抗體
Antibody

context: zh_tw: 每一條重鏈有兩個區域：恆定區與可變區。同種型的抗體，其恆定區都是一樣的，但不同種型之間該區域是不相同的。例如：γ、α 以及 δ 型重鏈由三個免疫球蛋白結構域串聯而成，並且還有一個用於增加彈性的鉸鏈區；而 μ 及 ε 型重鏈則包括四個免疫球蛋白結構域。不同 B 細胞所生產抗體的重鏈可變區是不同的，但是同一個 B 細胞及其克隆體所生產的不同種型抗體的可變區則是完全相同的。重鏈的可變區由一個結構域組成，包含大 110 個氨基酸。
en: Each heavy chain has two regions, the constant region and the variable region. The constant region is identical in all antibodies of the same isotype, but differs in antibodies of different isotypes. Heavy chains γ, α and δ have a constant region composed of three tandem (in a line) Ig domains, and a hinge region for added flexibility; heavy chains μ and ε have a constant region composed of four immunoglobulin domains. The variable region of the heavy chain differs in antibodies produced by different B cells, but is the same for all antibodies produced by a single B cell or B cell clone. The variable region of each heavy chain is approximately 110 amino acids long and is composed of a single Ig domain.
qas: question: zh_tw: γ、α 以及 s 型重鏈由多少個串聯而成？
en: How many tandems are heavy chains y, a, and s made from?
answers: zh_tw: text: 三
en: text: three

question: zh_tw: 一個重鏈中包含多少個氨基酸？
en: How many amino acids are in a heavy chain?
answers: zh_tw: text: 110 個
en: text: 110

context: zh_tw: 免疫球蛋白輕鏈由大約 211 至 217 個氨基酸組成，分為兩個結構域，分別是恆定區和可變區。哺乳動物的輕鏈有兩種，分別命名為 λ（lambda）和 κ（kappa）。每一個抗體的兩個輕鏈的恆定區永遠是完全相同的，例如對於哺乳動物而言，同一個抗體要麼是 λ 型，要麼是 κ，不會同時存在。在如軟骨魚綱（鯊魚）及真骨下綱的低階脊椎動物中，還可發現其它型別的輕鏈，如 ι（iota）型。
en: In mammals there are two types of immunoglobulin light chain, which are called lambda (λ) and kappa (κ). A light chain has two successive domains: one constant domain and one variable domain. The approximate length of a light chain is 211 to 217 amino acids. Each antibody contains two light chains that are always identical; only one type of light chain, κ or λ, is present per antibody in mammals. Other types of light chains, such as the iota (ι) chain, are found in other vertebrates like sharks (Chondrichthyes) and bony fishes (Teleostei).
qas: question: zh_tw: 鯊魚的學名叫什麼？
en: What is the scientific name for sharks?
answers: zh_tw: text: 軟骨魚綱
en: text: Chondrichthyes

context: zh_tw: 抗體的某些部分具有獨特的功能。比如說 Y 形的臂區，包含了兩個可以結合抗原的位點，是識別外來物的關鍵所在。該區域被稱為 Fab 區，即抗原結合區段（fragment, antigen binding）。無論是重鏈還是輕鏈，抗原結合區段均包括一個可變區與一個恆定區，其中可變區的互補位成型於抗體單體氨基酸鏈的末端。可變區又被稱為 FV 區，是與抗原結合的最關鍵區域，無論是輕鏈還是重鏈都包含該區域。實際上可變區的變化並非隨機或者均勻散佈的。更具體的說，這些變化分佈在三個可變的 β 摺疊 - 轉角上，該區域被稱為互補決定區（Complementarity Determining Region，CDR），也叫做高變區。喬西亞（Chothia）等人，以及後來的諾斯等人 對互補決定區的結構進行了歸類。在免疫網路理論中，每個抗體的互補決定區又被稱為獨特型或者基因型。適應性免疫系統的適應過程，就是依靠有各個獨特型之間的互動來進行調整的。
en: Some parts of an antibody have the same functions. The arms of the Y, for example, contain the sites that can bind to antigens (in general, identical) and, therefore, recognize specific foreign objects. This region of the antibody is called the Fab (fragment, antigen-binding) region. It is composed of one constant and one variable domain from each heavy and light chain of the antibody.
qas: question: zh_tw: 一個常數域和一個可變域組成什麼？
en: What is composed of one constant and one variable domain?
answers: zh_tw: text: Fab 區
en: text: the Fab

