TNF/TNFR1 signaling up-regulates CCR5 expression by CD8+ T lymphocytes and promotes heart tissue damage during Trypanosoma cruzi infection: beneficial effects of TNF-α blockade
Karina Kroll-Palhares, Jaline Coutinho Silvério, Andrea Alice da Silva, Vladimir Michailowsky, Ana Paula Marino, Neide Maria Silva, Cristiano Marcelo Espinola Carvalho, Luzia Maria de Oliveira Pinto, Ricardo Tostes Gazzinelli, Joseli Lannes-Vieira
2008
Memórias do Instituto Oswaldo Cruz
In Chagas disease, understanding how the immune response controls parasite growth but also leads to heart damage may provide insight into the design of new therapeutic strategies. Tumor necrosis factor-alpha (TNF-α) is important for resistance to acute Trypanosoma cruzi infection; however, in patients suffering from chronic T. cruzi infection, plasma TNF-α levels correlate with cardiomyopathy. Recent data suggest that CD8-enriched chagasic myocarditis formation involves CCR1/CCR5-mediated cell
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... igration. Herein, the contribution of TNF-α, especially signaling through the receptor TNFR1/p55, to the pathophysiology of T. cruzi infection was evaluated with a focus on the development of myocarditis and heart dysfunction. Colombian strain-infected C57BL/6 mice had increased frequencies of TNFR1/p55 + and TNF-α + splenocytes. Although TNFR1 -/mice exhibited reduced myocarditis in the absence of parasite burden, they succumbed to acute infection. Similar to C57BL/6 mice, Benznidazole-treated TNFR1 -/mice survived acute infection. In TNFR1 -/mice, reduced CD8-enriched myocarditis was associated with defective activation of CD44 + CD62L low/and CCR5 + CD8 + lymphocytes. Also, anti-TNF-α treatment reduced the frequency of CD8 + CCR5 + circulating cells and myocarditis, though parasite load was unaltered in infected C3H/HeJ mice. TNFR1 -/and anti-TNF-α-treated infected mice showed regular expression of connexin-43 and reduced fibronectin deposition, respectively. Furthermore, anti-TNF-α treatment resulted in lower levels of CK-MB, a cardiomyocyte lesion marker. Our results suggest that TNF/TNFR1 signaling promotes CD8-enriched myocarditis formation and heart tissue damage, implicating the TNF/TNFR1 signaling pathway as a potential therapeutic target for control of T. cruzi-elicited cardiomyopathy.
doi:10.1590/s0074-02762008000400011
pmid:18660993
fatcat:g7fh2ibs6rd5vbpv73uig4k2wq
