Author
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LOEB, MARCIA - RETIRED USDA |
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Submitted to: Archives of Insect Biochemistry and Physiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/29/2005 Publication Date: 2/12/2006 Citation: Loeb, M. 2006. Role of integrin b in proliferation and differentiation of cultured stem cells from midgut of heliothis virescens*. Archives of Insect Biochemistry and Physiology. Vol.61 pg. 55-64 (2006) Interpretive Summary: The caterpillar of the tobacco budworm is a severe pest of cotton and tobacco, as well as corn and several other vegetable crops. All of the food that the caterpillar consumes, as well as toxins applied to kill it, pass into the portion of the intestine known as the midgut. Mature midgut cells are often killed by the midgut, but the midgut stem cells, which are not mature, are able to increase in number and replace the cells that had been killed. If we understood why stem cells can continue to develop and divide while the mature cells die, then we could understand how to make the toxins work better and kill the stem cells, too. In this work we found that a particular chemical on the surface of cells known as Integrin B is important in the development and duplication of midgut cells. This information will be useful to scientists studying the physiology of midgut development, and to those working to improve the effectiveness of toxins in controlling the tobacco budworm. Technical Abstract: Cultured midgut cells from Heliothis virescens larvae were incubated with anti-human integrin ß1 made in rabbit and then passed over magnetic beads bound to anti-rabbit IGg. Cells bound to integrin ß1 antibody also bound to the anti-rabbit IGg on the magnetic beads (MACS) and were retained in the column while it remained in the magnetic field. Non-bound cells were eluted at this time. They did not stain with anti-integrin just after elution. Removing the column from the magnetic field allowed cells bound to the beads-integrin ß1 antibody to be eluted. All of these cells stained with anti-integrin upon elution. Each cell fraction was cultured in medium for 3 days. During this time, many of the cells returned to normal staining patterns. In a second experiment, midgut cells were incubated for 4 days with various titers of anti-integrin ß1 to block surface integrin ß1 sites. Cells that were initially integrin ß1-negative or blocked with antibody to integrin ß1 in culture exhibited approximately 15 fold greater rates of multiplication and differentiation than non-treated control cells and those showing anti-integrin ß1 positive stain upon elution. |
