The study aims to explore the role of mucosal immunity in
combating COVID-19 with the objective of developing novel prophylactic and
therapeutic strategies. Coronavirus disease 2019 (COVID-19) emerged as an
expeditiously growing pandemic, in the human population caused by the highly
transmissible RNA virus severe acute respiratory syndrome of coronavirus 2
(SARS-CoV-2). In clinical settings, SARS-CoV-2 infection can be elucidated on
the basis of amplification of viral RNA from nasopharyngeal swab samples, and
saliva tests (less invasive in nature), but sometimes faeces tests show the
presence of SARS-CoV-2 RNA even prior to symptoms appear and also long after a
patient has tested negative from a conventional swab. The interplay of
SARS-CoV-2 infection predominantly occurs at the angiotensin-converting enzyme
2 receptor and transmembrane protease serine-type 2 positive (ACE2 + TMPRSS2+)
epithelial cells of the mucosal surfaces like nasal, oral mucosae, and/or the
conjunctival surface of the eye where it interacts with the immune system. The
largest integrant of the entire immune system is the mucosal immune system
which is augmented to provide a defence mechanism against various environmental
pathogens at the mucosae. The primary host response towards the pathogen starts
from an immune microenvironment of nasopharynx-associated lymphoid tissue
(NALT) and mucosa-associated lymphoid tissue (MALT). The presence of exhausted
lymphocytes, lymphopenia, pneumonia, and cytokine storm is the hallmark of
COVID-19. The multifaceted nature of co-morbidity factors like obesity and type
2 diabetes and their effects on immunity can alter the pathogenesis of
SARS-CoV-2 infection. Adipose tissue is a crucial endocrine organ that secretes
a plethora of factors like adipokines, cytokines, and chemokines that have a
profound impact on metabolism and augment the expression of mucosal
pro-inflammatory cytokines, like tumour necrosis factor-alpha (TNF-α),
interferon-gamma (IFN-γ), and the interleukin-12 (IL-12)/IL-23. Mucosal immunization
could be a superior approach to activate mucosal and systemic immune responses
against pathogenic invasion at mucosal surface entry ports. Mucosal vaccines
are also able to generate strong systemic humoral immunity—required to
neutralize any virus particle that dodges the primary immune response. In the
case of various vaccines, the weakening of vaccine-induced immunity is
associated with breakthrough infections. On the other hand, several lines of
evidence suggest that mucosal immunization via natural infection or vaccination
induces a more robust immune response in respiratory mucosa, which is the prime
target of SARS-CoV-2 infection. To develop an efficient vaccine against mucosal
pathogens, contemplation of the design of the delivery route, immunomodulatory
features, and adjuvants are very important. In this article, evidence was provided to understand the
significant role of mucosal immunity, along with secretory and circulating
immunoglobulin A (IgA) antibodies in generating a novel mucosal vaccine against
COVID-19. Moreover, along with mucosal vaccines, a look must be given to
combination treatment strategies with plant bioactive molecules. Glycan-binding
lectins against viral proteins for targeted activation of the mucosal immune
response are one such example. These may play a promising role in halting this
emerging virus. In this review, the different aspect of mucosal immunization
and their probable prospect against the COVID-19 pandemic have been summarized.
Further study on the formulation of nasal spray or inhaler with such plant
bioactive molecules or engineered antibodies will be a potent therapeutic and
prophylactic strategy in the prevention of a larger array of SARS-CoV2 with
reduced side effects.
Author (s) Details
Dr. Swapan K.
Chatterjee
Molecular Pharma Pvt. Ltd., 102A
Windsor Palace, 6A, Iron Side Road, Kolkata 700019, West Bengal, India.
Dr. Snigdha Saha
Molecular Pharma Pvt. Ltd., 102A Windsor Palace, 6A,
Iron Side Road, Kolkata 700019, West Bengal, India.
Maria Nilda M. Munoz
Cagayan State University, Tuguegarao City & De La
Salle University, Manila 0900, Philippines.
Molecular Pharma Pvt. Ltd., 102A Windsor Palace, 6A, Iron Side Road, Kolkata 700019, West Bengal, India.
Molecular Pharma Pvt. Ltd., 102A Windsor Palace, 6A, Iron Side Road, Kolkata 700019, West Bengal, India.
Cagayan State University, Tuguegarao City & De La Salle University, Manila 0900, Philippines.
Please see the link:- https://doi.org/10.9734/bpi/dhrni/v9/2196