Immunodeficiencies

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What is the primary target of HIV infection in the immune system?

Macrophages

CD4+ T lymphocytes (correct)

Dendritic cells

CD8+ T lymphocytes

What is the function of the gp120 glycoprotein in HIV infection?

To regulate the transcription of viral genes

To synthesize DNA from RNA

To integrate viral DNA into the host genome

To bind to CD4 and chemokine receptors on host cells (correct)

What is the role of the integrase enzyme in the HIV life cycle?

To regulate the transcription of viral genes

To synthesize cDNA from RNA

To produce viral particles

To integrate viral DNA into the host genome (correct)

What is the type of receptor that gp120 binds to on CD4+ T lymphocytes?

Chemokine receptors Signup and view all the answers

What is the term for the integrated viral DNA in the host cell?

Provirus Signup and view all the answers

What is a consequence of the normal protective response of the infected T cell, macrophage, or dendritic cell?

Activation of the provirus Signup and view all the answers

Which cells are infected by HIV at sites of entry through epithelia, in lymphoid organs, and in the circulation?

CD4+ T cells, dendritic cells, and macrophages Signup and view all the answers

What is the primary site of destruction of infected T cells?

Mucosal tissues Signup and view all the answers

How do dendritic cells contribute to the infection?

By capturing the virus and transporting it to peripheral lymphoid organs Signup and view all the answers

What is the primary outcome for patients with SCID if their immune system is not reconstituted?

They are likely to die in early life Signup and view all the answers

What is the primary reason for the improvement in DiGeorge syndrome patients with age?

The small amount of thymic tissue supports some T cell maturation Signup and view all the answers

What is the usual treatment for selective B cell defects?

Intravenous injections of pooled immunoglobulin (IVIG) from healthy donors Signup and view all the answers

What is the primary cause of congenital immunodeficiencies?

Genetic defects Signup and view all the answers

What is the result of defects in the gene encoding Bruton tyrosine kinase (BTK)?

X-linked agammaglobulinemia Signup and view all the answers

What is the effect of mutations in the γc signaling subunit of the receptors for several cytokines?

Reduced survival and maturation of lymphocyte precursors Signup and view all the answers

What is the primary defect in DiGeorge syndrome?

Defective maturation of T cells Signup and view all the answers

What is the result of chromosomal deletion involving Ig heavy chain locus?

Deficiency in IgG, IgA, and IgE Signup and view all the answers

What is the effect of defects in JAK3?

Defective signaling by γc Signup and view all the answers

What is the result of mutations in RAG1 and RAG2 genes?

Severe combined immunodeficiency (SCID) Signup and view all the answers

What is the most reliable indicator of disease progression in HIV patients?

Decrease in the blood CD4+ T cell count Signup and view all the answers

What is the role of dendritic cells in HIV infection?

To present HIV peptides to CD4+ and CD8+ T cells Signup and view all the answers

What is the goal of highly active antiretroviral therapy (HAART) in HIV treatment?

To control replication of HIV and infectious complications Signup and view all the answers

Why is it difficult to develop antiviral drugs against HIV?

Because HIV mutates its genes, rendering drugs ineffective Signup and view all the answers

What happens when resting CD4+ T cells infected with HIV are activated by their specific antigens?

The latent provirus starts replication Signup and view all the answers

Which cells, in addition to T cells, can be infected by HIV and lead to destruction of lymphoid organ architecture?

Dendritic cells and macrophages Signup and view all the answers