RU-2861428-C1 - MOUSE HYBRIDOMA KAPPA LIGHT CHAIN (kLC), CLONE KBc-256, PRODUCING MONOCLONAL ANTIBODIES TO HUMAN KAPPA LIGHT CHAIN FOR DIAGNOSIS OF AL KAPPA AMYLOIDOSIS

RU2861428C1RU 2861428 C1RU2861428 C1RU 2861428C1RU-2861428-C1

Abstract

FIELD: biotechnology; medicine. SUBSTANCE: invention relates to hybridoma technology, and concerns a novel stable cell line - mouse hybridoma kappa light chain (kLC), clone KBc-256, producing monoclonal antibodies to the human kappa light chain. The invention can be used to obtain monoclonal antibodies that allow detecting and confirming AL kappa amyloidosis by immunohistochemistry, immunofluorescence, enzyme immunoassay and western blotting. EFFECT: research and production purposes for producing diagnostic monoclonal antibodies. 1 cl, 6 dwg, 6 ex

Inventors

GIOEVA ZARINA VLADISLAVOVNA
Tebenkova Anna Andreevna
Mikhaleva Liudmila Mikhailovna
Stepanova Irina Ildarovna
STEPANOV ALEKSANDR ALEKSEEVICH
Bykova Daria Viktorovna

Dates

Publication Date: 20260505
Application Date: 20251205

Claims (1)

The kappa light chain (kLC) hybridoma cell line culture, clone KBc-256, deposited at the National Bioresource Center - All-Russian Collection of Industrial Microorganisms (BRC VKPM) of the Kurchatov Institute Research Center under registration number H-245 dated September 9, 2025, is a producer of mouse monoclonal antibodies to the human kappa light chain, suitable for the detection of AL kappa amyloidosis.

Description

The invention relates to biotechnology and medicine, specifically to hybridoma technology, according to International Patent Classification C12N 5/12, and concerns a new stable cell line (strain)—a murine kappa light chain (kLC) hybridoma, clone KBc-256, producing monoclonal antibodies to the kappa light chain (kLC) of human immunoglobulins. The resulting hybridoma is intended for the production of monoclonal antibodies applicable in immunohistochemical and immunofluorescence analysis, enzyme-linked immunosorbent assay, and Western blotting for the detection of kappa light chains, particularly for the diagnosis of AL kappa amyloidosis. The invention may find application in both research and industrial production of immunodiagnostic reagents. The hybrid cell line strain, clone KBc-256, is deposited in the All-Russian Collection of Industrial Microorganisms and has registration number H-245 dated September 9, 2025. Amyloidosis is characterized by the extracellular deposition of amyloid fibrils in tissues, formed in most cases by misfolded precursor protein, in the form of a beta-pleated structure, the content of which in the fibril reaches 80% and is a specific feature for each type of amyloidosis, and also determines the properties of the fibrils [1]. The classification of amyloidosis is based on the biochemical type of the precursor protein. The amyloid type is named after the precursor protein, with the letter A (for amyloid) added. Currently, 42 types of amyloid are known, most of which have systemic distribution. AA amyloidosis fibrils are formed from the amyloidogenic isotype of the serum precursor protein serum amyloid A (SAA). ATTR amyloidosis fibrils are formed as a result of a mutation in the gene encoding the synthesis of transthyretin (TTR), which leads to the substitution of amino acids in the TTR molecule and leads to increased amyloidogenicity and the ability to polymerize [2]. In AL amyloidosis, the precursor protein is monoclonal free immunoglobulin light chains secreted by aberrant B cells in the bone marrow. This type of amyloidosis is the most common worldwide and is typically a systemic disease characterized by rapidly progressive extracellular deposition of amyloid in tissues and organs, followed by the development of multiple organ failure [3], [4]. Plasma cells in the bone marrow produce abnormal immunoglobulins, which are light chains of the lambda and kappa types, which are amyloidogenic [5]. Lambda chains are detected in 70-80% of people with AL amyloidosis, and kappa chains in 20-30%. Structurally, light chain fibrils in AL amyloidosis consist of full-length and often truncated light chains, which contributes to fibril heterogeneity [6]. In 12-15% of cases, AL amyloidosis can also occur in patients with multiple myeloma. Amyloidogenicity is ensured by certain structural features. For example, it was found that members of the IGKV1 gene family are frequently found in AL amyloidosis and MM, but the frequency is higher in AL (AL: 80%, MM: 53%, p = .002) [7]. The leading diagnostic method for amyloidosis is histological examination of tissue biopsies stained with Congo red and then microscopically examined under polarized light to detect the characteristic green birefringence. Following morphological and histological confirmation of amyloidosis, typing is a mandatory step to identify the precursor protein, which is crucial for determining the appropriate treatment strategy for the patient. Mass spectrometric proteomic analysis is the most reliable, but not readily available and expensive, method. Therefore, immunohistochemistry or immunofluorescence testing is currently the most common method for detecting the precursor protein using monoclonal or polyclonal antibodies. However, commercially available antibodies to kappa light chains (free or incorporated into immunoglobulin) are generally not tested for amyloidosis and either bind non-specifically to all possible immunoglobulin variants in tissues or fail to detect light chains within amyloid at all. For routine detection of kappa light chain by immunohistochemistry and immunofluorescence, there are currently a sufficient number of commercial antibodies, which are represented by rabbit and mouse monoclonal and rabbit polyclonal antibodies. Commercially available antibodies to kappa light chain can target either free kappa chains or kappa chains within IgG. We tested these antibodies on amyloid-containing samples and obtained accurate staining with two types of antibodies: Rabbit anti-Kappa light chain antibody, clone SP148 (Abcam, USA), and Moiuse monoclonal antibody kappa light chain, clone CH15 (Novocastra, UK). Despite the availability of antibodies to the kappa light chain on the global market, only a few have proven themselves suitable for the typing of AL kappa amyloidosis. Even a cohort study of commercially available antibodies for the diagnosis of AL amyloidosis identified difficulties with typing amyloidosis using such antib