Cellular immunity in type 1 diabetes: insights from comparative analysis with type 2 diabetes and healthy individuals by flow cytometry

Elena Zakharova; Anna Goncharenko; Ivan Golodnikov; Margarita Samsonova; Nadezhda Rusyaeva; Marina Shestakova; Marina Loginova

doi:10.1530/endoabs.99.EP31

Goal: Type 1 diabetes (T1D) development involves intricate interactions between pancreatic β-cells and immune cells. Our study analyzed cellular immunity parameters in adult T1D patients’ blood to identify factors influencing disease progression in comparison with healthy donors and type 2 diabetes (T2D) patients.

Methods: Three groups were studied - healthy volunteers (n=13), T1D patients (n=10), and T2D patients (n=13). Analysis included autoantibody measurement and flow cytometry (BD LSRFortessa) of peripheral blood.

Results: Analysis of the main populations of T cells (CD3⁺-cells), B-cells (CD19⁺-cells) and NK cells (CD3^-CD19^--cells) did not reveal significant differences between the values in healthy donors and patients with T1D and T2D (Table 1). However, CD3⁺CD8⁺T-cells and Immune Regulatory Index differed between healthy donors and T2D patients. In T1D, CD3^-CD19^-CD8^-CD38⁺ NK-cells decreased compared to controls and T2D, with a negative correlation to insulin autoantibodies. On the other hand, there is a trend towards an increase in the quantity of CD3^-CD19^-CD8⁺CD38⁺ NK-cells compared to the control group (Table 1). Effector NK-cells (CD3^-CD19^-CD16⁺⁺CD56⁺) decreased in T1D, while T2D had increased NK-cells with weak CD56 expression (Table 1). Correlation analysis did not reveal a connection between CD3^-CD19^-CD8^-CD38⁺ NK-cells of the three studied groups and the levels of autoantibodies to GAD, islet cells, and tyrosine phosphatase (Table 1).

Table 1. Comparison of cellular immunity parameters in patients with T1D, T2D and healthy volunteers.
Cellular parameters	Healthy	T1D	T2D	1vs2	1vs3	2vs3
CD3⁺Т-cells	73,2 70,6-79,3	76,1 69,7-80,8	73,4 65,7-80,4	–	–	–
CD3⁺CD4⁺ Th	45,5 40,8-52,1	47,9 46,6-54,5	49,9 44,5-55,8	–	–	–
CD3⁺CD8⁺ CTL	27,6 21,7-31,3	24,2 17,2-31,4	20,5 15,0-26,4	–	* P=0,0441	–
CD4⁺/CD8⁺	1,7 1,3-2,1	2,1 1,6-3,0	2,2 1,9-3,6	–	* P=0,0281	–
CD3⁺CD4⁺CD8⁺	1,2 0,6-2,3	1,2 0,8-2,4	1,4 0,9-2,0	–	–	–
CD3^-CD4^-CD8^-	5,4 3,8-8,4	4,6 3,2-6,0	3,3 2,2-5,5	–	* P=0,0387	–
CD3^-CD19⁺ В-cells	10,0 8,5-11,3	9,9 7,4-12,3	11,3 9,9-13,8	–	–	–
CD3^-CD19^-NK-cells	14,8 8,6-18,4	13,2 9,0-16,9	14,4 7,0-22,4	–	–	–
CD3^-CD19^-CD8^-CD38⁺ NK-cells	49,2 47,7-63,2	38,1 30,6-45,4	50,6 42,4-59,1	* P=0,0214	–	* P=0,0121
CD3^-CD19^-CD8⁺CD38⁺ NK-cells	36,7 21,1-47,0	44,3 38,9-56,9	40,1 34,5-46,6	– P=0,0647	–	–
CD3^-CD19^-CD56 ⁺ CD16⁺⁺ NK-cells	80,8 70,1-83,7	69,8 57,8-77,9	83,1 72,9-89,8	* P=0,0343		* P=0,0044
CD3^-CD19^-CD56⁺ CD16^- NK-cells	0,3 0,2-0,5	0,6 0,2-0,9	0,3 0,1-0,3	–	–	* P=0,0351
CD3^-CD19^-CD56⁺⁺CD16 ⁺⁺NK-cells	0,3 0,3-0,8	0,6 0,2-2,0	0,2 0,08-0,5	–	–	– P=0,0862

Conclusion: T2D shows reduced cytotoxic T-cells, while NK-cells play a crucial role in T1D. CD8^-CD38⁺ NK-cells reduction in T1D correlates with insulin autoantibodies. Functional activity differences in NK-cells between early and long-term treatment stages may exist in T1D and T2D patients.

Funding: Grant No122112200001-4

Endocrine Abstracts

EP31