Biosimilar Antibodies
C1q, Mouse, mAb JL-1, FITC, Hycult Biotech, HM1096F
The monoclonal antibody JL-1 recognizes the collagen-like region (CLR) of mouse C1q, a 459 kDa molecule consisting of three individual polypeptide chains . The antibody has been generated by immunization of C1q-/- C57BL/6 mice with purified mouse C1q. C1q forms together with C1r and C1s the C1 macromolecule, the first component of the classical complement pathway. Interaction of immune complexes with C1q induces a conformational change within the C1 complex, which results in activation of the classical pathway. C1q functions as recognition unit by binding to the heavy chain of IgG or IgM (Fc gamma and Fc micro) provided that the immunoglobulins are bound to their antigen. Furthermore, C1q can also recognize molecular patterns associated with pathogens and it can bind to apoptotic blebs, where it activates the classical complement pathway and mediates phagocytosis. As such, C1q promotes the clearance of apoptotic cells and subsequent exposure of auto antigens, thereby preventing stimulation of the immune system. C1q is predominantly produced by macrophages but also by follicular dendritic cells, interdigitating cells and cells of the monocyte-macrophage lineage. C1q deficiency has a profound effect on host defence and clearance of immune complexes. Absence of C1q may cause autoimmunity by impairment of the clearance of apoptotic cells. Inherited C1q deficiency is also associated with the development of systemic lupus erythematosus (SLE). The monoclonal antibody JL-1 is reactive with the collagen-like region (CLR) only, which is the same region to which autoantibodies in mice and humans are binding. Anti-C1q autoantibodies deposit in glomeruli together with C1q but induce overt renal disease only in the context of glomerular immune complex disease. This provides an explanation why anti-C1q antibodies are especially pathogenic in patients with SLE.
Host
Mouse
Reactivity
Applications
Conjugation
C1q, Mouse, mAb JL-1, Hycult Biotech, HM1096
The monoclonal antibody JL-1 is highly specific for the collagen-like region (CLR) of mouse C1q , a key component of the classical complement pathway. C1q is a large molecule (459 kDa) composed of three distinct polypeptide chains and plays a central role in immune recognition. The JL-1 antibody was developed by immunizing C1q-deficient ( C1q-/- ) mice (C57BL/6 strain) with purified mouse C1q, ensuring targeted immune response toward this specific region of C1q. C1q in the Classical Complement Pathway C1q is part of the C1 complex , which also includes C1r and C1s , forming the initial component of the classical complement pathway. Upon interaction with immune complexes, C1q undergoes a conformational shift that activates this pathway, essential for immune defense. As the recognition unit, C1q binds to the Fc region of IgG or IgM , provided they are attached to an antigen. Additionally, C1q identifies molecular patterns on pathogens and apoptotic cells, activating the pathway and facilitating phagocytosis . This function is crucial for clearing apoptotic cells, preventing the exposure of autoantigens, and reducing immune system activation. Importance of C1q in Immune Regulation C1q is primarily produced by macrophages , but it is also synthesized by follicular dendritic cells and other cells in the monocyte-macrophage lineage. Deficiency in C1q can lead to impaired clearance of immune complexes and apoptotic cells, contributing to autoimmune conditions such as systemic lupus erythematosus (SLE) . Inherited C1q deficiency has been strongly linked to the development of SLE, as the absence of C1q disrupts normal immune regulation. JL-1 Antibody and Its Role in Research The monoclonal antibody JL-1 specifically targets the collagen-like region of C1q, where autoantibodies bind in both mice and humans. These anti-C1q antibodies are often present in SLE patients and contribute to renal disease , especially in the context of glomerular immune complex disease . This makes JL-1 a valuable tool in studying autoimmune conditions like SLE and the mechanisms of C1q-related immune dysfunction. By focusing on C1q and its pivotal role in the immune system, JL-1 provides insight into immune regulation, complement activation, and the potential development of autoimmune disorders.
