• 1 Department of Orthopedics, School of Medical Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
  • 2 Department of Orthopedics, Government Medical College and Hospital, Dindigul, Tamil Nadu, India
  • 3 Quality and Regulatory Affairs, Infohealth FZE, United Arab Emirates
  • 4 School of Medical Sciences and Research, Sharda University, Greater Noida, Uttar Pradesh, India
  • 5 Department of Dermatology, Raja Rajeswari Medical College & Hospital, Bengaluru, Karnataka
  • 6 Department of Orthopedics, Kalpana Chawla Government Medical College & Hospital, Karnal, Haryana, India
  • 7 Department of Plastic Surgery, Topiwala National Medical College and BYL Nair Ch. Hospital, Mumbai, Maharashtra, India
  • 8 ESIS Hospital (Worli), Mumbai, Maharashtra, India
  • 9 Department of Biotechnology, School of Engineering &Technology, Sharda University, Greater Noida, Uttar Pradesh, 201310, India
  • 10 Amity Institute of Molecular Medicine & Stem Cell Research, Amity University Uttar Pradesh, Noida, India
  • 11 Department of Applied Physics, School of Science, Aalto University, Espoo, 00076, Finland
  • 12 Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, PO Box 17666, United Arab Emirates University, Al Ain, United Arab Emirates
  • 13 Indian Scientific Education and Technology Foundation, Lucknow, 226002, UP, India
  • 14 School of Pharmacy, Suresh Gyan Vihar University, Jagatpura, Jaipur, India
  • 15 Faculty of Pharmaceutical Sciences, Maharshi Dayanand University, Rohtak, India
  • 16 Department of Life Sciences, School of Pharmacy, International Medical University (IMU), Bukit Jalil, 57000, Kuala Lumpur, Malaysia
  • 17 School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, Punjab, 144411, India
  • 18 Department of Life Sciences, School of Basic Science and Research, Sharda University, Greater Noida, Uttar Pradesh, 201310, India
Heliyon, 2021 Jul;7(7):e07635.
PMID: 34312598 DOI: 10.1016/j.heliyon.2021.e07635


The contagiosity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has startled mankind and has brought our lives to a standstill. The treatment focused mainly on repurposed immunomodulatory and antiviral agents along with the availability of a few vaccines for prophylaxis to vanquish COVID-19. This seemingly mandates a deeper understanding of the disease pathogenesis. This necessitates a plausible extrapolation of cell-based therapy to COVID-19 and is regarded equivalently significant. Recently, correlative pieces of clinical evidence reported a robust decline in lymphocyte count in severe COVID-19 patients that suggest dysregulated immune responses as a key element contributing to the pathophysiological alterations. The large granular lymphocytes also known as natural killer (NK) cells play a heterogeneous role in biological functioning wherein their frontline action defends the body against a wide array of infections and tumors. They prominently play a critical role in viral clearance and executing immuno-modulatory activities. Accumulated clinical evidence demonstrate a decrease in the number of NK cells in circulation with or without phenotypical exhaustion. These plausibly contribute to the progression of pulmonary inflammation in COVID-19 pneumonia and result in acute lung injury. In this review, we have outlined the present understanding of the immunological response of NK cells in COVID-19 infection. We have also discussed the possible use of these powerful biological cells as a therapeutic agent in view of preventing immunological harms of SARS-CoV-2 and the current challenges in advocating NK cell therapy for the same.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.