Parallelism Between the Intestinal Immune System and the Respiratory Immune System

The diverse phenotype of the epithelial cells

In this article, I briefly describe the parallelism between the intestinal and respiratory immune systems. The Respiratory Tract The respiratory tract is responsible for breathing and exchanging oxygen and carbon dioxide between the body and the environment. It is divided into the upper respiratory tract and the lower respiratory tract. It is exposed directly to … Read more >>

Common Intestinal Diseases

Inflammatory Bowel Disease

In this article, I briefly describe the common diseases associated with the intestine. Inflammatory bowel disease, Crohn’s disease, and Celiac disease are common intestinal diseases. Our Intestinal Immune Response and Diseases The immune system’s response to both commensal and pathogenic microbes is not without cost. Even when inflammation successfully eliminates pathogens, it can still damage … Read more >>

Intestinal Immunity Can Initiate Both Type 1 and Type 2 Immune Responses

Contact of epithelial tuft cells with a worm results in major inductive events in the intestine

In this article, I briefly describe the type of immune responses of our intestines. Intestine and Pathogens Our intestinal immune system responses to specific pathogens reveal extra complexities. There are many bacteria and worms causing diseases in our bodies. Our immune system shows different types of responses to worms and bacteria. Bacteria get a type … Read more >>

The Intestinal Immune System Recognizes and Responds to Pathogens

Conditions cause a switch from homeostatic to inflammatory response

In this article, I provide a brief overview of how the intestinal immune system recognizes and responds to pathogens. Intestine and Pathogens Most organisms that live in harmony with us are not harmful and help create a tolerant environment in the intestines. The gut immune system ensures a safe separation between the epithelial surfaces and … Read more >>

Various Innate and Adaptive Cell Types Promote Immune Homeostasis in the Intestine

Homeostasis and microbiome tolerance are regulated at the intestinal surface

In this article, I briefly describe how various innate and adaptive cell types promote immune homeostasis in the intestine. Our Gastrointestinal Tract It is a tube-like structure running from the mouth to the anus. The gastrointestinal tract maintains our commensal microbiome and regulates local and systemic immune responses. Our gastrointestinal tract deals with billions of … Read more >>

Small and Large Intestines Possess Different Immune Systems

Effect of commensal bacteria

In this article, I briefly explain the disparity in immunity in the small and large intestines. Distinct Immunity in Small and Large Intestine The small and large intestines manage their relationship with the microbiome by sharing general strategies. However, the physiology of each section is distinct, as are the microbial communities and immune cells that … Read more >>

Negative regulation of B-cell activation

In this article, I briefly describe the negative regulation of B-cell activation. B-cell activation and control Presentation of antigens via MHC and receiving co-stimulatory signals (CD40-CD40L) from TH2 cells, results in the activation of B cells (figure 1). Following activation, B cells undergo cycles of mutation and selection to produce high-affinity memory B cells and … Read more >>

The absence of a costimulatory signal leads to clonal anergy

In this article, I briefly explain clonal anergy and its relation with a costimulatory signal. Clonal anergy A state of clonal anergy develops, when a naïve T cell engages its TCR with an antigen presented by an MHC, without a suitable costimulatory signal. It is a state, where the specific T cell clone shows no … Read more >>

The coinhibitory receptors: CTLA-4, PD-1, and BTLA

In this article, I briefly describe the working of the coinhibitory receptors CTLA-4, PD-1, and BTLA. Coinhibitory receptor Costimulatory and coinhibitory receptor molecules are vital in regulating immune responses to infections. Coinhibitory receptors bind with their ligands and suppress excess immune responses. When T cells get infected, they tend to express coinhibitory receptors and acquire … Read more >>

Costimulatory receptors for activation of T cells

In this article, I briefly describe costimulatory receptors CD28 and ICOS and how they bind with their ligands. Costimulatory receptors Co-stimulatory signals are required for optimal T-cell activation. T-cell non-responsiveness arises from high affinity TCR-MHC interactions in the absence of functional antigen presenting cells (APCs). It is called T cell anergy. The interaction between specific … Read more >>