Alister Curtis Ward

Acute myeloid leukemia (AML) is one of the most common types of hematological malignancies and a leading cause of cancer deaths. It is characterized by the rapid accumulation of typically immature myeloid cells that serve to disrupt the production of mature cells, leading to a range of clinical sequelae. The role of recurrent chromosomal aberrations has long been appreciated in this disease, but a myriad of gene mutations have been increasingly acknowledged as having important roles. This review provides a comprehensive overview of the mutational landscape of AML, discussing the various genetic lesions in terms of their function, classification, etiological role, prognostic value, therapeutic impact, detection, and monitoring, with a particular focus on gene mutations.

Cytokine inducible SH2-containing protein (CISH) was the founding member of the suppressor of cytokine signaling (SOCS) family of negative regulators. However, the subsequent elucidation of the physiological roles of CISH has been a slow process, reflecting its often subtle basal functions. Here we provide a narrative review of the literature highlighting the niche roles played by CISH principally in the control of cytokine signaling that impacts immune, blood and other cells. CISH regulates T cell production, polarization and activation through interleukin (IL)-2, IL-4 and the T cell receptor (TCR), natural killer (NK) cell production and activation via IL-15, generation and/or activation of neutrophil, dendritic cell (DC) and macrophage populations through granulocyte-macrophage colony-stimulating factor (GM-CSF), erythrocyte production via erythropoietin (EPO), and appetite control through leptin. Many of these roles are performed by CISH in concert with other SOCS proteins, providing additional complexity. CISH has also been identified in the etiology of several human diseases, particularly immune disorders, such as allergy and susceptibility to infectious disease, as well as a potential target to augment immunotherapy.

Cell–cell signaling through a network of cytokine receptors is pivotal for normal immune development and function, with disruptions of these signaling pathways being implicated in a variety of immune cell diseases. Signaling via the interleukin-7 receptor (IL-7R) facilitates the development and homeostasis of various T-cell, B-cell and other immune-cell populations. This is reflected in the raft of mutants and variants of IL-7R components and downstream signaling molecules that have been identified in the context of immunodeficiencies, autoimmune disorders and lymphoid malignancies, but also through the use of pathway modulators as therapeutics. This review provides an overview of IL-7R biology, the role of mutations and variants affecting IL-7R signaling pathway components in the etiology of immune cell diseases and the specific therapies related to this pathway.

Colony-stimulating factor 3 (CSF3), additionally called granulocyte colony-stimulating factor (G-CSF), is the major cytokine regulating neutrophil production and also impacting their function. The actions of this cytokine are mediated through its unique receptor, the colony-stimulating factor 3 receptor (CSF3R). Several classes of pathogenic mutations in the CSF3R gene have been identified that have distinct biological properties and clinical impacts. This review provides an overview of CSF3R, the various pathogenic CSF3R mutations/variants and their biological effects. It also details the diseases to which they contribute, notably including chronic neutrophilic leukemia (CNL) and other myeloproliferative neoplasms (MPNs), myelodysplastic neoplasms (MDS), combined MDS/MPN disorders such as atypical chronic myeloid leukemia (aCML) and chronic myelomonocytic leukemia (CMML), as well as acute myeloid leukemia (AML) and lymphoid malignancies.

Background: Suppressor of cytokine signaling (SOCS)3 is a regulatory protein that participates in an important negative feedback loop downstream of several critical cytokines, especially members of the interleukin-6 (IL-6) family. As a result, SOCS3 has been shown to impact the development and function of blood and immune cells. Zebrafish harbor duplicates of SOCS3, Socs3a and Socs3b, both of which possess conserved functional domains. Methods: This study explored the role of zebrafish Socs3a by creating a whole genome knockout using CRISPR/Cas9, with a focus on hematopoiesis and neuromast formation. Results: A zebrafish Socs3a knockout mutant was successfully generated. Characterization of this mutant revealed that normal hematopoiesis was not impacted nor was neutrophils lacking Socs3a displayed normal responses to injury or their production during emergency granulopoiesis. Neuromast formation was severely impacted in Socs3a knockout zebrafish. Conclusions: Zebrafish Socs3a mutants display normal hematopoiesis and myeloid function, but the formation of the lateral line neuromast was affected by the absence of Socs3a.

