A phase I study of multi-HLA-binding peptides derived from heat shock protein 70/glypican-3 and a novel combination adjuvant of hLAG-3Ig and Poly-ICLC for patients with metastatic gastrointestinal cancers: YNP01 trial.

BACKGROUND: This phase I study aimed to evaluate the safety, peptide-specific immune responses, and anti-tumor effects of a novel vaccination therapy comprising multi-HLA-binding heat shock protein (HSP) 70/glypican-3 (GPC3) peptides and a novel adjuvant combination of hLAG-3Ig and Poly-ICLC against metastatic gastrointestinal cancers. METHODS: HSP70/GPC3 peptides with high binding affinities for three HLA types (A*24:02, A*02:01, and A*02:06) were identified with our peptide prediction system. The peptides were intradermally administered with combined adjuvants on a weekly basis. This study was a phase I dose escalation clinical trial, which was carried out in a three patients' cohort; in total, 11 patients were enrolled for the recommended dose. RESULTS: Seventeen patients received this vaccination therapy without dose-limiting toxicity. All treatment-related adverse events were of grades 1 to 2. Peptide-specific CTL induction by HSP70 and GPC3 proteins was observed in 11 (64.7%) and 13 (76.5%) cases, respectively, regardless of the HLA type. Serum tumor marker levels were decreased in 10 cases (58.8%). Immunological analysis using PBMCs indicated that patients receiving dose level 3 presented with significantly reduced T cell immunoglobulin and mucin-domain containing-3 (TIM3)-expressing CD4 + T cells after one course of treatment. PD-1 or TIM3-expressing CD4 + T cells and T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)-expressing CD8 + T cells in PBMCs before vaccination were negative predictive factors for survival. CONCLUSIONS: This novel peptide vaccination therapy was safe for patients with metastatic gastrointestinal cancers.

Therapeutic effects of soluble human leukocyte antigen G2 isoform in lupus-prone MRL/lpr mice.

Human leukocyte antigen (HLA)-G, a non-classical HLA class I molecule, has one of the splicing isoforms, HLA-G2, which lacks one domain (α2) and forms a non-covalent homodimer. HLA-G2 is expressed on placental cells, regulatory T cells, tumor cells, and virus-infected cells, and is involved in immunosuppression. The major isoform of HLA-G, HLA-G1, binds to leukocyte immunoglobulin (Ig)-like receptor (LILR) B1 and LILRB2, on the contrary, HLA-G2 binds to only LILRB2. We previously reported that HLA-G2 bound LILRB2 more strongly than HLA-G1 and also to paired Ig-like receptor (PIR)-B, a mouse homolog of LILRBs. Furthermore, HLA-G2 showed immunosuppressive effects in both collagen-induced arthritis (CIA) and atopic dermatitis-like model mice. In this study, we examine in vivo effects of HLA-G2 in systemic lupus erythematosus (SLE) model mice. HLA-G2 showed the suppression of the typical SLE symptoms such as serum anti-dsDNA antibody level and urinary albumin index. Furthermore, HLA-G2 tended to downregulate B-lymphocyte stimulator (BLyS) production. This is the first observation of the immunosuppressive effects of HLA-G2 isoform in SLE model mice, suggesting that HLA-G2 could be a useful therapeutic agent for SLE.

Effects of everolimus and HLA-G on cellular proliferation and neutrophil adhesion in an in vitro model of cardiac allograft vasculopathy.

Human leukocyte antigen-G (HLA-G) expression is modulated by immunosuppressant use and is associated with lower incidence of graft rejection and cardiac allograft vasculopathy (CAV). We examined whether everolimus induces HLA-G expression and inhibits human coronary artery smooth muscle cell (HCASMC) proliferation, a critical event in CAV. Also, we examined whether TNFα-stimulated neutrophil adhesion is inhibited by HLA-G on human coronary artery endothelial cells (HCAECs). HLA-G expression in HCASMCs following everolimus treatment was determined by western-blot densitometric analysis. HCASMCs proliferation following incubation with recombinant HLA-G was determined by automated cell counter detecting 2-10 µm particles. Assessment of recombinant HLA-G on neutrophil adhesion to HCAECs in response to TNF-α induced-injury was determined by nonstatic adhesion assays. HLA-G expression was upregulated in HCASMCs following everolimus exposure (1000 ng/ml; P < .05). HLA-G (500, 1000 ng/ml; both P < .05) reduced HCASMC proliferation and inhibited TNFα-stimulated neutrophil adhesion to endothelial cells at all concentrations (0.1-1 ng/ml; all P < .001). Our study reveals novel regulation of HLA-G by everolimus, by demonstrating HLA-G upregulation and subsequent inhibition of HCASMC proliferation. HLA-G is a potent inhibitor of neutrophil adhesion to HCAECs. Findings support HLA-G's importance and potential use in heart transplantation for preventative therapy or as a marker to identify patients at high risk for developing CAV.

