Acute and chronic tissue injury results in the generation of a myriad of environmental cues that macrophages respond to by changing their phenotype and function. This phenotypic regulation is critical for controlling tissue inflammation and resolution. Here, we have identified the adaptor protein disabled homolog 2 (DAB2) as a regulator of phenotypic switching in macrophages.
Samantha E. Adamson, Rachael Griffiths, Radim Moravec, Subramanian Senthivinayagam, Garren Montgomery, Wenshu Chen, Jenny Han, Poonam R. Sharma, Garrett R. Mullins, Stacey A. Gorski, Jonathan A. Cooper, Alexandra Kadl, Kyle Enfield, Thomas J. Braciale, Thurl E. Harris, Norbert Leitinger
The generation of naive T cells is dependent on thymic output, but in adults, the naive T cell pool is primarily maintained by peripheral proliferation. Naive T cells have long been regarded as relatively quiescent cells; however, it was recently shown that IL-8 production is a signatory effector function of naive T cells, at least in newborns. How this functional signature relates to naive T cell dynamics and aging is unknown. Using a cohort of children and adolescents who underwent neonatal thymectomy, we demonstrate that the naive CD4+ T cell compartment in healthy humans is functionally heterogeneous and that this functional diversity is lost after neonatal thymectomy. Thymic tissue regeneration later in life resulted in functional restoration of the naive T cell compartment, implicating the thymus as having functional regenerative capacity. Together, these data shed further light on functional differentiation within the naive T cell compartment and the importance of the thymus in human naive T cell homeostasis and premature aging. In addition, these results affect and alter our current understanding on the identification of truly naive T cells and recent thymic emigrants.
Theo van den Broek, Eveline M. Delemarre, Willemijn J.M. Janssen, Rutger A.J. Nievelstein, Jasper C. Broen, Kiki Tesselaar, Jose A.M. Borghans, Edward E.S. Nieuwenhuis, Berent J. Prakken, Michal Mokry, Nicolaas J.G. Jansen, Femke van Wijk
T regulatory cells (Tregs) control immune homeostasis by preventing inappropriate responses to self and nonharmful foreign antigens. Tregs use multiple mechanisms to control immune responses, all of which require these cells to be near their targets of suppression; however, it is not known how Treg-to-target proximity is controlled. Here, we found that Tregs attract CD4+ and CD8+ T cells by producing chemokines. Specifically, Tregs produced both CCL3 and CCL4 in response to stimulation, and production of these chemokines was critical for migration of target T cells, as Tregs from
Scott J. Patterson, Anne M. Pesenacker, Adele Y. Wang, Jana Gillies, Majid Mojibian, Kim Morishita, Rusung Tan, Timothy J. Kieffer, C. Bruce Verchere, Constadina Panagiotopoulos, Megan K. Levings
Tumor cells frequently escape from CD8+ T cell recognition by abrogating MHC-I antigen presentation. Deficiency in processing components, like the transporter associated with antigen processing (TAP), results in strongly decreased surface display of peptide/MHC-I complexes. We previously identified a class of hidden self-antigens known as T cell epitopes associated with impaired peptide processing (TEIPP), which emerge on tumor cells with such processing defects. In the present study, we analyzed thymus selection and peripheral behavior of T cells with specificity for the prototypic TEIPP antigen, the “self” TRH4 peptide/Db complex. TEIPP T cells were efficiently selected in the thymus, egressed with a naive phenotype, and could be exploited for immunotherapy against immune-escaped, TAP-deficient tumor cells expressing low levels of MHC-I (MHC-Ilo). In contrast, overt thymus deletion and functionally impaired TEIPP T cells were observed in mice deficient for TAP1 due to TEIPP antigen presentation on all body cells in these mice. Our results strongly support the concept that TEIPPs derive from ubiquitous, nonmutated self-antigens and constitute a class of immunogenic neoantigens that are unmasked during tumor immune evasion. These data suggest that TEIPP-specific CD8+ T cells are promising candidates in the treatment of tumors that have escaped from conventional immunotherapies.
