We read with great interest a recent article published in this Journal by Peiseler et al. [1] and the accompanying editorial [2] on the T regulatory cells (Tregs) in autoimmune hepatitis (AIH). Peiseler et al. found that CD4+CD25highCD127lowFOXP3+ Tregs in AIH are “fully functional and not reduced in frequency”. Longhi et al [3], who previously published that Tregs are functionally impaired in AIH, first argued against the methodology used for assessing the Tregs suppressor activity since Peiseler et al. employed an “utterly non-physiological” suppressor/effector ratio Peiseler et al replied by stating that their methodology for staining proliferating cells by carboxyfluorescein succinimidyl ester (CFSE) is more appropriate than thymidine uptake and specifically stains the CD4+CD25- effector T cells. Another argument was raised regarding the choice of Tregs labeling gate that resulted in a lower Tregs frequency compared to that reported by others [4]. The author’s replied [5] stating that the frequency of peripheral blood Tregs in adults reported by Garg et al. is “not vastly different from the frequencies reported by us”. Garg et al. [4] extrapolated Tregs number from CD4+CD25high-labeled cells considering only the top 1% of CD25-staining CD4 T cells, being estimated to be >98% CD127low. We believe that the comparison of Tregs frequencies is questionable and age-related, as demonstrated by our data. Peripheral blood cells from 4 healthy, 4 AIH and 4 non-alcoholic steatohepatitis (NASH) children (age range: 10-14 years) were used to evaluate frequencies of CD4+CD25highCD127lowFOXP3+ Tregs (Fig. 1A, B, C). As reported in Fig. 1D, the number of CD25highCD127lowFOXP3+ Tregs within CD4+ population is equal in all group of children. Our data confirms that the number of CD4+CD25highCD127low ‘True’ Tregs remains unchanged in liver disease with autoimmune traits, including AIH and NASH. However, in children the number of CD25highCD127lowFOXP3+ Tregs among CD4+ ranges between 2.3% and 3.0%. In summary, all of these findings highlight the importance of a “consensus” in the standardization of protocols for evaluating Tregs function in AIH and NASH.In addition, we would raise a discussion concerning some aspects related to the non-alcoholic steatohepatitis (NASH). Peiseler et al. determined the intra-hepatic Tregs frequency by immunohistochemistry for FOXP3 in 8 NASH patients in comparison to AIH [1] and found an higher percentage of FOXP3+ cells in AIH patients compared to NASH subjects both in liver lobules and in portal tracts. Moreover, they determined the FOXP3+ cells within the CD3+ population in the liver showing no statistical differences between AIH and NASH patients. No information about the diagnosis and severity of NASH was provided by the authors. Further, the usage of the modified Histological Activity Index (mHAI) [7] for quantifying the degree of liver inflammation is not suitable for NASH patients who are histologically evaluated by using the NAFLD Clinical Research Network criteria [8]. As liver-resident inflammatory cells are a key component in NAFLD, particularly in children [9], their role in severity of NASH-associated necro-inflammation and fibrosis requires a particular attention. In fact, we demonstrated that CD3+ cells were significantly lower (P<0.01) in children with NAFLD activity score (NAS)≥5 and fibrosis with respect to children with NAS<5. Furthermore, our preliminary data in 30 NAFLD children indicates that liver-resident CD25+ cells are rare in this condition (not shown). These findings oppose to Peiseler et al. [1] stating about the presence of FOXP3+ in NASH.Despite, several criticisms, Peiseler’s study and Longhi’s comments raise new questions and provide experimental breakthrough about the study of Tregs frequency and function in inflammatory. liver diseases. The role of the innate and the adaptive immunity in NAFLD/NASH still remains an open intriguing issue [10]. References[1] Peiseler M, Sebode M, Franke B, Wortmann F, Schwinge D, Quaas A, et al. FOXP3+ regulatory T cells in autoimmune hepatitis are fully functional and not reduced in frequency. J Hepatol 2012;57:125-132.