Project description:Memory T cells are important for protective immunity against infectious microorganisms. Such protection is achieved by cooperative action of memory T cell populations that differ in their tissue localization and functionality. We report on the identification of the fractalkine receptor CX3CR1 as marker for stratification of memory T cells with cytotoxic effector function from those with proliferative function in both, mice and man. Based on CX3CR1 and CD62L expression levels four distinct memory T cell populations can be distinguished based on their functional properties. Transcriptome and proteome profiling revealed that CX3CR1 expression was superior to CD62L to resolve memory T cell functionality and allowed determination of a core signature of memory T cells with cytotoxic effector function. This identifies a CD62Lhi CX3CR1+ memory T cell population with an identical gene signature to CD62LlowCX3CR1+ effector memory T cells. In lymph nodes, this so far unrecognized CD62LhiCX3CR1+ T cell population shows a distinct migration pattern and anatomic positioning compared to CD62LhiCX3CR1neg TCM. Furthermore, CX3CR1+ memory T cells were scarce or absent during chronic HBV, HCV and HIV infection in man and chronic LCMV infection in mice confirming the value of CX3CR1+ in understanding principles of protective immune memory. CD8+ T cells were isolated and directly assessed or incubated with DC or LSEC. After harvesting, cells were immediately lysed in Trizol (Invitrogen) before storage at -80°C for RNA isolation.
Project description:Memory T cells are important for protective immunity against infectious microorganisms. Such protection is achieved by cooperative action of memory T cell populations that differ in their tissue localization and functionality. We report on the identification of the fractalkine receptor CX3CR1 as marker for stratification of memory T cells with cytotoxic effector function from those with proliferative function in both, mice and man. Based on CX3CR1 and CD62L expression levels four distinct memory T cell populations can be distinguished based on their functional properties. Transcriptome and proteome profiling revealed that CX3CR1 expression was superior to CD62L to resolve memory T cell functionality and allowed determination of a core signature of memory T cells with cytotoxic effector function. This identifies a CD62Lhi CX3CR1+ memory T cell population with an identical gene signature to CD62LlowCX3CR1+ effector memory T cells. In lymph nodes, this so far unrecognized CD62LhiCX3CR1+ T cell population shows a distinct migration pattern and anatomic positioning compared to CD62LhiCX3CR1neg TCM. Furthermore, CX3CR1+ memory T cells were scarce or absent during chronic HBV, HCV and HIV infection in man and chronic LCMV infection in mice confirming the value of CX3CR1+ in understanding principles of protective immune memory. CD8+ T cells were isolated and directly assessed. After harvesting, cells were immediately lysed in Trizol (Invitrogen) before storage at -80°C for RNA isolation.
Project description:Memory T cells are important for protective immunity against infectious microorganisms. Such protection is achieved by cooperative action of memory T cell populations that differ in their tissue localization and functionality. We report on the identification of the fractalkine receptor CX3CR1 as marker for stratification of memory T cells with cytotoxic effector function from those with proliferative function in both, mice and man. Based on CX3CR1 and CD62L expression levels four distinct memory T cell populations can be distinguished based on their functional properties. Transcriptome and proteome profiling revealed that CX3CR1 expression was superior to CD62L to resolve memory T cell functionality and allowed determination of a core signature of memory T cells with cytotoxic effector function. This identifies a CD62Lhi CX3CR1+ memory T cell population with an identical gene signature to CD62LlowCX3CR1+ effector memory T cells. In lymph nodes, this so far unrecognized CD62LhiCX3CR1+ T cell population shows a distinct migration pattern and anatomic positioning compared to CD62LhiCX3CR1neg TCM. Furthermore, CX3CR1+ memory T cells were scarce or absent during chronic HBV, HCV and HIV infection in man and chronic LCMV infection in mice confirming the value of CX3CR1+ in understanding principles of protective immune memory.
Project description:Memory T cells are important for protective immunity against infectious microorganisms. Such protection is achieved by cooperative action of memory T cell populations that differ in their tissue localization and functionality. We report on the identification of the fractalkine receptor CX3CR1 as marker for stratification of memory T cells with cytotoxic effector function from those with proliferative function in both, mice and man. Based on CX3CR1 and CD62L expression levels four distinct memory T cell populations can be distinguished based on their functional properties. Transcriptome and proteome profiling revealed that CX3CR1 expression was superior to CD62L to resolve memory T cell functionality and allowed determination of a core signature of memory T cells with cytotoxic effector function. This identifies a CD62Lhi CX3CR1+ memory T cell population with an identical gene signature to CD62LlowCX3CR1+ effector memory T cells. In lymph nodes, this so far unrecognized CD62LhiCX3CR1+ T cell population shows a distinct migration pattern and anatomic positioning compared to CD62LhiCX3CR1neg TCM. Furthermore, CX3CR1+ memory T cells were scarce or absent during chronic HBV, HCV and HIV infection in man and chronic LCMV infection in mice confirming the value of CX3CR1+ in understanding principles of protective immune memory.
