Immunology Today,voL 8, No. 3, 1987 .............."~,, :~, .............
.......................,-, .............................
.,~ ~..................
Experimentalautoimmune thyroiditis inducedby recombinantinterferon-~/ Sir, In mice with experimental autoimmune thyroiditis (EAT)~,-~ and in Hashimoto thyroiditis patients 3, T cells reactive with homogeneic or syngeneic thyroglobulin (Tg) can be demonstrated. The detection of class II major histocompatibility antigens on murine" or human thyroid cells5 and the modulation of this expression by interferon (IFN)-,y (Ref. 6) favors the hypothesis that class II antigen expression on thyroid epithelial cells (TEC) could be the primary event in the pathoger'esis of thyroiditis, the TEC being able to present thyroid antigen directly to helper T cells to initiate and perpetuate the diseasez. D. Rayner has recently suggested that IFN-~/not only induces class II antigen expression but also affects the susceptibility of TEC to cytotoxins such as tumor necrosis factor (TNF)8 [reported by A. Co,.,,,,. and colleagues (lmmunol. Today, 1986, 7, 325)J. The interplay between multiple cells and multiple cytokines may influence the result at the end organ level. Recent experiments in our laboratory appear to further clarify the triggering of thyroiditis. ,,~ u~ylu,u ylcsrlu~ two groups of 8-10 week-old CBA mice were injected with either one unit of murine recombinant IFN-~/ (rlFN--y), or the saline used to dilute the rlFN-~/. Using enzyme-linked immunoassay, anti-Tg antibodies were found in the 21 and 28 day sera of approximately 70% of the mice injected with rlFN-~t, but in none of the control sera. On blind examination of six to eight sections, each thyroid gland from animals which were injected with rlFN--/, including those from mice with no anti-Tg antibodies, exhibited all the typical histological criteria of th~roiditis, whereas those from the control group showed no such signs. There is a report of increased levels of IFN in sera from active rheumatoid disease patients9 and the enhanced production of IgM rheumatoid factor in-vitro by lymphocytes from rheumatoid arthritis patients in the presence of tFN (Ref. 10). Thyroid dysfunction and clinical hypothyroidism have been noted in @ 1987, [~sevJer Pubhcatlons, Cambridge
0167
~,,~...~:, ............. ~,~,~,...... • ........................... .............. ..........................
cancer patients treated with IFN-o~ (Ref. 11-13); in some of them, thyroid dysfunction was supposed to be due to IFN-5 contamination of the IFN-oL preparation 1~. In our experiments the rIFN-~ excluded such contaminants. Moreover, as a nonglycosylated molecule, it is known to be much less active than the natural product, indicating that in vivo minute local concentrations of IFN--y could be responsible for thyroiditis in genetically susceptible animals or people. The occurrence of EAT after injection of rlFN-~ permits investigation of whether class II antigen expression in vivo is secondary to lymphocytic infiltration rather than responsible for its initiation 14. Our results seem to favor a process of initiation by IFN--y. However, the very early events inducing thyroid gland invasion by lymphocytes are still poorly understood and at least two mechanisms can be postulated. A few contaminating and silent lymphocytes may be present in each thyroid gland from genetically susceptible strains of animals or humans, these lymphocytes being activated and able to proliferate when TEC become class II-am.igen-positive. Alternatively, lymphocyte attracting factors may be secreted by TEC in the presence of IFN-~/, triggering invasion of the thyroid gland by lymphoid cells. This second mechanism, which is comparable to the production of TNF by TEC, needs investigation.
Jean-Jacques Remy, Jean Salamero INSERMU. 283, H6pitalCochin
Marc MicheI-Bechet Facultede Medecine5ecteurNord, 13326 Marseille Cedex 75, France
Jeannine Charreire INSERMU. 283, H6pital Cochin, 75674 Paris Cedex 14, France
References 1 Rose,N.R., Kong, Y.C., Okayasu, I. et aL (1981) lmmunol. Rev. 55, 299- 314 2 Cha~reire,J. and MicheI-Bechet,M. (1982) Eur. J. ImmunoL 12,421-425 3 Canonica,G.W., Caria, M., Bagnasco, M. etal. (1985) C/in. Immunol. ImmunopathoL 36, 40--48 4 5alamero,J., Michel~Bechet,M. and Charmire, J. (1981) CR. Acad. Sci. [1111 293,745-750 5 Pujol-Borreff,it., Hanafusa,T., Chiovato, L. and Bottazzo, G.F.(1983) Nature (London) 304, 71-73
4g79/87/$02 00
. ...............................................
