Frontiers in Immunology
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2020
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IF 5.085
Wu Wen-Jun,Tan Ying,Liu Xiao-Ling,Yu Feng,Zhao Ming-Hui
To investigate the fine epitope(s) of anti-C1q A08 antibodies and their roles in complement activation in lupus nephritis, C1q A08 and related peptides with various amino acid sequences around A08 were synthesized. Anti-C1q A08 antibodies from 10 lupus nephritis patients were purified from plasmapheresis samples, and four monoclonal antibodies against C1q A08 were screened and identified from mouse hybridoma cells, to study the fine epitope(s) of C1q A08 using ELISA and Biolayer Interferometry (BLI). The biofunction of anti-C1q A08 antibodies for complement classical pathway activation was investigated by C3 activation assay. Anti-C1q A08 antibodies and anti-C1q antibodies were also detected in the sera of female BALB/C mice immunized by C1q A08 peptides. None of the anti-C1q A08 antibodies, which were affinity purified from the 10 lupus nephritis patients, could bind intact C1q coated on microtitre plates, neither could the anti-C1q antibodies bind to C1q A08 peptides coupled on resin, indicating that the human anti-C1q antibodies and anti-C1q A08 antibodies may recognize different epitopes of C1q. One of the four C1q A08 mAbs (32-4) bound to the six amino acids of N-terminus of C1q A08, while another C1q A08 mAb (17-9) bound to eight or 10 amino acids of C-terminus of A08. The third and fourth C1q A08 mAb (1A12 and 4B11) bound to the whole sequence of A08. Only 32-4 mAb bound to the intact C1q coating on an ELISA plate, whereas 17-9 mAb, 1A12 mAb, and 4B11 mAb could not. However, using a BLI assay, 17-9 mAb, 1A12 mAb, and 4B11 mAb, but not 32-4 mAb, could bind to intact C1q. Furthermore, 1A12 mAb and 4B11 mAb, but not 32-4 and 17-9 mAb, could inhibit the activation of complement classical pathway. Anti-C1q A08 antibodies were detected in all the female BALB/C mice in the experimental group but not in the control group. Two out of six in the experimental group developed anti-C1q antibodies. C1q A08 is a half-cryptic epitope of C1q involving N-terminal six amino acids of C1q A08, and this is important to the activation of a complement classical pathway, and some anti-C1q A08 antibodies were able to prevent this process. Epitope spreading of C1q occurred in the mice immunized with C1q A08 peptides.
研究领域:
免疫学
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风湿病学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Science
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2025
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IF 14.1
Yunzhi Liu,Cuicui Huang,Min Luo,Wenfu Lu,Baifeng Zhang,Lu Bai,Shuyue Zheng,Yanan Tan,Shanshan Li,Huali Wang,Lanqi Gong,Xinyuan Guan
Nasopharyngeal carcinoma (NPC) is one of the common head and neck cancers in Southern China and Southeast Asia. Although current studies have adequately characterized the tumor microenvironment (TME) of NPC, little attention has been paid to how cell-cell interactions within the TME promote tumorigenesis. In this study, it is found that C1q + tumor-associated macrophages (TAMs) are significantly enriched in NPC tumors. Moreover, both enriched C1q + TAMs and elevated C1q expression are associated with the progression and poor prognosis in NPC patients. In vitro and in vivo studies demonstrate that C1q directly boosts the malignancy and stemness of tumor cells. Mechanistically, C1q activates the Phosphatidylinositol-3-kinase (PI3K)/AKT pathway through interacting with GPR17, a member of the G protein-coupled receptor family, thereby inducing DNA hypermethylation of tumor cells to promote tumor development. It is further proved that DNA hypermethylated NPC cells induced by C1q elicited the immunosuppressive phenotype of TAMs. Targeted blockade of C1q with a neutralizing antibody restricts NPC progression in the humanized mouse model. It is assumed that the differentiation of C1q + TAMs possibly acquired both M1 and M2 polarization conditions. These findings provide new insights into the cellular communication in the TME of NPC and may have important applications for the development of new targeted therapies.
