Role of Receptors for Advanced Glycation End Products and High-Mobility Group Box 1 in the Outcome of Human T Cell Lymphotropic Type 1 Infection

HTLV-1-infected asymptomatic carriers compared to HAM/TSP patients over-express the apoptosis- and cytotoxicity-related molecules

HTLV-1 infection causes a chronic progressive debilitating neuroinflammatory disease which is called, HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). One of the host defense mechanisms against viral infection is apoptosis which may control HTLV-1 infection. Therefore, we aimed to investigate this process and its interaction with viral factors in HTLV-1-infected asymptomatic carriers (ACs) compared to HAM/TSP patients. Fas, FasL, TRAIL, perforin, granzyme A, granzyme B, and granulysin gene expression and serum levels of Fas, FasL, TRAIL, and granulysin in the peripheral blood of 21 sex- and age-matched healthy controls (HCs), ACs, and HAM/TSP patients were evaluated. Also, the level of granulysin secretion in the cell culture supernatant was measured. Finally, the correlation of the expression of these molecules with HTLV-1 proviral load (PVL), Tax, and HBZ mRNA expression was analyzed. ACs compared to HAM/TSP patients significantly over-expressed the Fas, FasL, TRAIL, perforin, and granzyme B molecules. Fas, FasL, TRAIL, and granulysin serum levels were not different among studied groups; whereas, the secretion of granulysin was significantly decreased in ACs and HAM/TSP patients compared to HCs. Also, HAM/TSP patients expressed higher levels of HTLV-1 PVL, Tax, and HBZ mRNA. In addition, in ACs, inverse correlations between the Fas, FasL, TRAIL, perforin, granzyme B, and granulysin levels with HBZ mRNA expression were seen. ACs compared to HAM/TSP patients over-expressed the apoptosis- and cytotoxicity-related molecules. It could be concluded that successful control of the HTLV-1 infection and suppression of HAM/TSP development stem from the strong apoptosis and cytotoxic activity in the peripheral blood of ACs.

Curcumin increased the expression of c-FLIP in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients

Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) disease is a chronic neuroinflammatory disease, which is associated with HTLV-1 infection. There is no effective and satisfactory treatment of HAM/TSP. It has been shown that curcumin exhibits modulatory effects on apoptosis and cytotoxicity-related molecules in HAM/TSP patients. In the present study, we examined the effect of curcumin on the gene expression of caspase-8, caspase-10, and anti-apoptotic protein c-FLIP, in HAM/TSP patients. Furthermore, we compared the expression of these molecules between HAM/TSP and asymptomatic carriers. Real-time PCR was performed to examine the mRNA expression of caspase-8, caspase-10, and c-FLIP in studied groups. The mRNA expression of caspase-8 and caspase-10 was similar before and after curcumin treatment in HAM/TSP patients (P > 0.05). The mRNA expression of c-FLIPL and c-FLIPs was higher after curcumin treatment compared with before treatment and significant differences were observed between the two groups (P = 0.004 and P = 0.044, respectively). The mRNA expression levels of caspase-8, caspase-10, c-FLIPL, and c-FLIPs were not statistically significant between HAM/TSP patients and asymptomatic carriers (P < 0.05). In conclusion, our results showed that curcumin increased the expression of c-FLIP in HAM/TSP patients which might suggest that, this molecule is involved in the apoptosis of HTLV-1-infected cells. Further studies with large sample size could be useful to clarify the role of this supplement in HAM/TSP patients.