,~:! ~i! I ~!~i i~!)i,~@, ::i' i,:i~i~ ~.........
6 Salamero,J., Michel-Bechet,M., Wietzerbin, J. and Charreire,J. (1985) TissueAntigens 25, 266-277
7 Bottazzo,G.F., PujoI-Borrell,R., Hanafusa,T. and Feldmann,M. (1983) Lancet ii, 1115-1119 8 Cooke, A., Rayner,D. and Lydyard,P. (1986) Immunol. Today 7, 325-327 9 Hooks,J.J., Moutsopoulos,H.M., Geis, S.A. etaL (1979)N. EngL J. Med. 301, 5-8 10 Rodriguez,MA., Prinz,W.A.. Sibbitt, W.L etal. (1983)Arthritis Rheum. 26, 1091- 1097 11 Burrnan,P., Karlsson,F.A., Oberg, K. and Aim, G. (1985)Lancetii, 100-101 12 Mowat, A. (1985) Lancetii, 283 13 Bhakri, H., Sriskandan,K., Davis,T. et aL (1985) Lancet ii, 457 14 twatani, Y., Gerstein, H.C., litaka, M. et aL (1986)J. Clin. Endocrinol. Metab. 63,695-708
Do natural autoantibodies prevent autoimmune disease? Sir, We wish to endorse I. R. Cohen and A. Cooke's proposal (Immunol. Today, 1987, 7, 363-364) that certain natural autoantibodies often prevent, rather than cause, autoimmune diseases. Indeed, we go fu~her and argue that an endogenous defence system based on immunoglobulins operates, with greater or lesser effectiveness, against many types of disorder. Burnet's idea ~ that forbidden clones arise from stem cells that have undergone somatic gene mutation has been tested by analysing the age-dependence of diseases that are usually regarded as autoimmune 2.3 and, subsequently, of disorders of many types - fatal and non-fatal, neoplastic and non-neoplastic, infectious and allergic 4.s. We conclude that each well-defined and accurately diagnosed disorder with a reproducible age-pattern is initiated by random events with properties that we attribute to a special type of somatic gene mutation 4.s. For many reasons we infer that these initiating somatic mutations occur in stem cei!s that serve normally as comparators in the central system of growth control 3-6. A mutant stem cell propagates, under certain conditions, a forbidden clone of descendant cells. Peripheral cells of the clone (m~tant T lymphocytes), or humoral products (never immunogiobulins) secreted,
73
Immunology Today !1ol 8. NO 3, 1987 .
possibly by mast cells, attack target are not generally regarded as infeccells that bear complementary rec- tious, or allergic, including our main ognition factors (major and minor killer, acute myocardial infarction 7. A mutant growth control stem cell histocompatibility, tissue-specific and mosaic-specific antigens) to is, in effect, 'non self' by virtue of its cause 'autoaggressive ° disease. mutant status. Its contact with conThat acute and infectious diseases tiguous non-mutant, and therefore fall into this general category has a complementary, cells often causes particular significance in the present both types to be damaged, with the context. Reproducibility of the form release of self and, in effect, non-self of the age-pattern in high and low antigens. These antigens elicit a epidemic years and from country to humoral (IgM and IgG)immune recountry implies that host factors de- sponse and thus the emergence of termine whether or not an infected autoantibodies both in health (when person will deve!op the associated the mutant stem cells stay suppresdisease4.5. These factors are the sed) and in dis~3se (when mutant presence in the host of one or more stem cell~ propagate forbidden mutant growth-control cells that clone~). An autoaggressive attack on remain suppressed by the target cells often results in further immunoglobulin-based defence sys- antigenic debris and consequent imtem in the absence of a competing munoglobulin autoantibodies. In this microorganism (or allergen where unified theory of growth and disease allergic diseases are concerned) and immunoglobulin autoantibodies are hence fail to propagate pathogenic never the primary pathogens in forbidden clones. A similar mechan- autoaggressive (including autoism can be inferred for diseases that immune) disease; to the contrary,
