Answer:Bacteria such as E. coli and Salmonella produce invasins that bind host cells, thus causing the cells release TNF.
Step-by-step explanation:
Tumor necrotic factor is a cell signalling protein which is involved in inflammation. These factors are being released into the system in response to toxins released by invading bacteria such as E. Coli and Salmonella into the body system. They help to fight the possible treat posed by the invasins released by the bacteria.
Invasins are proteins produced and released by bacteria which act against the host by breaking down the primary and secondary defence of the body.