The dotted line represents hSLAM staining of lymphocytes from C57BL/6 mice, and the solid line indicates hSLAM staining of lymphocytes from your transgenic mice. To monitor hSLAM expression after activation, B and T cells were purified from your spleen and subsequently activated. produced more computer virus particles. After intranasal and intraperitoneal inoculation of these mice with MV, infections of the thymus, spleen, nasal, mesenteric, and lower leg lymph nodes were detected. Upon necropsy, enlarged lymph nodes and spleen were apparent. Circulation cytometric analysis showed that abnormally large numbers of mature neutrophils and natural killer cells caused the splenomegaly. The hSLAM transgenic mouse constitutes an improved rodent model for studying the conversation of MV with immune cells that more accurately reflects the infection pattern found in humans. Keywords:activated lymphocytes, transgenic mouse, dendritic cells Measles viruses (MV) is one of the most contagious diseases known to man and is a major killer of children in the developing countries of Africa and South America. The high mortality rate associated with MV contamination results from increased susceptibility to opportunistic infections. Although MV has been analyzed extensively, the mechanism for the immunosuppressive effects observed during MV contamination remains unclear (1). The development of a mouse model may lead to a better understanding of the immune suppression induced by Rabbit Polyclonal to IL18R MV. This was previously attempted by expressing CD46, one of the two receptors for MV, in mice (2-6). However, CD46 receptor, a ubiquitously expressed glycoprotein, is only used by vaccine or laboratory adapted strains of MV. Recently, a second receptor for MV was discovered: CD150 or signaling lymphocytic activation molecule (SLAM) (7-9). SLAM is usually a host cell receptor for both vaccine and WT MV strains of MV. It is a 70-kDa, type I transmembrane glycoprotein expressed on immune cells such as activated T cells, B cells, macrophages, and dendritic cells (DC) (10). The N-terminal V domain name of SLAM interacts with the hemagglutinin protein (-)-Huperzine A of MV (9). (-)-Huperzine A SLAM determines Th2 cytokine production such as IL-4 and it may be involved in production of IL-12, TNF, and NO by macrophages (11). In addition, SLAM may induce B cell proliferation and Ig synthesis. SLAM transmission transduction in T cells is usually mediated through SAP (-)-Huperzine A (SLAM-associated protein). Mutations in SAP cause the lymphoproliferative disorder XLP, which results in an improper response to Epstein-Barr computer virus contamination (12). SAP is an SH2-made up of adapter protein that binds with high affinity to tyrosines of SLAM’s intracellular domain name. SAP binds to the membrane proximal tyrosine (Tyr-281) of SLAM’s cytoplasmic tail; it recruits and activates FynT (13). SAP conversation with the SH3 domain name of FynT stabilizes the open, active conformation of FynT. This active form then phosphorylates Tyr-307 and Tyr-372 of SLAM resulting in the recruitment of multiple players involved in SLAM signaling (14). To investigate MV receptor interactions and the effect of contamination on SLAM function, we launched a DNA fragment encompassing the entire humanSLAM(hSLAM) gene into a mouse genome using a bacterial artificial chromosome (BAC). We showed that ourhSLAM(+/+) mice express hSLAM in a regulated fashion and with an expression profile identical to that in humans. hSLAM+cells obtained from the transgenic mice, including activated B, T, and dendritic cells, were susceptible to contamination by MV in a receptor-dependent manner. To improve computer virus contamination, thehSLAMtransgenic mice were bred into astat1-deficient background, which renders mice more susceptible to pathogens (15-18). Inoculation of thehSLAM(+/+)/stat1(-/-) mice yielded a productive contamination of the lymphoid organs that resulted in enlarged lymph nodes and spleen. This mouse model should help experts study receptor tropism and the immune dynamics of MV, and will provide a useful tool for experts studying the designed vaccine and oncolytic potential of this computer virus (19-22). == Materials and Methods == Production of CD150 Mice.A BAC library from your Fondation Jean Dausset-Centre d’Etude Polymorphisme Humaine (Paris) was screened by using.