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CTLA4-Ig (abatacept) therapy modulates T cell effector functions in autoantibody-positive rheumatoid arthritis patients.

Pieper J, Herrath J, Raghavan S, Muhammad K, Vollenhoven Rv, Malmström V - BMC Immunol. (2013)

Bottom Line: Additionally within the ACPA-positive group significant down-regulation of all key T cell effector subsets including Th1, Th2, and Th17 was observed by analyzing cytokines by intracellular flow cytometry and in cell culture supernatants.RA synovial fluid samples were cultured in vitro in the presence or absence of CTLA4-Ig (abatacept).Our immunological study of T cell functionality in RA patients, both ACPA-positive and ACPA-negative starting biological therapy with the co-stimulation blockade abatacept (CTLA4-Ig) supports the recently published registry study implicating ACPA seropositivity as an independent predictive factor to treatment response as we observed the most striking effect on T cell subset modulation in ACPA-positive patients.These data further support the notion of RA as a disease with several sub-entities, where the ACPA-positive fraction represents a classical HLA-associated autoimmune disorder while ACPA-negative patients may have other driving forces apart from classical adaptive immune responses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Rheumatology Unit, Department of Medicine at Karolinska University Hospital, Karolinska Institute, Solna, Stockholm, Sweden.

ABSTRACT

Background: Rheumatoid arthritis is a chronic inflammatory disease with a strong MHC class II component and where many patients develop characteristic autoantibodies towards the noncoding amino acid citrulline. Such anti-citrullinated protein antibodies (ACPA) have recently been put forward as an independent predictive factor for treatment response by co-stimulation blockade by CTLA4-Ig (abatacept). We have performed a mechanism of action study to dissect T cell functionality in RA patients with long-standing disease undergoing abatacept treatment and the influence of ACPA status.

Results: Peripheral blood samples were collected from RA patients as they started CTLA4-Ig treatment and 3 and 6 months later. A general decrease of regulatory T cell subsets was observed in the cohort. Additionally within the ACPA-positive group significant down-regulation of all key T cell effector subsets including Th1, Th2, and Th17 was observed by analyzing cytokines by intracellular flow cytometry and in cell culture supernatants.RA synovial fluid samples were cultured in vitro in the presence or absence of CTLA4-Ig (abatacept). T cell cytokine production was diminished, but without increasing the functional capacity of CD4+CD25hi regulatory T cells as previously demonstrated in the context of TNF-blockade and anti-IL6R therapy.

Conclusions: Our immunological study of T cell functionality in RA patients, both ACPA-positive and ACPA-negative starting biological therapy with the co-stimulation blockade abatacept (CTLA4-Ig) supports the recently published registry study implicating ACPA seropositivity as an independent predictive factor to treatment response as we observed the most striking effect on T cell subset modulation in ACPA-positive patients. These data further support the notion of RA as a disease with several sub-entities, where the ACPA-positive fraction represents a classical HLA-associated autoimmune disorder while ACPA-negative patients may have other driving forces apart from classical adaptive immune responses.

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Treg frequency is diminished. PBMCs from baseline and 3 months following treatment (n=12) were obtained and multicolor flow cytometry was performed. A general reduction in frequency of several Treg associated markers could be seen (A-G). (A) The graph depicts a representative staining of CD4+FOXP3+ Treg before and after treatment. (B) The graph displays CD4+FOXP3+ Treg, (C) Helios+ T cells, (D) CD4+CD39+ T cells, (E) CD45RA+FOXP3+ Treg, (F) CTLA4+ FOXP3+Treg, and (G) CD39+FOXP3+ Treg.
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Figure 4: Treg frequency is diminished. PBMCs from baseline and 3 months following treatment (n=12) were obtained and multicolor flow cytometry was performed. A general reduction in frequency of several Treg associated markers could be seen (A-G). (A) The graph depicts a representative staining of CD4+FOXP3+ Treg before and after treatment. (B) The graph displays CD4+FOXP3+ Treg, (C) Helios+ T cells, (D) CD4+CD39+ T cells, (E) CD45RA+FOXP3+ Treg, (F) CTLA4+ FOXP3+Treg, and (G) CD39+FOXP3+ Treg.

Mentions: A representative staining of FOXP3 expression before and after therapy is depicted in Figure 4A. A significant reduction in the frequency of FOXP3+ Tregs, Helios+ and CD39+ T cells was observed at 3 months as compared to baseline (Figure 4B-D). To dissect this further, we also analyzed the proportion of naïve thymus-derived Tregs based on CD45RA expression in conjunction with FOXP3, the proportion of Th17-suppressive Tregs based on CD39 expression, as well as the expression of the Treg effector molecule CTLA4. As shown in Figure 4E-G, all Treg subsets were considerably reduced at the 3 month time point. For 4 of the included patients, we also studied the Treg phenotype at 6 months and the decline in frequencies remained low, suggesting that this is a general outcome of costimulation-blockade and not a transient effect (Additional file 1: Figure S1).