Host
Mouse
Reactivity
Applications
Conjugation
C1q, Rat, pAb, Hycult Biotech, HP8021
The polyclonal antibody recognizes rat C1q, a 459 kDa molecule consisting of three individual polypeptide chains. C1q composes together with C1r and C1s the C1 macromolecule, the first component of the classical complement pathway. Interaction of immune complexes with C1q induces a conformational change within the C1 complex, which results in activation of the classical pathway. C1q functions as recognition unit by binding to the heavy chain of IgG or IgM (Fc gamma and Fc micro) provided that the immunoglobulins are bound to their antigen. Furthermore C1q can bind to apoptotic blebs, where it activates the classical complement pathway and mediates phagocytosis. As such, C1q promotes the clearance of apoptotic cells and subsequent exposure of auto antigens, thereby preventing stimulation of the immune system. C1q is predominantly produced by macrophages but also by follicular dendritic cells, interdigitating cells and cells of the monocyte-macrophage lineage. C1q deficiency has a profound effect on host defence and clearance of immune complexes. Absence of C1q may cause autoimmunity by impairment of the clearance of apoptotic cells. Inherited C1q deficiency is also associated with the development of systemic lupus erythematosus (SLE).
Host
Rat
Reactivity
Applications
Conjugation
C1s/C1-INH Complex, Human, ELISA kit, Hycult Biotech, HK399
The C1s/C1-INH complex actively controls the complement system’s classical pathway, crucial for the body’s innate immune defense against infections. This complex forms when C1 inhibitor (C1-INH) binds with C1r and C1s, effectively regulating the proteolysis-based activation cascade and preventing overreaction of the immune system. In diseases like Hereditary Angioedema (HAE) and Systemic Lupus Erythematosus (SLE), the altered levels of the C1s/C1-INH complex provide key insights into immune activity, establishing its importance as a biomarker for monitoring immune responses.
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Reactivity
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C1s, Human, clone 10/12, Hycult Biotech, HM2412
Antibody 10/12 recognizes human activated C1s, a molecule of the complement C1 complex and hence part of the component that initializes classical pathway activation. Upon recognition of immune complexes by C1q, C1r is autoactivated and subsequently activates C1s, which is then able to cleave C4 and C2, leading to the formation of the C3 convertase and further activation of the terminal pathway of the complement system. C1s deficiencies are associated with impaired function of the classical complement pathway. The inhibition of the classical complement pathway with at C1s can be measured with the Classical complement pathway assay ( HK3010 ). The zymogen form of C1s is a glycosylated single chain polypeptide with a MW of around 85kDa and the domain architecture CUB1-EGF-CUB2-CCP1-CCP2-SP, while activation through C1r leads to a 58kDa and a 27kDa chain, linked by disulfide bonds. Monoclonal antibody 10/12 is a murine IgG1 antibody directed against the CCP1-CCP2-SP domains of activated C1s and can detect human C1s in immunoassays.
Host
Human
Reactivity
Applications
Conjugation
C1s, Human, mAb M81, Hycult Biotech, HM2108
Monoclonal antibody M81 reacts with an epitope on human C protein activated C1s, a subcomponent of the first component of C (C1). Activated C1s is a glycosylated single-polypeptide zymogen, MW 85 kD. Activation of the proenzyme C1s occurs through cleavage by the active form of C1r. The activated protease, activated C1s, consists of a disulfide-linked H chain and a L chain. Activated C1s is a serine protease and its catalytic site is located in the L chain. Activation of the classical C pathway is triggered by activated C1s which cleaves C4 and C2 to form the C3 convertase, C4bC2a. The epitope recognised by the antibody M81 is domain IV and/or V of the gamma-domain of activated C1s. Monoclonal antibody M81 blocks C4 activation and C4 binding to activated C1s. The antibody reacts around the binding site of C1s and reacts with both active and inactive C1s.
