TH2 and TH1 are different stages of a linear pattern of T lineages differentiation
Until basic immunology has been imprinted by the static view in which
the cells at periphery had to be mature, only a divergent interpretation
of the TH2/TH1 paradigm was available.
Cumulated evidence for maturational events occurring at the periphery, in
allergic diseases, support the concept of a peripheral leukocytopoiesis as
a common origin for the allergic systemic inflammation (1-4). Consequently
a more recent version of the paradigma has been developed: TH2 represent
the early and TH1 the late stages of a linear model of differentiation (5-
6). TH2 can ultimate their differentiation into TH1 only under the
maturational influence of IL12 and IFNgamma. Functionally distinct helper
populations (H2 and H1), with distinct cytokine profiles, have been well
identified as belonging to different stages of a linear developmental
process, in other leukocyte lineages such as Natural Killer (NK)(7-8) and
Dendritic Cells (DC)(9-10).
Concluding, since receptors for Th2 cytokines and chemokines are expressed
at the very early stages of T- ontogeny (CD34+ Lymphoid Stem cell),
Investigators should experimentally prove that TH2 cells are mature and
actually express the T-cell Receptor (11).
1.Kim, Y.K., Uno, M., Hamilos, D.L., Beck, L. et al.
Immunolocalization of CD34 in nasal polyposis. Am J Respir Cell Mol Biol
1999, 20: 388-97.
2.Mastrandrea, F., Cadario, G., Nicotra, M.R. et al. Hemopoietic
progenitor cells in atopic dermatitis skin lesions. Invest Allergol Clin
Immunol 1999, 9: 386-91.
3.Cyr MM, Denburg JA. Systemic aspects of allergic diseases: the role of
the bone marrow. Curr Opin Immunol 2001, 13: 727-32.
4.Mastrandrea F, Coradduzza G, De Vita L et al. CD34+ cells in peripheral
blood of healthy human beings and allergic subjects: clue to acute and
minimal persistent inflammation. Allergol et Immunopathol 2002; 30: 209-17
5.Mastrandrea F. Immunotherapy in atopic dermatitis. Exp Opin Invest Drugs
2001; 10: 49-63
6.Loza MJ, Perussia B. Peripheral immature CD2-/low T cell development
from type 2 to type 1 cytokine production. J Immunol 2002; 169: 3061-8
7.Loza MJ, Perussia B. Final steps of natural killer cell maturation: a
model for type 1- type2 differentiation. Nat Immunol 2001; 2: 917-24
8.Loza MJ, Zamai L, Azzoni L, Rosati E, Perussia B. Expression of type 1
(interferon gamma) and type 2 (interleukin-13, interleukin-5) cytokines at
distinct stages of natural killer cell differentiation from progenitor
cells. Blood 2002; 99: 1273-81
9.Gadue P, Stein PL. NK T cell precursors exhibit differential cytokine
regulation and require Itk for efficient maturation. J Immunol 2002; 169:
2397-406
10.Klangsinsirikul P, Russell NH. Peripheral blood stem cell harvested
from G-CSF-stimulated donors contain a skewed Th2 CD4 phenotype and a
predominance of type 2 dendritic cells. Exp Hematol 2002; 30: 495-501
11.Mastrandrea F, Cadario G, Bedello PG, Nicotra MR, Natali PG. Expression
of T-lineage early developmental markers by cells establishing atopic
dermatitis skin infiltrates. Invest Allergol Clin Immunol 1998; 8: 359-364
Rapid Response:
TH2 and TH1 are different stages of a linear pattern of T lineages differentiation
Until basic immunology has been imprinted by the static view in which
the cells at periphery had to be mature, only a divergent interpretation
of the TH2/TH1 paradigm was available.
Cumulated evidence for maturational events occurring at the periphery, in
allergic diseases, support the concept of a peripheral leukocytopoiesis as
a common origin for the allergic systemic inflammation (1-4). Consequently
a more recent version of the paradigma has been developed: TH2 represent
the early and TH1 the late stages of a linear model of differentiation (5-
6). TH2 can ultimate their differentiation into TH1 only under the
maturational influence of IL12 and IFNgamma. Functionally distinct helper
populations (H2 and H1), with distinct cytokine profiles, have been well
identified as belonging to different stages of a linear developmental
process, in other leukocyte lineages such as Natural Killer (NK)(7-8) and
Dendritic Cells (DC)(9-10).
Concluding, since receptors for Th2 cytokines and chemokines are expressed
at the very early stages of T- ontogeny (CD34+ Lymphoid Stem cell),
Investigators should experimentally prove that TH2 cells are mature and
actually express the T-cell Receptor (11).
1.Kim, Y.K., Uno, M., Hamilos, D.L., Beck, L. et al.
Immunolocalization of CD34 in nasal polyposis. Am J Respir Cell Mol Biol
1999, 20: 388-97.
2.Mastrandrea, F., Cadario, G., Nicotra, M.R. et al. Hemopoietic
progenitor cells in atopic dermatitis skin lesions. Invest Allergol Clin
Immunol 1999, 9: 386-91.
3.Cyr MM, Denburg JA. Systemic aspects of allergic diseases: the role of
the bone marrow. Curr Opin Immunol 2001, 13: 727-32.
4.Mastrandrea F, Coradduzza G, De Vita L et al. CD34+ cells in peripheral
blood of healthy human beings and allergic subjects: clue to acute and
minimal persistent inflammation. Allergol et Immunopathol 2002; 30: 209-17
5.Mastrandrea F. Immunotherapy in atopic dermatitis. Exp Opin Invest Drugs
2001; 10: 49-63
6.Loza MJ, Perussia B. Peripheral immature CD2-/low T cell development
from type 2 to type 1 cytokine production. J Immunol 2002; 169: 3061-8
7.Loza MJ, Perussia B. Final steps of natural killer cell maturation: a
model for type 1- type2 differentiation. Nat Immunol 2001; 2: 917-24
8.Loza MJ, Zamai L, Azzoni L, Rosati E, Perussia B. Expression of type 1
(interferon gamma) and type 2 (interleukin-13, interleukin-5) cytokines at
distinct stages of natural killer cell differentiation from progenitor
cells. Blood 2002; 99: 1273-81
9.Gadue P, Stein PL. NK T cell precursors exhibit differential cytokine
regulation and require Itk for efficient maturation. J Immunol 2002; 169:
2397-406
10.Klangsinsirikul P, Russell NH. Peripheral blood stem cell harvested
from G-CSF-stimulated donors contain a skewed Th2 CD4 phenotype and a
predominance of type 2 dendritic cells. Exp Hematol 2002; 30: 495-501
11.Mastrandrea F, Cadario G, Bedello PG, Nicotra MR, Natali PG. Expression
of T-lineage early developmental markers by cells establishing atopic
dermatitis skin infiltrates. Invest Allergol Clin Immunol 1998; 8: 359-364
Competing interests:
None declared
Competing interests: No competing interests