文献

重组大鼠IgG2a同型对照抗体，体内实验级（In Vivo Grade Recombinant Rat IgG2a Isotype Control Antibody，Syd Labs PA007143）

大鼠 IgG2a 同型对照及其突变体（天然型与工程化 rtIgG2a 同型对照）在基于动物模型的多种体外（in vitro）和体内（in vivo）功能研究与科研应用中具有重要价值，包括酶联免疫吸附实验（ELISA）、蛋白质印迹（WB）、流式细胞术（Flow）、免疫沉淀（IP）、石蜡切片免疫组化（IHC (P)）以及冰冻切片免疫组化（IHC (F)）。相比于大鼠 IgG2b 抗体，大鼠 IgG2a 和 IgG1 抗体在性质上更接近于小鼠 IgG1。绝大多数大鼠抗体均被用于研究小鼠和人的目标蛋白。

如需获取带 Avi 标签、His 标签、Flag 标签工程化改造的大鼠 IgG2a 同型对照突变体、rtIgG2a 同型对照及其突变体，以及生物素化 rtIgG2a 同型对照与突变体的报价，欢迎随时联系我们。我们还提供大鼠 IgG2a 同型对照及 Fc 突变体与多种偶联物（如染料和荧光素）结合的定制产品。

大鼠 IgG 抗体主要根据重链的同型分为四个亚型（重链包括 IgG1、IgG2a、IgG2b 和 IgG2c；轻链包括 kappa 和 lambda），其中血清中最丰富的是 IgG1 和 kappa。IgG 抗体是由四条肽链组成的大分子蛋白，分子量约为 150 kDa，包含两条约 50 kDa 的相同重链和两条约 25 kDa 的相同轻链。这四条肽链通过重链之间以及重链与轻链之间形成的二硫键连接，排列成 Y 型四聚体结构。

重组大鼠IgG2a同型对照抗体引用文献:

1. TIGIT predominantly regulates the immune response via regulatory T cells
Kurtulus, S., et al. J Clin Invest. 2015 Nov;125(11):4053-62. PMID: 26413872
“In some experiments, mice were treated with 250 μg isotype (rat IgG2a) or anti–TIM-3 Abs on the days indicated in the legend for Figure 7. …A recent study suggests that TIGIT regulates T cell function by inhibiting CD226 dimerization and downstream signaling. …Upregulation of these receptors on effector T cells terminates T cell responses, while their expression on Tregs promotes their suppressor function. …T cell Ig and ITIM domain (TIGIT) is a recently identified coinhibitory receptor that is found on the surface of a variety of lymphoid cells, and its role in immune regulation is just beginning to be elucidated. …We demonstrated that TIGIT signaling in Tregs directs their phenotype and that TIGIT primarily suppresses antitumor immunity via Tregs and not CD8+ T cells. Moreover, TIGIT+ Tregs upregulated expression of the coinhibitory receptor TIM-3 in tumor tissue, and TIM-3 and TIGIT synergized to suppress antitumor immune responses.”

2. Animal model of respiratory syncytial virus: CD8+ T cells cause a cytokine storm that is chemically tractable by sphingosine-1-phosphate 1 receptor agonist therapy
Walsh, K. B., et al. J Virol. 2014 Jun;88(11):6281-93. PMID: 24672024
“For cell depletion experiments, 250 μg of anti-NK1.1 and/or 500 μg of anti-CD8 antibodies were administered i.p. to mice 1 day before and 1 day after infection. Rat IgG2a was administered at equivalent concentrations for isotype control-treated mice within the cell depletion experiments. …The cytokine storm is an intensified, dysregulated, tissue-injurious inflammatory response driven by cytokine and immune cell components. …Now we describe a novel event where virus-specific T cells induce a cytokine storm. …The paramyxovirus pneumonia virus of mice (PVM) is a model of human respiratory syncytial virus (hRSV). …Blockading these cytokines with neutralizing antibodies blunts the cytokine storm and protects the host.”

3. The oestrous cycle stage affects mammary tumour sensitivity to chemotherapy
Bornes, L., et al. Nature. 2025 Jan;637(8044):195-204. PMID: 39633046
“Individual mice were treated every week with either 60 mg kg−1 of either InVivoMAb anti-mouse CSF1R (CD115) monoclonal antibody or InVivoMAb rat IgG2a isotype control (clone 2A3, catalogue no. BE0089), or received InVivoMAb anti-mouse CD4 and InVivoMAb anti-mouse CD8 three times per week, every other day, with a first dose of 400 µg followed by 200 µg per antibody. …The response of breast cancer to neoadjuvant chemotherapy (NAC) varies substantially, even when tumours belong to the same molecular or histological subtype. …In three mouse models of breast cancer, we show reduced responses to NAC when treatment is initiated during the dioestrus stage, when compared with initiation during the oestrus stage. …Similar findings were observed in retrospective premenopausal cohorts of human patients. …Whereas NAC disrupts the oestrous cycle, this elevated macrophage prevalence persists and depletion of macrophages mitigates the reduced therapy response observed when initiating treatment during dioestrus.”