which appears to play an important role in the binding to the ELISA plates. However, this ssDNA was not detected after coating under our Sir, technica! conditions and, in agreeThe claim by S. Ghcsh and A. M. ment with previous studies 1, $1 nucCampbell :immunoL Today, 1986, 7, lease treatment of the plates did not 355) that ELISA is unreliable for the modify the results of the anti-dsDNA measurement of antibodies to assay (except for plates that were double-stranded (ds) DNA because kept at 4°C without caution, where of the detection of antibodies to denaturation occurred within a few single-stranded (ss) DNA cannot be days). Inhibition experiments have left unanswered because of its im- led to the same conclusion 2. The portant practical implications in value of ELISA for the detection of clinical immunology. We have been anti-dsDNA antibodies is illustrated using such an ELISA routinely for by our results in more than 400 several years: plates coated with antinuclear antibody containing 5 i~g/ml calf thymus DNA are used sera. There was a very good correlaeither immediately or after short (less tion with the Farr assay except that than 2 months) storage at -80°C. ELISA was more sensitive in systemic The problem of anti-ssDNA anti- lupus erythematosus (SLE). Very high bodies was, of course, a major con- titer antibodies were found by ELISA cern and we examined it from four in active SLE exclusively. Antibodies approaches: (1) $1 nuclease treat- belonging to the three main imment of the DNA in solution before munoglobulin classes, to IgG and coating and of the coated plates; (2) IgM or IgG and IgA were usually comparison with ELISAplates coated present at high titer and virtually with ssDNA, (3) use of sera from restricted to SLE, except for antipatients with drug-induced lupus bodies from a few patients with acthat contained high titer anti-ssDNA tive chronic hepatitis, scleroderma, antibodies and none or virtually no rheumatoid arthritis or Sj0gren's anti-ds DNA antibodies as controls; syndrome 3.4. In contrast, we found and (4) comparison with the Farr low titer IgM antibodies in certain assay. patients without SLE, which is not The results showed that calf thy- surprising since normal lymphoid tismus DNA indeed contains ssDNA sue in vitro produce anti-dsDNA anti-
Anti-DNAantibodiesby ELISA
74
.
.
.
.
.
.
.
they often suppress the growth of forbidden clones.
P. R. J. Burch N. R. Rowell Departmentsof MedicalPhysicsand Dermatology, Universi~of Leeds,TheGeneral Infirmary, LeedsLS13EX,UK References 1 Burnet, F. M. (1959) The Clonal Selection Theory of Acquired Immunity, Vanderbilt UniversityPress,Nashville 2 Burch, P. R. J. and Rowell, N. R. (1963) Lancet ii, 507-513 3 Burch, P. R. J. and Rowell, N. R. (1968) Acta Dermatol. Venereol. Stockholm 48, 33--46 4 Burch, P. R. J. (1968)An Inquiry Concerning Growth, Diseaseand Ageing, Oliver & Boyd, Edinburgh 5 Burch, P. R. J. (1976) The Bio/ogy of Cancer. A New Approach, MPT Press, Lancaster 6 Burch, P. R. J. and Burwell, R. G. (1965) O. Rev. Biol. 40, 252-279 7 Burch, P. R. J. (1980) Cardiovasc. Res. 14, 307-338
bodies of the IgM but not of the IgG classs and since, as discussed by Isenberg et al. 6, hybridomas secreting IgM anti-dsDNA may be derived from normal subjects. Specificity of such IgM monoclonal antibodies derived from normal lymphocytes has been demonstrated by methods other than ELISA, such as inhibition radioimm,-noassay 7.
Jean-Louis Preud'Homme Laboratoryof Immunologyand Immunopathology, (O,'RSUA 1172),Poitiers JniversityHospital, .%021PoitiersCedex, France
References 1 Klotz, J. L., Minami, R. M. and Teplitz, R. L. (1979)J. ImmunoL Meth. 29, 155-165 2 Gripenberg, M. and Kurki, P. (1986) J. ImmunoL Meth. 92, 145-159 3 Stollar, B. D. (1981)Clin. ImmunoL Allergy 1,243-260 4 Tan, E. M. (1982)Adv. ImmunoL 33, 167-240 5 Cairns, E., Germain,J. and Bell, D. A. (1985)J. ImmunoL 135, 3839-3844 6 Isenberg,D., Dudeney,C. and Williams, W. (1986) Immunol. Today 12, 354--355 7 Hoch, S. and Schwaber,J. (1986) J. Immunol. 136, 892-897
~ 1987, ElsevierPubhcatlon5,Cambndge 0167 4919/87/$02 00
.......................,-, .............................