context: zh_tw: 幾乎所有的微生物都可以觸發抗體的免疫應答。若想要成功識別並清除各種微生物，需要豐富多樣的抗體，而這種多樣性來自於抗體氨基酸的重組變化。據估算，人類可以產生大約 100 億種不同的抗體，每一種都可以與特定抗原的表位相結合。儘管每個人可以產生的抗體是如此之多，但是產生這些蛋白質的相關基因卻十分有限。脊椎動物發展出了一些複雜的基因機制，使得其 B 細胞可以利用有限的基因產生非常多樣的抗體。
en: Virtually all microbes can trigger an antibody response. Successful recognition and eradication of many different types of microbes requires diversity among antibodies; their amino acid composition varies allowing them to interact with many different antigens. It has been estimated that humans generate about 10 billion different antibodies, each capable of binding a distinct epitope of an antigen. Although a huge repertoire of different antibodies is generated in a single individual, the number of genes available to make these proteins is limited by the size of the human genome. Several complex genetic mechanisms have evolved that allow vertebrate B cells to generate a diverse pool of antibodies from a relatively small number of antibody genes.
qas: question: zh_tw: 有多少種微生物可以觸發抗體反應？
en: How many type of microbes can cause an antibody response?
answers: zh_tw: text: 幾乎所有
en: text: Virtually all

context: zh_tw: 生產抗體種型的轉換，是透過一種稱為種型轉換重組（CSR）的機制對編碼重鏈的基因座進行重組來完成的。該機制依賴被稱為 “交換區” 的保守核苷酸模體，該模體存在於除 δ 鏈以外其它重鏈恆定區基因的上游 DNA 序列中。透過一系列酶的作用後 DNA 鏈的兩個特定交換區被剪斷，然後透過非同源性末端接合的過程，將可變區外顯子與需要的恆定區如 γ、α、ε 鏈重新接合在一起。透過該過程，一段編碼抗體的基因即可產生不同種型的抗體。
en: Isotype or class switching is a biological process occurring after activation of the B cell, which allows the cell to produce different classes of antibody (IgA, IgE, or IgG). The different classes of antibody, and thus effector functions, are defined by the constant (C) regions of the immunoglobulin heavy chain. Initially, naive B cells express only cell-surface IgM and IgD with identical antigen binding regions. Each isotype is adapted for a distinct function; therefore, after activation, an antibody with an IgG, IgA, or IgE effector function might be required to effectively eliminate an antigen. Class switching allows different daughter cells from the same activated B cell to produce antibodies of different isotypes. Only the constant region of the antibody heavy chain changes during class switching; the variable regions, and therefore antigen specificity, remain unchanged. Thus the progeny of a single B cell can produce antibodies, all specific for the same antigen, but with the ability to produce the effector function appropriate for each antigenic challenge. Class switching is triggered by cytokines; the isotype generated depends on which cytokines are present in the B cell environment.Class switching occurs in the heavy chain gene locus by a mechanism called class switch recombination (CSR). This mechanism relies on conserved nucleotide motifs, called switch (S) regions, found in DNA upstream of each constant region gene (except in the δ-chain). The DNA strand is broken by the activity of a series of enzymes at two selected S-regions. The variable domain exon is rejoined through a process called non-homologous end joining (NHEJ) to the desired constant region (γ, α or ε). This process results in an immunoglobulin gene that encodes an antibody of a different isotype.
qas: question: zh_tw: 這個機制依賴什麼？
en: What does this mechanism rely on?
answers: zh_tw: text: 核苷酸模體
en: text: conserved nucleotide motifs

context: zh_tw: Rho (D) 是對人類 RhD 抗原特異的抗體，是避免上述情形發生的產前治療方案之一。對懷有 RhD 陽性胎兒的 RhD 陰性母親來說，在接觸到 RhD 抗原之前，或者至少在剛接觸之時，透過給予 RhD 抗體的治療方案是非常必要的。透過注射這種抗體，可以迅速有效地清除從胎兒血液中帶來的包含 RhD 抗原表位的血細胞。這樣可以避免刺激母親的免疫系統產生能夠生產 RhD 抗體的 B 細胞，尤其是記憶 B 細胞。因此，母親的免疫系統就不會生產 RhD 抗體，也就不會攻擊有 RhD 抗原的胎兒。儘管該治療方案可以避免 Rh 血型新生兒溶血癥的發生，但卻不能治療已經產生抗體所導致的情況。
en: Rh factor, also known as Rh D antigen, is an antigen found on red blood cells; individuals that are Rh-positive (Rh+) have this antigen on their red blood cells and individuals that are Rh-negative (Rh–) do not. During normal childbirth, delivery trauma or complications during pregnancy, blood from a fetus can enter the mother's system. In the case of an Rh-incompatible mother and child, consequential blood mixing may sensitize an Rh- mother to the Rh antigen on the blood cells of the Rh+ child, putting the remainder of the pregnancy, and any subsequent pregnancies, at risk for hemolytic disease of the newborn.Rho(D) immune globulin antibodies are specific for human RhD antigen. Anti-RhD antibodies are administered as part of a prenatal treatment regimen to prevent sensitization that may occur when a Rh-negative mother has a Rh-positive fetus. Treatment of a mother with Anti-RhD antibodies prior to and immediately after trauma and delivery destroys Rh antigen in the mother's system from the fetus. It is important to note that this occurs before the antigen can stimulate maternal B cells to "remember" Rh antigen by generating memory B cells. Therefore, her humoral immune system will not make anti-Rh antibodies, and will not attack the Rh antigens of the current or subsequent babies. Rho(D) Immune Globulin treatment prevents sensitization that can lead to Rh disease, but does not prevent or treat the underlying disease itself.
qas: question: zh_tw: Rh 抗原會產生什麼？
en: What does the Rh antigen produce?
answers: zh_tw: text: 記憶 B 細胞
en: text: memory B cells