Antígeno leucocitario humano-G soluble en el lavado broncoalveolar de pacientes con cáncer pulmonar / Soluble human leukocyte antigen-G in the bronchoalveolar lavage of lung cancer patients

Antecedentes. La molécula antígeno leucocitario humano G (HLA-G), en sus formas unida a membrana y soluble, tiene como función principal inhibir la respuesta inmune actuando sobre los linfocitos T/CD4+, T/citotóxicos, células NK y células dendríticas. El cáncer de pulmón es una de las principales causas de muerte en el mundo, con una alta tasa de incidencia anual tanto en mujeres como en hombres. Algunos estudios han reportado un incremento de HLA-G sérica en el cáncer de pulmón, probablemente como un mecanismo de escape de la célula tumoral a la respuesta inmune antitumoral. En este estudio se midió la concentración de HLA-G soluble, en el lavado broncoalveolar (LBA), en pacientes con cáncer de pulmón primario y metastásico para determinar su relación con el tipo histológico tumoral y estado general del paciente usando la escala de Karnofsky. Métodos. Se incluyeron 31 pacientes con diagnóstico de cáncer de pulmón y mediante fibrobroncoscopia se tomó biopsia de la neoplasia para determinar el tipo de tumor usando la coloración de hematoxilina y eosina, y líquido del lavado broncoalveolar para medir la concentración de la molécula HLA-G soluble mediante un ELISA tipo sándwich. Resultados. El valor medio de la HLA-G soluble fue de 49,04ng/ml. No se observó ninguna correlación entre los niveles de HLA-G soluble y la edad, género o índice de tabaquismo. Se observó una diferencia altamente significativa en los niveles de HLA-G soluble en LBA de pacientes con diversos tipos histológicos de cáncer de pulmón, principalmente en tumores metastásicos. El índice de Karnofsky mostró una correlación significativa e inversa con el nivel de HLA-G soluble en LBA. Conclusiones. La proteína HLA-G soluble puede ser útil como marcador pronóstico del cáncer pulmonar al asociarse significativamente a los tumores metastásicos y a los pacientes con menor índice de Karnofsky

Background. The main function of the HLA-G molecule in its membrane-bound and soluble forms is to inhibit the immune response by acting on CD4+ T cells, cytotoxic T cells, NK cells and dendritic cells. Lung cancer is a leading cause of death worldwide, and annual incidence is high in both women and men. Some studies have reported an increase of HLA-G serum levels in lung cancer, probably generated by tumor cells escaping the antitumor immune response. In this study the concentration of soluble HLA-G in bronchoalveolar lavage (BAL) in patients with primary and metastatic lung cancer was measured to determine its relation with tumor histological type and overall patient status according to the Karnofsky scale. Methods. Thirty-one lung cancer patients were included. A tumor biopsy was obtained by bronchoscopy and the tumor type was determined by hematoxylin and eosin staining. BAL samples were obtained to measure soluble HLA-G concentrations in an ELISA sandwich assay. Results. The average value of soluble HLA-G was 49.04ng/mL. No correlation between soluble HLA-G levels and age, gender or smoking was observed. A highly significant difference was observed in the levels of soluble HLA-G in BAL from patients with different histological types of lung cancer, especially in metastatic tumors. The Karnofsky index showed a significant and inverse correlation with soluble HLA-G levels in BAL. Conclusions. Soluble HLA-G protein is significantly associated with metastatic tumors and patients with lower Karnofsky index and may be useful as a prognostic marker in lung cancer

The long-term immunosuppressive effects of disulfide-linked HLA-G dimer in mice with collagen-induced arthritis.

HLA-G, a natural immunosuppressant present in the human placenta during pregnancy, prevents fetal destruction by the maternal immune system. The immunosuppressive effect of HLA-G is mediated by the immune cell inhibitory receptors, LILRB1 and LILRB2. HLA-G forms disulfide-linked dimers by natural oxidation, and the dimer associates with LILRB1/B2 much more strongly than the monomer. Furthermore, the dimer formation remarkably enhanced the LILRB-mediated signaling. In this report, we studied the in vivo immunosuppressive effect of the HLA-G dimer, using the collagen-induced arthritis model mouse. Mice were treated with the HLA-G monomer or dimer intracutaneously at the left foot joint, once or for 5 days, and the clinical severity was evaluated daily in a double-blind study. The HLA-G monomer and dimer both produced excellent anti-inflammatory effects with a single, local administration. Notably, as compared to the monomer, the dimer exhibited significant immunosuppressive effects at lower concentrations, which persisted for about two months. In accordance with this result, a binding study revealed that the HLA-G dimer binds PIR-B, the mouse homolog of the LILRBs, with higher affinity and avidity than the monomer. The HLA-G dimer is expected to be quite useful as an anti-rheumatoid arthritis agent, in small amounts with minimal side effects.