scholarly journals B Cell Orchestration of Anti-tumor Immune Responses: A Matter of Cell Localization and Communication

Author(s):  
Gabriela Sarti Kinker ◽  
Glauco Akelinghton Freire Vitiello ◽  
Wallax Augusto Silva Ferreira ◽  
Alexandre Silva Chaves ◽  
Vladmir Cláudio Cordeiro de Lima ◽  
...  

The immune system plays a crucial role in cancer development either by fostering tumor growth or destroying tumor cells, which has open new avenues for cancer immunotherapy. It was only over the last decade that the role of B cells in controlling anti-tumor immune responses in the tumor milieu has begun to be appreciated. B and plasma cells can exert anti-tumor effects through antibody-dependent cell cytotoxicity (ADCC) and activation of the complement cascade, even though their effector functions extend beyond the classical humoral immunity. In tumor tissues, B cells can be found in lymphoid aggregates, known as tertiary lymphoid structures (TLSs), well-organized non-encapsulated structures composed of immune and stromal cells. These structures reflect a process of lymphoid neogenesis occurring in peripheral tissues upon long-lasting exposure to inflammatory signals. The TLS provides an area of intense B cell antigen presentation that can lead to optimal T cell activation and effector functions, as well as the generation of effector B cells, which can be further differentiated in either antibody-secreting plasma cells or memory B cells. Of clinical interest, the crosstalk between B cells and antigen-experienced and exhausted CD8+ T cells within mature TLS was recently associated with improved response to immune checkpoint blockade (ICB) in melanoma, sarcoma and lung cancer. Otherwise, B cells sparsely distributed in the tumor microenvironment or organized in immature TLSs were found to exert immune-regulatory functions, inhibiting anti-tumor immunity through the secretion of anti-inflammatory cytokines. Such phenotype might arise when B cells interact with malignant cells rather than T and dendritic cells. Differences in the spatial distribution likely underlie discrepancies between the role of B cells inferred from human samples or mouse models. Many fast-growing orthotopic tumors develop a malignant cell-rich bulk with reduced stroma and are devoid of TLSs, which highlights the importance of carefully selecting pre-clinical models. In summary, strategies that promote TLS formation in close proximity to tumor cells are likely to favor immunotherapy responses. Here, the cellular and molecular programs coordinating B cell development, activation and organization within TLSs will be reviewed, focusing on their translational relevance to cancer immunotherapy.

Author(s):  
Thomas Dörner ◽  
Peter E. Lipsky

B cells have gained interest in rheumatoid arthritis (RA) beyond being the precursors of antibody-producing plasma cells since they are also a broader component of the adaptive immune system. They are capable of functioning as antigen-presenting cells for T-cell activation and can produce an array of cytokines. Disturbances of peripheral B-cell homeostasis together with the formation of ectopic lymphoid neogenesis within the inflamed synovium appears to be a characteristic of patients with RA. Enhanced generation of memory B cells and autoreactive plasma cells producing IgM-RF and ACPA-IgG antibodies together with formation of immune complexes contribute to the maintenance of RA, whereas treatment with B-cell-directed anti-CD20 and CLTA4-Ig therapy provides clinical benefit.


2002 ◽  
Vol 195 (6) ◽  
pp. 771-780 ◽  
Author(s):  
Hedda Wardemann ◽  
Thomas Boehm ◽  
Neil Dear ◽  
Rita Carsetti

Splenectomized individuals are prone to overwhelming infections with encapsulated bacteria and splenectomy of mice increases susceptibility to streptococcal infections, yet the exact mechanism by which the spleen protects against such infections is unknown. Using congenitally asplenic mice as a model, we show that the spleen is essential for the generation of B-1a cells, a B cell population that cooperates with the innate immune system to control early bacterial and viral growth. Splenectomy of wild-type mice further demonstrated that the spleen is also important for the survival of B-1a cells. Transfer experiments demonstrate that lack of these cells, as opposed to the absence of the spleen per se, is associated with an inability to mount a rapid immune response against streptococcal polysaccharides. Thus, absence of the spleen and the associated increased susceptibility to streptococcal infections is correlated with lack of B-1a B cells. These findings reveal a hitherto unknown role of the spleen in generating and maintaining the B-1a B cell pool.


2011 ◽  
Vol 07 (02) ◽  
pp. 130
Author(s):  
Mario Salvi ◽  
Guia Vannucchi ◽  
Paolo Beck-Peccoz ◽  
◽  
◽  
...  