Elien M. Doorduijn, Marjolein Sluijter, Bianca J. Querido, Cláudia C. Oliveira, Adnane Achour, Ferry Ossendorp, Sjoerd H. van der Burg, Thorbald van Hall
The immunoregulatory cytokine macrophage migration inhibitory factor (MIF) is encoded in a functionally polymorphic locus that is linked to the susceptibility of autoimmune and infectious diseases. The
Jie Yao, Lin Leng, Maor Sauler, Weiling Fu, Junsong Zheng, Yi Zhang, Xin Du, Xiaoqing Yu, Patty Lee, Richard Bucala
In vivo protection by antimicrobial neutralizing Abs can require the contribution of effector functions mediated by Fc-Fcγ receptor (Fc-FcγR) interactions for optimal efficacy. In influenza, broadly neutralizing anti-hemagglutinin (anti-HA) stalk mAbs require Fc-FcγR interactions to mediate in vivo protection, but strain-specific anti-HA head mAbs do not. Whether this rule applies only to anti-stalk Abs or is applicable to any broadly neutralizing Ab (bNAb) against influenza is unknown. Here, we characterized the contribution of Fc-FcγR interactions during in vivo protection for a panel of 13 anti-HA mAbs, including bNAbs and non-neutralizing Abs, against both the stalk and head domains. All classes of broadly binding anti-HA mAbs required Fc-FcγR interactions to provide protection in vivo, including those mAbs that bind the HA head and those that do not neutralize virus in vitro. Further, a broadly neutralizing anti-neuraminidase (anti-NA) mAb also required FcγRs to provide protection in vivo, but a strain-specific anti-NA mAb did not. Thus, these findings suggest that the breadth of reactivity of anti-influenza Abs, regardless of their epitope, necessitates interactions with FcγRs on effector cell populations to mediate in vivo protection. These findings will guide the design of antiviral Ab therapeutics and inform vaccine design to elicit Abs with optimal binding properties and effector functions.
David J. DiLillo, Peter Palese, Patrick C. Wilson, Jeffrey V. Ravetch
Group A streptococcal (GAS) infection induces the production of Abs that cross-react with host neuronal proteins, and these anti-GAS mimetic Abs are associated with autoimmune diseases of the CNS. However, the mechanisms that allow these Abs to cross the blood-brain barrier (BBB) and induce neuropathology remain unresolved. We have previously shown that GAS infection in mouse models induces a robust Th17 response in nasal-associated lymphoid tissue (NALT). Here, we identified GAS-specific Th17 cells in tonsils of humans naturally exposed to GAS, prompting us to explore whether GAS-specific CD4+ T cells home to mouse brains following i.n. infection. Intranasal challenge of repeatedly GAS-inoculated mice promoted migration of GAS-specific Th17 cells from NALT into the brain, BBB breakdown, serum IgG deposition, microglial activation, and loss of excitatory synaptic proteins under conditions in which no viable bacteria were detected in CNS tissue. CD4+ T cells were predominantly located in the olfactory bulb (OB) and in other brain regions that receive direct input from the OB. Together, these findings provide insight into the immunopathology of neuropsychiatric complications that are associated with GAS infections and suggest that crosstalk between the CNS and cellular immunity may be a general mechanism by which infectious agents exacerbate symptoms associated with other CNS autoimmune disorders.
