Promastigote form of Leishmania, an intracellular pathogen, delays phagosome 
maturation and resides inside macrophages. But till date limited study has been 
done to manipulate the phagosomal machinery of macrophages to restrict 
Leishmania growth. Attenuated Leishmania strain exposed RAW 264.7 cells showed a 
respiratory burst and enhanced production of pro-inflammatory mediators. The 
augmentation of pro-inflammatory activity is mostly attributed to p38 MAPK and 
p44/42 MAPK. In our study, these activated macrophages are found to induce 
phagosome maturation when infected with pathogenic Leishmania donovani. 
Increased co-localization of carboxyfluorescein succinimidyl ester labeled 
pathogenic L. donovani with Lysosome was found. Moreover, increased 
co-localization was observed between pathogenic L. donovani and late phagosomal 
markers viz. Rab7, Lysosomal Associated Membrane Protein 1, Cathepsin D, Rab9, 
and V-ATPase which indicate phagosome maturation. It was also observed that 
inhibition of V-type ATPase caused significant hindrance in attenuated 
Leishmania induced phagosome maturation. Finally, it was confirmed that p38 MAPK 
is the key player in acidification and maturation of phagosome in attenuated 
Leishmania strain pre-exposed macrophages. To our knowledge, this study for the 
first time reported an approach to induce phagosome maturation in L. donovani 
infected macrophages which could potentiate short-term prophylactic response in 
future.