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The tyrosine kinase Itk suppresses CD8+ memory T cell development in response to bacterial infection.

Huang F, Huang W, Briggs J, Chew T, Bai Y, Deol S, August A - Sci Rep (2015)

Bottom Line: Here, we have examined the role of Itk, a tyrosine kinase critical for TcR signaling, in CD8(+) effector and memory T cell differentiation during Listeria monocytogenes infection.This is accompanied by increased early Eomesodermin, IL-7Rα expression and memory precursor effector cells.Furthermore, Itk is required for optimal cytokine production in responding primary effector cells, but not secondary memory responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology &Immunology, Cornell University, Ithaca, NY, 14853.

ABSTRACT
Vaccine efficacy depends on strong long-term development of immune memory and the formation of memory CD8(+) T cells is critical for recall responses to infection. Upon antigen recognition by naïve T cells, the strength of the TcR signal influences the subsequent effector and memory cells differentiation. Here, we have examined the role of Itk, a tyrosine kinase critical for TcR signaling, in CD8(+) effector and memory T cell differentiation during Listeria monocytogenes infection. We found that the reduced TcR signal strength in Itk deficient naïve CD8(+) T cells enhances the generation of memory T cells during infection. This is accompanied by increased early Eomesodermin, IL-7Rα expression and memory precursor effector cells. Furthermore, Itk is required for optimal cytokine production in responding primary effector cells, but not secondary memory responses. Our data suggests that Itk-mediated signals control the expression of Eomesodermin and IL-7Rα, thus regulating the development of memory CD8(+) T cells, but not subsequent response of memory cells.

No MeSH data available.


Related in: MedlinePlus

Itk tunes the expression of Eomes and development of MPECS during infection.Naïve WT or Itk−/− T cells were transferred separately into WT mice, which were infected with L. monocytogenes. Mice were bled on the indicated days and cells analyzed as indicated. (A) Cell number. (B) Bacterial numbers in liver determined from mice infected for day 2 or day 7, and. n = 4, 3 independent experiments, no bacteria detected. (C) Percent SLEC and MPEC. (D) Percent T-bet and Eomes. *p < 0.05, n = 3–8 mice, 3 independent experiments. (E) Flow cytometric analysis of the expression of CD127 (left panels) or Eomes (right panels) in representative mice. (F) Naïve WT or Itk−/− T cells were stimulated with 20 μg/ml OVA plus antigen presenting cells over 5 days. Cells were analyzed for expression of IRF4 by flow cytometry. n = 3. (G) IRF4 expression was determined by flow cytometry in WT or Itk−/− OTI/Rag−/− T cells following transfer into WT mice and infection with L. monocytogenes for 5 days. n = 3–8 mice, 3 independent experiments. All error bars indicate the value of +/−SEM.
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f2: Itk tunes the expression of Eomes and development of MPECS during infection.Naïve WT or Itk−/− T cells were transferred separately into WT mice, which were infected with L. monocytogenes. Mice were bled on the indicated days and cells analyzed as indicated. (A) Cell number. (B) Bacterial numbers in liver determined from mice infected for day 2 or day 7, and. n = 4, 3 independent experiments, no bacteria detected. (C) Percent SLEC and MPEC. (D) Percent T-bet and Eomes. *p < 0.05, n = 3–8 mice, 3 independent experiments. (E) Flow cytometric analysis of the expression of CD127 (left panels) or Eomes (right panels) in representative mice. (F) Naïve WT or Itk−/− T cells were stimulated with 20 μg/ml OVA plus antigen presenting cells over 5 days. Cells were analyzed for expression of IRF4 by flow cytometry. n = 3. (G) IRF4 expression was determined by flow cytometry in WT or Itk−/− OTI/Rag−/− T cells following transfer into WT mice and infection with L. monocytogenes for 5 days. n = 3–8 mice, 3 independent experiments. All error bars indicate the value of +/−SEM.

Mentions: We next examined Itk's role in the CD8+ T cell response in vivo during infection with L. monocytogenes carrying the model antigen Ovalbumin (LM-OVA). We transferred naïve WT or Itk−/− T cells into CD45.1 congenic WT mice, followed by infection with 5 × 105LM-OVA within 24 hours after adoptive transfer. Blood (and spleens) from infected mice were analyzed over time to monitor the response of the transferred T cells. Infection with LM-OVA resulted in similar expansion of WT and Itk−/− T cells 7–12 post infection, but while WT T cells underwent rapid contraction to a low number by day 21, a significantly higher number of Itk−/− T cells remained at 21 and 30 days post infection (Fig. 2A), indicating that Itk signals suppress the conversion of effector CD8+ T cells to long-term memory cells during this infection. There was no difference in bacterial clearance between recipient mice, which was cleared by day 7 post-infection (Fig. 2B). These data suggest that Itk signals play a negative role in the response of CD8+ T cells during infection with L. monocytogenes.


