- Email: [email protected]
Response to commentary by Pujol-Borrell and Botazzo
Immunology Today, VoL 10, No. 5, 1989
trol of leukocyte migration is more various and complex than a simple receptor-ligand interaction, is exactly the conclusion reached in the article.
References
1 Duijvestijn,A. and Hamann,A. (1989) ImmunoL Today 10, 23-28 2 Hendriks, H.R., Duijvestijn,A.M. and Kraal, G. (1987)Eur. J. Immunnl. 17, 1691-1695 3 Gowans,J.L. and Knight, E.J.(1964) Adrian M. Duijvestijn Proc. R. 5oc. London 5er. B 159, 257-281 Dept of lmmunology, Universityof Limburg, 4 Freitas,A.A. de, Rose,M.L. and Parrott, POBox 616, 6200MB Maastricht, The D.M.V. (1977) Nature 270, 731-733 Netherlands. $ Freitas,A.A. de, Rose,M.L. and Rocha,
Responseto Commentary by Pujoi-Borrelland Bottazzo Sir, The commentary by PujoI-Borreli and Bottazzo on the use of transgenic mice for studying the pathogenesis of Type I diabetes (Immunol. Today, 1988, 9, 303-306) deserves further comment. The issue of pancreatic beta cell death because of concurrent expression of MHC class I or class II genes linked to the insulin promoter has been analysed superbly by P. Parham 1, to which the authors unfortunately refer only briefly. While PujoI-Borrell and Bottazzo are correct in claiming that introducing MHC class I or class II genes with the insulin promoter into beta cells is not the proper way to study the mode of autoimmune pathogenesis of Type i diabetes, they leave the question of the role of de novo expression of MHC class I1 genes in beta cells in the pathogenesis of Type I diabetes unanswered. It has been claimed by these and other authors that the expression of MHC class II molecules on the surface of human beta cells in vivo 2.3 may be a necessary step in the pathogenesis of Type I diabetes. The evidence so far produced concerns immunocytochemical studies on the pancreas of one newly-diagnosed Type I diabetic2, similar studies from the pancreases of several patients who died a few days after onset of the disease3 and lymphokine-activated human and rat islet cells in vitro 4.s. In the studies with human tissues and cells (using immunofluorescence and/ or immunoperoxidase techniques), it was shown that a considerable proportion of intact cells that stained positively for intracytoplasmic insulin, showed increased ex-
pression of MHC class I molecules and expression of class II molecules (the latter considered de novo, as pancreatic beta cells do not normally express MHC class II molecules). Cells staining positively for glucagon or somatostatin did not show any MHC class II expression in vivo z.3, while in response to gamma-interferon (IFN~/) alone or with tumor necrosis factor-~ in vitro, all islet cell types showed reactivity to anti-MHC class II antibodies4.s. In none of these studies was the de novo synthesis of MHC class II molecules by the beta cells proved (for example by cDNA hybridization). Furthermore, in a study on the time course of the pathogenesis of Type I diabetes in BB rats, it was shown that the first histopathological sign in the islets of Langerhans was the MHC class II expression in the proximal endothelial cells, followed by infiltration of lymphocytes and later on by MHC cla.