.,~ ~..................
Experimentalautoimmune thyroiditis inducedby recombinantinterferon-~/ Sir, In mice with experimental autoimmune thyroiditis (EAT)~,-~ and in Hashimoto thyroiditis patients 3, T cells reactive with homogeneic or syngeneic thyroglobulin (Tg) can be demonstrated. The detection of class II major histocompatibility antigens on murine" or human thyroid cells5 and the modulation of this expression by interferon (IFN)-,y (Ref. 6) favors the hypothesis that class II antigen expression on thyroid epithelial cells (TEC) could be the primary event in the pathoger'esis of thyroiditis, the TEC being able to present thyroid antigen directly to helper T cells to initiate and perpetuate the diseasez. D. Rayner has recently suggested that IFN-~/not only induces class II antigen expression but also affects the susceptibility of TEC to cytotoxins such as tumor necrosis factor (TNF)8 [reported by A. Co,.,,,,. and colleagues (lmmunol. Today, 1986, 7, 325)J. The interplay between multiple cells and multiple cytokines may influence the result at the end organ level. Recent experiments in our laboratory appear to further clarify the triggering of thyroiditis. ,,~ u~ylu,u ylcsrlu~ two groups of 8-10 week-old CBA mice were injected with either one unit of murine recombinant IFN-~/ (rlFN--y), or the saline used to dilute the rlFN-~/. Using enzyme-linked immunoassay, anti-Tg antibodies were found in the 21 and 28 day sera of approximately 70% of the mice injected with rlFN-~t, but in none of the control sera. On blind examination of six to eight sections, each thyroid gland from animals which were injected with rlFN--/, including those from mice with no anti-Tg antibodies, exhibited all the typical histological criteria of th~roiditis, whereas those from the control group showed no such signs. There is a report of increased levels of IFN in sera from active rheumatoid disease patients9 and the enhanced production of IgM rheumatoid factor in-vitro by lymphocytes from rheumatoid arthritis patients in the presence of tFN (Ref. 10). Thyroid dysfunction and clinical hypothyroidism have been noted in @ 1987, [~sevJer Pubhcatlons, Cambridge
0167
~,,~...~:, ............. ~,~,~,...... • ........................... .............. ..........................
cancer patients treated with IFN-o~ (Ref. 11-13); in some of them, thyroid dysfunction was supposed to be due to IFN-5 contamination of the IFN-oL preparation 1~. In our experiments the rIFN-~ excluded such contaminants. Moreover, as a nonglycosylated molecule, it is known to be much less active than the natural product, indicating that in vivo minute local concentrations of IFN--y could be responsible for thyroiditis in genetically susceptible animals or people. The occurrence of EAT after injection of rlFN-~ permits investigation of whether class II antigen expression in vivo is secondary to lymphocytic infiltration rather than responsible for its initiation 14. Our results seem to favor a process of initiation by IFN--y. However, the very early events inducing thyroid gland invasion by lymphocytes are still poorly understood and at least two mechanisms can be postulated. A few contaminating and silent lymphocytes may be present in each thyroid gland from genetically susceptible strains of animals or humans, these lymphocytes being activated and able to proliferate when TEC become class II-am.igen-positive. Alternatively, lymphocyte attracting factors may be secreted by TEC in the presence of IFN-~/, triggering invasion of the thyroid gland by lymphoid cells. This second mechanism, which is comparable to the production of TNF by TEC, needs investigation.
Jean-Jacques Remy, Jean Salamero INSERMU. 283, H6pitalCochin
Marc MicheI-Bechet Facultede Medecine5ecteurNord, 13326 Marseille Cedex 75, France
Jeannine Charreire INSERMU. 283, H6pital Cochin, 75674 Paris Cedex 14, France
References 1 Rose,N.R., Kong, Y.C., Okayasu, I. et aL (1981) lmmunol. Rev. 55, 299- 314 2 Cha~reire,J. and MicheI-Bechet,M. (1982) Eur. J. ImmunoL 12,421-425 3 Canonica,G.W., Caria, M., Bagnasco, M. etal. (1985) C/in. Immunol. ImmunopathoL 36, 40--48 4 5alamero,J., Michel~Bechet,M. and Charmire, J. (1981) CR. Acad. Sci. [1111 293,745-750 5 Pujol-Borreff,it., Hanafusa,T., Chiovato, L. and Bottazzo, G.F.(1983) Nature (London) 304, 71-73
4g79/87/$02 00
. ...............................................
