Chinese dual-use facilities in Myanmar and Sri Lanka raise security concerns in India (GS Paper 2, International Organisation)
Why in news?
- The construction of a military facility on Coco Islands in Myanmar and a proposed remote satellite receiving ground station system in Sri Lanka, both coming up with Chinese help, have raised concern in India of possible surveillance across the region.
Details:
- Recent satellite images show the construction of a military facility on Coco Islands, located very close to the Andaman and Nicobar island chain.
- In the second case, China has proposed setting up a remote satellite receiving ground station system through a collaborative effort between the Aerospace Information Research Institute, under the Chinese Academy of Sciences, and the University of Ruhuna in southern Sri Lanka.
- Given its critical location, it can be used to spy on Indian assets and intercept sensitive information and also across the region.
Activities on the Coco Islands:
- It is believed to be a complete military base being built entirely by the Chinese on the Coco Islands. “There are obvious concerns.
- There was a radome (dome-shaped structure to protect radars) spotted on the island recently through satellite images, the island is being connected to the southern landmass using a new bridge that is 175 m in length and approximately 8 m wide.
- The facility can always be used by the Chinese military when required.
- Earlier, the London-based think tank Chatham House published a report based on the satellite imagery of January 2023 from Maxar Technologies, which showed large-scale construction activity on the strategic archipelago.
What it translates for India?
- The satellite tracking facilities are inherently dual use in nature, the Chinese civil space programme is known to work closely with the Chinese military.
- China’s expanding ground stations in the region could potentially be used to intercept sensitive information about Indian assets.
- India’s satellite launch facilities in Sriharikota and the integrated missile test range in Odisha could come under the scanner of the ground station, and launches from there could be tracked to obtain sensitive data.
- Similar to the recent instance of a Chinese research and survey vessel docking at Hambantota in Sri Lanka, the stations are likely to work in coordination with such vessels to gather vital information in the region.
- For example, space tracking and surveillance ships can perform many of the same functions as ground stations, with the added benefit of mobility.
Omicron variants evolve strategies to evade T cell immunity
(GS Paper 3, Science and Technology)
Why in news?
- A recent study found that the SARS-CoV-2 virus encodes multiple viral factors that modulate major histocompatibility complex class I (MHC I) expression in the host cells.
- The MHC I plays an important role in alerting the immune system to virally infected cells. The MHC I molecules are expressed on the surface of all infected cells.
CD8 T cells:
- Much like many other viruses that have developed strategies to evade T cell-mediated clearance by humans, SARS-CoV-2 virus too has the ability to evade the CD8 T cells.
- While neutralising antibodies are responsible for preventing infection, CD8 T cells play a huge role in reducing the viral load and clearing the infection by detecting and killing infected cells. The CD8 T cells cannot prevent infection.
MHC I molecules:
- One of the common tricks that viruses use to avoid killing is to inhibit MHC I expression and presentation. SARS-CoV-2 is no exception.
- The SARS-CoV-2 virus has evolved multiple strategies to inhibit MHC I expression, which is not seen in the case of the influenza virus. The suppression of MHC I is specifically seen in the infected cells and varies between different viral strains.
- The data showed that MHC I suppression is mediated by a number of viral gene products and affects only the infected cells. Such a mechanism will not lead to generalised immunodeficiency but reflects a specific survival mechanism for SARS-CoV-2.
- Immune evasion from CD8 T cells could allow the virus in infected cells to survive better in the host. The virus could establish a safe niche for prolonged replication. To eliminate such persistent reservoirs, there is need to employ antivirals or antibody therapy.
Superior capacity of Omicron:
- The ancestral strain first found in Wuhan, China and a few other variants that came up later already had the ability to escape from T cell-mediated immunity by reducing the expression of MHC I.
- The Omicron subvariants (BA.1, BA.2.12.1, XAF, and BA.4) had a “superior capacity” to suppress MHC I levels on the surface of the cells infected by the virus compared with the ancestral strain and other variants.
- Besides being endowed with greater ability to evade neutralising antibodies, the Omicron subvariants are better at evading recognition by the killer T cells.
- Looking for the molecular mechanism of the enhanced MHC I inhibition by Omicron subvariants, they identified common mutations in the E protein (T9I) which are shared among all Omicron subvariants used in the study.
- Mice infected with SARS-CoV-2 (MA10) showed that MHC I elevation was completely shut down in the infected lung epithelial cells unlike the lung epithelial cells infected with influenza virus.