~s II expression in cells staining positively for intrac~oplasmic insulin6. Bottazzo and collaborators have, therefore, postulated that MHC class II expression is an obligatory step in the pathogenesis of Type I diabetes, that allows very efficient antigen presentation in situ and consequent activation of neiper and cytotoxic T cells, and leads eventually to the destruction of beta cells. In our opiron, the hypothesis of obligatory M~.iC class II expression by the beta cells during the course of pathogenesis of Type i diabetes has been laid to rest by the results of recent experiments from D. Pipeleers' laboratory. Specifically, it has been shown that in both normal and diabetic rats (either streptozotocin-induced or spontaneous (BB)) all cells that sorted because of surfacP. MHC class II expression, also stained positively for intracytoplasmic insulin7.8. However, the examination
~) 1989, ElsevierSciencePublishersLtd, UK. 0167-4919/89/$02.00
B. (1980) Cell Immunol. 56, 29-35 6 Stevens,S.K.,Weissman, I.L.and Butcher, E.C.(198~ j. Immunol. 128, 844-851 7 Kraal, G., Weissman, I.L. and Butcher, E.C. (1983)J. Immunol. 130, 1097-1102 8 Jalkanen,S., Reichert,R.A., Gallatin, W.M. etaL (1986)Immunol. Rev. 91, 39--60 9 Smith, M.E., Martin, A.F. and Ford, W.L. (1980)Monogr. Allergy 16, 203-232
of these cells by electron microscope showed that they were macrophage/ monocytic-iike and that their insulin was contained in lysosomes, and not in the typical insulin granules that are so characteristic of the beta celP. Furthermore, these double-positive cells (insulin and MHC class II) bear on their surface typical membrane determinants of monocytes and macrophages8. We can safely assume that such macrophages are activated in the course of beta cell destruction, and hence the insulin in the lysosomes. Such macrophagic cells were shown to exist in the islets of non-diabetic mice9. While nonobese diabetic (NOD) mice are shown to express MHC class II antige,~s before lymphocytic infiltration into the islet 10, no comparative experiments have been reported with the non-obese normal (NON) mouse strain. In the light of recent evidence, it would indeed be very interesting to go back to the original tissue from patients and perform electron microscope studies to see if such macrophages are the source of the double-positive cells of the diabetic isl ~.ts of L.~ngerhans. If this is so, it would mean that we have to develop anew the framework for the pathogenesis of Type t diabetes, but then, why not? Immunology is such a rapidly changing field that we cannot hope that all has been said about the pathogenesis of Type I diabetes. We see a unique opportunity for obtaining more information on the pathogenesis, primarily from animal models, and then formulating hypotheses in the light of current immunological knowledge. Note added in proof: After this letter was submitted we became aware of recent work (Farr, A.G., Mannschreck,J.W. and Anderson, S.K. (1988) Diabetes 37, 1373-1379) showing that MHC class II
149
-fellers References 1 Parham,P. (1988) IVature 333, 500-503 2 Bottazzo,G.F., Dean, B.M., McNally, J.M. et al.(1985) New Engl. J. Med. 313, 353-360 3 Foulis,A.K., Farquharson,M.A. and Hardman, R. (1987) Diabetologia 28, Antonia Pantelidou 333-343 George K. Papadopoulos 4 PujoI-Borrell,R., Todd, I., Doshi, M. et al. (1987) Nature 326, 304-306 Laboratory of BiologicalChemistry,Medical 5 Wright, J.R., Lacy, P.E.,Unanue, E.R., School, Universityof Ioannina, GR453 32 Muszynski,C. and Haupffeld, V. (1986) loanui.,J, ~,~ ~'Y'~ Diabetes 35, 1174-1177
expression in streptozotocin-induced diabetic mice (strain C57BUKsJ)was lii lited to cells of the ductular epithelium assooat~d vvith the exocrine pancreas. There was also transient MHC class II ~xp,-ession by vascular endothelial cells but not by islet endocrine cells.
