Specific Immune Cell Types Involved with Microbiota Related Immune System Effects
Sasha Paquette
1211202
November 11, 2023
Gut microbiota consists of numerous unique microorganisms and contributes to various
functions within the human body (Wen et al. 2022). The relationship between microbiota – in
particular, gut microbiota – and its respective host is fundamental to the development and
maintenance of the intestinal immune system (Daniel et al. 2021). Consequently, there is an
inherent relationship between specific immune cells and microbiota. Specific immune cells that
are involved in various microbiota-immune system-related effects include macrophages, T-cells,
and B-cells.
Macrophages, a type of intestinal immune cell, are involved in a regulatory circuit in the
intestine, promoting the self-renewal of intestinal stem cells (Zhu et al. 2022). This circuit of
interactions is crucial for maintaining the health and function of the intestinal lining and the
intestinal immune system. The circuit at play is a system beginning with microbiota – acting on
immune cells (such as macrophages), transmitting neuron signals, ultimately resulting in the
renewal of stem cells (Zhu et al. 2022). The intestinal microbiota is required for stem cell
renewal, with macrophages acting as an intermediate step in this immune system effect. This
chain of reactions, beginning with the relationship between microbiota and macrophages
encourages stem cell renewal, which contributes to the ability of the immune system to maintain
immune functions.
Immune cells involved in antibody production, such as B-lineage cells, are directly
influenced by microbiota in the gut (Wen et al. 2022). Microbiota releases signals that can
influence the growth of B-lineage cells. B-cells produce immunoglobin A (IgA) whilst IgA
shares a direct relationship with microbiota (Wen et al. 2022). Thus, if there is a balanced array
of IgA in the intestine, the gut microbiome will also be balanced. When the gut microbiome is
healthy and in balance, B-cells behave properly, preventing uncontrolled immunological
reactions and maintaining the integrity of the intestinal barrier (Wen et al. 2022). The interplay
between microbiota, B-cells, and IgA demonstrates the direct effects that microbiota can have on
specific immune cell and immune system responses.
An adaptive immune response, such as a T-cell-dependent response is triggered when the
host encounters harmful microorganisms (Bunker and Bendelac 2019). T-cells prevent the
immune system from overreacting to harmless microbes in the microbiota. An adaptive immune
response involves antibodies that continuously refine to target pathogens, keeping the host's
health a priority. The T-cell-dependent response requires the maintenance of a beneficial
relationship with the microbiota in the gut (Bunker and Bendelac 2019). For an adaptive immune
response to be effective, T-cells must be able to recognize harmful microbiota to reduce
autoimmune reactions.
Ultimately, various specific immune cell types are dependent on microbiota. Effective
functions of such cells – such as macrophages, B-cells, and T-cells – in immune system effects
depend on the presence and regulation of gut microbiota. The complexity and intricacy of these
relationships are notable. Further exploration regarding the interconnectedness of immune cell
types and their functions in response to microbiota is an area of interest that could assist in the
understanding of immune system responses.
Reference List
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Daniel, N., Lecuyer, E., Chassaing, B., Host/microbiota interactions in health and diseases –
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Wen, X., Ye, X., Yang, X., et al. The crosstalk between intestinal bacterial microbiota and
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Zhu, P., Lu, T., Wu, J., et al. Gut microbiota drives macrophage-dependent self-renewal of
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