Host
Human
Reactivity
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Conjugation
C3 (beta-chain), Human, clone 169.5, Hycult Biotech, HM2377
Exploring the C3 (Beta-Chain) The C3 (beta-chain) plays a pivotal role in the body’s immune response, recognized by the antibody clone 169.5. This specific ß chain of C3, weighing 71 kDa, is not only a part of C3 but also found in its activation products C3b, iC3b, and C3c. The complement system, where the C3 (beta-chain) is a key component, is integral to both innate and adaptive immune responses, offering protection against pathogens through inflammatory reactions. Comprising a complex family of proteins and receptors, the complement system is present in circulation, tissues, and various body fluids. There are three pathways of complement activation: the classical pathway initiated by immune complexes, the lectin pathway by surface-bound lectins, and the alternative pathway (AP) activated by unprotected surfaces. Each pathway generates a C3 convertase, a serine protease that cleaves the central complement protein C3, leading to the formation of C3b. The C3 (beta-chain) is also central to the formation of C3 and C5 convertases, which are enzymatic complexes that drive the activity of the complement pathways, eventually leading to the formation of the cytolytic membrane attack complex (MAC). The synthesis of C3, with a molecular weight of approximately 185kDa, is tissue-specific and modulated by various stimulants. Notably, C3 is the most abundant complement system protein with serum levels around 1.3 mg/ml. Upon cleavage by C3 convertase, the anaphylotoxin C3a and the activating fragment C3b are formed. C3b, when bound to the cell surface, initiates the terminal pathway of complement, leading to the formation of C5 convertase. Produced primarily by the liver, C3 is also synthesized in macrophages, neutrophils, endothelial, and epithelial cells. The high levels of C3 (beta-chain) in circulation, combined with its low biological reactivity, enable a fast and potent response to dangers such as pathogens. However, defects in C3 can lead to recurrent infections or autoimmune diseases. C3 deficiency, though rare, results in recurrent infections and impaired immune cell development. Additionally, polymorphisms in C3 have been linked to conditions like AMD and aHUS. The C3 (beta-chain) removes immune complexes, aiding macrophages’ phagocytic capacity. Malfunction in this system can cause autoimmune diseases, stressing C3’s role in immune balance. Not sure which C3 antibody to use? With numerous options available, it is essential to select the right C3 antibody to ensure the success of your research. We designed a guide to assist you in making an informed decision: Go to our C3 researcher’s guide and choose the right antibody
Host
Human
Reactivity
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Conjugation
C3/C3a, Human, mAb 2898, Hycult Biotech, HM2075
C3/C3a Abundant and Crucial in the Complement System C3, the most abundant protein in the complement system, plays a central role in innate immunity with serum levels approximately 1.3 mg/ml. As a critical component of the complement system, which includes three pathways, C3 and its fragment C3a are integral to both the classical, alternative, and lectin pathways of complement activation. The Activation and Function of C3/C3a The activation of C3 leads to the formation of various products, including C3a, which bear neo-epitopes absent in their native form. Monoclonal antibodies like the 2898 are instrumental in directly quantifying these activation stages. Tissue-specific synthesis of C3, responsive to numerous stimulants, further underscores the dynamic nature of C3/C3a in immune responses. Moreover, a deficiency in C3 can predispose individuals to frequent bacterial infections, emphasizing the protective role of C3/C3a in the immune system. This is particularly evident in conditions like ulcerative colitis and chronic inflammatory bowel disease, where abnormal C3 deposition is observed. Proteolytic Cleavage and the Stability of C3a Enzymatic proteolysis of C3 releases the anaphylatoxin C3a and C3b. The C3a fragment, a protein of 74 amino acids, is inherently short-lived, quickly transforming into the more stable form, C3a-desArg. This transformation makes C3a-desArg a reliable marker for complement activation levels in test samples, showcasing the significance of C3/C3a in immunological assays. C3a’s Role in Inflammatory Responses C3a is a potent mediator in local inflammatory processes. It induces smooth muscle contraction, increases vascular permeability, and triggers histamine release from mast cells and basophils. C3a mediates inflammation, impacting conditions like sepsis, ischemic heart disease, and autoimmune diseases. Conclusion The comprehensive understanding of C3/C3a, from its detection by monoclonal antibodies to its role in immune responses and diseases, is crucial. The study of C3/C3a not only illuminates key aspects of the immune system but also aids in the development of targeted therapeutic interventions. Not sure which C3 antibody to use? With numerous options available, it is essential to select the right C3 antibody to ensure the success of your research. We designed a guide to assist you in making an informed decision: Go to our C3 researcher’s guide and choose the right antibody