Project description:CD8+ T cells play a critical role in the immune response to viral pathogens. Persistent human CMV (HCMV) infection results in a strong increase in the number of virus-specific, quiescent effector-type CD8+ T cells with constitutive cytolytic activity, but the molecular pathways involved in the induction and maintenance of these cells are unknown. We show here that HCMV infection induced acute and lasting changes in the transcriptomes of virus-reactive T cells collected from HCMV-seropositive patients at distinct stages of infection. Enhanced cell cycle and metabolic activity was restricted to the acute phase of the response, but at all stages, HCMV-specific CD8+ T cells expressed the Th1-associated transcription factors T-bet (TBX21) and eomesodermin (EOMES), in parallel with continuous expression of IFNG mRNA and IFN-g–regulated genes. The cytolytic proteins granzyme B and perforin as well as the fractalkine-binding chemokine receptor CX3CR1 were found in virus-reactive cells throughout the response. During HCMV latency, virus-specific CD8+ T cells lacked the typical features of exhausted cells found in other chronic infections. Persistent effector cell traits together with the permanent changes in chemokine receptor usage of virus-specific, nonexhausted, long-lived CD8+ T cells may be crucial to maintain lifelong protection from HCMV reactivation. CD8+ T cells of naive, effector, and memory type were isolated from six latently chronic-infected healthy donors. For RNA isolation and microarray analysis, 3 independent donors and a pool of 3 additional healthy individuals were used. Total RNA of all naive CD8+ T cells was pooled and used as a common reference sample.
Project description:We describe a novel subset of CD8+ DCs in lymphoid organs of naïve mice characterized by expression of the CX3CR1 chemokine receptor. CX3CR1+CD8+ DCs lack hallmarks of classical CD8+ DCs, including IL12 secretion, the capacity to cross-present antigen and their developmental independence of the transcriptional factor BatF3. Gene expression profiling showed that CX3CR1+CD8+ DCs resemble CD8- cDCs. The microarray analysis further revealed a unique plasmacytoid DC (PDC) gene signature of CX3CR1+ CD8+ DCs. A PDC relationship of the cells is further supported by the fact that they harbor characteristic D-J immunoglobulin gene rearrangements and that development of CX3CR1+CD8+ DCs requires E2-2, the critical transcriptional regulator of PDCs. Thus, CX3CR1+ CD8+ DCs represent a unique DC subset, related to but distinct from PDCs. After collagenase D digestion, spleens from Cx3cr1gfp/+ C57BL/6 mice were enriched for CD11c+ cells by magnetic separation according to the manufacturer’s protocol (MiltenyiBiotec GmbH). Splenic CD11chi cells were isolated using the FACS ARIA high-speed sorter (Becton-Dickinson). Total RNA was extracted and subjected to gene expression profiling using the Mouse Genome 430.2 Affymetrix GeneChip
Project description:We describe a novel subset of CD8+ DCs in lymphoid organs of naïve mice characterized by expression of the CX3CR1 chemokine receptor. CX3CR1+CD8+ DCs lack hallmarks of classical CD8+ DCs, including IL12 secretion, the capacity to cross-present antigen and their developmental independence of the transcriptional factor BatF3. Gene expression profiling showed that CX3CR1+CD8+ DCs resemble CD8- cDCs. The microarray analysis further revealed a unique plasmacytoid DC (PDC) gene signature of CX3CR1+ CD8+ DCs. A PDC relationship of the cells is further supported by the fact that they harbor characteristic D-J immunoglobulin gene rearrangements and that development of CX3CR1+CD8+ DCs requires E2-2, the critical transcriptional regulator of PDCs. Thus, CX3CR1+ CD8+ DCs represent a unique DC subset, related to but distinct from PDCs.
Project description:Persistent Ag induces a dysfunctional CD8 T cell state known as "exhaustion" characterized by PD-1 expression. Nevertheless, exhausted CD8 T cells retain functionality through continued differentiation of progenitor into effector cells. However, it remains ill-defined how CD8 T cell effector responses are sustained in situ. In this study, we show using the mouse chronic lymphocytic choriomeningitis virus infection model that CX3CR1+ CD8 T cells contain a T-bet-dependent TIM3-PD-1lo subpopulation that is distinct from the TIM3+CX3CR1+PD-1+ proliferative effector subset. The TIM3-CX3CR1+ cells are quiescent and express a low but significant level of the transcription factor TCF-1, demonstrating similarity to TCF-1hi progenitor CD8 T cells. Furthermore, following the resolution of lymphocytic choriomeningitis virus viremia, a substantial proportion of TCF-1+ memory-like CD8 T cells show evidence of CX3CR1 expression during the chronic phase of the infection. Our results suggest a subset of the CX3CR1+ exhausted population demonstrates progenitor-like features that support the generation of the CX3CR1+ effector pool from the TCF-1hi progenitors and contribute to the memory-like pool following the resolution of viremia.