T and B cells Both T and B cells are involved in the immune response and under the light microscope can not be distinguished.Surface markers are used to distinguish T and B cells. Surface Markers of T and B Cells Lymphocyte Human Mouse T Cells immature CD5,CD1,CD2, Thy-1,Ly-1,2,3,and TI Mature Subsets TH and TD Cells CD4,CD3,TCR Ty-1 Ly-1.L3T4,Qo1 B Cells CD19-22,CR,mlg u3,5,mlg NCN LAK RkPle9hgoTgormarners T and B cells Both T and B cells are involved in the immune response and under the light microscope can not be distinguished. Surface markers are used to distinguish T and B cells