[2] Oo YH, Hubscher SG, Adams DH. Autoimmune hepatitis: new paradigms in the pathogenesis, diagnosis, and management. Hepatol Int 2010;4:475-493.[3] Longhi MS, Ma Y, Mieli-Vergani G, Vergani D. Regulatory T cells in autoimmune hepatitis. J Hepatol 2012 Jun 27.[4] Garg G, Tyler JR, Yang JH, Cutler AJ, Downes K, Pekalski M, et al. Type 1 diabetes-associated IL2RA variation lowers IL-2 signaling and contributes to diminished CD4+CD25+ regulatory T cell function. J Immunol 2012;188:4644-4653.[5] Peiseler M, Sebode M, Schramm C, Herkel J. Reply to: "Regulatory T cells in autoimmune hepatitis". J Hepatol 2012 Jun 27. [6] Wang P, Longhi MS, Mieli-Vergani G, Vergani D, Ma Y.Multiple defects of the immunoregulatory system contribute to the development of autoimmune hepatitis. Hepatology 2011;54:910A-911A.[7] Ishak K, Baptista A, Bianch L, Callea F, De Groote J, Gudat F, et al. Histological grading and staging of chronic hepatitis. J Hepatol 1995;22:696-699.[8] Kleiner DE, Brunt EM, Van Natta M, Behling C, Contos MJ, Cummings OW, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology 2005;41:1313-1321.[9] De Vito R, Alisi A, Masotti A, Ceccarelli S, Panera N, Citti A, et al. Markers of activated inflammatory cells correlate with severity of liver damage in children with nonalcoholic fatty liverdisease. Int J Mol Med 2012;30:49-56.[10] Söderberg C, Marmur J, Eckes K, Glaumann H, Sällberg M, Frelin L, et al. Microvesicular fat, inter cellular adhesion molecule-1 and regulatory T-lymphocytes are of importance for the inflammatory process in livers with non-alcoholic steatohepatitis. APMIS 2011;119:412-420.
T regulatory cell number and function: the autoimmune traits in liver diseases
Fierabracci A
;
2012-01-01
Abstract
We read with great interest a recent article published in this Journal by Peiseler et al. [1] and the accompanying editorial [2] on the T regulatory cells (Tregs) in autoimmune hepatitis (AIH). Peiseler et al. found that CD4+CD25highCD127lowFOXP3+ Tregs in AIH are “fully functional and not reduced in frequency”. Longhi et al [3], who previously published that Tregs are functionally impaired in AIH, first argued against the methodology used for assessing the Tregs suppressor activity since Peiseler et al. employed an “utterly non-physiological” suppressor/effector ratio Peiseler et al replied by stating that their methodology for staining proliferating cells by carboxyfluorescein succinimidyl ester (CFSE) is more appropriate than thymidine uptake and specifically stains the CD4+CD25- effector T cells. Another argument was raised regarding the choice of Tregs labeling gate that resulted in a lower Tregs frequency compared to that reported by others [4]. The author’s replied [5] stating that the frequency of peripheral blood Tregs in adults reported by Garg et al. is “not vastly different from the frequencies reported by us”. Garg et al. [4] extrapolated Tregs number from CD4+CD25high-labeled cells considering only the top 1% of CD25-staining CD4 T cells, being estimated to be >98% CD127low. We believe that the comparison of Tregs frequencies is questionable and age-related, as demonstrated by our data. Peripheral blood cells from 4 healthy, 4 AIH and 4 non-alcoholic steatohepatitis (NASH) children (age range: 10-14 years) were used to evaluate frequencies of CD4+CD25highCD127lowFOXP3+ Tregs (Fig. 1A, B, C). As reported in Fig. 1D, the number of CD25highCD127lowFOXP3+ Tregs within CD4+ population is equal in all group of children. Our data confirms that the number of CD4+CD25highCD127low ‘True’ Tregs remains unchanged in liver disease with autoimmune traits, including AIH and NASH. However, in children the