Innate Immunity
These cells, along with being Sela's favorite, are the most abundant white blood cells and are the first responders to bacterial infections, performing phagocytosis and respiratory burst.
What are neutrophils?
These helper T cells recognize antigens presented on MHC Class II molecules and help activate macrophages and other immune cells to kill microbes.
What are CD4 helper T cells?
This final step of the complement cascade involves C5 convertase binding C6, C7, and C8, then cleaving C9 to form this structure that causes cell lysis.
What is the membrane attack complex (MAC)?
This cytokine, along with being a nickname for someone here, is released by Tregs along with IL-35 and TGF-β to inhibit immune cells and maintain immune tolerance.
What is IL-10?
This alpha herpesvirus causes chicken(gwen)pox in children and establishes latency in neurons, potentially reactivating later as shingles.
What is VZV (Varicella-Zoster Virus)?
This cytokine, along with being the cytokine audre thinks about the most, is produced by macrophages, T cells, NK cells, and mast cells causes fever and can lead to septic shock in severe cases.
What is TNF (Tumor Necrosis Factor)?
This process allows B cell receptors to acquire genetic diversity through V-D-J recombination mediated by RAG1 and RAG2 enzymes.
What is somatic recombination?
Both the classical and lectin pathways converge to form this C3 convertase, while the alternative pathway forms C3bBb.
What is C4b2a?
This cytokine is produced by macrophages and has both local and systemic effects, including causing fever and septic shock, and can be therapeutically targeted by drugs like etanercept and infliximab in rheumatoid arthritis.
What is TNF (Tumor Necrosis Factor)?
This gamma herpesvirus, along with sounding suspiciously similar to a list Phillip is on, causes infectious mononucleosis in first infections, remains latent in B cells, and can be diagnosed by the heterophile antibody test that causes agglutination of animal RBCs.
What is EBV (Epstein-Barr virus)?
These pattern recognition receptors are located in the cytosol and specifically detect bacterial components, while RIG receptors detect this type of nucleic acid.
What are NLR (NOD-like receptors) and viral RNA?
This Th1 cytokine, along with being Julias least favorite, promotes phagocytosis, increases oxidative burst, and stimulates isotype switching to create IgG antibodies for enhanced phagocytosis.
What is IFN-gamma (interferon-gamma)?
This complement pathway is initiated when mannose binds to microbes, bypassing the need for antibodies or spontaneous C3 activation.
What is the lectin pathway?
In giant cell arteritis, these two specific T helper cell subsets drive granulomatous inflammation by releasing IL-6, IFN-γ, IL-1, and IL-23, making IL-6 inhibitors an effective targeted therapy alongside steroids.
What are Th1 and Th17 cells?
In Type 1 hypersensitivity reactions, this cytokine released by Th2 cells helps B cells undergo class switching from IgM to IgE, while this other cytokine recruits and activates eosinophils during the effector phase.
What are IL-4 and IL-5?
In this four-step process of inflammation, selectins mediate rolling, integrins enable adhesion, and WBCs follow chemokine gradients during this final migration step.
What is chemotactic migration (or chemotaxis)?
In T-dependent B cell activation, after the first signal from BCR-antigen binding, this second signal can come from either CD21/CD19-antigen interaction or T cell costimulation, leading to differentiation into short-lived plasma cells producing this antibody isotype initially.
What is IgM?
These two complement inhibitors work together to control C3b activity - one dissociates the C3 convertase while the other binds to MCP and cleaves C3b into nonfunctional pieces.
What are Factor H and Factor I?
When bacterial superantigens cause nonspecific constitutive activation of T cells, this phenomenon occurs where overwhelming development of these signaling molecules leads to fever, rash, and shock - exemplified by toxic shock syndrome.
What is cytokine storm?
This autoimmune condition involves immune complexes depositing in joints and activating complement, leading to recruitment of neutrophils and inflammation. Treatment includes methotrexate and targeted therapies like TNF inhibitors, IL-6 inhibitors, and JAK inhibitors.
What is rheumatoid arthritis?
Patients with this genetic disorder have deficient NADPH oxidase activity, resulting in recurrent infections with catalase-positive organisms due to impaired oxidative burst during phagocytosis, and require treatment with antibiotics and potentially bone marrow transplantation.
What is CGD (Chronic Granulomatous Disease)?
Oh no! Christians Brother presents with recurrent bacterial infections and laboratory studies reveal absent mature B cells and severely low immunoglobulin levels. Genetic testing shows mutations affecting Bruton's tyrosine kinase, preventing proper B cell development at the pre-B cell stage, resulting in this X-linked immunodeficiency disorder that requires lifelong immunoglobulin replacement therapy.
What is X-linked agammaglobulinemia (XLA)?
Kristin's mom presents with recurrent episodes of facial and laryngeal swelling triggered by stress and minor trauma. Laboratory studies show low C4 levels and deficient activity of this complement inhibitor that normally regulates C1 activation. The condition is treated with C1 esterase inhibitor replacement therapy and can be prevented with danazol to increase endogenous production.
What is C1 inhibitor (causing hereditary angioedema)?
Jordans mom a (Jordan how old is your mom?)-year old woman presents to rheumatology clinic with a 6-month history of joint pain and morning stiffness lasting over 1 hour. Physical examination reveals swollen, tender joints in both hands (MCPs and PIPs) and both wrists, with symmetrical involvement. Laboratory studies show:
This central inflammatory cytokine, when blocked by biologics like adalimumab or infliximab, prevents the activation of macrophages, fibroblasts, and dendritic cells that would otherwise lead to osteoclast activation and joint destruction in this 45-year-old woman with symmetrical polyarthritis, positive RF, and anti-CCP antibodies.
What is TNF-alpha (or tumor necrosis factor-alpha)?
A 45-year-old immunocompromised transplant recipient named Lisha presents with fever, pneumonia, and colitis three months post-transplant. PCR testing reveals this beta herpesvirus that remains latent in CD34+ hematopoietic progenitor cells and characteristically shows "owl eye" intranuclear inclusion bodies on tissue biopsy. Unlike HSV, this virus requires its own kinase enzyme for phosphorylation and is treated with ganciclovir rather than acyclovir.
What is CMV (cytomegalovirus)?