Micro Immunity To Infx And Mycololgy

Ergosterol is the dominant sterol in the fungal membranes. Peptidoglycan and teichoic acids are unique to bacteria. Gram negative bacteria have endotoxin. A few fungi or endotoxin-like compounds. Fungi are heterotrophic, deriving their nutrition from organic compounds so are not photosynthetic so do not have chlorophyll.

IgE is an antibody that is specifically involved in allergic reactions and immune responses against parasites. Mast cells are effector cells that are found in tissues and release inflammatory mediators in response to the binding of IgE antibodies to their surface receptors. This antibody/effector cell tandem is therefore specific for metazoan parasites, making IgE/mast cell the correct answer.

TLR-4 is the correct answer because it is the receptor of phagocytic cells that recognizes LPS (lipopolysaccharide). LPS is a component of the outer membrane of gram-negative bacteria and is recognized by TLR-4, leading to the activation of the immune response and the initiation of an inflammatory reaction. TLR-4 is expressed on the surface of macrophages, dendritic cells, and other phagocytic cells, allowing them to detect and respond to bacterial infections.

ADCC relies on the antibody class IgG because IgG antibodies have the ability to bind to target cells and recruit immune cells, such as natural killer cells, to destroy the target cells. This process is mediated by the Fc region of the IgG antibody, which interacts with Fc receptors on immune cells. IgA, IgD, IgE, and IgM do not play a significant role in ADCC.

Coccioides is a dimorphic fungus. This means it has filamentous forms and spores found in nature and the more yeast-like form (Although in Coccidioides it is not actually yeast but single cells round cells inside a spherule) found in the lungs. (You’ll learn what it looks like later.) So the correct answer is C. (Remember “mold” is the name for hyphal forms.)

First you needed to recognize Blastomyces as the name of a dimorphic fungus and then remember what form the fungus would take in the body (yeast) and then to remember that fungi on a PAS will show up as hot pink-red color so the answer is the third choice.

Naked viruses are not sensitive to the complement-activated membrane attack complex. This is because naked viruses lack an envelope, which is a lipid bilayer that is susceptible to disruption by the membrane attack complex. Therefore, naked viruses are able to evade the immune response mediated by the complement system. In contrast, enveloped viruses have a lipid envelope that can be targeted and destroyed by the membrane attack complex. Fungi and helminths, which are not viruses, are also not sensitive to the membrane attack complex.

The difference between questions 2 and 3 is the level of detail. CD4+ T lymphocyte activation requires Ag presentation (which is done by an APC) and cytokine stimulation. Remember however that efficient Ag presentation by APCs also requires two signals: MHC class II antigen presentation and CD86 co-stimulation. So CD4+ T lymphocyte activation actually requires 3 signals: MHC class II Ag presentation, co-stimulation and cytokine stimulation. Therefore, question 2 implies that, during Ag presentation by dendritic cells, both MHC class II Ag presentation and co-stimulation have occurred.

MHC class I antigen presentation, CD86 co-stimulation, and IL-12 are required for the initiation of a protective cell-mediated response. MHC class I antigen presentation allows the presentation of intracellular antigens to CD8+ T cells, which are important for cell-mediated immunity. CD86 co-stimulation provides a second signal to T cells, enhancing their activation and proliferation. IL-12 is a cytokine that promotes the differentiation of CD4+ T cells into Th1 cells, which are crucial for cell-mediated immune responses. Therefore, the combination of MHC class I antigen presentation, CD86 co-stimulation, and IL-12 is necessary for the initiation of a protective cell-mediated response.

TLR-9 is the correct answer because it is a toll-like receptor that recognizes DNA viruses. Toll-like receptors are a type of pattern recognition receptor that play a crucial role in the innate immune response by recognizing specific patterns on pathogens. TLR-9 specifically recognizes unmethylated CpG motifs that are commonly found in DNA viruses. This recognition triggers a signaling cascade that leads to the activation of phagocytic cells and the production of pro-inflammatory cytokines, ultimately helping to eliminate the viral infection.

Basophils and CD4+ T lymphocytes are the cells responsible for secreting IL-4 during a TH2 response. Basophils are a type of white blood cell that play a role in allergic reactions and release IL-4 to promote the differentiation of CD4+ T lymphocytes into TH2 cells. CD4+ T lymphocytes, also known as helper T cells, are a type of immune cell that release IL-4 to stimulate the production of antibodies and activate other immune cells during a TH2 response. Therefore, the correct answer is Basophils & CD4+ T lymphocytes.

The cells responsible for secreting IFN-y during a TH1 response are NK cells, CD4+ T lymphocytes, and CD8+ T lymphocytes. These cells play a crucial role in the immune response by producing IFN-y, which is a key cytokine involved in the activation of macrophages and the elimination of intracellular pathogens. Macrophages and dendritic cells also play important roles in the immune response, but they are not the primary cells responsible for secreting IFN-y during a TH1 response. Eosinophils are typically associated with allergic responses and are not major producers of IFN-y.

Macrophages, neutrophils, and NK cells are all effector cells involved in antibody-dependent cellular cytotoxicity (ADCC). ADCC is a process in which antibodies bind to target cells, marking them for destruction. These effector cells recognize the antibodies bound to the target cells and release cytotoxic molecules to kill the target cells. B lymphocytes and CD8+ T lymphocytes are not typically involved in ADCC as they primarily function in antibody production and cell-mediated cytotoxicity, respectively.

CD4 T lymphocyte activation against extracellular pathogens requires antigen presentation by dendritic cells, which allows the T cells to recognize the pathogen. Additionally, IL-4 production by basophils and IL-17 production by IL-6 and TGF-B are also required for the activation of CD4 T lymphocytes. These cytokines play important roles in regulating the immune response and promoting the activation and differentiation of T cells.