From the Guidelines
Viruses protect themselves from immune system recognition primarily through antigenic variation, which involves changing their surface proteins or antigens, making it difficult for the immune system to identify and target them effectively. This mechanism is crucial for viruses like influenza, which regularly mutate their surface proteins, creating new strains that can evade previously developed antibodies 1. Antigenic variation can occur through antigenic drift, where minor changes in individual amino acids of the hemagglutinin (HA) or neuraminidase (NA) proteins allow the virus to evade existing humoral immunity 1. Additionally, some viruses employ molecular mimicry by displaying proteins similar to host cells, making it harder for the immune system to distinguish them as foreign. Others can hide within host cells, limiting their exposure to immune surveillance, or directly interfere with immune signaling pathways. Some viruses even encode proteins that inhibit components of the immune response.
The ability of viruses to change their surface antigens is a key factor in their ability to cause recurring outbreaks and chronic infections despite immune system efforts to eliminate them. For example, influenza A viruses are further categorized into subtypes based on their surface HA and NA proteins, and antibody against one influenza virus type or subtype confers little or no protection against another virus type or subtype 1. The frequent development of antigenic variants through antigenic drift is the virologic basis for seasonal epidemics and the reason for the incorporation of one or more new strains in each year's influenza vaccine 1.
Recent studies have also highlighted the importance of viroporins, viral membrane proteins that can increase membrane permeability to ions and other small solutes, in the virus life cycle and as potential targets for antiviral therapeutics 1. However, antigenic variation remains the primary mechanism by which viruses protect themselves from immune system recognition, and understanding this mechanism is crucial for the development of effective vaccines and antiviral therapies.
Key points to consider:
- Antigenic variation is a key mechanism by which viruses protect themselves from immune system recognition
- Antigenic drift and shift are important factors in the ability of viruses to cause recurring outbreaks and chronic infections
- Viroporins are a class of viral membrane proteins with potential as targets for antiviral therapeutics
- Understanding the mechanisms of immune evasion used by viruses is crucial for the development of effective vaccines and antiviral therapies.
From the Research
Virus Characteristics and Immune System Evasion
- The provided studies do not directly address the characteristic of a virus that protects it from immune system recognition.
- However, some studies discuss the mechanisms of antiviral therapies and the development of resistance to these therapies 2, 3, 4, 5, 6.
- For example, the study by 5 discusses the development of resistance to antiviral drugs such as oseltamivir and amantadine, which target specific proteins on the surface of influenza viruses.
- Another study by 6 examines the impact of oseltamivir treatment on influenza A and B virus dynamics in human volunteers, but does not address the specific characteristic of viruses that protects them from immune system recognition.
Antiviral Therapies and Resistance
- The studies provide information on various antiviral therapies, including lopinavir/ritonavir, remdesivir, and oseltamivir, and their effectiveness in treating COVID-19 and influenza infections 2, 3, 4, 5, 6.
- The development of resistance to these therapies is also discussed, highlighting the need for ongoing research and development of new antiviral compounds 5.
- However, the specific characteristic of viruses that protects them from immune system recognition is not addressed in these studies.
Limitations of Current Research
- The provided studies do not provide a clear answer to the question of what characteristic of a virus protects it from immune system recognition.
- Further research is needed to understand the mechanisms of immune system evasion and to develop effective antiviral therapies that can target these mechanisms 2, 3, 4, 5, 6.