This study by Bianco, Patrick, and Nussenzweig investigates a population of lymphocytes that bind to antigen-antibody-complement (Ag-Ab-C) complexes. The researchers observed that some lymphocytes, referred to as CRL (complement receptor lymphocytes), bind to these complexes, while others do not. The binding of EAC (erythrocytes sensitized with antibody and complement) to lymphocytes was found to be C3-dependent. CRL could be specifically depleted from lymphocyte populations using a method involving ultracentrifugation in a BSA gradient. CRL and non-CRL lymphocytes were distinguished by their ability to bind to nylon wool, their distribution in BSA density gradients, and their presence among cells bearing immunoglobulin determinants. CRL were more prevalent in spleen and lymph nodes compared to thymus, and they were not found in antibody-producing cells. The study suggests that CRL may play a role in antigen localization and the accumulation of lymphocytes in inflammatory sites.This study by Bianco, Patrick, and Nussenzweig investigates a population of lymphocytes that bind to antigen-antibody-complement (Ag-Ab-C) complexes. The researchers observed that some lymphocytes, referred to as CRL (complement receptor lymphocytes), bind to these complexes, while others do not. The binding of EAC (erythrocytes sensitized with antibody and complement) to lymphocytes was found to be C3-dependent. CRL could be specifically depleted from lymphocyte populations using a method involving ultracentrifugation in a BSA gradient. CRL and non-CRL lymphocytes were distinguished by their ability to bind to nylon wool, their distribution in BSA density gradients, and their presence among cells bearing immunoglobulin determinants. CRL were more prevalent in spleen and lymph nodes compared to thymus, and they were not found in antibody-producing cells. The study suggests that CRL may play a role in antigen localization and the accumulation of lymphocytes in inflammatory sites.