number of CD25highCD127lowFOXP3+ Tregs among CD4+ ranges between 2.3% and 3.0%. In summary, all of these findings highlight the importance of a “consensus” in the standardization of protocols for evaluating Tregs function in AIH and NASH.In addition, we would raise a discussion concerning some aspects related to the non-alcoholic steatohepatitis (NASH). Peiseler et al. determined the intra-hepatic Tregs frequency by immunohistochemistry for FOXP3 in 8 NASH patients in comparison to AIH [1] and found an higher percentage of FOXP3+ cells in AIH patients compared to NASH subjects both in liver lobules and in portal tracts. Moreover, they determined the FOXP3+ cells within the CD3+ population in the liver showing no statistical differences between AIH and NASH patients. No information about the diagnosis and severity of NASH was provided by the authors. Further, the usage of the modified Histological Activity Index (mHAI) [7] for quantifying the degree of liver inflammation is not suitable for NASH patients who are histologically evaluated by using the NAFLD Clinical Research Network criteria [8]. As liver-resident inflammatory cells are a key component in NAFLD, particularly in children [9], their role in severity of NASH-associated necro-inflammation and fibrosis requires a particular attention. In fact, we demonstrated that CD3+ cells were significantly lower (P<0.01) in children with NAFLD activity score (NAS)≥5 and fibrosis with respect to children with NAS<5. Furthermore, our preliminary data in 30 NAFLD children indicates that liver-resident CD25+ cells are rare in this condition (not shown). These findings oppose to Peiseler et al. [1] stating about the presence of FOXP3+ in NASH.Despite, several criticisms, Peiseler’s study and Longhi’s comments raise new questions and provide experimental breakthrough about the study of Tregs frequency and function in inflammatory. liver diseases. The role of the innate and the adaptive immunity in NAFLD/NASH still remains an open intriguing issue [10]. References[1] Peiseler M, Sebode M, Franke B, Wortmann F, Schwinge D, Quaas A, et al. FOXP3+ regulatory T cells in autoimmune hepatitis are fully functional and not reduced in frequency. J Hepatol 2012;57:125-132.[2] Oo YH, Hubscher SG, Adams DH. Autoimmune hepatitis: new paradigms in the pathogenesis, diagnosis, and management. Hepatol Int 2010;4:475-493.[3] Longhi MS, Ma Y, Mieli-Vergani G, Vergani D. Regulatory T cells in autoimmune hepatitis. J Hepatol 2012 Jun 27.[4] Garg G, Tyler JR, Yang JH, Cutler AJ, Downes K, Pekalski M, et al. Type 1 diabetes-associated IL2RA variation lowers IL-2 signaling and contributes to diminished CD4+CD25+ regulatory T cell function. J Immunol 2012;188:4644-4653.[5] Peiseler M, Sebode M, Schramm C, Herkel J. Reply to: "Regulatory T cells in autoimmune hepatitis". J Hepatol 2012 Jun 27. [6] Wang P, Longhi MS, Mieli-Vergani G, Vergani D, Ma Y.Multiple defects of the immunoregulatory system contribute to the development of autoimmune hepatitis. Hepatology 2011;54:910A-911A.[7] Ishak K, Baptista A, Bianch L, Callea F, De Groote J, Gudat F, et al. Histological grading and staging of chronic hepatitis. J Hepatol 1995;22:696-699.[8] Kleiner DE, Brunt EM, Van Natta M, Behling C, Contos MJ, Cummings OW, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease. Hepatology 2005;41:1313-1321.[9] De Vito R, Alisi A, Masotti A, Ceccarelli S, Panera N, Citti A, et al. Markers of activated inflammatory cells correlate with severity of liver damage in children with nonalcoholic fatty liverdisease. Int J Mol Med 2012;30:49-56.[10] Söderberg C, Marmur J, Eckes K, Glaumann H, Sällberg M, Frelin L, et al. Microvesicular fat, inter cellular adhesion molecule-1 and regulatory T-lymphocytes are of importance for the inflammatory process in livers with non-alcoholic steatohepatitis. APMIS 2011;119:412-420.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
