. 2022 Jan 25;14(2):242. doi: 10.3390/v14020242

Table 1.

The role of T cell populations of CHIKV, DENV and ZIKV during different disease stages, and their respective function, gene expression and regulation profile.

Virus	T Cell Type/Phenotype	Disease Condition	Markers	Gene Regulation	Function	References
CHIKV	CD8⁺ T cells	Acute	$CD 69, CD 107 a, Granzyme B, Perforin, IFN γ$	Upregulation	T cell activation, destroy virus infected cells	[32,34,35,36]
		Acute	IL-17, IL-10 R	Downregulation	develop joint symptoms in acute phase and maintain these symptoms in the chronic phase	[35]
		Chronic	CD95L	Upregulation	involved in CHIKV chronicity mechanism	[35]
	CD4⁺ T cells	Acute	CD95L	Upregulation	apoptosis of CD4 T cells	[32]
		Chronic	$IFN γ$ ,	Upregulation	inflammation and joint swelling	[39]
	$γ δ$ T cells	Acute	$CCL 2, CXCL 9, IFN γ$	Downregulation	reduced foot swelling in mice	[45,46,109]
	CD4-T_reg	recovery	IL-10	Up regulation	resolution of the disease	[48]
DENV	CD8⁺ T cells	Acute	CCR5, CXCR3, CXCR6	Upregulation	supporting T cells to migrate in to peripheral inflamed tissues	[53,54]
			CLA	Upregulation	influx of T cells to skin providing immediate onsite protection	[117]
			CD69, HLA-DP, DQ, DR, CD38, cytotoxic granule TIA-1, VLA-4, ICAM-1, LFA-1CD44, CD11a	Upregulation	T cell activation, elimination the virus, induce inflammation	[117]
	HLA-DR⁺CD38⁺ CD8⁺T cells	Acute	PD-1, Lag3, KLRG1, CTLA-4, CD160	Upregulation	T cell activation, Proliferation, cytotoxicity and migration	[72]
	HLA-DR⁻CD38⁺ CD8⁺ T cells	Acute	AKT3, ACTN1	Downregulation	TCR signaling, amplification and synapse	[72]
	CD8⁺T_em (CD45RA⁻CCR7⁻) and T_emra (CD45RA⁺CCR7⁻)	Acute	$IFN γ, CCL 3 / CCL 4, CD 69, CRTAM, IFN γ$ , TNFα, CTLA4, ICOS, LIGHT, IRF4, IRF8, SLAMF7, KIR2DL3	Upregulation	T cell activation, proliferation and polyfunctional properties, narrow transcriptional responses	[73]
	CXCR5⁺CD8⁺ T cells (T_FH)	Chronic	PD-1	Upregulation	T cell proliferation and exert effector functions	[74]
	CD4⁺ T cells		$IFN γ$	Upregulation	cytotoxic effects	[77,79]
	CD4⁺Temra CD45RA⁺CCR7⁻		$CX 3 CR 1, serine protease granzyme, IFN γ$	Upregulation	cytotoxic, protective role in DENV with HLA DR allele	[81]
	CD4⁺CD25⁺FoxP3⁺ T_reg	acute	CTLA-4	Upregulation	producing immunosuppressive cytokines	[82,83]
	T_FH	critical	CD40L	Upregulation	strong activator of B cells	[86,87]
	T_FHCXCR5⁺CD45RA⁻CD4⁺Tcells	Critical	PD-1, CD38	Upregulation	predictor for neutralizing antibody titer and disease severity	[85]
ZIKV	CD8⁺IFN-γ⁺ T cells	acute	granzyme B, CRTAM, X-C motif chemokine ligand 1 and 2, CC3, CC4	Upregulation	cytotoxicity, T cell activation and regulation, proinflammation, T cell homing	[101]
	CD8⁺IFN-γ⁺ T cells	Acute	$IFN γ$ , TNF-α, Granzyme B	Upregulation	Th1, Th2, Th17 and Th9 responses	[17,102]
	$V δ$ 2 T cells	Acute	Granzyme B	Upregulation	antiviral and stimulatory activities	[115,116]