T cells have characteristic surface glycoproteins and their own form of receptors.

Helper T cells recognise foreign antigens in association with HLA class II antigens on presenting cells.

Survival of T cells varies from several weeks to the lifetime of an individual, such as the T cells in thymus.

They secrete IL-2 when activated.

B-lymphocytes express immunoglobulins on their surface and secrete immunoglobulins (not T cells).