Immunology today, Vol. 10. No. 5, 1989
6 Dean, B.M., Walker, R., Bone,A.J., Baird, J.D. and Cooke, A. (1985) Diabetolo~ia 28, 464--466 7 Pipeleers,D.G., in't Veld, P.A., Pipeleers-Marichal,M., Gepts, W. and Van De Winkel, M. (1987) Diabetes 36, 872-876 R In't Veld, P.A.and Pipeleers,D.G. (1988) J. Clin. Invest. 82, 1123-1128 9 Farr,A.G. and Anderson, S.K. (1985) Diabetes 34, 987-990 10 Hanafusa,T., Fujino-Kurihara,H., Miyazaki, A. etal. (1987) Diabetologia 30, 104-108
Reply to Pantelidou and Papadopoulos
the demonstration that in the islets R. PujoI-Borrell of streptozotocin-induced and BB Hospital 'GermansTriasi Pujol" Universidad diabetic rats the insulin-containing Aut6noma de Barcelona,PO Box 72, 08916 Sir, cells also show macrophage feaeadalona, Spain. The letter by Pantelidou and Papa- tures. However, these observations dopoulos raises some doubts on do not apply to the human situation, whether islet beta cells do express where double-labeling experiments I-ILA c!~s~ ii n~olccu!es in the pan- carried out by Alan Foulis1 using Reference creas of newly diagnosc-,d diabetic mAb against T200 rule out this 1 Foulis,A. K. and Farquharson,M. A. patients. They base these doubts on possib=lity. (19;36)Diabetes 35, 121 5-1224
Our preliminary data showed significantly increased concentrations of IFN-lt in AIDS patients5. A more detailed study confirms these results and shows a close correlation beSir: __tweenthe !FN-~, levels and neoptefin R.M. Zinkemagel (Imrnunol. Today, concentrations6. We also found in1988, 9, 370-372) recently pro- creased kynurenine and decreased posed a possible role for cytotoxic T tryptophan concentrations in the cells in the development of AIDS by blood of patients with HIV infeceliminating CD4 + cells infected w,th tion 7. These data can be referred human immunodeficiency virus to activity of indoleamine(2,3)(HIV). The assumption is based on dioxygenase and this enzyme is data obtained from mice during induced by IFN-~8. Circulating lymphocytic choriorneningitis virus IFN-~ in patients with HIV infection (LCMV) infection 1. is of particular interest since lymphoIf cytotoxicity of T cells plays a role kines can induce reproduction of HIV in the immunopathogenesis of AIDS, in latently infected cells9.10. markers of stimulated immune reThe presence of IFN-~/in patients sponse should be detectable and with HIV infection shows on the one parallel or even precede the course hand that reduced capacity of T cells of disease in patients infected by to produce IFN-~/ on stimulation in HIV. We have accumulated data vitro does not necessarily reflect the from neopterin measurements that in-vivo situation 2. On the other suggest that early events of T-cell hand, macrophages respond to and macrophage interaction are acti- IFN-~/production releasing neopterin vated in patients with HIV infection and degrading tryptophan via the and cellular immune activation is kynurenine pathway. The induction most expressed in AIDS2. Increasing of specific enzymic pathways shows neopterin levels precede a sub- that the IFN-~/ detected is actively sequent loss of CD4 + T cells3.4. recognized by macrophages. Neopterin is a product of macroIn conclusion, our data fully supphages that are stimulated with port the concept proposed by R.M. gamma-interferon (IFN-~/). Zinkernagel.
Cell-mediated immunoreactivity in AIDS
150
Dietmar Fuchs~ Ernst R. Wemer ~ ..U.anfred P. D~erich2J Helmut Wachter~ i institute of Medical Chemistryand Biochemistry,and 2Institute of Hygiene, Universityof lnnsbruck, and 3Ludwiq Boltzmann Institute of AIDS Research,A-6020 Innsbruck, Austria.
References 1 Leist,T.P., Eppler, M., Ruedi, E. and Zinkernagel, R.M. (1988)J. Exp. Med. 167, 1749-1754 2 Fuchs,D., Hausen,A., Reibnegger,G. et aL (1988) Immunol. Today9, 150-155 3 Fuchs,D., Banekovich,M., Hausen,A. et al. (1988) Clin. Chem. 34, 2415-2417 4 Melmed, R.N.,Taylor,J.M.G., Detels, R., Bozorgmehri, M. and Fahey,J.L.J. AIDS (in press) 5 Fuchs,D. and Wachter, H. (1988)Brit. Meal. J. 297, 422-423 6 Fuchs,D., Hausen,A., Reibnegger,G. et al. J. AIDS (in press) 7 Werner, E.R.,Fuchs,D., Hausen,A. et al. (1988) Biol. Chem. Hoppe-Seyler 369, 337-340 8 Takikawa,O., Kuroiwa,T., Yarnazaki, F. and Kido, R. (1988)J. Biol. Chem. 263, 2041-2043 9 Siliciano,R.F.,Lawton, T., Knall, C. et al. (1988) Cell 54, 561-575 10 Koyanagi,Y., O'Brien, W.A., Zhao, J.O. et al. (1988)Science241, 1673-1675 (~) 1989, ElsevierSciencePublishersLtd, UK. 0167-4919189/$02.00
trol of leukocyte migration is more various and complex than a simple receptor-ligand interaction, is exactly the conclusion reached in the article.
