The Jak/Stat Signaling Pathway

jak/stat pathway
Perhaps the most exciting recent advance in the cytokine signaling field has been the elucidation of the Jak/Stat pathway. The Janus kinase (Jak) family consists of four known enzymes (Jak1, Jak2, Jak3, and Tyk2), each of which associates specifically with the cytoplasmic tails of one or more cytokine receptor subunits. For example, IL-2R associates with both Jak1 and Jak3, which bind its α and γ subunits, respectively. Cytokine binding brings the receptor subunits together and allows the associated Jak proteins to phosphorylate and activate one another. The primary substrates of the activated Jaks are a family of transcription factors called the Stat (for signal transducers and activators of transcription) proteins. The Stat proteins contain SH2 domains and so are recruited to the vicinity of an activated receptor when its kinases become active. (more…)

Bronchial Asthma Symptoms and the Immune Response

Bronchial Asthma Symptoms
Local micro environmental factors are crucial in determining both susceptibility to vascular remodeling and the extent of angiogenesis. Major exogenous triggers of airway inflammation in asthma include viruses and inhaled aeroallergens, both of which are known to be associated with the production of angiogenic factors . These stimuli elicit reciprocal immune responses, through elaboration of Th1 and Th2 cytokines. (more…)

Therapeutic Exploitation of the Biology of the Innate Immune System

Activation of the innate immune system is an integral part of the pathology of allergic diseases such as asthma, with a dual role that has different emphases in disease initiation and disease perpetuation. Sadly underappreciated in the past, the resurgence in interest in innate immunobiology has been spearheaded by the identification of the TLR system and its huge contribution to health and disease. (more…)

Humoral Factors in Innate Immunity

Innate immune responses are seen in a very broad range of tissues. Indeed, the Toll-like receptors (TLRs, one of the most important series of innate immune response proteins, described in detail below) are probably represented at some level in every cell in the body. Even before such systems are engaged, however, other levels of defense have important roles in mediating successful immunity. (more…)

Allergic Reactions and Autoimmunity - When Immune System Functions Go Wild

immune system functions

Allergic Reactions

For daily life, of course we need our immune system. Without having immune system, we could not survive long, but there are times when the immune system may harm us rather than helps us. If you suffer from sneezing and stuffy nose, watery eyes, every spring or fall, your doctor may assured your hay fever symptoms. These symptoms are allergic reaction to pollen, dust and spores in the air. (more…)

Natural Immune System – Natural Killer Cells and Innate Immune Response

natural immune system innate response
Natural killer cells: history and current status

Natural killer cells are a major component of the immune system, which play important roles in host defense against cancer and microbial infections. Natural killer cells are distinct from T or B lymphocytes, with a characteristic morphology of large granular cells, and can be readily identified by characteristic cell surface molecules. (more…)