The critical role of CD4T cell metabolism <i>per se</i> and downstream mTOR in CD4T cells in host resistance was shown in mice lacking mTOR in CD4T cells that failed to expel their parasites and developed chronic infection.<h4>Conclusion</h4>Our study shows that mTOR is essential for optimal functioning of T cells during whipworm infection and that deletion of Slc7a5 significantly delays worm clearance indicating a key role for amino acid acquisition by CD4T cells in resistance to helminth infection. The gene discussed is SLC7A5; the disease is helminthiasis.