The contribution of B-cells to human autoimmune disease has recently been underscored because of the therapeutic benefit of B-cell depleting therapies. B-cells are involved in the production of autoantibodies, and in CD4+ T-cell activation, control of T-cell function, and inflammation through cytokine production. B-cells are also important antigen-presenting cells. Rituximab (RTX) has been used off-label in various autoimmune disorders and has been shown to effectively deplete mature and memory CD20+ B-cells, but not long-lived plasma cells. The rationale behind the use of RTX in Graves’ disease (GD) and Graves’ orbitopathy (GO) relies on its putative effect on pathogenic autoantibodies causing hyperthyroidism. RTX in patients with active GO has been shown to have a significant effect on the inflammatory activity and severity of GO. However, caution is suggested before proposing RTX as a novel therapeutic tool in this disease until randomized controlled trials are available. Should preliminary observations be confirmed, an optimal strategy for controlling the progression of GO would be to pursue B-cell depletion shortly after diagnosis, rather than only as an alternative therapeutic option when standard immunosuppression has failed.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 337-337 ◽  
Author(s):  
Ulf Klein ◽  
Stefano Casola ◽  
Giorgio Cattoretti ◽  
Qiong Shen ◽  
Marie Lia ◽  
...  

Abstract Most types of human B-cell lymphomas harbor somatically mutated Ig variable region genes, reflecting their origin from cells that have undergone the germinal center (GC) reaction of T-dependent immune responses. The lymphomas exhibit diverse phenotypes and clinical behaviors, likely as a consequence of differences both in the mechanisms of transformation and in the specific target cell. We have recently identified two distinct subsets of GC B-cells that may represent late stages of the GC-reaction and may be the precursors of plasma cells and memory B-cells. The corresponding subsets are characterized by downregulation of the GC-marker BCL6 and the alternative expression of IRF-4/MUM-1 or nuclear c-Rel. These two subsets seem to reflect distinct cellular programs which are altered during B-lymphomagenesis in various tumor subtypes which co-express BCL6, IRF-4 and nuclear c-Rel, an event never observed in normal B-cells. In order to gain insights into the physiologic role of IRF-4/MUM-1 and nuclear c-Rel in GC-development, we are ablating their expression specifically in mouse GC B-cells. Transgenic mice were generated that carry an IRF-4/MUM-1 null allele and a conditional IRF-4/MUM-1 allele which, following Cre-mediated deletion of the loxP-flanked promotor region and exons 1 and 2, expresses eGFP, thus allowing to track the development of the IRF-4/MUM-1 deficient cells at the single cell level. IRF-4/MUM-1fl/- mice were crossed with transgenic mice that express the Cre-recombinase specifically in B-cells undergoing class-switch to IgG1, an event occurring in a large fraction of GC B-cells. Upon immunization with sheep red blood cells or nitrophenyl-(NP)-KLH, mice unable to express IRF-4/MUM-1 in late GC B-cells (IRF-4/MUM-1fl/-/Cγ 1Cre/+), in contrast to control mice (IRF-4/MUM-1fl/+/Cγ 1Cre/+), did not develop plasma cells (IgG1+CD138+) in the peripheral lymphoid organs, blood, and bone marrow. On the other hand, the generation of memory B-cells appears normal since antigen-specific B-cells were present in the spleen (eGFP+B220+PNA-IgG1+) and blood (eGFP+B220+CD38+IgG1+). These results suggest that the IRF-4/MUM-1 gene product is required for the development of antigen-selected GC B-cells into plasma cells. We suggest that the expression of IRF-4/MUM-1 in a GC centrocyte is the critical event in the commitment of B-cells to differentiate into a plasma cell versus a memory B-cell, and are currently testing the role of nuclear c-Rel in the same process.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 80-80
Author(s):  
Mohamed-Rachid Boulassel ◽  
Bader Yassine-Diab ◽  
Don Healey ◽  
Charles Nicolette ◽  
Rafick-Pierre Sékaly ◽  
...  

