Question

I have some cell biology questions that I would like a bit of explaining. Thank you!

Antibodies are proteins manufactured by B lymphocytes against specific antigens. An initial B lymphocyte has variety in the antibodies it will manufacture, but when triggered to produce antibodies, will make specific antibodies for the rest of its life. How might this be accomplished? Hybridoma cells - how can these form? What properties of a fusion agent would be needed? What are the benefits and limitations to hybridoma cells? What properties of proteins allow for separation from solution mixtures? What types of separation methods are possible? How can you extract the proteins/DNA/RNA that you want from a solution? How can you tell that you actually have gotten the specific material you wanted from the solution? You want to express the protein insulin in an E. coli cell. What steps would be necessary to accomplish this? What "tools" (i.e. Proteins, constructs) would be needed?

Answer 1

Answer:

1. VDJ recombination is the process by which T cells and B cells randomly assemble different gene segments, known as variable (V), diversity (D) and joining (J) genes in order to generate unique receptors that can collectively recognize many different types of molecule.

Each B cell produces a single species of antibody through VDJ recombination, each with a unique antigen-binding site. When a naïve or memory B cell is activated by antigen (with the aid of a helper T cell), it proliferates and differentiates into an antibody-secreting effector cell.

Such cells make and secrete large amounts of soluble (rather than membrane-bound) antibody, which has the same unique antigen-binding site as the cell-surface antibody that served earlier as the antigen receptor. Effector B cells can begin secreting antibody while they are still small lymphocytes, but the end stage of their maturation pathway is a large plasma cell, which continuously secretes antibodies at the astonishing rate of about 2000 molecules per second.