References
1 Duijvestijn,A. and Hamann,A. (1989) ImmunoL Today 10, 23-28 2 Hendriks, H.R., Duijvestijn,A.M. and Kraal, G. (1987)Eur. J. Immunnl. 17, 1691-1695 3 Gowans,J.L. and Knight, E.J.(1964) Adrian M. Duijvestijn Proc. R. 5oc. London 5er. B 159, 257-281 Dept of lmmunology, Universityof Limburg, 4 Freitas,A.A. de, Rose,M.L. and Parrott, POBox 616, 6200MB Maastricht, The D.M.V. (1977) Nature 270, 731-733 Netherlands. $ Freitas,A.A. de, Rose,M.L. and Rocha,
Responseto Commentary by Pujoi-Borrelland Bottazzo Sir, The commentary by PujoI-Borreli and Bottazzo on the use of transgenic mice for studying the pathogenesis of Type I diabetes (Immunol. Today, 1988, 9, 303-306) deserves further comment. The issue of pancreatic beta cell death because of concurrent expression of MHC class I or class II genes linked to the insulin promoter has been analysed superbly by P. Parham 1, to which the authors unfortunately refer only briefly. While PujoI-Borrell and Bottazzo are correct in claiming that introducing MHC class I or class II genes with the insulin promoter into beta cells is not the proper way to study the mode of autoimmune pathogenesis of Type i diabetes, they leave the question of the role of de novo expression of MHC class I1 genes in beta cells in the pathogenesis of Type I diabetes unanswered. It has been claimed by these and other authors that the expression of MHC class II molecules on the surface of human beta cells in vivo 2.3 may be a necessary step in the pathogenesis of Type I diabetes. The evidence so far produced concerns immunocytochemical studies on the pancreas of one newly-diagnosed Type I diabetic2, similar studies from the pancreases of several patients who died a few days after onset of the disease3 and lymphokine-activated human and rat islet cells in vitro 4.s. In the studies with human tissues and cells (using immunofluorescence and/ or immunoperoxidase techniques), it was shown that a considerable proportion of intact cells that stained positively for intracytoplasmic insulin, showed increased ex-
pression of MHC class I molecules and expression of class II molecules (the latter considered de novo, as pancreatic beta cells do not normally express MHC class II molecules). Cells staining positively for glucagon or somatostatin did not show any MHC class II expression in vivo z.3, while in response to gamma-interferon (IFN~/) alone or with tumor necrosis factor-~ in vitro, all islet cell types showed reactivity to anti-MHC class II antibodies4.s. In none of these studies was the de novo synthesis of MHC class II molecules by the beta cells proved (for example by cDNA hybridization). Furthermore, in a study on the time course of the pathogenesis of Type I diabetes in BB rats, it was shown that the first histopathological sign in the islets of Langerhans was the MHC class II expression in the proximal endothelial cells, followed by infiltration of lymphocytes and later on by MHC cla.~s II expression in cells staining positively for intrac~oplasmic insulin6. Bottazzo and collaborators have, therefore, postulated that MHC class II expression is an obligatory step in the pathogenesis of Type I diabetes, that allows very efficient antigen presentation in situ and consequent activation of neiper and cytotoxic T cells, and leads eventually to the destruction of beta cells. In our opiron, the hypothesis of obligatory M~.iC class II expression by the beta cells during the course of pathogenesis of Type i diabetes has been laid to rest by the results of recent experiments from D. Pipeleers' laboratory. Specifically, it has been shown that in both normal and diabetic rats (either streptozotocin-induced or spontaneous (BB)) all cells that sorted because of surfacP. MHC class II expression, also stained positively for intracytoplasmic insulin7.8. However, the examination
