News from the In Vitro Animal Cell Sciences Section

Smithsonian accessions microscope from University of California, San Francisco Professor of Anatomy, Dr. Leonard Hayflick.

December 18, 2006, published by Smithsonian

The Division of Medicine & Science at the National Museum of American History (Smithsonian Institution, Washington, DC) has an extensive biomedical collection-including such icons as a vial of Robert Koch's tuberculin and a sample of Alexander Fleming's penicillin; base pair plates from Watson's and Crick's "double helix" model and Stanley Cohen's notebook from the first recombinant DNA experiment; the first commercial PCR machine and an automated gene sequencer from the Human Genome Project. Now, the museum has acquired a historically important object from UCSF Professor, Dr. Leonard Hayflick. It is a Leitz inverted microscope of the late 1950's that Professor Hayflick converted from crystallography work to the study of cultured cells while at the Wistar Institute in Philadelphia. This microscope is the predecessor of all subsequent inverted microscopes used worldwide today in virtually all cell culture laboratories, academic research centers, and indusrial manufacturing facilities.

Hayflick was first to observe through this instrument the colonies of one of the smallest free living microorganisms that he and his colleagues determined to be the cause of what is known as "walking pneumonia." This led to easier identification and treatment of this common disease. He is better known, though, for the so-called "Hayflick limit," referring to the 1961 study he and Paul Moorhead published on the serial cultivation of human diploid cell strains. By demonstrating that normal human cells have a finite ability to divide-refuting long held dogma at the time-Hayflick and Moorhead established the first important fact in the molecular mechanisms of aging. By discovering that normal cells are mortal-as opposed to immortal cancer cells-their discovery opened the field of cancer research that explored how normal cells became immortalized. Biologists now know that the shortening of chromosome tips (telomeres) underlies the Hayflick limit and that the expression of the enzyme telomerase leads to the immortalization of normal cells.

Mankind is most indebted to Hayflick for his cultivation of several human embryonic cell strains derived from elected abortions that became the preferred substrate for producing viral vaccines. One strain, Wistar Institute-38 or simply "WI-38" became the most widely used material for making polio, measles, adenovirus, mumps, chickenpox, hepatitis A, rabies, and rubella vaccines. A single WI-38 cell that can undergo fifty population doublings, has a potential to yield twenty million metric tons of cells for vaccine production. Nearly every vaccinated person alive today has a product of cultured embryonic cells in their bodies-making embryonic cell research critical to safe vaccine production and among medicine's greatest contributions to health. This, then, is the meaning of Dr. Hayflick's microscope in the National Museum of American History.

Provided by G. Terry Sharrer, Ph. D., Curator, Medicine & Science, sharrert@si.edu, 202-633-3418.

Changes at Beltsville Agricultural Research Center
After more than 50 years of research on insect cell and tissue culture, the Beltsville Agricultural Research Center (BARC) in Maryland now has no scientist whose primary responsibility is the study and development of insect cell cultures. Dr. Dwight E. Lynn, Research Entomologist in the Insect Biocontrol laboratory is leaving the USDA after 25 years at Beltsville.

BARC came to prominence in the area of insect cells in the 1960s and '70s when Drs. James L. Vaughn and Ronald H. Goodwin were pioneering researchers in the field. Goodwin joined the lab in 1968 and developed cell lines from the corn earworm, cabbage looper, and gypsy moth through the 1970's. His gypsy moth cell lines in particular were the basis of extensive research, since they were the first capable of replicating the nucleopolyhedrovirus from that insect. Goodwin also put considerable effort into developing new cell culture media, with a special focus on developing serum-free formulations. He had a major role in the development of IPL-41 medium that has been the basis of most formulations used in the commercially available serum-free insect cell culture media available today.
Preceding and concurrent with Goodwin's research, Vaughn was also a driving force in the development of cell lines for baculovirus research. His SF-21 fall armyworm cell line (officially designated IPLB-SF21AE) is the parent line that was used for developing the SF-9 cloned line. Both the parent and clone are widely used with the baculovirus expression vector.

While Lynn's departure may mark the end of the development of new insect cell lines at Beltsville, the insect virus program will remain active through the research of Drs. Dawn Gundersen-Rindal (polydnaviruses) and Robert L. Harrison (baculoviruses). Plans are also being considered to create a curator position in the laboratory to manage the insect cell and virus collections.

Lynn will continue research at the laboratory for a few months to complete some ongoing projects, but plans to relocate to Maine sometime in the summer of 2007. He plans to start a consulting firm to advise the biotech and pharmaceutical industries on aspects of insect cell culture related to the baculovirus expression vector system, but also plans to spend much more time outdoors hiking, biking, and kayaking.