Failures of Host Defense Mechanisms

A patient with a history of recurrent infection by pyogenic, or pus-forming, bacteria would suggest a defect in which three components of the immune system?

What is the most frequent form of severe combined immunodeficiency (SCID), and what is its genetic cause?

A deficiency in the enzyme adenosine deaminase (ADA) results in the accumulation of which toxic precursors, leading to a form of SCID?

Omenn syndrome is a severe disease characterized by rashes, eosinophilia, and enlarged lymph nodes. What is the underlying genetic cause of this syndrome?

Wiskott-Aldrich syndrome (WAS) is an immunodeficiency caused by a defect in the WASp protein. What is the key function of WASp that is disrupted in this syndrome?

DiGeorge syndrome is a disorder where the thymic epithelium fails to develop normally, resulting in SCID. What is the underlying genetic abnormality?

What is the molecular basis for Bruton’s X-linked agammaglobulinemia (XLA), which results in a profound B-cell deficiency?

A B-cell-intrinsic hyper-IgM syndrome, characterized by a failure to switch antibody isotype and reduced somatic hypermutation, is due to mutations in which enzyme?

The autosomal dominant variant of hyper-IgE syndrome (HIES), also called Job's syndrome, is caused by an inherited defect in which transcription factor?

Patients with mutations in the gene encoding the p40 subunit of IL-12 (IL12B) show heightened susceptibility to which specific types of pathogens?

Familial hemophagocytic lymphohistiocytosis (FHL) is a severe syndrome of uncontrolled immune activation. The FHL2 variant is caused by an inherited deficiency in which specific cytolytic granule protein?

X-linked lymphoproliferative (XLP) syndrome, characterized by a fatal response to Epstein-Barr virus infection, results from mutations in one of which two X-linked genes?

An autosomal dominant mutation of which transcription factor results in DCML deficiency, a condition characterized by a progressive loss of dendritic cells and monocytes?

Defects in the membrane-attack components of the complement system, specifically components C5 through C9, are associated with a limited susceptibility almost exclusively to which genus of bacteria?

The most common causes of severe congenital neutropenia (SCN) are mutations in the gene that encodes which protein component of azurophilic granules?

Familial Mediterranean fever (FMF) is an autoinflammatory disease caused by mutations in the MEFV gene. This gene encodes which protein?

Over 90 known serotypes of Streptococcus pneumoniae are distinguished by antigenic variation. This variation occurs in the structure of which bacterial component?

The protozoan parasite Trypanosoma brucei evades the host antibody response through antigenic variation. It is coated with a single type of glycoprotein that it can change through gene rearrangement. What is this glycoprotein called?

The genome of the parasite Trypanosoma brucei contains a large repertoire of genes that allow it to perform antigenic variation. Approximately how many variant-specific glycoprotein (VSG) genes does the trypanosome genome contain?

Influenza virus undergoes antigenic drift, which allows it to evade neutralization by existing antibodies in the population every few years. This process is caused by point mutations in the genes encoding which two major viral surface glycoproteins?

Infectious mononucleosis, also known as glandular fever, is a disease caused by the primary infection of B cells by which specific herpesvirus?

HIV-1 is classified into four major genetic groups (M, N, O, and P). Which of these groups is responsible for the vast majority, approximately 99 percent, of HIV-1 infections worldwide?

According to the textbook, what was the estimated number of people who died from AIDS-related causes worldwide in the year 2012?

Like other retroviruses, the HIV genome is small and contains three major genes that encode structural and enzymatic proteins. What are these three major genes?

The HIV accessory protein Vif (viral infectivity factor) is crucial for viral replication because it counteracts a host antiviral restriction factor. What is the name of this host cellular protein that Vif overcomes?

A natural genetic resistance to HIV-1 infection is conferred by being homozygous for a nonfunctional variant of which chemokine co-receptor?

The CCR5-delta-32 allele, which confers resistance to HIV infection, is found at a relatively high frequency of 0.09 in which population group?

The progression of HIV infection eventually leads to Acquired Immune Deficiency Syndrome (AIDS). How is the onset of AIDS clinically defined in terms of peripheral blood CD4 T cell count?

Latently infected CD4 memory T cells form a long-lived reservoir for HIV, making the virus impossible to eradicate with current therapies. What is the estimated mean half-life of these cells?

Since the earliest recognition of AIDS, which pathogen has been the most common cause of opportunistic pneumonia and was typically fatal before effective therapy was introduced?

Various drugs are used to block HIV replication. What was the first anti-HIV drug to be licensed for use in the United States?

The introduction of combination therapy dramatically reduced mortality from advanced HIV infection. What is the name for this therapy, which typically includes a cocktail of viral protease inhibitors and nucleoside analogs?

HIV replicates at an extremely high rate in an infected individual. What is the approximate number of virions generated every day?

The high mutation rate of HIV is due to the error-prone nature of its reverse transcriptase enzyme. What is the approximate rate of substitution per nucleotide per cycle of replication?

In the context of human immunodeficiency syndromes, what is the specific term used for a pus-forming bacterium?

In the context of X-linked severe combined immunodeficiency (XSCID), the kinase Jak3 is crucial for immune cell development. What is its specific function?

A specific class of SCID called radiation-sensitive SCID (RS-SCID) is caused by defects in ubiquitous DNA repair proteins. Which set of genes, when defective, causes RS-SCID?

The complex syndrome APECED (autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy) is characterized by autoimmunity and immunodeficiency. This condition is caused by defects in which gene?

Among the various primary immunodeficiency diseases, which condition is the most common?

Inherited deficiencies in IL-17F and IL-17RA, which impair type 3 immunity, confer susceptibility to infections by which two specific types of organisms?

Chediak-Higashi syndrome is an immunodeficiency characterized by abnormal giant lysosomes and granules in various cells. This is caused by mutations in the CHS1 protein, which has what primary function?

Deficiencies in the membrane-associated complement-control proteins DAF (CD55) or protectin (CD59) lead to the destruction of red blood cells, resulting in what specific disease?

Autosomal recessive deficiency of the adaptor molecule CARD9 impairs signaling from C-type lectin receptors. This leads to impaired Th17 responses and susceptibility to chronic mucocutaneous candidiasis and what other specific type of fungal infection?

An autoinflammatory disease with clinical features similar to Familial Mediterranean Fever (FMF), known as TRAPS, is caused by mutations in the gene that encodes which molecule?

RNA viruses like influenza have a higher rate of mutation compared to DNA viruses, which contributes to their ability to evade the immune system. This is because their RNA polymerases lack what specific capability?

Herpes simplex virus (HSV-1) produces an immunoevasin protein called ICP47 that prevents the presentation of viral peptides on MHC class I molecules. What is the specific mechanism of action of ICP47?

In the course of an untreated HIV infection, what is the 'viral set point' and what does it indicate?

During the acute phase of HIV infection, an adaptive immune response is mounted, which is marked by the appearance of virus-specific antibodies in the serum. What is the term for this development?

Genetic polymorphisms in the HLA class I locus are a major factor in determining the rate of progression to AIDS. Which of the following HLA alleles are associated with a better prognosis and slower disease progression?

There is increasing interest in using antiretroviral drugs to prevent HIV infection in high-risk individuals. What is the term for this prophylactic use of these drugs?