Wasting, ischemia, and lymphoid abnormalities in mice expressing T cell-targeted human tumor necrosis factor transgenes.

Abstract

To evaluate the biologic potential of T cell-specific TNF production in vivo, we have generated transgenic mice constitutively expressing TNF in their T cell compartment. This was achieved by placing a wild-type or a 3'-UTR modified fragment of the human TNF gene under the influence of the T cell-specific, locus control region of the human CD2 gene. Transgenic mice that express human TNF mRNA in T cells develop marked histologic and cellular changes locally in their lymphoid organs and a lethal wasting syndrome associated with widespread vascular thrombosis and tissue necrosis. The extent of pathologic changes and their time of onset appear to reflect levels of transgene expression. Thus, transgenic lines that express the transgene at high levels show both lymphoid organ and systemic abnormalities with wasting. In one transgenic line, mice express lower levels of the transgene and develop normally despite pronounced local lymphoid organ defects, confirming in vivo, the differential potential of localized and systemic TNF action. All pathologic changes could be neutralized by the administration of mAb specific for human TNF. These results demonstrate the important role of T cell-specific TNF production in the development of specific pathology and provide a means by which to evaluate the role of TNF in thymocyte development. Transgenic mice that express TNF constitutively in the T cell compartment offer a unique in vivo system by which to analyze the molecular character of systemic vs contact-dependent and paracrine modes of TNF action. Furthermore, given the species-specific nature of the mouse p75 TNF receptor, it is assumed that the pathology induced by human TNF in these transgenic mice is associated exclusively with p55 TNF receptor signaling. Conceivably, the differential contribution of each of the two TNF receptors in thymus development and TNF-mediated disease can be assessed by comparison of the biologic potential of human vs mouse TNF in the transgenic system developed.

Synergistic roles of tristetraprolin family members in myeloid cells in the control of inflammation

“…The severe phenotype observed in the M-triple KO mice could therefore be in part because of a combination of direct pathogenic effects of the elevated TNF, and autocrine/paracrine effects of TNF to promote the secretion of many other pro-inflammatory cytokines, including itself ( Grivennikov et al, 2005 ; Kruglov et al, 2008 ; Moudgil & Choubey, 2011 ; Steinkamp et al, 2018 ; Yao et al, 2021 ). Similar severe phenotypes have been observed in mice with direct transgenic overexpression of TNF ( Keffer et al, 1991 ; Probert et al, 1993 ), or mice in which an AU-rich instability region of the Tnf mRNA have been removed, resulting in systemic TNF overexpression ( Kontoyiannis et al, 1999 ). It will be of great interest to see whether the M-triple KO phenotype can be modified by interfering with TNF activity, as has been done in the case of the conventional TTP KO mice ( Taylor et al, 1996 ; Carballo & Blackshear, 2001 ), and other pro-inflammatory pathways that have been shown to have an ameliorating effect on the whole-body TTP-deficiency syndrome ( Molle et al, 2013 ).…”

“…Pvalues are reported under the gene names as determined by Repeated Measures (RM) two-way ANOVA with the Geisser-Greenhouse correction and Šíd ák's multiple comparison test. Probert et al, 1993), or mice in which an AU-rich instability region of the Tnf mRNA have been removed, resulting in systemic TNF overexpression (Kontoyiannis et al, 1999). It will be of great interest to see whether the M-triple KO phenotype can be modified by interfering with TNF activity, as has been done in the case of the conventional TTP KO mice (Taylor et al, 1996;Carballo & Blackshear, 2001), and other pro-inflammatory pathways that have been shown to have an ameliorating effect on the whole-body TTP-deficiency syndrome (Molle et al, 2013).…”