Related Experiment Video
Updated: Jun 25, 2026
13:01
Anti-Nuclear Antibody Screening Using HEp-2 Cells
Published on: June 23, 2014
Heterogeneous nuclear ribonucleoprotein h1, a novel nuclear autoantigen
Karolien Van den Bergh1, Herbert Hooijkaas, Daniel Blockmans
1Laboratory Medicine, Immunology, University Hospitals Leuven, Leuven, Belgium.
Clinical Chemistry
|March 7, 2009
Summary
Researchers identified heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) as a novel autoantigen in connective tissue diseases. Autoantibodies against hnRNP H1 may serve as an additional diagnostic marker for Sjögren syndrome.
Area of Science:
- Immunology
- Proteomics
- Autoimmunity
Background:
- Patients with autoimmune connective tissue diseases often exhibit antinuclear antibodies (ANA) with a finely speckled pattern.
- These antibodies may target unknown nuclear antigens, necessitating further investigation.
Purpose of the Study:
- To identify novel nuclear autoantigens in patients with high-titer ANA and finely speckled fluorescence.
- To investigate the diagnostic potential of identified autoantigens in connective tissue diseases.
Main Methods:
- An immunoproteomics approach was employed to screen patient sera.
- Western blot and indirect immunofluorescence assays were used to detect and confirm autoantibodies.
Main Results:
- Heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) was identified as a novel autoantigen.
- Anti-hnRNP H1 antibodies were detected in 48% of primary Sjögren syndrome patients and 5.2% of disease controls.
- These antibodies were found in Sjögren syndrome patients negative for anti-SSA/SSB antibodies, suggesting a distinct diagnostic role.
Conclusions:
- hnRNP H1 is a newly discovered autoantigen.
- Anti-hnRNP H1 antibodies show potential as an additional diagnostic marker for Sjögren syndrome and related autoimmune conditions.
Related Concept Videos
01:26Antigens Involved in Adaptive Immunity
An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
01:42Nuclear Export
The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
01:34Nuclear Protein Sorting
Nuclear protein sorting is the selective trafficking of histones, polymerases, gene regulatory proteins into the nucleus and exporting RNAs and ribosomes to the cytosol. It is a tightly controlled process that regulates gene expression within a cell.
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
01:28Diversity of Antigen Receptors
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
01:45Regulation of Nuclear Protein Sorting
Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...