Abstract
Human memory T cells are comprised of distinct populations with different homing potential and effector functions: central memory T cells that mount recall responses to Ags in secondary lymphoid organs, and effector memory T cells that confer immediate protection in peripheral tissues. In the present study we demonstrate that a proportion of effector memory T cells express FcgammaRIIIa (CD16), are perforin positive, and directly mediate Ab-dependent cytotoxicity ex vivo. This particular alphabeta T lymphocyte subset has the morphology of large granular lymphocytes, increases proportionately in vivo during reactive lymphocytosis, and can be detected in vitro among EBV-specific T lymphocytes after stimulation with EBV Ags. Consequently, during a normal immune response, amplification of these effector memory T lymphocytes that are capable of Ab-dependent cytotoxicity may have beneficial or harmful consequences depending on the presence of pathogen- or tissue-specific Abs, respectively.
Highlights
Why The JI? Submit online. Rapid Reviews! 30 days* from submission to initial decision No Triage! Every submission reviewed by practicing scientists Fast Publication! 4 weeks from acceptance to publicatio
May-Grunwald-Giemsa coloration of FACS-sorted CD16ϩ ␣ T lymphocytes showed that these cells are characterized by an abundant basophilic cytoplasm with azurophilic granules typical of large granular lymphocytes (LGL) (Fig. 1C)
Because a lack of CD28 and presence of CD57 on CD8ϩ T cells are generally associated with a status of replicative senescence, altogether these results suggest that CD8ϩCD16ϩ ␣ T lymphocytes belong to a small population that has been previously described as TEMRA lymphocytes for terminally T effector memory CD45RAϩ lymphocytes [28, 29]
Summary
Both CD16ϩ NK cells and CD16ϩ ␣ T lymphocytes killed the BLCL incubated with anti-CD20 mAb. This cytotoxicity was not observed in the presence of antiHer2/neu mAb. Together, these results demonstrate that despite expressing low levels of CD16, CD16ϩ ␣ T lymphocytes all express perforin (one example of six donors tested is presented in Fig. 2B) and are able to mediate ADCC ex vivo.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