Host
Human
Reactivity
Applications
Conjugation
C3/C3a, Human, mAb 474, Hycult Biotech, HM2073
Understanding Complement Protein C3/C3a and its Role in Innate Immunity The complement system, a crucial component of innate immunity, includes a pivotal element known as complement protein C3/C3a. This protein plays a central role in the classical, alternative, and lectin pathways of complement activation, underlining its importance in the immune response. The Synthesis and Function of Complement Protein C3/C3a Complement protein C3/C3a is synthesized in a tissue-specific manner, influenced by various stimulatory agents. A significant aspect of C3/C3a’s function involves its cleavage during complement activation. This cleavage releases C3a, an anaphylatoxic peptide consisting of 74 amino acids, approximately 10 kDa in size. C3a, known for its transient nature in serum, is quickly converted into a more stable form, C3a-desArg (also referred to as acylation stimulating protein, ASP). C3a’s Mechanism of Action C3a operates through a specific receptor, C3aR, belonging to the G-protein coupled receptor family. This receptor’s expression across various cell types, including myeloid and non-myeloid cells, underscores its broad impact. Notably, C3aR’s presence on hematopoietic stem/progenitor cells enhances their trafficking to the bone marrow. Additionally, C3aR’s engagement with dendritic cells (DCs) and T cells has been shown to augment their functions. C3a’s Role in Inflammatory Processes Complement protein C3/C3a, particularly C3a, is a key mediator in local inflammatory processes. It induces smooth muscle contraction, increases vascular permeability, and prompts histamine release from mast cells and basophilic leukocytes. The involvement of C3a in inflammatory responses is evident in conditions such as gram-negative bacterial sepsis, ischemic heart disease, and various autoimmune diseases. Not sure which C3 antibody to use? With numerous options available, it is essential to select the right C3 antibody to ensure the success of your research. We designed a guide to assist you in making an informed decision: Go to our C3 researcher’s guide and choose the right antibody
Host
Human
Reactivity
Applications
Conjugation
C3/C3b, Human, mAb 755, Hycult Biotech, HM2072
Exploring the Role of C3/C3b in Innate Immunity and Complement Activation The complement system, a cornerstone of innate immunity, involves crucial components like C3/C3b. This key element is central to the classical, alternative, and lectin pathways of complement activation, highlighting its significance in immune defense mechanisms. Synthesis and Abundance The synthesis of C3, is tissue-specific and influenced by various stimulatory agents. As the most abundant protein in the complement system, C3 has significant serum protein levels, about 1.3 mg/ml. Understanding the synthesis and regulation of C3 helps in comprehending the dynamics of C3/C3b. Disease and Immune Response A deficiency in C3/C3b can lead to increased susceptibility to bacterial infections, underlining its protective role. In contrast, the deposition of C3 fragments, including C3/C3b, is observed in diseases like ulcerative colitis and chronic inflammatory bowel disease, indicating its role in immunopathology. The Mechanism of C3/C3b Formation and Function Upon activation of the complement system, enzymes cleave C3 into C3b (part of C3/C3b) and C3a. C3b binds to immune complexes and undergoes further cleavage into various fragments. Within the alternative pathway, C3b is essential for amplifying the immune response, highlighting the critical role in this process. Not sure which C3 antibody to use? With numerous options available, it is essential to select the right C3 antibody to ensure the success of your research. We designed a guide to assist you in making an informed decision: Go to our C3 researcher’s guide and choose the right antibody
Host
Human
Reactivity
Applications
Conjugation
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