~) 1989, ElsevierSciencePublishersLtd, UK. 0167-4919/89/$02.00
B. (1980) Cell Immunol. 56, 29-35 6 Stevens,S.K.,Weissman, I.L.and Butcher, E.C.(198~ j. Immunol. 128, 844-851 7 Kraal, G., Weissman, I.L. and Butcher, E.C. (1983)J. Immunol. 130, 1097-1102 8 Jalkanen,S., Reichert,R.A., Gallatin, W.M. etaL (1986)Immunol. Rev. 91, 39--60 9 Smith, M.E., Martin, A.F. and Ford, W.L. (1980)Monogr. Allergy 16, 203-232
of these cells by electron microscope showed that they were macrophage/ monocytic-iike and that their insulin was contained in lysosomes, and not in the typical insulin granules that are so characteristic of the beta celP. Furthermore, these double-positive cells (insulin and MHC class II) bear on their surface typical membrane determinants of monocytes and macrophages8. We can safely assume that such macrophages are activated in the course of beta cell destruction, and hence the insulin in the lysosomes. Such macrophagic cells were shown to exist in the islets of non-diabetic mice9. While nonobese diabetic (NOD) mice are shown to express MHC class II antige,~s before lymphocytic infiltration into the islet 10, no comparative experiments have been reported with the non-obese normal (NON) mouse strain. In the light of recent evidence, it would indeed be very interesting to go back to the original tissue from patients and perform electron microscope studies to see if such macrophages are the source of the double-positive cells of the diabetic isl ~.ts of L.~ngerhans. If this is so, it would mean that we have to develop anew the framework for the pathogenesis of Type t diabetes, but then, why not? Immunology is such a rapidly changing field that we cannot hope that all has been said about the pathogenesis of Type I diabetes. We see a unique opportunity for obtaining more information on the pathogenesis, primarily from animal models, and then formulating hypotheses in the light of current immunological knowledge. Note added in proof: After this letter was submitted we became aware of recent work (Farr, A.G., Mannschreck,J.W. and Anderson, S.K. (1988) Diabetes 37, 1373-1379) showing that MHC class II
149
-fellers References 1 Parham,P. (1988) IVature 333, 500-503 2 Bottazzo,G.F., Dean, B.M., McNally, J.M. et al.(1985) New Engl. J. Med. 313, 353-360 3 Foulis,A.K., Farquharson,M.A. and Hardman, R. (1987) Diabetologia 28, Antonia Pantelidou 333-343 George K. Papadopoulos 4 PujoI-Borrell,R., Todd, I., Doshi, M. et al. (1987) Nature 326, 304-306 Laboratory of BiologicalChemistry,Medical 5 Wright, J.R., Lacy, P.E.,Unanue, E.R., School, Universityof Ioannina, GR453 32 Muszynski,C. and Haupffeld, V. (1986) loanui.,J, ~,~ ~'Y'~ Diabetes 35, 1174-1177
expression in streptozotocin-induced diabetic mice (strain C57BUKsJ)was lii lited to cells of the ductular epithelium assooat~d vvith the exocrine pancreas. There was also transient MHC class II ~xp,-ession by vascular endothelial cells but not by islet endocrine cells.