Evasion strategy:
- They demonstrated that the ability to reduce MHC I expression remained unchanged throughout the pre-Omicron variant-of-concern evolution. These findings suggested three important perspectives on the MHC I evasion strategy of SARS-CoV-2.
- First, the virus utilises multiple redundant strategies to suppress MHC-I expression.
- Second, MHC I downregulation may not only impair cytotoxic T lymphocytes (CTL) recognition of infected cells for killing but may also impair priming of T cells.
Way Forward:
- The study provided evidence of inhibition of MHC I upregulation in SARS-CoV-2-infected cells in both in vitro and in vivo settings.
- The cellular mechanisms and consequences of enhanced MHC I inhibition by Omicron variants on infection and disease remain to be determined.
L&T gets order to build prototype of light tank for Sino-India border
(GS Paper 2, Defence)
Why in news?
- Recently, the Defence Research & Development Organisation (DRDO) and Larsen & Toubro (L&T) have joined hands to develop an indigenous light tank that is optimised for the extreme cold and high altitude of Ladakh and Arunachal Pradesh.
- Having co-designed an indigenous, 25-tonne, light tank, the DRDO has placed a development order on L&T to build the first prototype.
AoN:
- Meanwhile, the Defence Acquisition Council (DAC), the Ministry of Defence’s (MoD’s) apex body for capital purchases has granted an Acceptance of Necessity (AoN) for seven light tank regiments, each equipped with 45 tanks.
- The AoN requires L&T to build one regiment of light tanks, while the MoD acquires the other six regiments under the “Make” procedure.
Key Features:
- The light tank will have a hull, co-developed by DRDO and L&T, that will house an 800 horsepower (HP) engine optimised for high altitudes. The engine will be provided by German firm MTU, which is a subsidiary of Rolls-Royce.
- Mounted on this hull will be a 105-millimetre gun turret, procured ready-built from Belgian firm, John Cockerill.
ZTQ 105:
- The armoured challenge from the People’s Liberation Army (PLA) in Ladakh is centred on China’s new light tank, the agile and versatile ZTQ 105 also known as the Type 15 –developed by China’s North Industries Group Corporation (NORINCO) and unveiled during the Zhuhai Air Show in 2016.
- The ZTQ 105 has a 105-mm rifled gun that can destroy enemy tanks at ranges of two-to-three kilometres (km). It also fires anti-tank guided missiles to knock out tanks at ranges of five km.
T-72 and T-90 tanks:
- The Indian Army currently uses Russian T-72 and T-90 tanks on the Sino-Indian border. But these hefty, 42-45-tonne main battle tanks are designed for the plains. Movement is difficult for them on steep and narrow mountain roads.
- There are also limitations on how much their heavy 120-mm guns can be depressed or elevated, sometimes preventing them from engaging targets on hilltops or in valleys. That is why the Army took only small numbers of T-72 and T-90 tanks into Ladakh to counter the Chinese intrusions in 2020, and used them only sparingly.
Earlier light tanks used by Indian Army:
- In contrast, the Army has a formidable combat tradition of using light tanks in the mountains. In 1944, it used Stuart and Sherman tanks in the battle of Kohima. In 1948, these same tanks pushed back Pakistan forces in the Zoji-la pass.
- Against China in 1962, the Army used light AMX-13 tanks in the battle of Gurung Hill near Pangong Tso and deployed them in Bomdila and Dirang in Arunachal Pradesh.
- In the 1971 Bangladesh campaign, French AMX-13 and Soviet PT-76 tanks played a stellar role in the battle of Garibpur.
Situation post 2020:
- Although the K-9 Vajra artillery gun is designed for use in plains terrain, the Sino-Indian border tensions in 2020 saw a full regiment of these long-range, self-propelled guns deployed in eastern Ladakh, to increase the army’s long-range firepower.
- Their successful deployment prompted the Army to consider diverting significant numbers of K-9 Vajras for use in mountainous terrain. This requires L&T to build 100 more K-9 Vajras; as well as induction of the Ordnance Factory Board’s indigenous 155 mm, 45 calibre Dhanush howitzers, and imported M777 ultralight guns.
- To cater for this enhanced firepower, L&T has built 100 K-9 Vajras in Hazira, near Surat, with technology transferred from South Korean defence major Hanwha Defense. It handed over the 100th SP howitzer in February 2021.
Way Forward:
- Now the MoD is pursuing the “Vajra repeat programme”, which requires L&T to build another 100 K-9 Vajra howitzers.