CTLA4-Ig (abatacept) therapy modulates T cell effector functions in autoantibody-positive rheumatoid arthritis patients.

Pieper J, Herrath J, Raghavan S, Muhammad K, Vollenhoven Rv, Malmström V - BMC Immunol. (2013)

Treg frequency is diminished. PBMCs from baseline and 3 months following treatment (n=12) were obtained and multicolor flow cytometry was performed. A general reduction in frequency of several Treg associated markers could be seen (A-G). (A) The graph depicts a representative staining of CD4+FOXP3+ Treg before and after treatment. (B) The graph displays CD4+FOXP3+ Treg, (C) Helios+ T cells, (D) CD4+CD39+ T cells, (E) CD45RA+FOXP3+ Treg, (F) CTLA4+ FOXP3+Treg, and (G) CD39+FOXP3+ Treg.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3750242&req=5

Figure 4: Treg frequency is diminished. PBMCs from baseline and 3 months following treatment (n=12) were obtained and multicolor flow cytometry was performed. A general reduction in frequency of several Treg associated markers could be seen (A-G). (A) The graph depicts a representative staining of CD4+FOXP3+ Treg before and after treatment. (B) The graph displays CD4+FOXP3+ Treg, (C) Helios+ T cells, (D) CD4+CD39+ T cells, (E) CD45RA+FOXP3+ Treg, (F) CTLA4+ FOXP3+Treg, and (G) CD39+FOXP3+ Treg.
Mentions: A representative staining of FOXP3 expression before and after therapy is depicted in Figure 4A. A significant reduction in the frequency of FOXP3+ Tregs, Helios+ and CD39+ T cells was observed at 3 months as compared to baseline (Figure 4B-D). To dissect this further, we also analyzed the proportion of naïve thymus-derived Tregs based on CD45RA expression in conjunction with FOXP3, the proportion of Th17-suppressive Tregs based on CD39 expression, as well as the expression of the Treg effector molecule CTLA4. As shown in Figure 4E-G, all Treg subsets were considerably reduced at the 3 month time point. For 4 of the included patients, we also studied the Treg phenotype at 6 months and the decline in frequencies remained low, suggesting that this is a general outcome of costimulation-blockade and not a transient effect (Additional file 1: Figure S1).

Bottom Line: Additionally within the ACPA-positive group significant down-regulation of all key T cell effector subsets including Th1, Th2, and Th17 was observed by analyzing cytokines by intracellular flow cytometry and in cell culture supernatants.RA synovial fluid samples were cultured in vitro in the presence or absence of CTLA4-Ig (abatacept).Our immunological study of T cell functionality in RA patients, both ACPA-positive and ACPA-negative starting biological therapy with the co-stimulation blockade abatacept (CTLA4-Ig) supports the recently published registry study implicating ACPA seropositivity as an independent predictive factor to treatment response as we observed the most striking effect on T cell subset modulation in ACPA-positive patients.These data further support the notion of RA as a disease with several sub-entities, where the ACPA-positive fraction represents a classical HLA-associated autoimmune disorder while ACPA-negative patients may have other driving forces apart from classical adaptive immune responses.

View Article: PubMed Central - HTML - PubMed

Affiliation: Rheumatology Unit, Department of Medicine at Karolinska University Hospital, Karolinska Institute, Solna, Stockholm, Sweden.

ABSTRACT

Background: Rheumatoid arthritis is a chronic inflammatory disease with a strong MHC class II component and where many patients develop characteristic autoantibodies towards the noncoding amino acid citrulline. Such anti-citrullinated protein antibodies (ACPA) have recently been put forward as an independent predictive factor for treatment response by co-stimulation blockade by CTLA4-Ig (abatacept). We have performed a mechanism of action study to dissect T cell functionality in RA patients with long-standing disease undergoing abatacept treatment and the influence of ACPA status.

Results: Peripheral blood samples were collected from RA patients as they started CTLA4-Ig treatment and 3 and 6 months later. A general decrease of regulatory T cell subsets was observed in the cohort. Additionally within the ACPA-positive group significant down-regulation of all key T cell effector subsets including Th1, Th2, and Th17 was observed by analyzing cytokines by intracellular flow cytometry and in cell culture supernatants.RA synovial fluid samples were cultured in vitro in the presence or absence of CTLA4-Ig (abatacept). T cell cytokine production was diminished, but without increasing the functional capacity of CD4+CD25hi regulatory T cells as previously demonstrated in the context of TNF-blockade and anti-IL6R therapy.

Conclusions: Our immunological study of T cell functionality in RA patients, both ACPA-positive and ACPA-negative starting biological therapy with the co-stimulation blockade abatacept (CTLA4-Ig) supports the recently published registry study implicating ACPA seropositivity as an independent predictive factor to treatment response as we observed the most striking effect on T cell subset modulation in ACPA-positive patients. These data further support the notion of RA as a disease with several sub-entities, where the ACPA-positive fraction represents a classical HLA-associated autoimmune disorder while ACPA-negative patients may have other driving forces apart from classical adaptive immune responses.

Show MeSH
Related in: MedlinePlus