,~:! ~i! I ~!~i i~!)i,~@, ::i' i,:i~i~ ~.........
6 Salamero,J., Michel-Bechet,M., Wietzerbin, J. and Charreire,J. (1985) TissueAntigens 25, 266-277
7 Bottazzo,G.F., PujoI-Borrell,R., Hanafusa,T. and Feldmann,M. (1983) Lancet ii, 1115-1119 8 Cooke, A., Rayner,D. and Lydyard,P. (1986) Immunol. Today 7, 325-327 9 Hooks,J.J., Moutsopoulos,H.M., Geis, S.A. etaL (1979)N. EngL J. Med. 301, 5-8 10 Rodriguez,MA., Prinz,W.A.. Sibbitt, W.L etal. (1983)Arthritis Rheum. 26, 1091- 1097 11 Burrnan,P., Karlsson,F.A., Oberg, K. and Aim, G. (1985)Lancetii, 100-101 12 Mowat, A. (1985) Lancetii, 283 13 Bhakri, H., Sriskandan,K., Davis,T. et aL (1985) Lancet ii, 457 14 twatani, Y., Gerstein, H.C., litaka, M. et aL (1986)J. Clin. Endocrinol. Metab. 63,695-708
Do natural autoantibodies prevent autoimmune disease? Sir, We wish to endorse I. R. Cohen and A. Cooke's proposal (Immunol. Today, 1987, 7, 363-364) that certain natural autoantibodies often prevent, rather than cause, autoimmune diseases. Indeed, we go fu~her and argue that an endogenous defence system based on immunoglobulins operates, with greater or lesser effectiveness, against many types of disorder. Burnet's idea ~ that forbidden clones arise from stem cells that have undergone somatic gene mutation has been tested by analysing the age-dependence of diseases that are usually regarded as autoimmune 2.3 and, subsequently, of disorders of many types - fatal and non-fatal, neoplastic and non-neoplastic, infectious and allergic 4.s. We conclude that each well-defined and accurately diagnosed disorder with a reproducible age-pattern is initiated by random events with properties that we attribute to a special type of somatic gene mutation 4.s. For many reasons we infer that these initiating somatic mutations occur in stem cei!s that serve normally as comparators in the central system of growth control 3-6. A mutant stem cell propagates, under certain conditions, a forbidden clone of descendant cells. Peripheral cells of the clone (m~tant T lymphocytes), or humoral products (never immunogiobulins) secreted,
73
Immunology Today !1ol 8. NO 3, 1987 .
possibly by mast cells, attack target are not generally regarded as infeccells that bear complementary rec- tious, or allergic, including our main ognition factors (major and minor killer, acute myocardial infarction 7. A mutant growth control stem cell histocompatibility, tissue-specific and mosaic-specific antigens) to is, in effect, 'non self' by virtue of its cause 'autoaggressive ° disease. mutant status. Its contact with conThat acute and infectious diseases tiguous non-mutant, and therefore fall into this general category has a complementary, cells often causes particular significance in the present both types to be damaged, with the context. Reproducibility of the form release of self and, in effect, non-self of the age-pattern in high and low antigens. These antigens elicit a epidemic years and from country to humoral (IgM and IgG)immune recountry implies that host factors de- sponse and thus the emergence of termine whether or not an infected autoantibodies both in health (when person will deve!op the associated the mutant stem cells stay suppresdisease4.5. These factors are the sed) and in dis~3se (when mutant presence in the host of one or more stem cell~ propagate forbidden mutant growth-control cells that clone~). An autoaggressive attack on remain suppressed by the target cells often results in further immunoglobulin-based defence sys- antigenic debris and consequent imtem in the absence of a competing munoglobulin autoantibodies. In this microorganism (or allergen where unified theory of growth and disease allergic diseases are concerned) and immunoglobulin autoantibodies are hence fail to propagate pathogenic never the primary pathogens in forbidden clones. A similar mechan- autoaggressive (including autoism can be inferred for diseases that immune) disease; to the contrary,
