Molecular Biology of the Cell

It is estimated that there are more than 10 million -perhaps 100 million- living species on Earth today.

Sayfa 2

Zilan

MHC proteins

Almost all of our nucleated cells express class I proteins.

Sayfa 1327

Reklam

Zilan

Cell culture

Tissue culture began in 1907 with an experiment designed to settle a controversy in neurobiology. The hypothesis under examination was known as the neuronal doctrine, which states that each nerve fiber is the outgrowth of a single nerve cell and not the product of the fusion of many cells. To test this contention, small pieces of spinal cord were placed on clotted tissue fluid in a warm, moist chamber and observed at regular intervals under the microscope. After a day or so, individual nerve cells could be seen extending long, thin filaments (axons) into the clot. Thus, the neuronal doctrine received strong support, and the foundation was laid for the cell-culture revolution.

Sayfa 441

Zilan

Antibodies

Synthesized exclusively by B cells, antibodies are produced in billions of forms, each with a different amino acid sequence. They belong to the class of proteins called immunoglobulins (Igs) and are among the most abundant protein components in the blood.

Sayfa 1315

Zilan

In principle, therefore, a monoclonal antibody can be made against any protein in a biological sample. Once an antibody has been made, it can be used to localize the protein in cells and tissues, to follow its movement, and to purify the protein to study its structure and function.

Sayfa 445

Zilan

Two such proteins expressed by T cells have attracted great attention because of their roles in suppressing the ability of T cells to inhibit cancer progression: CTLA4 and PD1 proteins inhibit T cell activity in different ways, and monoclonal antibodies against either or especially both can relieve the inhibition and allow T cells to dramatically destroy the tumors in some patients with metastatic cancer.

Sayfa 1337