MSR1 and infection: In contrast, the inhibition was relieved and the monocytes differentiated and expressed the CD204 and CD206 markers to normal levels when the cells were infected with doubly mutated B. pertussis AC− PT− bacteria not producing active CyaA or PT, as well as upon infection with a B. pertussis ΔBvgA mutant that does not produce any of the known B. pertussis toxins and virulence factors.