Toward a Consensus in the Repertoire of Hemocytes Identified in Drosophila

Abstract

The catalog of the Drosophila immune cells was until recently limited to three major cell types, based on morphology, function and few molecular markers. Three recent single cell studies highlight the presence of several subgroups, revealing a large diversity in the molecular signature of the larval immune cells. Since these studies rely on somewhat different experimental and analytical approaches, we here compare the datasets and identify eight common, robust subgroups associated to distinct functions such as proliferation, immune response, phagocytosis or secretion. Similar comparative analyses with datasets from different stages and tissues disclose the presence of larval immune cells resembling embryonic hemocyte progenitors and the expression of specific properties in larval immune cells associated with peripheral tissues.

Characterization of the Drosophila Adult Hematopoietic System Reveals a Rare Cell Population With Differentiation and Proliferation Potential

“…Importantly though, the col-GAL4 lines pcol85 and GMR13A11 are not only expressed in blood cell progenitors present in the lymph gland posterior lobes but also in the PSC ( Benmimoun et al, 2012 ; Ghosh et al, 2015 ; Rodrigues et al, 2021 ). Moreover, recent single-cell RNA-seq analyses revealed that PSC-like cells expressing col and Antp are present in circulating larval blood cells ( Cattenoz et al, 2021 ). Hence, these putative adult hematopoietic progenitors could have diverse origins.…”

“…Interestingly, differentiated larval plasmatocytes can not only proliferate but also transdifferentiate into crystal cells ( Makhijani et al, 2011 ; Leitao and Sucena, 2015 ), and it was proposed that the increase in peripheral blood cells during larval development relies on self-renewing plasmatocytes ( Gold and Bruckner, 2015 ). Yet, undifferentiated blood cells were also described among peripheral hemocytes ( Sinenko et al, 2010 ) and recent single-cell sequencing experiments suggest that proliferative plasmatocytes retain a progenitor signature ( Cattenoz et al, 2020 , 2021 ; Tattikota et al, 2020 ). In parallel, a second wave of hematopoiesis takes place during the larval stages in a specialized organ called the lymph gland ( Lanot et al, 2001 ).…”

Health of the black soldier fly and house fly under mass-rearing conditions: innate immunity and the role of the microbiome

“…Journal of Insects as Food and Feed categorise entities on a continuous scale into discrete categories (Cattenoz et al, 2021;Fu et al, 2020;Tattikota et al, 2020).…”

Characterization of the Drosophila adult hematopoietic system reveals a rare cell population with differentiation and proliferation potential

“…Importantly though, the col-GAL4 lines pcol85 and GMR13A11 are not only expressed in blood cell progenitors present in the lymph gland posterior lobes but also in the PSC (Benmimoun et al, 2012; Ghosh et al, 2015; Rodrigues et al, 2021). Moreover, recent single-cell RNA-seq analyses revealed that PSC-like cells expressing col and Antp are present in circulating larval blood cells (Cattenoz et al, 2021). Hence, these putative adult hematopoietic progenitors could have diverse origin.…”

“…Interestingly, differentiated larval plasmatocytes can not only proliferate but also transdifferentiate into crystal cells (Leitao and Sucena, 2015; Makhijani et al, 2011), and it was proposed that the increase in peripheral blood cells during larval development relies on self-renewing plasmatocytes (Gold and Bruckner, 2015). Yet, undifferentiated blood cells were also described among peripheral hemocytes (Sinenko et al, 2010) and recent single-cell sequencing experiments suggest that proliferative plasmatocytes retain a progenitor signature (Cattenoz et al, 2021; Cattenoz et al, 2020; Tattikota et al, 2020). In parallel, a second wave of hematopoiesis takes place during the larval stages in a specialized organ called the lymph gland (Lanot et al, 2001).…”