Abstract We demonstrated the enhancement of CD8-specific responses following the administration of an immune-based therapy consisting of dendritic cells (DC) electroporated with autologous amplified HIV-1 RNA and CD40 ligand (CD40 L) RNA manufactured by the Arcelis™ process in HIV patients receiving antiretroviral therapy (ART). We conducted a sub study on circulating B cell populations to further assess changes induced by this autologous DC therapy as CD40L is a major B cell co-stimulatory factor. To this end, we assessed B cell subset changes in relation to the proliferative capacity of CD4+ and CD8+ T cells response to DC targets containing the 4 HIV-1 antigens (Gag, Vpr, Rev, Nef). The co-expression of CD19, CD38, IgD, CD10, CD23, CD27, CD5, and CD138 were analyzed by multi-parametric flow cytometry to assess circulating B cell subsets such as naïve resting B-cells (Bm1), activated naïve B cells (Bm2), GC founder cells (Bm2’), centroblasts and centrocytes (Bm3 and Bm4), early memory B cells (eBm5), memory B cells (Bm5), IgD memory cells, plasma cells, and B-1 cells. Changes in B cells subsets were analyzed before and after the four intradermal injections of this immunotherapeutic product containing 1.2 × 107 DC. Ten ART treated subjects with undetectable viral load (< 50 copies/ml), median CD4+ count of 440 cells/μl (range: 316–1102), and with a CD4+ nadir > 200 cells/μl were studied. Throughout the study, no significant changes in CD4+ cell count, CD4/CD8 ratio, and no viral blips were noticed. The percentage of total B cells, Bm1, Bm2, Bm2′, eBm5, IgD memory, plasma cells, and B-1 cell subsets did not significantly change. However, a decrease in the percentage of Bm3 and Bm4 cells was found (0.36 [0.06–0.86] versus 0.11 [0.04–0.36]; P=0.05). Conversely, an important increase in the Bm5 cell subset was evidenced (10.4 [1.6–24.2] versus 18.1 [5.1–27.5]; P=0.005) suggesting a proliferation of B memory cells induced by DC immunization. In addition, the multifunctional and polyvalent CD8+ T cell proliferative responses to the 4 HIV genes used in this immunotherapy were noticed in 8 out of 9 subjects available for analysis and characterized by an effector memory phenotype. No CD4+ T cell immune responses were detected, consistent with the endogenous HLA class I loading of the antigens. Collectively, these results indicate that this immunotherapy induces an increase in the B memory cell population in the absence of inducing any clinically apparent autoimmunity along with strong HIV specific multifunctional CD8+ T cell specific immune responses.


2018 ◽  
Vol 215 (10) ◽  
pp. 2485-2496 ◽  
Author(s):  
Michelle N. Wray-Dutra ◽  
Fahd Al Qureshah ◽  
Genita Metzler ◽  
Mohamed Oukka ◽  
Richard G. James ◽  
...  

Activated PI3K-delta syndrome (APDS) is an immunodeficiency caused by gain-of-function mutations in PIK3CD. This disease exhibits complex immune phenotypes including increased IgM, recurrent infection, and impaired vaccine responses. To better understand the impact of B cells in this disease, we generated an inducible model of the common APDS mutation (hPIK3CD-E1021K; referred to as aPIK3CD) and intercrossed these mice with B cell–specific Cre models. Mb1-aPIK3CD mice exhibited bone marrow B lymphopenia and, conversely, expansion of the peripheral innate B1a and MZ B cell compartments. aPIK3CD B cells manifest increased pS6 and increased survival at several stages, without alterations in cycling, and baseline increases in plasma cells, natural IgM, and IgG3. Finally, Mb1-aPIK3CD mice exhibited blunted T cell–independent immune responses, and both AID- and CD21-aPIK3CD mice displayed reduced class-switched antibodies following T cell–dependent immunization. Thus, aPIK3CD alters B cell development and function and is counter-productive during immune responses, providing insight into B cell–intrinsic contributions to the APDS phenotype.


2020 ◽  
Vol 217 (11) ◽  
Author(s):  
Dan Liu ◽  
Jiaxi Wu ◽  
Jinping An ◽  
Jason G. Cyster

The marginal zone (MZ) of the spleen contains multiple cell types that are involved in mounting rapid immune responses against blood-borne pathogens, including conventional dendritic cells (cDCs) and MZ B cells. MZ B cells develop later than other B cell types and are sparse in neonatal mice. Here, we show that cDC2s are abundant in the MZ of neonatal compared with adult mice. We find that conditions associated with reduced MZ B cell numbers in adult mice cause increased cDC2 occupancy of the MZ. Treatment with the S1PR1-modulating drug, FTY720, causes cDC2 movement into the MZ through the indirect mechanism of displacing MZ B cells into follicles. Splenic cDC2s express high amounts of α4β1 and αLβ2 integrins and depend on these integrins and the adaptor Talin for their retention in blood-exposed regions of the spleen. Splenic CD4 T cell activation by particulate antigens is increased in mice with higher cDC2 density in the MZ, including in neonatal mice. Our work establishes requirements for homeostatic cDC2 positioning in the spleen and provides evidence that localization in blood-exposed regions around the white pulp augments cDC2 capture of particulate antigens. We suggest that MZ positioning of cDC2s partially compensates for the lack of MZ B cells during the neonatal period.