4. Chimeric antigen receptor macrophages (CAR-M) sensitize HER2+ solid tumors to PD1 blockade in pre-clinical models
Pierini, S., et al. Nat Commun. 2025 Jan 15;16(1):706. PMID: 39814734
“In designated experiments, 10 µg/mL of InVivoMAb anti-mouse PD-1 or 10 µg/mL InVivoMAb rat IgG2a isotype control (BE0089) was added to the wells. …We previously developed human CAR macrophages (CAR-M) and demonstrated redirection of macrophage anti-tumor function leading to tumor control in immunodeficient xenograft models. …In vivo, anti-HER2 CAR-M significantly reduce tumor burden, prolong survival, remodel the TME, increase intratumoral T cell and natural killer (NK) cell infiltration, and induce antigen spreading. …CAR-M therapy protects against antigen-negative relapses in a T cell dependent fashion, confirming long-term anti-tumor immunity. …These results demonstrate synergy between CAR-M and T cell checkpoint blockade and provide a strategy to potentially enhance response to aPD1 therapy for patients with non-responsive tumors.”

5. Tamm-Horsfall protein augments neutrophil NETosis during urinary tract infection
Mercado-Evans, V., et al. JCI Insight. 2025 Jan 9;10(1):e180024. PMID: 39589812
“Serial dilutions of homogenates and urine were plated on LB agar to enumerate CFU. For neutrophil depletion, mice injected i.p. with 10 μg of anti-Ly6G or rat IgG2a isotype in 100 μL prior to infection. …Urinary neutrophils are a hallmark of urinary tract infection (UTI), yet the mechanisms governing their activation, function, and efficacy in controlling infection remain incompletely understood. …Tamm-Horsfall glycoprotein (THP), the most abundant protein in urine, uses terminal sialic acids to bind an inhibitory receptor and dampen neutrophil inflammatory responses. …In a UTI model, THP-deficient mice showed elevated urinary tract bacterial burdens, increased neutrophil recruitment, and more severe tissue histopathological changes compared with WT mice. …These effects were observed only in the presence of a NETosis stimulus and could not be solely replicated with equivalent levels of sialic acid alone.”

重组大鼠IgG2a同型对照抗体相关问答:

问：为什么你们的重组大鼠 IgG 同型对照（Recombinant Rat IgG Isotype Control）会采用小鼠可变区？

答： 绝大多数用于体内（in vivo）功能研究的级大鼠 IgG 抗体，都是用来研究小鼠靶蛋白的。理想的同型对照应当与实验所用的对照一抗亚型完全匹配，同时又不具备对目标靶点的结合能力。它通常作为阴性对照，用于区分特异性抗体信号与非特异性背景信号。采用小鼠可变区可以降低传统大鼠杂交瘤细胞系生产的大鼠 IgG 同型对照中，由大鼠可变区在小鼠体内诱发潜在免疫原性的风险。

问：与传统的杂交瘤方法相比，重组抗体生产方法有什么优势？

答： 我们采用化学成分确定的无血清培养基（Chemically Defined Medium）进行细胞培养，以生产重组大鼠 IgG 同型对照。这种体外表达方法具备显著优势：

1. 无需使用小鼠腹水： 我们不使用小鼠腹水进行抗体生产。大鼠杂交瘤细胞系通常对体外培养环境适应较差，往往需要在免疫缺陷小鼠（而非大鼠）体内产生腹水。

2. 克服生产失败率： 尽管超过 90% 的杂交瘤细胞可以通过细胞培养生产抗体，但仍存在明确且不可忽视的失败率，重组表达技术可以有效解决这一难题。

3. 避免外源抗体污染： 部分公司和科研人员会在杂交瘤细胞培养基中添加胎牛血清（FBS），这会导致牛抗体/牛免疫球蛋白污染。而重组抗体的生产过程则完全不存在此类污染。

4. 易于工程化改造： 我们可以极其便捷地更换不同种属或亚型的抗体恒定区，并引入特定的 Fc 突变（例如用于治疗性抗体研究的 D265A 突变）。在实验中使用具备相同 Fc 突变形式的同型对照是更为严谨的选择。

问：你们开发重组大鼠 IgG 同型对照时，使用的是 MOPC21（杂交瘤克隆号，亚型：小鼠 IgG1, kappa）还是 C1.18.4（杂交瘤克隆号，亚型：小鼠 IgG2a, kappa）的抗体序列？

答： 我们的重组大鼠 IgG 同型对照产品——包括大鼠 IgG2a 同型对照（货号：PA007143）——序列并非来源于 MOPC21，也非来源于 C1.18.4（尽管我们也同时生产和销售衍生自 MOPC21 与 C1.18.4 的大鼠 IgG 同型对照）。如果您对衍生自 MOPC21 或 C1.18.4 的重组大鼠 IgG kappa 同型对照感兴趣，欢迎随时联系我们进行咨询。