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杂交瘤技术用于大规模生产单克隆抗体。单克隆抗体仅与单一的抗原决定簇或表位结合。此类抗体被广泛用于研究、诊断和疾病治疗。乔治·科勒 (Georges Köhler) 和塞萨尔·米尔斯坦 (Cesar Milstein) 于 1975 年建立了杂交瘤技术,因其在研究和治疗领域的革命性贡献,于1984年荣…
杂交瘤技术用于大规模生产单克隆抗体,这些抗体只能与单一表位结合——表位是抗原中引发免疫反应的部分。
该过程 首先向小鼠注射一种靶向抗原,数周后取出其脾脏,以分离能够产生抗体的B细胞。这些细胞寿命有限,无法在实验室中进行培养。
接下来,利用电脉冲或聚乙二醇将B细胞与骨髓瘤细胞——一种永生化的癌性白细胞——进行融合,从而形成能够永生且产生抗体的杂交细胞,称为杂交瘤细胞。
根据是否存在有功能的次黄嘌呤-鸟嘌呤磷酸核糖转移酶(HGPRT)酶,杂交瘤细胞进一步在含有次黄嘌呤(hypoxanthine)、氨基蝶呤(aminopterin)和胸腺嘧啶(thymidine)的HAT培养基上进行筛选。
在这种培养基中,HGPRT阴性的骨髓瘤细胞和HGPRT阳性但寿命较短的B细胞均无法长期存活。然而,具有HGPRT酶的永生化杂交瘤细胞则能够增殖。
筛选后,鉴定出能产生对目标表位具有强亲和力的单克隆抗体的杂交瘤细胞,并将其作为起始细胞用于建立抗体生产细胞系。
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Q1: What is the main purpose of hybridoma technology?
Hybridoma technology enables mass production of monoclonal antibodies that bind to a single epitope on an antigen. These antibodies are valuable in research, diagnostics, and disease therapy because they target only one specific antigenic determinant, providing high specificity and consistency for applications requiring precise immune targeting.
Q2: How are B cells and myeloma cells combined in hybridoma creation?
B cells harvested from a mouse spleen are fused with immortal myeloma cells using electric pulses (electroporation) or polyethylene glycol (PEG). This fusion creates hybrid cells called hybridomas that combine the antibody-producing ability of B cells with the unlimited growth capacity of myeloma cells, overcoming the natural limitation that B cells cannot survive long in culture.
Q3: Why is HAT medium used in hybridoma selection?
HAT medium selectively allows only hybridoma cells to survive by blocking default nucleotide synthesis. Myeloma cells lacking the HGPRT enzyme cannot use the salvage pathway and die, while short-lived B cells also perish. Only hybrid cells with functional HGPRT from B cells and immortality from myeloma cells proliferate, ensuring pure hybridoma populations for antibody production.
Q4: What happens during hybridoma screening after HAT selection?
Hybridoma cultures are plated in 96-well plates with one cell per well. Each well is screened using enzyme linked immunosorbent assay to identify cells producing antibodies specific to the target epitope. Positive cells are then grown in larger culture vessels to establish permanent hybridoma cell lines that serve as unlimited sources of monoclonal antibodies.
Q5: Why are monoclonal antibodies more useful than polyclonal antibodies?
Monoclonal antibodies bind to only a single epitope, providing high specificity and consistency. This single-target binding makes them ideal for precise research, diagnostic, and therapeutic applications where cross-reactivity must be minimized. Polyclonal antibodies, by contrast, recognize multiple epitopes and lack this specificity.
Q6: What is the significance of the HGPRT enzyme in HAT medium selection?
The HGPRT enzyme enables cells to synthesize nucleotides via the salvage pathway when aminopterin blocks the default synthesis route. Myeloma cells are HGPRT-negative and cannot survive in HAT medium, while B cells are HGPRT-positive but short-lived. Only hybridomas with functional HGPRT and immortality survive, making this enzyme critical for selecting true hybrid cells.
Q7: How does hybridoma technology overcome the limitations of natural B cells?
Natural B cells produce antibodies but have a limited lifespan and cannot be cultured indefinitely in the laboratory. Hybridoma technology fuses these cells with immortal myeloma cells, creating hybrid cells that retain antibody-producing capability while gaining unlimited growth potential. This overcomes both the finite lifespan and culture limitations of primary B cells.