Complex sentence: He then transferred to the (now) Department of Microbiology, Immunology and Human Genetics at UCLA, from which he received a doctorate in philosophy (Ph.D.) in 1977, on the subject of comparative immunology of graft rejection.
Split into simpler sentences: He then transferred to the Department of Microbiology, Immunology and Human Genetics at UCLA. He received a doctorate in philosophy (Ph.D.) in 1977, on the subject of comparative immunology of graft rejection.