Thamotharampillai Dileepan, Erica D. Smith, Daniel Knowland, Martin Hsu, Maryann Platt, Peter Bittner-Eddy, Brenda Cohen, Peter Southern, Elizabeth Latimer, Earl Harley, Dritan Agalliu, P. Patrick Cleary
Adoptive cell transfer (ACT) of purified naive, stem cell memory, and central memory T cell subsets results in superior persistence and antitumor immunity compared with ACT of populations containing more-differentiated effector memory and effector T cells. Despite a clear advantage of the less-differentiated populations, the majority of ACT trials utilize unfractionated T cell subsets. Here, we have challenged the notion that the mere presence of less-differentiated T cells in starting populations used to generate therapeutic T cells is sufficient to convey their desirable attributes. Using both mouse and human cells, we identified a T cell–T cell interaction whereby antigen-experienced subsets directly promote the phenotypic, functional, and metabolic differentiation of naive T cells. This process led to the loss of less-differentiated T cell subsets and resulted in impaired cellular persistence and tumor regression in mouse models following ACT. The T memory–induced conversion of naive T cells was mediated by a nonapoptotic Fas signal, resulting in Akt-driven cellular differentiation. Thus, induction of Fas signaling enhanced T cell differentiation and impaired antitumor immunity, while Fas signaling blockade preserved the antitumor efficacy of naive cells within mixed populations. These findings reveal that T cell subsets can synchronize their differentiation state in a process similar to quorum sensing in unicellular organisms and suggest that disruption of this quorum-like behavior among T cells has potential to enhance T cell–based immunotherapies.
Christopher A. Klebanoff, Christopher D. Scott, Anthony J. Leonardi, Tori N. Yamamoto, Anthony C. Cruz, Claudia Ouyang, Madhu Ramaswamy, Rahul Roychoudhuri, Yun Ji, Robert L. Eil, Madhusudhanan Sukumar, Joseph G. Crompton, Douglas C. Palmer, Zachary A. Borman, David Clever, Stacy K. Thomas, Shashankkumar Patel, Zhiya Yu, Pawel Muranski, Hui Liu, Ena Wang, Francesco M. Marincola, Alena Gros, Luca Gattinoni, Steven A. Rosenberg, Richard M. Siegel, Nicholas P. Restifo
The production of high-affinity antibodies by B cells is essential for pathogen clearance. Antibody affinity for antigen is increased through the affinity maturation in germinal centers (GCs). This is an iterative process in which B cells cycle between proliferation coupled with the acquisition of mutations and antigen-based positive selection, resulting in retention of the highest-affinity B cell clones. The posttranscriptional regulator microRNA-155 (miR-155) is critical for efficient affinity maturation and the maintenance of the GCs; however, the cellular and molecular mechanism by which miR-155 regulates GC responses is not well understood. Here, we utilized a miR-155 reporter mouse strain and showed that miR-155 is coexpressed with the proto-oncogene encoding c-MYC in positively selected B cells. Functionally, miR-155 protected positively selected c-MYC+ B cells from apoptosis, allowing clonal expansion of this population, providing an explanation as to why
Rinako Nakagawa, Rebecca Leyland, Michael Meyer-Hermann, Dong Lu, Martin Turner, Giuseppina Arbore, Tri Giang Phan, Robert Brink, Elena Vigorito
Type 1 diabetes (T1D) patients show abnormalities in early B cell tolerance checkpoints, resulting in the accumulation of large numbers of autoreactive B cells in their blood. Treatment with rituximab, an anti-CD20 mAb that depletes B cells, has been shown to preserve β cell function in T1D patients and improve other autoimmune diseases, including rheumatoid arthritis and multiple sclerosis. However, it remains largely unknown how anti–B cell therapy thwarts autoimmunity in these pathologies. Here, we analyzed the reactivity of Abs expressed by single, mature naive B cells from 4 patients with T1D before and 52 weeks after treatment to determine whether rituximab resets early B cell tolerance checkpoints. We found that anti–B cell therapy did not alter the frequencies of autoreactive and polyreactive B cells, which remained elevated in the blood of all patients after rituximab treatment. Moreover, the limited proliferative history of autoreactive B cells after treatment revealed that these clones were newly generated B cells and not self-reactive B cells that had escaped depletion and repopulated the periphery through homeostatic expansion. We conclude that anti–B cell therapy may provide a temporary dampening of autoimmune processes through B cell depletion. However, repletion with autoreactive B cells may explain the relapse that occurs in many autoimmune patients after anti–B cell therapy.
Nicolas Chamberlain, Christopher Massad, Tyler Oe, Tineke Cantaert, Kevan C. Herold, Eric Meffre, the Type 1 Diabetes TrialNet Pathway to Prevention Study Group