context: zh_tw: 透過向小鼠、大鼠或者兔身上注射特定的抗原，可以得到少量相應特異性的抗體。而如果需要得到大量的抗體，則需要向山羊、綿羊或者馬身上注射相應的抗原。對這些實驗動物的血液進行分離後，可以在血清中得到 “多克隆抗體”。即，針對相同抗原的多種不同的抗體。這種方法制備的抗體又叫做抗血清。另一種製備抗體的方式是透過向受精蛋中注射抗原，然後從蛋清中獲得抗體。為了獲得針對某一抗原單一抗原表位的特異性抗體，需要從動物身上分離出相應的抗體分泌淋巴細胞，然後透過與癌細胞株相融合使之可無限增值。這種融合細胞叫做雜交瘤，可以在培養環境中不停分泌抗體。透過稀釋克隆法將單個雜交瘤細胞隔離出來，這種細胞克隆方法所製備出來的抗體是完全一樣的，被稱為單克隆抗體。多克隆抗體和單克隆抗體的製備，通常還需要使用 A/G 蛋白質或者抗體親和色譜法來進行提純。
qas: question: zh_tw: 淋巴細胞與什麼融合？
en: Lymphocytes are fused to what?
answers: zh_tw: text: 癌細胞株

question: zh_tw: 什麼單克隆抗體用來提純？
en: What monoclonal antibodies use to purify?
answers: zh_tw: text: A/G 蛋白質或者抗體親和色譜法

question: zh_tw: 哪種型別的克隆法將單個雜交瘤細胞隔離出來？
en: What type of cloning are single hybridoma cells isolated by?
answers: zh_tw: text: 稀釋克隆法

context: en: Specific antibodies are produced by injecting an antigen into a mammal, such as a mouse, rat, rabbit, goat, sheep, or horse for large quantities of antibody. Blood isolated from these animals contains polyclonal antibodies—multiple antibodies that bind to the same antigen—in the serum, which can now be called antiserum. Antigens are also injected into chickens for generation of polyclonal antibodies in egg yolk. To obtain antibody that is specific for a single epitope of an antigen, antibody-secreting lymphocytes are isolated from the animal and immortalized by fusing them with a cancer cell line. The fused cells are called hybridomas, and will continually grow and secrete antibody in culture. Single hybridoma cells are isolated by dilution cloning to generate cell clones that all produce the same antibody; these antibodies are called monoclonal antibodies. Polyclonal and monoclonal antibodies are often purified using Protein A/G or antigen-affinity chromatography.In research, purified antibodies are used in many applications. Antibodies for research applications can be found directly from antibody suppliers, or through use of a specialist search engine. Research antibodies are most commonly used to identify and locate intracellular and extracellular proteins. Antibodies are used in flow cytometry to differentiate cell types by the proteins they express; different types of cell express different combinations of cluster of differentiation molecules on their surface, and produce different intracellular and secretable proteins. They are also used in immunoprecipitation to separate proteins and anything bound to them (co-immunoprecipitation) from other molecules in a cell lysate, in Western blot analyses to identify proteins separated by electrophoresis, and in immunohistochemistry or immunofluorescence to examine protein expression in tissue sections or to locate proteins within cells with the assistance of a microscope. Proteins can also be detected and quantified with antibodies, using ELISA and ELISPOT techniques.Antibodies used in research are some of the most powerful, yet most problematic reagents with a tremendous number of factors that must be controlled in any experiment including cross reactivity, or the antibody recognizing multiple epitopes and affinity, which can vary widely depending on experimental conditions such as pH, solvent, state of tissue etc. Multiple attempts have been made to improve both the way that researchers validate antibodies and ways in which they report on antibodies. Researchers using antibodies in their work need to record them correctly in order to allow their research to be reproducible (and therefore tested, and qualified by other researchers). Less than half of research antibodies referenced in academic papers can be easily identified. Papers published in F1000 in 2014 and 2015 provide researchers with a guide for reporting research antibody use. The RRID paper, is co-published in 4 journals that implemented the RRIDs Standard for research resource citation, which draws data from the antibodyregistry.org as the source of antibody identifiers (see also group at Force11)
qas: question: zh_tw: 哪種型別的克隆法將單個雜交瘤細胞隔離出來？
answers: en: text: dilution cloning

question: zh_tw: 淋巴細胞與什麼融合？
answers: en: text: cancer cell line

question: zh_tw: 什麼單克隆抗體用來提純？
answers: en: text: Protein A/G or antigen-affinity chromatography