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Microbes & Immunity Role of SRCR proteins in inflammation

glycoprotein primarily expressed by macrophages, documented, and its presence in the lungs, saliva, intestinal
interacts with various types of bacteria and viruses. 6 surfaces, amniotic fluid, and newborn meconium indicates
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Although the anti-inflammatory potential of individual its critical role in regulating inflammatory responses.
SRCR proteins has been recognized for years, their DMBT1 enhances classical complement pathway
collective significance in inflammation modulation has activation by interacting with complement proteins,
often been overlooked. Emerging evidence suggests particularly C1q, thereby shaping an anti-inflammatory
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that most, if not all, SRCR proteins possess crucial anti- immune response. DMBT1 significantly influences the
inflammatory properties that may operate independently production and secretion of pro-inflammatory cytokines,
or alongside microbial targeting. These insights underscore such as interleukin (IL)-6, aiding in the regulation of
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the important functions of SRCR proteins in controlling inflammatory processes. Furthermore, it has been shown
inflammation and facilitating tissue repair, revealing their to promote vascular endothelial growth factor (VEGF)
multifaceted roles in immune defense and the resolution of while suppressing IL-6 production in alveolar tissues,
inflammatory responses. indicating its capacity to mediate the transition from
inflammation to tissue regeneration. This dual capability
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2. Circulating SRCRs establishes DMBT1 as a valuable clinical marker for
Soluble SRCRs play a pivotal role in modulating managing inflammatory conditions.
inflammation, displaying distinct functional characteristics Upregulation of DMBT1 occurs in various
that influence immune responses (Figure 1). The inflammatory states, including chronic nasal polyposis and
inflammation-reducing properties of DMBT1 are well- cigarette smoke exposure, and is particularly pronounced

Figure 1. Schematic representation of selected scavenger receptor cysteine-rich (SRCR) superfamily soluble and membrane-anchored members and their
anti-inflammatory properties. More details and corresponding literature references can be found in the main text. Figure created using Biorender.com.
https://BioRender.com/k15w818.
Abbreviations: SRCR: scavenger receptor cysteine-rich; DAMPs: Damage-associated molecular patterns; DMBT1: Deleted in malignant brain tumors 1;
IL: Interleukin; SSC4D: SRCR family member with 4 domains; SSC5D: SRCR family member with 5 domains; TLR: Toll-like receptor.

Volume 2 Issue 2 (2025) 47 doi: 10.36922/mi.5741