Immunology today, Vol. 10. No. 5, 1989
6 Dean, B.M., Walker, R., Bone,A.J., Baird, J.D. and Cooke, A. (1985) Diabetolo~ia 28, 464--466 7 Pipeleers,D.G., in't Veld, P.A., Pipeleers-Marichal,M., Gepts, W. and Van De Winkel, M. (1987) Diabetes 36, 872-876 R In't Veld, P.A.and Pipeleers,D.G. (1988) J. Clin. Invest. 82, 1123-1128 9 Farr,A.G. and Anderson, S.K. (1985) Diabetes 34, 987-990 10 Hanafusa,T., Fujino-Kurihara,H., Miyazaki, A. etal. (1987) Diabetologia 30, 104-108
Reply to Pantelidou and Papadopoulos
the demonstration that in the islets R. PujoI-Borrell of streptozotocin-induced and BB Hospital 'GermansTriasi Pujol" Universidad diabetic rats the insulin-containing Aut6noma de Barcelona,PO Box 72, 08916 Sir, cells also show macrophage feaeadalona, Spain. The letter by Pantelidou and Papa- tures. However, these observations dopoulos raises some doubts on do not apply to the human situation, whether islet beta cells do express where double-labeling experiments I-ILA c!~s~ ii n~olccu!es in the pan- carried out by Alan Foulis1 using Reference creas of newly diagnosc-,d diabetic mAb against T200 rule out this 1 Foulis,A. K. and Farquharson,M. A. patients. They base these doubts on possib=lity. (19;36)Diabetes 35, 121 5-1224
Our preliminary data showed significantly increased concentrations of IFN-lt in AIDS patients5. A more detailed study confirms these results and shows a close correlation beSir: __tweenthe !FN-~, levels and neoptefin R.M. Zinkemagel (Imrnunol. Today, concentrations6. We also found in1988, 9, 370-372) recently pro- creased kynurenine and decreased posed a possible role for cytotoxic T tryptophan concentrations in the cells in the development of AIDS by blood of patients with HIV infeceliminating CD4 + cells infected w,th tion 7. These data can be referred human immunodeficiency virus to activity of indoleamine(2,3)(HIV). The assumption is based on dioxygenase and this enzyme is data obtained from mice during induced by IFN-~8. Circulating lymphocytic choriorneningitis virus IFN-~ in patients with HIV infection (LCMV) infection 1. is of particular interest since lymphoIf cytotoxicity of T cells plays a role kines can induce reproduction of HIV in the immunopathogenesis of AIDS, in latently infected cells9.10. markers of stimulated immune reThe presence of IFN-~/in patients sponse should be detectable and with HIV infection shows on the one parallel or even precede the course hand that reduced capacity of T cells of disease in patients infected by to produce IFN-~/ on stimulation in HIV. We have accumulated data vitro does not necessarily reflect the from neopterin measurements that in-vivo situation 2. On the other suggest that early events of T-cell hand, macrophages respond to and macrophage interaction are acti- IFN-~/production releasing neopterin vated in patients with HIV infection and degrading tryptophan via the and cellular immune activation is kynurenine pathway. The induction most expressed in AIDS2. Increasing of specific enzymic pathways shows neopterin levels precede a sub- that the IFN-~/ detected is actively sequent loss of CD4 + T cells3.4. recognized by macrophages. Neopterin is a product of macroIn conclusion, our data fully supphages that are stimulated with port the concept proposed by R.M. gamma-interferon (IFN-~/). Zinkernagel.
Cell-mediated immunoreactivity in AIDS
150
Dietmar Fuchs~ Ernst R. Wemer ~ ..U.anfred P. D~erich2J Helmut Wachter~ i institute of Medical Chemistryand Biochemistry,and 2Institute of Hygiene, Universityof lnnsbruck, and 3Ludwiq Boltzmann Institute of AIDS Research,A-6020 Innsbruck, Austria.
References 1 Leist,T.P., Eppler, M., Ruedi, E. and Zinkernagel, R.M. (1988)J. Exp. Med. 167, 1749-1754 2 Fuchs,D., Hausen,A., Reibnegger,G. et aL (1988) Immunol. Today9, 150-155 3 Fuchs,D., Banekovich,M., Hausen,A. et al. (1988) Clin. Chem. 34, 2415-2417 4 Melmed, R.N.,Taylor,J.M.G., Detels, R., Bozorgmehri, M. and Fahey,J.L.J. AIDS (in press) 5 Fuchs,D. and Wachter, H. (1988)Brit. Meal. J. 297, 422-423 6 Fuchs,D., Hausen,A., Reibnegger,G. et al. J. AIDS (in press) 7 Werner, E.R.,Fuchs,D., Hausen,A. et al. (1988) Biol. Chem. Hoppe-Seyler 369, 337-340 8 Takikawa,O., Kuroiwa,T., Yarnazaki, F. and Kido, R. (1988)J. Biol. Chem. 263, 2041-2043 9 Siliciano,R.F.,Lawton, T., Knall, C. et al. (1988) Cell 54, 561-575 10 Koyanagi,Y., O'Brien, W.A., Zhao, J.O. et al. (1988)Science241, 1673-1675 (~) 1989, ElsevierSciencePublishersLtd, UK. 0167-4919189/$02.00