whereas the HLA-C mismatch or HLA-class II (DRB1 and/or DQB1) mismatch did not. Furthermore, multiple mismatch of the HLA locus was found to reduce survival in leukemia cases. Thus, the role of the HLA class I allele in unrelated bone marrow transplantation was elucidated. Notably, HLA-C alleles had a different mode from HLA-A or -B alleles for acute GVHD and survival.

Generation of Fas-independent CD4+ cytotoxic T-cell clone specific for p190 minor bcr-abl fusion peptide.

In the majority of Ph+ALL patients, p190 bcr-abl fusion protein is generated in the Philadelphia chromosome. The fusion protein may serve as a leukemia antigen because it is not expressed in normal cells and hardly in any other malignancy. From a healthy donor, we have established a p190 bcr-abl fusion peptide-specific CD4+ cytotoxic T-cell clone, activation of which depends on HLA-DRB1*1501. This T-cell clone has a strong cytotoxic activity against autologus MoDCs pulsed with e1a2 peptide and its cytotoxicity is not mediated by Fas/Fas ligand or perforin pathway. Success in establishment of the p190 bcr-abl fusion peptide-specific T-cell clone encourages us to develop a new approach to an effective immunotherapy for Ph+ALL.