Question

What are the reservoir cells of the infected HTLV-I? a. T cells b. \(\mathrm{B}\) cells c. Macrophages

Short answer

#Short Answer# The reservoir cells of the infected HTLV-I (Human T-cell lymphotropic virus type 1) are T cells. HTLV-I mainly infects CD4+ T cells, which serve as the primary reservoir cells, allowing the virus to persist and eventually reactivate, causing disease or spreading the infection to new hosts.

Step-by-step solution

Introduction to Reservoir Cells

Reservoir cells are a group of cells in the body that can harbor a virus or pathogen for an extended period without being detected or cleared by the immune system. These cells can serve as a "safe haven" for viruses, allowing them to persist and eventually reactivate, causing disease or spreading the infection to new hosts.

Human T-cell Lymphotropic Virus Type 1 (HTLV-I)

HTLV-I is a human retrovirus that infects CD4+ T cells and is responsible for causing adult T-cell leukemia (ATL) and inflammatory diseases such as HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The HTLV-I virus can be transmitted through blood transfusion, sexual contact, or from mother to child during birth or breastfeeding.

Identifying the Reservoir Cells

As mentioned above, HTLV-I mainly infects CD4+ T cells in the human body. The primary reservoir cells of HTLV-I are therefore the infected T cells, which allow viral replication and persistence without being detected or cleared by the immune system efficiently.

Conclusion

Based on the information provided, the correct answer is: a. T cells

Key concepts

Reservoir Cells

In virology, reservoir cells play a critical role in the persistence and spread of viral infections. They are specialized cells that viruses can inhabit for long periods without being noticed by the body's immune defenses. This makes them perfect hideouts for pathogens.

For viruses to continue surviving and multiplying within the host, they rely on these reservoir cells. They function as a "safe haven" which allows the virus to remain latent. Even if the host's immune system is active and fighting infections, it may still not be able to spot these hidden viruses.

Reservoir cells are important for our understanding of diseases. They can help explain why some viruses, like HIV or HTLV-I, cause long-term infections and are hard to cure. Recognizing and targeting these cells is a key focus in virology research to prevent and treat chronic viral diseases effectively.

Human T-cell Lymphotropic Virus Type 1

Human T-cell Lymphotropic Virus Type 1 (HTLV-I) is a significant human retrovirus, known to be the first identified human retrovirus. Its notoriety comes from its infection patterns and the serious conditions it can cause.

HTLV-I is primarily known for infecting the human immune system, specifically targeting CD4+ T cells. These are a critical component of our immune defenses, and when they are compromised, it can lead to serious health issues. HTLV-I infection is linked with adult T-cell leukemia (ATL), a type of cancer that affects T cells, and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), an inflammatory neurological disorder.

The virus spreads through various means:

• Blood transfusions
• Sexual contact
• Mother-to-child transmission during childbirth or breastfeeding

Understanding HTLV-I's transmission methods and its impact on the immune system is crucial for controlling its spread and managing the diseases it causes.

Immune System

Our immune system is the body's defense mechanism against infections and diseases. It comprises a complex network of cells, tissues, and organs that work together to defend against harmful invaders such as viruses, bacteria, and other pathogens.

Key players in the immune system include:

• T cells: They are essential for identifying and killing infected cells. CD4+ T cells, a subtype of T cells, are particularly important because they help orchestrate the body's overall immune response.
• B cells: Responsible for producing antibodies, they mark pathogens for destruction.
• Macrophages: These cells engulf and digest cellular debris and pathogens, acting as the body's clean-up crew.

Efficient functioning of the immune system is vital for health. However, some viruses, like HTLV-I, have adapted to evade immune detection, infecting and residing within T cells. This evasion not only allows the virus to persist but also can harm the immune system itself, weakening the body's ability to fight off other pathogens. Understanding how these processes work is fundamental for developing strategies to combat and eradicate viral infections.