BEC 445/545 Study Guide: Cell Culture and Transfection

Vocabulary flashcards covering recombinant protein production, CHO cell platforms, antibody mechanisms (ADCC and CDC), cell culture types, and transfection methods from the BEC 445/545 Quiz 1 Study Guide.

Trastuzumab

A full monoclonal antibody (immunoglobulin) consisting of two heavy and two light chains (4 polypeptides) joined with a disulfide bond at the hinge region, used to treat certain HER2-positive cancers by preventing EGF binding and stimulating ADCC.

HER2

A protein on cell surfaces that binds to Human epidermal growth factor (EGF) and stimulates proliferation; its overproduction in certain breast, stomach, and gastroesophageal junction cancers enables uncontrolled cell reproduction.

Variable region

The regions of a monoclonal antibody where it binds to specific antigens.

Constant region

The structural region of a monoclonal antibody that allows for killer cell binding and contains carbohydrate units required for effector functions.

CHO cells

A continuous cell line production platform for therapeutic proteins that is safe, FDA-approvable, adapted to suspension and serum-free media, can secrete products into extracellular media, and performs efficient post-translational modifications.

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

An immune response where carbohydrate units attached to the constant region of an antibody allow it to bind to killer cells, triggering the lysis of the targeted cell.

Complement-Dependent Cytotoxicity (CDC)

A cytotoxic mechanism where glycosylation maintains the constant region in the specific shape needed to bind complement protein C1q, triggering a cascade of interactions that causes cell lysis.

C1q

A complement protein that binds to the properly glycosylated constant region of an antibody to initiate the cascade leading to complement-dependent cytotoxicity.

Glycosylation

The attachment of carbohydrate units to the antibody constant region, essential for ADCC, CDC, and preserving thermal stability.

Primary cell culture

The growth of cells taken directly from a living organism, consisting of many different cell types, some of which continue proliferating in vitro while others do not.

Cell line culture

The first subculture derived from a primary culture.

Cell strain culture

A cell line that has acquired additional genetic changes following the initiation of the parent line.

Finite cell line

A cell line whose cells can divide only a limited number of times due to telomere shortening with each division, which eventually blocks division and leads to apoptosis.

Continuous cell line

A cell line that has been transformed to acquire the ability to divide indefinitely, such as CHO cells.

Anchorage-independent cells

Cells typically found in blood, spleen, or bone marrow that can grow in suspension without surface attachment, facilitating easier subculturing and scale-up in shake flasks, bioreactors, or wave bags.

Anchorage-dependent cells

Adherent cells derived from tissue that must attach to a surface to survive and proliferate, often dying once confluent and requiring enzymatic detachment to subculture.

Trypsin

An enzyme used during the subculture of anchorage-dependent cells to detach them from the culture vessel surface.

Transfection

The introduction of foreign DNA into the nucleus of eukaryotic cells.

Cationic lipid transfection (lipofection)

A transfection method utilizing cationic liposomes to encapsulate negatively charged DNA, facilitating binding to the negatively charged cell membrane and entry via endocytosis.

Liposomes

Lipid bilayers structured as hollow spheres that interact with and enclose DNA to deliver it into the cell.