Un filmulet cu limfocite T citotoxice distrugand celule canceroase

200 de secunde de film-de-actiune, varianta cu celule. In rolul lui Chuck Norris: celula T citotoxica.🙂

Celulele T se leaga de celula-tinta printr-un set de proteine-receptor, numite receptorul de celula T (TCR). Mai precis, TCR se leaga de niste antigene (proteine) dintr-o polipeptida prezenta pe membrana celulara, numita complex major de histocompatibilitate (MHC). “Chestiile” mici si rosii din video sunt niste proteine (perforine) si enzime (granzime) care provoaca apoptoza (moartea) celulei odata ce intra in aceasta. Celulele T citotoxice pot ucide si prin legarea cu celula-tinta printr-o proteina transmembranara (ligandul FAS – care are un rol si in dezvoltarea rezistentei celulelor canceroase la atacul celulelor T). Mai multe informatii aici.

apoptoza ca urmare a actiunii celulelor TDe asta nu murim toti de cancer in primii ani de viata. Avem aproximativ 37,2 mii de miliarde de celule in corpul unui adult mediu, si teoretic oricare, oricand, poate dezvolta o mutatie la nivel genetic care ii va permite sa se multiplice si sa traiasca anormal de mult => cancer. Deci e esential faptul ca avem celule in sistemul nostru imunitar care pot sa le omoare pe cele care o iau razna. Problema e ca celulele canceroase sunt extrem de adaptative – invata sa se ascunda de sofisticatul nostru sistem de aparare.

Cateva “poze” (pentru ca sunt imagini SEM colorate) cu celule T in splendoarea activitatii lor anticanceroase:

^BT lymphocytes and cancer cell.^b Coloured scanning electron micrograph (SEM) of T lymphocyte cells (orange) attached to a cancer cell. T lymphocytes are a type of white blood cell and one of the components of the body's immune system. They recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. Cytotoxic T lymphocytes eliminate the cell themselves by releasing a protein that forms pores in the cell's membrane. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell's surface. Magnification: x1600 at 10 centimetres wide.
^BT lymphocytes and cancer cell.^b Coloured scanning electron micrograph (SEM) of T lymphocyte cells (orange) attached to a cancer cell. T lymphocytes are a type of white blood cell and one of the components of the body’s immune system. They recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. Cytotoxic T lymphocytes eliminate the cell themselves by releasing a protein that forms pores in the cell’s membrane. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell’s surface. Magnification: x1600 at 10 centimetres wide.
T lymphocyte and prostate cancer cell. Coloured scanning electron micrograph (SEM) of a T lymphocyte cell (yellow) attached to a prostate cancer cell. T lymphocytes are a type of white blood cell that recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell's surface. Magnification: x3500 when printed at 10 centimetres wide.
T lymphocyte and prostate cancer cell. Coloured scanning electron micrograph (SEM) of a T lymphocyte cell (yellow) attached to a prostate cancer cell. T lymphocytes are a type of white blood cell that recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell’s surface. Magnification: x3500 when printed at 10 centimetres wide.
T lymphocytes and cancer cell. Coloured scanning electron micrograph (SEM) of T lymphocyte cells (pink) attached to a cancer cell. T lymphocytes are a type of white blood cell that recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell's surface. Magnification: x2300 when printed at 10 centimetres wide.
T lymphocytes and cancer cell. Coloured scanning electron micrograph (SEM) of T lymphocyte cells (pink) attached to a cancer cell. T lymphocytes are a type of white blood cell that recognise a specific site (antigen) on the surface of cancer cells or pathogens and bind to it. Some T lymphocytes then signal for other immune system cells to eliminate the cell. The genetic changes that cause a cell to become cancerous lead to the presentation of tumour antigens on the cell’s surface. Magnification: x2300 when printed at 10 centimetres wide.

Drepturi imagini (si explicatiile imaginilor): sciencephotolibrary

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