After disrupting the CCR5 gene in the two macrophages cell lines 4 and 7 (now called edit 4 and edit 7), what will be your next experimental step to verify that these cell lines are now HIV-resistant macrophages?

cell lines should be resistant to HIV infection, thereby preventing its integration into the host genome. In consequence, verification can be done by measuring intracellular HIV DNA declines (for example, by real-time quantitative PCR).

Explanation:

HIV (human immunodeficiency virus) is an RNA retrovirus that infects components of the human immune system including, among others, macrophage cells. After infection, the HIV genome is reverse transcribed into DNA and integrated into the genome of the host cells, thereby enabling virus to replicate its genetic material and synthesize protein viral components. Monocyte-like cell lines are able to differentiate into macrophages. When immune cell lines (both monocyte and macrophage cell lines) become resistant to this virus, HIV genome integration is inhibited, affecting the replication cycle of HIV. Thus, it is possible to verify that viral integration did not occur by measuring intracellular HIV DNA declines.

c is the correct answer!