Cytokine receptor-like factor 3 (CRLF3) has an extended evolutionary history, which has been conserved across metazoan species. It consists of several structural elements, notably including a fibronectin type 3 (FBNIII) domain containing a WSXWS motif that is synonymous with so-called class I cytokine receptors present throughout bilaterial species, and a proposed spl1 and ryanodine receptor (SPRY) domain that represents a widespread protein–protein interaction module. The function of CRLF3 has remained enigmatic, but several recent investigations have revealed critical insights into its biological roles. These studies suggest that CRLF3 principally functions in neural and hematopoietic cells, where it plays critical and diverse roles in the development and function of specific cell populations. Disruption of CRLF3 has also been associated with several human diseases, mainly associated with these same lineages but also including malignancy. The mechanisms by which CRLF3 exerts these diverse effects remain uncertain, although a number of potential options have emerged.

Neutrophils are a critical component of immunity, particularly against bacteria and other pathogens, but also in inflammation and tissue repair. As a consequence, individuals with neutropenia, defined by a reduction in absolute neutrophil counts, exhibit a strong propensity to severe infections that typically present with muted symptoms. Neutropenias encompass a heterogeneous set of disorders, comprising primary neutropenias, in which specific genes are mutated, and the more common secondary neutropenias, which have diverse non-genetic causes. These include hematological and other cancers, involving both direct effects of the cancer itself and indirect impacts via the chemotherapeutic, biological agents and cell-based approaches used for treatment. Other significant causes of secondary neutropenias are non-chemotherapeutic drugs, autoimmune and other immune diseases, infections and nutrient deficiencies. These collectively act by impacting neutrophil production in the bone marrow and/or destruction throughout the body. This review describes the biological and clinical manifestations of secondary neutropenias, detailing their underlying causes and management, with a discussion of alternative and emerging therapeutic approaches.

Nutrition, the gut microbiota and immunity are all important factors in the maintenance of health. However, there is a growing realization of the complex interplay between these elements coalescing in a nutrition–gut microbiota–immunity axis. This regulatory axis is critical for health with disruption being implicated in a broad range of diseases, including autoimmune disorders, allergies and mental health disorders. This new perspective continues to underpin a growing number of innovative therapeutic strategies targeting different elements of this axis to treat relevant diseases. This review describes the inter-relationships between nutrition, the gut microbiota and immunity. It then details several human diseases where disruption of the nutrition–gut microbiota–immunity axis has been identified and presents examples of how the various elements may be targeted therapeutically as alternate treatment strategies for these diseases.

B cell lymphoma 6 (BCL6) is a conserved multi-domain protein that functions principally as a transcriptional repressor. This protein regulates many pivotal aspects of immune cell development and function. BCL6 is critical for germinal center (GC) formation and the development of high-affinity antibodies, with key roles in the generation and function of GC B cells, follicular helper T (Tfh) cells, follicular regulatory T (Tfr) cells, and various immune memory cells. BCL6 also controls macrophage production and function as well as performing a myriad of additional roles outside of the immune system. Many of these regulatory functions are conserved throughout evolution. The BCL6 gene is also important in human oncology, particularly in diffuse large B cell lymphoma (DLBCL) and follicular lymphoma (FL), but also extending to many in other cancers, including a unique role in resistance to a variety of therapies, which collectively make BCL6 inhibitors highly sought-after.

The suppressor of cytokine signaling (SOCS) family of proteins were named after their defining role as negative feedback regulators of signaling initiated by numerous cytokine receptors. However, multiple members of the SOCS family likely function outside of this paradigm, including SOCS4. Zebrafish possess two SOCS4 paralogues, with socs4a previously shown to participate in central nervous system development and function. This study examined the role of the other paralogue, socs4b, through expression analysis and functional investigations in vivo and in vitro. This revealed maternal deposition of socs4b mRNA, specific zygotic expression during late embryogenesis, including in the brain, eye and intestine, and broad adult expression that was highest in the brain. A mutant allele, socs4bΔ18, was generated by genome editing, in which the start codon was deleted. Fish homozygous for this likely hypomorphic allele showed no overt developmental phenotypes. However, in vitro studies suggested the Socs4b protein may be able to regulate EGFR signaling.