Why in News?
A new study has revealed that TR1 (Type-1 Regulatory T-cells)—not TH1 cells—are the main drivers of the immune response to malaria, challenging long-standing assumptions in immunology.
What are TR1 Cells?
| Aspect | Details |
|---|---|
| Definition | TR1 (Type-1 Regulatory T-cells) are a subset of CD4+ T helper cells that regulate immune responses, especially by controlling inflammation. |
| Function | They prevent excessive immune reactions, ensuring balance between pathogen elimination and host protection. |
| Role in Malaria | TR1 cells modulate immune response against Plasmodium falciparum, promoting tolerance and helping in developing clinical immunity (reduced severity of illness over time). |
Key Components of the Human Immune System
| Component | Function |
|---|---|
| Physical Barriers | First line of defense: skin, mucous membranes. |
| Innate Immunity | Non-specific, rapid response: neutrophils, macrophages, NK cells, inflammation. |
| Adaptive Immunity | Specific and memory-based: B-cells (produce antibodies), T-cells (helper, killer, regulatory). |
| Lymphatic System | Includes lymph nodes, spleen, thymus; coordinates immune cell production and pathogen filtration. |
| Cytokines | Chemical messengers that regulate immune activity and cell communication. |
What is Malaria?
| Aspect | Details |
|---|---|
| Cause | Parasitic infection by Plasmodium species (notably P. falciparum and P. vivax). |
| Transmission | Spread by infected female Anopheles mosquito; parasites invade liver and red blood cells. |
| Symptoms | Fever, chills, vomiting, anemia, in severe cases—organ failure or death. |
| Treatment | ACTs for P. falciparum, chloroquine for P. vivax, primaquine for liver-stage forms. |
| Vaccines | WHO-approved RTS,S/AS01 (Mosquirix) and R21/Matrix-M (developed by SII & Oxford). |
| India’s Response | National Framework for Malaria Elimination (2016–2030), MERA-India, NVBDCP, NMCP. |
Prelims Practice Questions
- Which of the following best describes the role of TR1 cells?
A) Destroy virus-infected cells
B) Produce antibodies against pathogens
C) Regulate immune responses and control inflammation
D) Activate B-cells to produce antibodies
Answer: C - The R21/Matrix-M vaccine, recently recommended by WHO, is used against:
A) Dengue
B) Tuberculosis
C) Malaria
D) Japanese Encephalitis
Answer: C - Which of the following is not a part of the innate immune system?
A) Neutrophils
B) Cytokines
C) B-cells
D) Natural Killer cells
Answer: C
