Disruption of T Lymphocyte Reappearance in Anti-Thy-1-Treated Animals in Vivo with Soluble CD44 and L-Selectin Molecules

Abstract We used polyclonal rabbit anti-Thy-1 antiserum to eliminate T lymphocytes in the peripheral blood, lymph nodes, and spleens but not in the thymus of normal mice. T lymphocytes began to reappear in the peripheral lymphoid compartments 2 weeks after termination of the treatment. By 4 weeks, the numbers of peripheral T lymphocytes had recovered to normal levels. We found that injection of recombinant soluble forms of human CD44 or L-selectin but not human CD8 molecules delayed the reappearance of peripheral T lymphocytes in anti-Thy-1-treated mice. This delay in recovery most likely reflects the ability of these soluble receptors to interfere with lymphocyte migration in vivo . Our results provide in vivo evidence that CD44 and L-selectin regulates lymphocyte trafficking and suggest that soluble forms of both molecules provide useful tools for the study of lymphocyte migration in vivo .