Probes for PAX5

The genetic causes of primary antibody deficiencies and autism spectrum disorder (ASD) are largely unknown. Here, we report a patient with hypogammaglobulinemia and ASD who carries biallelic mutations in the transcription factor PAX5. A patient-specific Pax5 mutant mouse revealed an early B cell developmental block and impaired immune responses as the cause of hypogammaglobulinemia. Pax5 mutant mice displayed behavioral deficits in all ASD domains. The patient and the mouse model showed aberrant cerebellar foliation and severely impaired sensorimotor learning. PAX5 deficiency also caused profound hypoplasia of the substantia nigra and ventral tegmental area due to loss of GABAergic neurons, thus affecting two midbrain hubs, controlling motor function and reward processing, respectively. Heterozygous Pax5 mutant mice exhibited similar anatomic and behavioral abnormalities. Lineage tracing identified Pax5 as a crucial regulator of cerebellar morphogenesis and midbrain GABAergic neurogenesis. These findings reveal new roles of Pax5 in brain development and unravel the underlying mechanism of a novel immunological and neurodevelopmental syndrome.

AIMS: The purpose of this study was to compare the immunohistochemical staining profiles of PAX8-polyclonal, PAX8-monoclonal, PAX5-monoclonal, and PAX6-monoclonal antibodies in several histologic types of primary thoracic and thyroid tumors. In addition, we analyzed PAX8 mRNA expression by using in situ hybridization. METHODS AND RESULTS: We compared polyclonal PAX8 and monoclonal PAX8, PAX5, and PAX6 antibodies in 962 samples (687 cases of lung carcinoma, 40 cases of malignant pleural mesothelioma, 138 cases of thymic tumor, and 97 cases of thyroid tumors) using tissue microarray technique. Among thyroid tumors, the monoclonal and polyclonal PAX8 antibodies showed a high positive rate (98.0%). Of 167 polyclonal PAX8 antibody-positive tumors, except for thyroid tumors, 54 cases tested positive for PAX5 and/or PAX6 (31 lung carcinomas and 23 thymic tumors). No PAX8 mRNA expression was detected using RNAscope (in situ hybridization technique) other than in thyroid tumors. A portion of polyclonal PAX8 antibody-positive tumors showed cross-reactivity for PAX5 or PAX6 protein. CONCLUSIONS: Monoclonal PAX8 antibody showed high specificity to thyroid tumors and was superior to the polyclonal antibody. This article is protected by copyright. All rights reserved.

Tissue-based T cells are important effectors in the prevention and control of mucosal viral infections; less is known about tissue-based B cells. We demonstrate that B cells and antibody-secreting cells (ASCs) are present in inflammatory infiltrates in skin biopsy specimens from study participants during symptomatic herpes simplex virus 2 (HSV-2) reactivation and early healing. Both CD20+ B cells, most of which are antigen inexperienced based on their coexpression of IgD, and ASCs - characterized by dense IgG RNA expression in combination with CD138, IRF4, and Blimp-1 RNA - were found to colocalize with T cells. ASCs clustered with CD4+ T cells, suggesting the potential for crosstalk. HSV-2-specific antibodies to virus surface antigens were also present in tissue and increased in concentration during HSV-2 reactivation and healing, unlike in serum, where concentrations remained static over time. B cells, ASCs, and HSV-specific antibody were rarely detected in biopsies of unaffected skin. Evaluation of samples from serial biopsies demonstrated that B cells and ASCs followed a more migratory than resident pattern of infiltration in HSV-affected genital skin, in contrast to T cells. Together, these observations suggest the presence of distinct phenotypes of B cells in HSV-affected tissue; dissecting their role in reactivation may reveal new therapeutic avenues to control these infections.

The brainstem dorsal vagal complex (DVC) is known to regulate energy balance and is the target of appetite-suppressing hormones, such as glucagon-like peptide 1 (GLP-1). Here we provide a comprehensive genetic map of the DVC and identify neuronal populations that control feeding. Combining bulk and single-nucleus gene expression and chromatin profiling of DVC cells, we reveal 25 neuronal populations with unique transcriptional and chromatin accessibility landscapes and peptide receptor expression profiles. GLP-1 receptor (GLP-1R) agonist administration induces gene expression alterations specific to two distinct sets of Glp1r neurons-one population in the area postrema and one in the nucleus of the solitary tract that also expresses calcitonin receptor (Calcr). Transcripts and regions of accessible chromatin near obesity-associated genetic variants are enriched in the area postrema and the nucleus of the solitary tract neurons that express Glp1r and/or Calcr, and activating several of these neuronal populations decreases feeding in rodents. Thus, DVC neuronal populations associated with obesity predisposition suppress feeding and may represent therapeutic targets for obesity.

HBZ-ISH was performed to detect HTLV-1 in tissue specimens from 21 HTLV-1–seropositive cases with CHL-like morphology (supplemental Table 1). Three cases were nonevaluable due to negativity for the positive control (_PPIB_). HRS-like cells were negative for HBZ-ISH in 10 cases. Among them, 3 cases showed HRS-like cells positive for EBER-ISH and/or PAX5 as well as monoclonal TCR-γ chain gene rearrangement or loss of pan-T-cell antigens in the background cells, corresponding to the currently recognized pathological features of Hodgkin-like ATLL.16,17  Thus, 8 cases, including a recently described case (case 1)19  with a positive HBZ-ISH signal in HRS-like cells, were considered to be ATLL with HTLV-1–infected HRS-like cells. The clinical characteristics of these cases are shown in Table 1. The median age of the patients (4 males and 4 females) was 73 years (range, 55-81 years). All patients showed nodal or mediastinal lesions. Five patients (63%) were in an advanced stage of disease (Ann Arbor stage III or IV) at presentation. Bone marrow and hepatosplenic involvement was observed in 3 and 2 cases, respectively, but no other extranodal lesions were present in any of the cases. All patients except for case 6, who was treated with palliative care because of the co-occurrence of severe liver cirrhosis, received systemic combination chemotherapy. Two patients (cases 1 and 3) were mainly treated with ABVD, a standard therapy for CHL, and 5 patients were treated with a combination chemotherapy regimen such as CHOP. All cases, with enough follow-up period, treated with chemotherapy achieved complete remission, except for case 4, but a longer remission (>2 years) was achieved in 2 patients treated with CHOP. One patient (case 4) had been followed up for chronic-type ATLL before lymph node biopsy. This patient had very high serum levels of soluble interleukin-2 receptor, a prognostic biomarker for poor outcome,8  was refractory to systemic chemotherapy, and died 3 months after diagnosis (Table 1).