Author(s):  
Yun Xing ◽  
Zhiqiang Wang ◽  
Zhou Lu ◽  
Jie Xia ◽  
Zhangjuan Xie ◽  
...  

Abstract MicroRNA (miRNA) is a class of endogenous small non-coding RNA of 18–25 nucleotides and plays regulatory roles in both physiological and pathological processes. Emerging evidence support that miRNAs function as immune modulators in tumors. MiRNAs as tumor suppressors or oncogenes are also found to be able to modulate anti-tumor immunity or link the crosstalk between tumor cells and immune cells surrounding. Based on the specific regulating function, miRNAs can be used as predictive, prognostic biomarkers and therapeutic targets in immunotherapy. Here, we review new findings about role of miRNAs in modulating immune responses, as well as discuss mechanisms underlying their dysregulation, and their clinical potentials as indicators of tumor prognosis or to sensitize cancer immunotherapy.


2021 ◽  
Vol 9 (6) ◽  
pp. e002273
Author(s):  
Kevin T Lynch ◽  
Samuel J Young ◽  
Max O Meneveau ◽  
Nolan A Wages ◽  
Victor H Engelhard ◽  
...  

BackgroundTertiary lymphoid structures (TLSs) are immune aggregates in peripheral tissues that may support adaptive immune responses. Their presence has been associated with clinical response to checkpoint blockade therapy (CBT), but it is unknown whether TLS have prognostic significance independent of CBT in melanoma. We hypothesized that TLS in melanoma metastases would be associated with increased intratumoral lymphocyte infiltration, but that the intra-TLS immunological milieu would be distinct from the intratumoral immunological milieu. We also hypothesized that the presence of TLS would be associated with improved survival, and that TLS maturation or intra-TLS lymphocyte activity would also correlate with survival.MethodsCutaneous melanoma metastases (CMM) from 64 patients were evaluated by multiplex immunofluorescence for the presence and maturation status of TLS. Intra-TLS lymphocyte density, proliferation and B-cell Ig somatic hypermutation (AID+) were analyzed, as were markers of T-cell exhaustion and Th1/Tc1 differentiation. Associations between TLS maturation and intra-TLS immunologic activity were assessed, as well as associations with intratumoral immune cell infiltration. Independent associations with overall survival (OS) were assessed using log-rank tests and Cox proportional hazards models.ResultsTLS were identified in 30 (47%) of 64 CMM (TLS+) and were associated with increased intratumoral lymphocyte infiltration. However, proliferation of intra-TLS lymphocytes did not correlate with intratumoral lymphocyte proliferation. Most were early TLS; however, subsets of primary or secondary follicle-like TLS were also present. TLS+ lesions were associated with lower risk of tumor recurrence after metastasectomy and with improved OS in multivariate analyses (HR 0.51, p=0.04). OS was longer for TLS with low fractions of CD21+ B-cells (HR 0.29, p=0.02) and shorter for those with low AID+ fraction of B-cells (HR 2.74, p=0.03).ConclusionsThe presence of TLS in CMMs is associated with improved OS in patients treated with surgery before CBT, but TLS vary widely in maturation state, in proportions of proliferating T and B cells, and in markers of B cell function, including AID and CD21. Importantly, these features have additional prognostic significance, which suggest that some TLS may have regulatory function, while others functioning to support antigen-driven immune responses, depending on the cellular composition and activation status.


2020 ◽  
Author(s):  
Daniele Biasci ◽  
James Thaventhiran ◽  
Simon Tavaré

While the role of CD8+ T cells in mediating response to cancer immunotherapy is well established, the role of B cells remains more controversial (1–3). By conducting a large gene expression study of response to immune checkpoint inhibitors (ICI), we show that pre-treatment expression of B cell genes is associated with ICI response independently of CD8+ T cells. However, we discovered that such association can be completely explained by a single gene (FDCSP) expressed outside of the B cell compartment, in fibroblastic reticular cells (FRCs), which form the reticular network that facilitates interactions between B cells, T cells and cognate antigens (4–6) and are required to initiate efficient adaptive immune responses in secondary lymphoid organs (SLO) and tertiary lymphoid structures (TLS) (4, 7). We validated this finding in three independent cohorts of patients treated with ICI in melanoma and renal cell carcinoma. Taken together, these results suggest that FDCSP is an independent predictor of ICI response, thus opening new avenues to explain the mechanisms of resistance to cancer immunotherapy.


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