Cytomegalovirus and Immune Response

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Questions and Answers

What is a key characteristic of cytomegalovirus (CMV) infections in hematopoietic cell transplant (HCT) patients?

Patients with HCT do not require any form of monitoring for CMV.

CMV has no impact on the outcome of HCT procedures.

CMV typically causes mild symptoms in all patients.

CD8 T cells play a significant role in controlling CMV infections. (correct)

Which of the following populations is particularly at risk for CMV-related diseases?

Pregnant women and their fetuses. (correct)

Individuals with high CD4 T cell counts.

Individuals with no prior exposure to CMV.

Healthy individuals with robust immune systems.

How does CMV evade the immune system?

By suppressing all forms of immune response permanently.

By enhancing the production of antibodies against itself.

Through the downregulation of MHC molecules on infected cells. (correct)

By solely infecting and destroying immune cells.

What condition was the patient diagnosed with six months after the transplant?

HCMV pneumonia Signup and view all the answers

What is a primary reason for focusing on congenital CMV infection in vaccine development?

Congenital CMV infection often leads to severe health complications. Signup and view all the answers

Which T cell type is primarily responsible for controlling CMV infections in individuals?

CD8 T cells Signup and view all the answers

What was the likely reason for the patient's respiratory failure after the transplant?

Lack of T-cell response against HCMV Signup and view all the answers

What is the mechanism by which ganciclovir works against herpesviruses?

Inhibits DNA synthesis Signup and view all the answers

What characterizes the immune response of an immunocompetent host to HCMV?

Presence of latent infection without symptoms Signup and view all the answers

What contributes to the high risk of infection in transplant recipients post-transplant?

Profoundly immunocompromised state Signup and view all the answers

What distinguishes HCMV-specific CD8+ T cells from resting memory cells?

They have the immediate ability to kill infected cells. Signup and view all the answers

Why are HCMV+ transplant patients who develop HCMV-specific CD8 cytotoxic T cell responses at low risk for pneumonia?

They have a robust response to HCMV controlling the virus. Signup and view all the answers

What role do HCMV-specific CD4 T cells play in the immune response?

They help limit viral shedding and prevent tissue damage. Signup and view all the answers

In HIV patients with low CD4+ T cell counts, why is there still a high risk for diseases like chorioretinitis?

CD8+ T cell numbers remain moderately decreased. Signup and view all the answers

What is the likely reason for CMV's persistent challenge to the host immune system?

CMV undergoes constant productive infection attempts. Signup and view all the answers

What is the typical presentation of cytomegalovirus (CMV) infection in immunocompetent individuals?

Asymptomatic or mild infectious mononucleosis Signup and view all the answers

Which of the following is NOT a common manifestation of cytomegalovirus (CMV) disease in immunocompromised patients?

Asymptomatic infection Signup and view all the answers

What is a leading infectious cause of hearing loss in neonates due to cytomegalovirus (CMV) congenital infection?

Cytomegalovirus Signup and view all the answers

In immunocompetent hosts, CMV is kept under control by which immune response mechanism?

Vigorous cellular immune response Signup and view all the answers

What is the most common manifestation of cytomegalovirus (CMV) disease in transplant patients?

Retinitis Signup and view all the answers

What typically occurs upon reactivation of CMV in immunocompromised patients?

Viremia leading to disease Signup and view all the answers

Which term describes the condition caused by the appearance of HCMV-specific TH1 CD4+ helper T cells during primary CMV infection?

Immune response proliferation Signup and view all the answers

Which symptom is associated with congenital CMV infection in neonates?

Petechial rash known as 'blueberry muffin' rash Signup and view all the answers

What plays a critical role in controlling cytomegalovirus (CMV) during primary infection?

T cells and their cytokines Signup and view all the answers

What can exacerbate the situation of unchecked CMV replication in immunocompromised patients?

Concomitant inflammatory state driven by co-infections Signup and view all the answers

What is the role of CD8+ T cells in the context of HCMV?

They provide substantial protection from death or serious disease caused by HCMV. Signup and view all the answers

What is a significant risk factor for CMV disease in AIDS patients?

Low CD4 T cell counts Signup and view all the answers

Which of the following is a key characteristic of HCMV?

It can undergo latency and reactivation. Signup and view all the answers

What mechanism does CMV use to evade the immune response?

Producing immunoevasive proteins that impair antigen presentation. Signup and view all the answers

Why might long-term ganciclovir therapy not prevent pneumonia in HCMV?

T cell reconstitution might be delayed. Signup and view all the answers

What remains unknown regarding HCMV despite vaccination efforts?

Constants of protective immunity against HCMV. Signup and view all the answers

Which of the following is a common transmission route for HCMV?

Saliva, urine, and sexual contact Signup and view all the answers

What condition is characterized by severe disease due to HCMV in neonates?

Congenital CMV infection Signup and view all the answers

Study Notes

Cytomegalovirus (CMV)

CMV is enveloped and contains double-stranded DNA.
CMV can be latent and re-activate.
CMV is transmitted via urine, saliva, sex, and organ transplants.
CMV can cause severe disease in newborns and potentially fatal end-organ disease in immunocompromised individuals.
CMV can cause mononucleosis in immunocompetent patients.

CMV and the Immune System

Viral-specific CD8+ T cells are essential for controlling CMV infection.
HCMV-specific CD8 T cells are effector cells, not resting memory cells.
Patients who receive HCMV-specific CD8+ T cells through infusion have a significantly lower risk of death or severe disease from CMV.
CD4+ T cells are crucial for limiting viral shedding and preventing tissue dissemination.
AIDS patients with low CD4+ T cell counts are at high risk for CMV disease, especially retinitis.

CMV Immune Evasion

CMV has multiple proteins that help it evade the immune system.
CMV can interfere with MHC class I and II antigen presentation to prevent T cell recognition.
CMV can inhibit natural killer (NK) cell activation, which is important for early immune response.
CMV can disable the interferon response, which is a critical antiviral pathway.
CMV can interfere with the detection of viral DNA by pattern recognition receptors (PRRs).
CMV can produce chemokine mimics to recruit immune cells, potentially distracting them from the site of infection.

Vaccine Development

CMV immune evasion mechanisms make it difficult to achieve sterilizing immunity or long-lasting protection.
The correlates of protection for CMV are still poorly understood.

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Description

This quiz explores the characteristics of Cytomegalovirus (CMV), its transmission methods, and its effects on the immune system. Learn about the role of T cells in controlling CMV infection and how the virus evades immune responses. Test your knowledge on the implications of CMV in immunocompromised individuals and newborns.