  We present the results of a search for gravitational lensing of the cosmic
microwave background (CMB) in cross-correlation with the projected density of
luminous red galaxies (LRGs). The CMB lensing reconstruction is performed using
the first year of Wilkinson Microwave Anisotropy Probe (WMAP) data, and the
galaxy maps are obtained using the Sloan Digital Sky Survey (SDSS) imaging
data. We find no detection of lensing; our constraint on the galaxy bias
derived from the galaxy-convergence cross-spectrum is $b_g=1.81\pm 1.92$
($1\sigma$, statistical), as compared to the expected result of $b_g\sim 1.8$
for this sample. We discuss possible instrument-related systematic errors and
show that the Galactic foregrounds are not important. We do not find any
evidence for point source or thermal Sunyaev-Zel'dovich effect contamination.