The tyrosine kinase Itk suppresses CD8+ memory T cell development in response to bacterial infection.

Huang F, Huang W, Briggs J, Chew T, Bai Y, Deol S, August A - Sci Rep (2015)

Itk tunes the expression of Eomes and development of MPECS during infection.Naïve WT or Itk−/− T cells were transferred separately into WT mice, which were infected with L. monocytogenes. Mice were bled on the indicated days and cells analyzed as indicated. (A) Cell number. (B) Bacterial numbers in liver determined from mice infected for day 2 or day 7, and. n = 4, 3 independent experiments, no bacteria detected. (C) Percent SLEC and MPEC. (D) Percent T-bet and Eomes. *p < 0.05, n = 3–8 mice, 3 independent experiments. (E) Flow cytometric analysis of the expression of CD127 (left panels) or Eomes (right panels) in representative mice. (F) Naïve WT or Itk−/− T cells were stimulated with 20 μg/ml OVA plus antigen presenting cells over 5 days. Cells were analyzed for expression of IRF4 by flow cytometry. n = 3. (G) IRF4 expression was determined by flow cytometry in WT or Itk−/− OTI/Rag−/− T cells following transfer into WT mice and infection with L. monocytogenes for 5 days. n = 3–8 mice, 3 independent experiments. All error bars indicate the value of +/−SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

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f2: Itk tunes the expression of Eomes and development of MPECS during infection.Naïve WT or Itk−/− T cells were transferred separately into WT mice, which were infected with L. monocytogenes. Mice were bled on the indicated days and cells analyzed as indicated. (A) Cell number. (B) Bacterial numbers in liver determined from mice infected for day 2 or day 7, and. n = 4, 3 independent experiments, no bacteria detected. (C) Percent SLEC and MPEC. (D) Percent T-bet and Eomes. *p < 0.05, n = 3–8 mice, 3 independent experiments. (E) Flow cytometric analysis of the expression of CD127 (left panels) or Eomes (right panels) in representative mice. (F) Naïve WT or Itk−/− T cells were stimulated with 20 μg/ml OVA plus antigen presenting cells over 5 days. Cells were analyzed for expression of IRF4 by flow cytometry. n = 3. (G) IRF4 expression was determined by flow cytometry in WT or Itk−/− OTI/Rag−/− T cells following transfer into WT mice and infection with L. monocytogenes for 5 days. n = 3–8 mice, 3 independent experiments. All error bars indicate the value of +/−SEM.
Mentions: We next examined Itk's role in the CD8+ T cell response in vivo during infection with L. monocytogenes carrying the model antigen Ovalbumin (LM-OVA). We transferred naïve WT or Itk−/− T cells into CD45.1 congenic WT mice, followed by infection with 5 × 105LM-OVA within 24 hours after adoptive transfer. Blood (and spleens) from infected mice were analyzed over time to monitor the response of the transferred T cells. Infection with LM-OVA resulted in similar expansion of WT and Itk−/− T cells 7–12 post infection, but while WT T cells underwent rapid contraction to a low number by day 21, a significantly higher number of Itk−/− T cells remained at 21 and 30 days post infection (Fig. 2A), indicating that Itk signals suppress the conversion of effector CD8+ T cells to long-term memory cells during this infection. There was no difference in bacterial clearance between recipient mice, which was cleared by day 7 post-infection (Fig. 2B). These data suggest that Itk signals play a negative role in the response of CD8+ T cells during infection with L. monocytogenes.

Bottom Line: Here, we have examined the role of Itk, a tyrosine kinase critical for TcR signaling, in CD8(+) effector and memory T cell differentiation during Listeria monocytogenes infection.This is accompanied by increased early Eomesodermin, IL-7Rα expression and memory precursor effector cells.Furthermore, Itk is required for optimal cytokine production in responding primary effector cells, but not secondary memory responses.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology &Immunology, Cornell University, Ithaca, NY, 14853.

ABSTRACT
Vaccine efficacy depends on strong long-term development of immune memory and the formation of memory CD8(+) T cells is critical for recall responses to infection. Upon antigen recognition by naïve T cells, the strength of the TcR signal influences the subsequent effector and memory cells differentiation. Here, we have examined the role of Itk, a tyrosine kinase critical for TcR signaling, in CD8(+) effector and memory T cell differentiation during Listeria monocytogenes infection. We found that the reduced TcR signal strength in Itk deficient naïve CD8(+) T cells enhances the generation of memory T cells during infection. This is accompanied by increased early Eomesodermin, IL-7Rα expression and memory precursor effector cells. Furthermore, Itk is required for optimal cytokine production in responding primary effector cells, but not secondary memory responses. Our data suggests that Itk-mediated signals control the expression of Eomesodermin and IL-7Rα, thus regulating the development of memory CD8(+) T cells, but not subsequent response of memory cells.

No MeSH data available.


Related in: MedlinePlus