which appears to play an important role in the binding to the ELISA plates. However, this ssDNA was not detected after coating under our Sir, technica! conditions and, in agreeThe claim by S. Ghcsh and A. M. ment with previous studies 1, $1 nucCampbell :immunoL Today, 1986, 7, lease treatment of the plates did not 355) that ELISA is unreliable for the modify the results of the anti-dsDNA measurement of antibodies to assay (except for plates that were double-stranded (ds) DNA because kept at 4°C without caution, where of the detection of antibodies to denaturation occurred within a few single-stranded (ss) DNA cannot be days). Inhibition experiments have left unanswered because of its im- led to the same conclusion 2. The portant practical implications in value of ELISA for the detection of clinical immunology. We have been anti-dsDNA antibodies is illustrated using such an ELISA routinely for by our results in more than 400 several years: plates coated with antinuclear antibody containing 5 i~g/ml calf thymus DNA are used sera. There was a very good correlaeither immediately or after short (less tion with the Farr assay except that than 2 months) storage at -80°C. ELISA was more sensitive in systemic The problem of anti-ssDNA anti- lupus erythematosus (SLE). Very high bodies was, of course, a major con- titer antibodies were found by ELISA cern and we examined it from four in active SLE exclusively. Antibodies approaches: (1) $1 nuclease treat- belonging to the three main imment of the DNA in solution before munoglobulin classes, to IgG and coating and of the coated plates; (2) IgM or IgG and IgA were usually comparison with ELISAplates coated present at high titer and virtually with ssDNA, (3) use of sera from restricted to SLE, except for antipatients with drug-induced lupus bodies from a few patients with acthat contained high titer anti-ssDNA tive chronic hepatitis, scleroderma, antibodies and none or virtually no rheumatoid arthritis or Sj0gren's anti-ds DNA antibodies as controls; syndrome 3.4. In contrast, we found and (4) comparison with the Farr low titer IgM antibodies in certain assay. patients without SLE, which is not The results showed that calf thy- surprising since normal lymphoid tismus DNA indeed contains ssDNA sue in vitro produce anti-dsDNA anti-
Anti-DNAantibodiesby ELISA
74
.
.
.
.
.
.
.
they often suppress the growth of forbidden clones.
P. R. J. Burch N. R. Rowell Departmentsof MedicalPhysicsand Dermatology, Universi~of Leeds,TheGeneral Infirmary, LeedsLS13EX,UK References 1 Burnet, F. M. (1959) The Clonal Selection Theory of Acquired Immunity, Vanderbilt UniversityPress,Nashville 2 Burch, P. R. J. and Rowell, N. R. (1963) Lancet ii, 507-513 3 Burch, P. R. J. and Rowell, N. R. (1968) Acta Dermatol. Venereol. Stockholm 48, 33--46 4 Burch, P. R. J. (1968)An Inquiry Concerning Growth, Diseaseand Ageing, Oliver & Boyd, Edinburgh 5 Burch, P. R. J. (1976) The Bio/ogy of Cancer. A New Approach, MPT Press, Lancaster 6 Burch, P. R. J. and Burwell, R. G. (1965) O. Rev. Biol. 40, 252-279 7 Burch, P. R. J. (1980) Cardiovasc. Res. 14, 307-338
bodies of the IgM but not of the IgG classs and since, as discussed by Isenberg et al. 6, hybridomas secreting IgM anti-dsDNA may be derived from normal subjects. Specificity of such IgM monoclonal antibodies derived from normal lymphocytes has been demonstrated by methods other than ELISA, such as inhibition radioimm,-noassay 7.
Jean-Louis Preud'Homme Laboratoryof Immunologyand Immunopathology, (O,'RSUA 1172),Poitiers JniversityHospital, .%021PoitiersCedex, France
References 1 Klotz, J. L., Minami, R. M. and Teplitz, R. L. (1979)J. ImmunoL Meth. 29, 155-165 2 Gripenberg, M. and Kurki, P. (1986) J. ImmunoL Meth. 92, 145-159 3 Stollar, B. D. (1981)Clin. ImmunoL Allergy 1,243-260 4 Tan, E. M. (1982)Adv. ImmunoL 33, 167-240 5 Cairns, E., Germain,J. and Bell, D. A. (1985)J. ImmunoL 135, 3839-3844 6 Isenberg,D., Dudeney,C. and Williams, W. (1986) Immunol. Today 12, 354--355 7 Hoch, S. and Schwaber,J. (1986) J. Immunol. 136, 892-897
~ 1987, ElsevierPubhcatlon5,Cambndge 0167 4919/87/$02 00
