L. pneumophila is an intracellular bacterium that replicates 
inside a membrane-bound vacuole called Legionella
Containing Vacuole (LCV), where it profusely releases its 
HtpB chaperonin. From LCV, HtpB reaches the host cell 
cytoplasm, where it interacts with SAMDC, a cytoplasmic 
protein required for synthesis of host polyamines that are 
important for intracellular growth of L. pneumophila. 
Moreover, cytoplasmic expression of HtpB in S. cerevisiae 
induces pseudohyphal growth, and in mammalian cells 
recruits mitochondria to LCV and modifies actin 
microfilaments organization. This led us to hypothesize here 
that HtpB recruits a protein(s) from eukaryotic cells that is 
involved in emergence of the aforementioned phenotypes. 
To identify this protein, a commercially available HeLa 
cDNA library was screened using a yeast two-hybrid 
system. Approximately 5 x 106 yeast clones carrying HeLa 
cDNA library plasmid were screened. Twenty one positive 
clones were identified. DNA sequence analysis revealed that 
all of these positive clones encoded the mammalian small 
heat shock protein Hsp10. Based on the fact that 
chaperonins are required to interact with co-chaperonins to 
function properly in protein folding, thus, HtpB may recruit 
the host cell Hsp10 to appropriately interact with SAMDC 
and to induce the cellular phenotypes deemed important for 
L. pneumophila pathogenesis.