CHARACTERIZATION OF HUMAN 2B4 AND 2B4 GENE KNOCKOUT MICE

Project Details

Description

DESCRIPTION: (Adapted from applicant's abstract) Natural killer (NK) cells are
large granular lymphocytes of bone marrow origin that exhibit cytolytic
activity against some tumor and virally infected cells in the absence of prior
stimulation. We have previously identified murine 2B4 as an NK receptor
expressed on a subset of T cells as well as on all murine NK cells. 2B4 is
expressed early in NK cell development, before expression of other NK cell
specific markers such NK 1.1 or Ly-49 family members. 2B4 is a member Df the
CD2 subfamily of the immunoglobulin superfamily and is expressed as 2
alternative splice variants. Ligation of 2B4 with mAb modulates target cell
lysis and IFN-y production. Recently, we have shown CD48 to be the high
affinity counter-receptor for 2B4. CD48 is widely expressed on cells of
hematopoietic origin, and is important in both T cell and B cell activation.
The overall goal of this application is to investigate the role of 2B4 in the
immune system, both as a NK cell receptor and as a counter-receptor for CD48.
First, we will clone and characterize the human homologues of murine 2B4. To
complement the murine 2B4 reagents we already have, we will generate monoclonal
antibodies against human 2B4, and soluble fusion proteins of 2B4 and CD48.
Using these reagents, we will study the expression pattern of 2B4 in detail.
Next, the role of 2B4 in the cytolytic function and IFN-y production of human
NK cells will be analyzed. Furthermore, these reagents will allow us to study
the role of 2B4-CD48 interactions on the regulation of CD48+ lymphocytes by
2B4+ cells. The effect of 2B4-CD48 interactions on B cells will be studied by
analyzing their ability to provide (or block) costimulatory signals. This
effect will be measured by proliferation and immunoglobulin production.
Finally, the role of 2B4 in NK cell development and function will be
established by using a 2B4 gene knockout mouse model. The experiments proposed
in this project should provide a clearer understanding of the role of 2B4 in
modulating various functions of human NK cells and may reveal new insights and
open new avenues for cancer immunotherapy.
StatusFinished
Effective start/end date17/01/0131/12/01