The human IgH 3' enhancers, located downstream of each of the two Calpha genes, modulate germline (GL) transcription of the IgH genes by influencing the activity of promoter-enhancer complexes upstream of the switch and intervening (I) regions. The regulation of GL alpha1 and alpha2 promoters by different human 3' enhancer fragments was investigated in cell lines representing various developmental stages. Both alpha1HS1,2 and alpha2HS1,2 fragments show equally strong enhancer activity on the GL alpha1 and alpha2 promoters in both orientations when transiently transfected into a number of mature B cell line (DG75, CL-01, and HS Sultan). However, there is no activity in a human pre-B cell line (NALM-6) nor a human T cell line (Jurkat). HS3 shows no enhancer activity by itself in any of the cell lines, whereas a modest effect is noted using HS4 in the three mature B cell lines. However, the combination of the alpha2HS3-HS1,2-HS4 fragments, which together form a potential locus control region, displays a markedly stronger enhancer activity than the individual fragments with a differential effect on the alpha1 and alpha2 promoters as compared with the gamma3 promoter. Our results suggest that the human GL alpha promoter may be regulated by two independent pathways. One pathway is induced by TGF-beta1 which directs IgA isotype switch through activation of the GL alpha promoter and no TGF-beta1-responsive elements are present in the different 3' enhancer fragments. The other route is through the human 3' enhancer regions that cis-up-regulate the GL alpha promoter activity in mature B cells.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.4049/jimmunol.164.12.6380 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The unique structure of the highly conserved PPLP region in HIV-1 Vif is critical for the formation of APOBEC3 recognition interfaces.
mBio
January 2025
Department of Infectious Diseases and Immunology, Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Aichi, Japan.
The human cellular cytidine deaminases APOBEC3s (A3s) inhibit virion infectivity factor (Vif)-deficient HIV-1 replication. However, virus-encoded Vifs abolish this defense system by specifically recruiting A3s to an E3 ubiquitin ligase complex to induce their degradation. The highly conserved Vif PPLP motif is critical for the Vif-mediated antagonism of A3s and is believed to be important for Vif multimerization.
View Article and Find Full Text PDFEnhanced effect of the immunosuppressive soluble HLA-G2 homodimer by site-specific PEGylation.
Sci Rep
January 2025
Laboratory of Biomolecular Science, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, 060-0812, Japan.
Human leukocyte antigen (HLA)-G is a nonclassical HLA class I molecule that has an immunosuppressive effect mediated by binding to immune inhibitory leukocyte immunoglobulin-like receptors (LILR) B1 and LILRB2. A conventional HLA-G isoform, HLA-G1, forms a heterotrimeric complex composed of a heavy chain (α1-α3 domains), β2-microglobulin (β2m) and a cognate peptide. One of the other isoforms, HLA-G2, lacks a α2 domain or β2m to form a nondisulfide-linked homodimer, and its ectodomain specifically binds to LILRB2 expressed in human monocytes, macrophages, and dendritic cells.
View Article and Find Full Text PDFModulatory roles of capsaicin on thermogenesis in C2C12 myoblasts and the skeletal muscle of mice.
Chem Biol Interact
January 2025
Department of Biotechnology, Daegu University, Gyeongsan, Gyeongbuk, 38453, Republic of Korea. Electronic address:
Capsaicin, a polyphenol, is known to regulate energy expenditure and thermogenesis in adipocytes and muscles. However, its role in modulating uncoupling proteins (UCPs) and adenosine triphosphate (ATP)-dependent thermogenesis in muscles remains unclear. This study investigated the mechanisms underlying the role of capsaicin in modulating the UCP- and ATP-dependent thermogenesis in C2C12 myoblasts, as well as the gastrocnemius (GM) and soleus muscles (SM) of mice.
View Article and Find Full Text PDFAnaemia of Inflammation Preceding Dyspnoea, Dry Cough and Weight Loss in Primary Pulmonary Lymphoma.
Eur J Case Rep Intern Med
December 2024
The Faculty of Medicine, Hebrew University and Hadassah Medical School, Jerusalem, Israel.
Introduction: There is little information in the literature on the early, sub-clinical stage and laboratory test results in patients with primary mucosa-associated lymphoid tissue (MALT) lymphoma of the lung, a rare disease.
Case Description: In a 75-year-old man, an open lung biopsy-confirmed diagnosis of primary pulmonary lymphoma was preceded by almost six months of anaemia of inflammatory disease and monocytosis without any pulmonary symptoms. When he developed a dry cough, increasing dyspnoea and marked weight loss, these changes deepened and became associated with reactive thrombocytosis; markedly increased ferritin and C-reactive protein (positive acute-phase reactants), as well as reduced albumin and transferrin (negative acute-phase reactants).
Molecular characterisation and expression profiles of an odorant-binding proteins gene (FoccOBP9) from .
Bull Entomol Res
January 2025
Ningxia Academy of Agriculture and Forestry Sciences, Institute of Plant Protection, Yinchuan, China.
Insect odorant-binding proteins (OBPs) are the key proteins in insect olfactory perception and play an important role in the perception and discrimination of insects. is a polyphagous pest and seriously harms the quality and yield of fruits, flowers and crops worldwide. Therefore, the discovery of OBPs has greatly improved the understanding of behavioural response that mediates the chemoreception of .
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!