تحسين تفعيل اللمفاويات التائية البشرية في الزجاج و في الحي بواسطة طلاء الخلايا بالبروتين الخيمري المأشوب B7-1 : Fcγ1

Abstract EN

Background& Objective: T cells express co-stimulatory molecules on their surfaces in both normal and pathologic settings; however, the possibility that expression of these co-stimulators may enable individual T cells to co-stimulate themselves has not been investigated.

This study aims at assessing the possible potentiation of T cells activation and proliferation both in vitro and in vivo via enforced B7-1 expression on T lymphocytes using a non-genetic approach, i.e.

cell painting, that comprises binding of recombinant B7-1 to plasma membrane-anchored palmitoylated protein A.

Materials & Methods: A recombinant chimeric human co-stimulatory B7-1 protein that encompasses the extracellular domain of CD80 (B7-1) fused to the crystal fragment Fcγ of human IgG antibody was engineered and produced in human kidney cell line 293.

Recombinant protein A was chemically palmitoylated and inserted into cell membranes of T lymphocytes highly purified using negative selection.

Subsequently, B7-1·Fcγ1 was added to protein A-decorated cells allowing its binding via the Fc portion.

Quantitative transfer of B7-1 was assessed using flow cytometry, and in vitro proliferation and IL-2 production were measured.

Moreover, in vivo engraftment of painted cells was evaluated using the immune deficient mouse model NOD/SCID/B2M K/O.

Results: Results from this study demonstrate the feasibility of “cell painting” using a two-step approach to quantitatively transfer palmitoylated protein A and B7-1·Fcγ to T cells.

B7-1 painted T lymphocytes exhibited augmented in vitroproliferation, enhanced IL-2 production, and superior in vivo engraftment.

Conclusions: Cell painting technique enables arming T lymphocytes with co-stimulatory proteins that provide second signal inevitable for activation, proliferation, and production of IL-2.

These results may pave the way for future applications that include but is not limited to cancer targeted immunotherapy and congenital and/or acquiredimmunodeficiency.

This study was conducted in the laboratories of The School of Medicine, University of Pennsylvania, USA, and The National Commission for Biotechnology, Damascus between 2010 and 2012.