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Advanced Neurology Role of immunosuppressants in autism

modification of NK cells [111] . Patients with ASD have been production by NK cells [116] . The number of NK cells in
found to have NK cell counts that are roughly 40% greater rapamycin-treated recipients was much lower, as reported
than the general population . KIR and HLA are two of by the author. These data indicate that immunosuppressive
[37]
the NK cell receptors. HLA is a gene that produces proteins drugs have differential effects on NK cell function that
found in all nucleated cells and is connected to the NK cell may impact the immune response to a transplant. The
receptor (killer immunoglobulin-like receptors). KIR is number of NK cells in rapamycin-treated recipients was
encoded by the NK cells, which are affected by HLA ligands, much lower, as reported by the author. Inhibition of RNK-
through the leukocyte receptor complex by attaching to 16 cell proliferation and primary NK cell proliferation by
cell surface receptor proteins . KIR2DS2 levels as well as rapamycin was dose-dependent, with a noticeable effect
[81]
the inhibition of KIR were found to be higher in children detected even at the minimum concentration of rapamycin
with ASD compared to the general population . Recent tested (0.01 ng/mL) and a more pronounced effect shown
[38]
research by Marçais et al. demonstrated the critical role at higher rapamycin concentrations. Rapamycin inhibits
of mTOR in the maturation of NK cells [112,113] . As reported NK cell progression from the G1 to the S phase of the
by Marçais et al., the Akt/mTOR signaling pathway was cell cycle, which explains why rapamycin-treated graft
found to be specifically activated in reactive NK cells [112] . recipients had a significant drop in NK cells beginning on
This was characterized by an increase in the basal day 5 post-transplant, as shown in Figure 4 [117] . From the
phosphorylation of direct and indirect targets of both above, we know that rapamycin, an immunosuppressant,
mTOR complexes (mTORC1 and mTORC2) in precise can be used as a mTOR inhibitor through which it inhibits
association with the level of reactivity. The data showed NK cells by inhibiting mTOR linked with NK cells, by
that NK cell receptivity was closely tied to mTOR activity, inhibiting mTORC1, as well as killer cell immunoglobin,
which could be altered using exogenous cytokines or to treat autism, and rapamycin is an food and drug
pharmacological interventions. Furthermore, mTOR may administration (FDA)-approved drug for the treatment of
control NK cell reactivity by incorporating signals outside autistic symptoms.
of NK cell inhibitor receptor (NKIR) ligands. The non- 5. Role of familial adenomatous polyposis
redundant function of mTORC1 is revealed by the fact (FAP) in the activation of mTOR and link
that rapamycin, an inhibitor of mTORC1, is sufficient to
diminish the response [112] . with peroxisome proliferator activated
Increased cytokine responses are seen when NK cells receptor gamma (PPAR)
are activated with IL-15, during microbial infections. PPAR is involved in the pathogenesis of ASD as it activates
Mice given rapamycin to block the mTOR pathway had FAP gene, resulting in overexpression of mTOR, and this
difficulties growing, producing IFN-γ and granzyme B, and leads to activation of NK cells that has been found to be
multiplying. Mice treated with rapamycin had lower levels elevated in the autistic patient [118] as shown in Figure 5.
of IFN-γ production in their infected spleens, as reported PPARα, PPARβ, and PPARγ are the three members of the
by Nandagopal et al. [114] Rapamycin’s ability to inhibit PPAR family that are each encoded by a gene on human
mTOR affects the cytotoxicity and proliferative responses chromosomes 22, 6, and 3, respectively. When these
of NK cell in the context of murine cytomegalovirus three PPAR members are dysregulated, they cause CNS
(MCMV) infection [114] . Modulating NK cell maturation, dysfunction [119] . PPAR is a ligand-activated transcriptional
differentiation, and activation requires the PI3K-AKT- element that, when working in concert with the retinoid
mTOR pathway. X receptor, operates as a heterodimer to stimulate certain
peroxisome response elements. This is accomplished
During MCMV infection, rapamycin-treated mice had through the formation of a heterodimer (PPRE). The
a dramatic decrease in NK cells. Independent research activation of PPAR has been linked to a variety of cellular
confirms that mTOR is essential for NK cell proliferation and processes, including proliferation, differentiation, and
that NK cell-specific mTOR-deficient animals have severe angiogenesis [120,121] . Furthermore, stimulation is involved
defects in their ability to proliferate early during MCMV in anti-apoptosis, anti-inflammatory, and anti-oxidant
infection [113,115] . When mice are given poly (I) or infected processes, as well as the prevention of carcinogenesis.
with MCMV, mTORC1 activity increases dramatically. PPAR is responsible for controlling a large number of
Natural killer cell cytotoxicity toward YAC-1 tumor cells signaling pathways, some of which include the regulation
was inhibited by the mTORC1 inhibitor rapamycin during of connective tissue, the stimulation of mesenchymal
MCMV infection. At 1.5 days after infection, Nandagopal cells, and fibrogenesis. Furthermore, PPAR expression
et al., who administered the mTOR inhibitor rapamycin to can also be seen in a variety of other routes and functions,
mice infected with MCMV, reported a decrease in IFN-γ including the metabolism of lipids, the modulation of

Volume 2 Issue 2 (2023) 12 https://doi.org/10.36922/an.391