研究领域:
肿瘤学
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免疫学
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分子生物学
✓ 已验证
DOI
PubMed
高影响因子
DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY
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2018
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IF 2.913
Meng Chen,Mingmei Ding,Yuan Li,Xiaofang Zhong,Shuo Liu,Zheng Guo,Xiaoxue Yin,Shengli Fu,Jianmin Ye
Complement component 1q (C1q) is the initial protein of the classical complement pathway and plays an important role in immune response against bacterial infection. In this study, the full-length of C1q subcomponent A, B and C chain genes ( C1qA , C1qB and C1qC ) were identified and characterized from Nile tilapia ( Oreochromis niloticus ). Molecular characterization of these three C1q subcomponents ( OnC1qs ) harbored conserved amino acids through analyses of multiple sequence alignment and phylogenetic tree , which were homologous to other teleost species. Expression analysis revealed that the OnC1qs were highly expressed in liver. After the in vivo challenges of Streptococcus agalactiae and LPS , the mRNA expressions of OnC1qs were significantly up-regulated in liver. Meanwhile, the concentration variation of OnC1qs at the protein level from tilapia serum after challenge with S. agalactiae were measured by a competitive-inhibition ELISA . In addition, the up-regulation expressions of OnC1qs were also demonstrated in head kidney adherent leukocytes and the cell culture medium in vitro stimulation with S. agalactiae , Aeromonas hydrophila and LPS, respectively. Moreover, the recombinant OnC1qs enhanced expression of cytokines IL-6, IL-8 and IL-10 in head kidney adherent leukocytes, and were able to bind both heat-aggregated mouse IgG and IgM. Taken together, the results of this study indicated that OnC1qs might be involved in host defense against bacterial infection in Nile tilapia.
研究领域:
免疫学
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水产养殖学
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分子生物学
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
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2025
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IF 6.7
Yuxin Zheng,Limin Ma,Yu Wang,Jianshe Huang,Jianshan Ye,Xiurong Yang
Several different receptor candidates have been identified that bind monomeric, oligomeric, or fibrillar forms of amyloid-β (Aβ) protein, thus being involved in the clearance or cytotoxic action of Aβ. Component protein C1q, the initiator of the classical complement pathway, has been extensively reported to mediate neuroprotection or synapse loss through interactions with different effectors. Therefore, quantification of the C1q–Aβ interaction is a prerequisite for a better understanding of its implications in disease. Herein, we established a layer-by-layer interface sensing platform to precisely quantify the biomolecular interactions occurring between component C1q and amyloid-β protein 42 (Aβ42) in distinct morphological states. By leveraging the dual polarization interferometry (DPI) technique, we obtained real-time data pertaining to the mass, thickness, and density of the biomolecular layers during the binding process and calculated the binding dynamic parameters. From the in-depth analysis of the kinetic results and electrochemical verification, we determined that Aβ42 monomer (Aβ42M) exhibited a higher affinity for C1q than the Aβ42 oligomer (Aβ42O). This affinity could potentially account for the possibility that the C1q–Aβ42M interaction may be the first step to mediate the pivotal roles of C1q in Alzheimer’s disease (AD). This study provides a new perspective on the interaction between C1q and Aβ42, and it offers new information on the C1q-involved signaling pathway to advance our understanding of the molecular mechanism of AD.
研究领域:
生物化学
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分子生物学
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神经科学
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免疫学
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生物物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
AQUACULTURE
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2018
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IF 2.71
Meng Chen,Shuo Liu,Fangfang Yan,Enxu Zhou,Xiaofang Zhong,Mingmei Ding,Jianmin Ye
Complement 1q-binding protein (gC1qR), a multi-functional cellular protein, is able to bind the globular head region of C1q molecule (gC1q), playing an important role in regulation of immune response and host defense against bacterial infection. In this study, the full length of a gC1qR ortholog ( OngC1qR ) was identified and characterized from Nile tilapia ( Oreochromis niloticus ). The cDNA of OngC1qR ORFs consisted of 870 bp of nucleotide sequence encoding a 289 amino acid residue polypeptide . The deduced amino acid sequence is highly homologous to teleost, containing a MAM33p domain, two potential glycosylation sites, and a putative cell adhesion site EGD (Glu-Gly-Asp). Spatial mRNA expression analysis revealed that the OngC1qR was expressed ubiquitously in all examined tissues, with a high expression in the liver. The OngC1qR expression was significantly up-regulated in liver, spleen and head kidney following in vivo challenges with Streptococcus agalactiae . A high up-regulation was also detected in head kidney leukocytes in vitro stimulation with Streptococcus agalactiae . In addition, immunofluorescence detection illustrated that the OngC1qR was located at the cell surface of leukocytes. Recombinant OngC1qR protein was able to not only bind LPS, LTA, S. agalactiae and Aeromonas hydrophila , but also possess binding capability with the ligand OnC1qs. Taken together, the results indicated that OngC1qR might be involved in host defense against bacterial infection in Nile tilapia.
研究领域:
免疫学
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分子生物学
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鱼类病害学
✓ 已验证
DOI
高影响因子
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