Cell Lines

A cell line is permanently established cell culture that will proliferate indefinitely given appropriate fresh medium and space. A cell culture developed from a single cell and therefor consisting of cells with a uniform genetic makeup. There is presence of several cell linkages either similar or distinct.

Generally stem cells are used in this culture. After the subculture, the primary culture becomes a cell line and may be propagated and sub cultured several times. Some species, particularly rodents, give rise to lines relatively easily, whereas other species do not. No cell lines have been produced from avian tissues and establishment of cell lines from human tissue is difficult.

Continuous cell lines

Most of cell lines grow for a limited number of generations after which they cease. Cell lines which either occur spontaneously or induced virally are chemically transformed into continuous cell lines

Selection of appropriate cell line

Criteria are followed for the selection of cell lines;

Species:

While selecting cell lines species difference need to be taken in account. Non-human cell lines are preferred because have less chance of contamination or any biohazards.

Functional characteristics:

We should select the cell line according to our need, e.g. If we want to perform the toxicity test then we will chose the liver and kidney derived cell lines.

Selective cell lines:

HeLa cell line:
It was developed in the 1950s from a particularly aggressive strain of cervical cancer cell take during a routine biopsy from a 30 years old lady, Henrietta Lacks. These are immortal cell lines that could be used in medical research. Henrietta was diagnosed in 1950 and died within a year at age of 31 but her cells lived on and became the first human cell line to be established. In addition to cervical cancer caused the Human Papilloma Virus (HPV) multiple copies of HPV genome were later found in the HeLa cell lines. The cell were used in the laboratories around the world and have been crucial for the development of vaccines for instance, the polio vaccine.

Uses of HeLa cells:

HeLa cells were the first human cells to be successfully cloned in 1953 by Theodore Puck and Philip I Marcus at the University of Colorado, Denver. Since that time, HeLa cells have "continually been used for research into cancer, AIDS, the effects of radiation and toxic substances, gene mapping, and countless other scientific pursuits." According to author Rebecca Skloot, by 2009, "more than 60,000 scientific articles had been published about research done on HeLa, and that number was increasing steadily at a rate of more than 300 papers each month.

Vero cell line:

It was originated from African Green monkey (Cercopithecus aethiops)’s kidney. Vero cells are a lineage of cells used in cell cultures.  The 'Vero' lineage was isolated from kidney epithelial cells The Vero cell lineage is continuous and aneuploidy, meaning that it has an abnormal number of chromosomes. A continuous cell lineage can be replicated through many cycles of division and not become senescent. Vero cells are interferon deficient; unlike normal mammalian cells, they do not secrete interferon alpha or beta when infected by viruses. However, they still have the Interferon-alpha/beta receptor, so they respond normally when recombinant interferon is added to their culture media. The whole genome sequence of a Vero cell line was determined by Japanese investigators in 2014.The genome analysis indicated that the Vero cell lineage is derived from a female Chlorocebus sabaeus.

Uses of Vero cells:

Vero cells are used for many purposes, including:

• screening for the toxin of Escherichia coli  first named "Vero toxin" after this cell line, and later called "Shiga-like toxin" due to its similarity to Shiga toxin isolated from Shigella dysenteries
• as host cells for growing viruses; for example, to measure replication in the presence or absence of a research pharmaceutical, the testing for the presence of rabies virus, or the growth of viral stocks for research purposes
• as host cells for eukaryotic parasites, specially of the trypanosomatids

3T3 cell line:

3T3 cells come from a cell line established in 1962 by two scientists then at the Department of Pathology in the New York University School of Medicine, George Todaro and Howard Green. Todaro and Green originally obtained their 3T3 cells from Swiss albino mouse embryo tissue. The '3T3' designation refers to the abbreviation of "3-day transfer, inoculum 3×10⁵ cells." This cell line was originally established from the primary mouse embryonic fibroblast cells that were cultured by the designated protocol, so-called '3T3 protocol'. The primary mouse embryonic fibroblast cells were transferred (the "T") every 3 days (the first "3"), and inoculated at the rigid density of 3×10⁵ cells per 20 cm² dish (the second "3") continuously. The spontaneously immortalized cells with stable growth rate were established after 20 to 30 generations in culture, and then named '3T3' cells. Specifically, "3T3-L1" is one of the current lines.

Uses of 3T3 cells:

§  3T3 cells are often used in the cultivation of keratinocytes, with the 3T3 cells secreting growth factors favourable to these kinds of cells

§  The 3t3 cell line is a standard fibroblast cell line used in a wide spectrum of research and industrial biomedical application

Fibroblast cell line:

Fibroblast cells are established from skin biopsies that are usually taken from the neck under the mane, or the fore part of the chest, both from live and from dead animals. A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen produces the structural framework for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals. The human fibroblast cell line VA13 was the first cell type where a low-affinity adenosine receptor was originally described back in 1980 (Burns), and later designated as A_2B. Fibroblasts represent a heterogeneous population of cells, which may differ in phenotype and function not only between anatomical sites but also even within a single tissue where immature cells (often called mesenchymal fibroblasts) exist with fibroblasts of various degree of differentiation. Fibroblasts play an important role in the progression of inflammation by secreting various factors that define the tissue microenvironment and modulate immune cell functions. They also contribute to tissue remodelling by increased proliferation, differentiation, and generation of various components of the extracellular matrix. Fibroblast cells are established from skin biopsies that are usually taken from the neck under the mane, or the fore part of the chest, both from live and from dead animals.

Uses of Fibroblast cells:

Fibroblasts, the most common mammalian connective tissue cells, form fibrous supporting structures consisting of collagen and other extracellular matrix (ECM) molecules.  The flat, elongated cells vary in shape from stellate (young) to fusiform and spindle shaped, with cytoplasmic processes present in connective tissue. With their ability to liberate growth factors, lay down fibroblastic matrices, and proliferate at sites of inflammation, fibroblasts play critical roles in wound healing, tissue repair, and remodelling.  As immature cells, fibroblasts can differentiate into other connective tissue cells, such as chondroblasts and osteoblasts.  Human Dermal Fibroblasts (HDF, from Cell Applications) can also be converted into induced pluripotent stem cells (iPSC), a Nobel-prize awarded technology

WEHI cell line:

This cell line originated from Mus, musculus, in blood tissues of Mouse. This cell line is B lymphocytes and immature lymphoblast. While culturing they suspend and multicellular aggregates. This cell line is a suitable transfection host. Expresses surface igm but does not secrete IgG. Secretion of Igm can be induced with LPS. WEHI 231 is a B cell lymphoma of BALB/c x NXB F1 origin induced by mineral oil injection.

Uses of WEHI cells:

This cell line is a suitable transfection host.

https://www.linkedin.com/posts/ruqiya-sania-1737291b2_cell-lines-activity-6688507346148196352-06nu