Toward Sézary Syndrome immunotherapy

Sézary syndrome (SS) is a leukemic form of cutaneous mature T-cell lymphoma characterized by circulating malignant CD4 T lymphocytes (Sezary cells). Patients with SS have a poor prognosis and current treatment options show high rates of relapse, morbidity or mortality. Thus, there is an unmet need for an efficient and safe treatment. Sézary cells have unique clonal potentially targetable epitopes, including their TCR, and TCR- and neoantigen-derived HLA-restricted peptides.

Our general aim is to design a patient-tailored two-pronged strategy against SS. The specific aims are 1) to target SS clonal TCR B cell epitopes using mAb and/or CAR T cells, 2) to target SS HLA-restricted T-cell epitopes using TCR peptide- and/or neoantigen-specific human T cells, and 3) to validate efficacy in vitro and in mouse models.

For the generation of mAb, apheresis-purified SS cells or SS TCR CDR3beta peptides were used for immunizations, and screening was done on SS vs non-SS CD4 cells as defined by flow cytometry using CD26 and/or PD-1. For in vitro expansion of SS peptide-specific T cells, SS patient-derived non-SS PBMC were stimulated in 96-well plates with IL-2 and pooled HLA class I+II SS peptides, 10 μM each, defined by SS WGS, WES and RNAseq-based predictions or peptidome studies. After one week, cells were exposed to autologous DC pre-loaded with peptide pools, and cytokine production was analyzed by flow cytometry.

We have obtained preliminary data on aims 1 and 2 studying two SS patients with monoclonal T cell lymphomas, including potential mouse antibodies against a clonal SS TCR using cell and peptide immunization and T-cell hits that seem to be specific of a SS TCR HLA class-I-restricted CDR3beta sequence.

Month of birth, HLA-DRB1*15 locus and risk of multiple sclerosis in offspring

INTRODUCTION

A relationship among April births, HLA-DRB1*15:01 genotype and risk of multiple sclerosis (MS) has been described. We aim to determine this association in our cohort of Spanish MS patients.

SUBJECTS AND METHODS

We genotyped HLA-DRB1*15:01 allele in 326 MS patients and 226 controls (non-neurological disease patients) by SSP-PCR and compared month of birth with local births during the same period.

RESULTS

MS patients carrying HLA-DRB1*15 allele were more frequently born in December (10.3% HLA-DRB1*15+ vs. 3.8% HLA-DRB1*15-; p = 0.019). Controls carrying HLA-DRB1*15 allele were less frequently born in December than non-carrier controls (0% HLA-DRB1*15+ vs. 10.3% HLA-DRB1*15-; p = 0.028). Thus, December was confirmed as the common month of birth for HLA-DRB1*15-non-carrier controls and MS HLA-DRB1*15-carrier patients.

CONCLUSIONS

Month of birth, HLA-DRB1 genotype and risk of MS are associated. In Spain, this association was found in December, supporting the potential interaction of a seasonal risk factor in winter, inside/close to HLA-DRB1*15 locus, during pregnancy or after birth.

High expression of CD38, CD69, CD95 and CD154 biomarkers in cultured peripheral T lymphocytes correlates with an increased risk of acute rejection in liver allograft recipients

The mayor goal still outstanding into the solid organ transplantation field involves the search of surrogate biomarkers able to predict several clinical events, such as acute rejection (AR) or opportunistic infection. In the present multicenter study, a series of interesting surface antigens with important activator or inhibitory immune functions on cultured peripheral T cells were monitored in liver transplant recipients drawn at baseline and up to one year after transplantation. Sixty-four patients were included in the multicenter study during 3 years. Pre- and post-transplantation surface antigens levels displayed significant differences between AR and non acute rejection (NAR) groups, and also this differential expression was used to construct a risk predictive model based on a composite panel of outcome biomarkers (CD38, CD69, CD95 and CD154). The model was able to stratify these patients at high risk of AR. These preliminary results could provide basic information to improve the immunosuppressive treatment and it might better help to predict AR episodes.

A new HLA-B allele, HLA-B*4068, identified in an Equatorian individual

HLA-B*4068 shares exon 2 with HLA-B*4008 and exon 3 with HLA-B*4004.

Differential contribution of HLA-DR, DQ, and TAP2 alleles to systemic lupus erythematosus susceptibility in Spanish patients: role of TAP2*01 alleles in Ro autoantibody production

OBJECTIVE

To study the influence MHC class II and TAP2 alleles exert on systemic lupus erythematosus (SLE) susceptibility and on the clinical and serological manifestations of the disease, in a cohort of Spanish patients.

METHODS

HLA-DR serological typing and HLA-DQA, DQB, and TAP2 DNA sequence specific oligotyping, were carried out in 85 unrelated Spanish SLE patients and 186 healthy controls. Autoantibodies detection was carried out by indirect immunofluorescence and counter immunoelectrophoresis.

RESULTS

Total SLE group: the frequency of HLA-DR3 and HLA-DQA1*0501 is significantly increased in this group (pc < 0.005, delta = 0.34 and pc < 0.005, delta = 0.45, respectively) although the highest delta value (delta = 0.87) is obtained when the TAP2*01 alleles are considered. No DQB allele shows significant deviation from the control group. Renal damage: it mainly occurs in HLA-DR3 patients (pc < 0.0005 and delta = 0.72). HLA-DQA1*0501 (p < 0.05, delta = 0.57 and DQB1*0201 (pc NS, delta = 0.56) are weaker susceptibility factors. Ro+ (but not LA) group: this autoantibody response is associated with TAP2*01 alleles in homozygosity (p < 0.05, delta = 0.81). R0/La+ group: it has a different genetic background as HLA-DQA1*0501 (delta = 1) and HLA-DQB1*0201 (delta = 1) are the main susceptibility factors.

CONCLUSIONS

A differential association between HLA-DR, DQA1, and DQB1 alleles and SLE or its clinical and serological manifestations are found. Furthermore, the associations are different to the ones reported in other ethnic groups. Finally, TAP2*01 group of alleles are associated with the highest susceptibility to SLE (higher than HLA-DR3) and may influence Ro (but not La) autoantibodies production, whereas HLA-DQA1*0501 and DQB1*0201 mediates concomitant Ro and La productions.