1.Introduction
Primary Sjogren’s syndrome(pSS) is a complex autoimmune disease, which
is characterized by the infiltration of lymphocytes from exocrine
glands, leading to the dysfunction of gland secretion, and then a series
of symptoms of gland injuries, such as dry mouth, dry eye and swelling
of parotid gland, as well as extraglandular manifestations such as
arthralgia, interstitial lung disease(ILD), renal tubular acidosis and
primary biliary cholangitis(PBC),and part of patients have systemic
manifestations, such as fatigue, fever and weight
loss[1, 2]. Until now, the pathogenesis of pSS has
not been clarified.Generally speaking, the pathogenesis of pSS is
related to environmental factors,genetic susceptibility and immune
disorder.It is well known that pSS is mainly mediated by T cells and B
cells, but innate immune cells such as NK cells also play an important
role in the pathogenesis of pSS[3].Recent studies
have found that the expression of NK cells in peripheral blood or
salivary glands of pSS patients or model mice was abnormal, which was
related to the activity and severity of the
disease[4-6].
CD161 is one of a member of human NKRP1 subfamily which is called NK
cell receptor protein 1A (NKR-P1A) or killer cell lectin-like receptor
subfamily B member 1 (KLRB1),and it’s also a type II transmembrane
C-type lectin glycoprotein receptor, which is called C-type lectin
domain family 5 member B (CLEC5B)[7]. CD161 is
mostly expressed on NK cells and T cell subsets such as CD4+T cells,CD8
αβT cells, γδT cells and NKT cells[8].In humans,
the ligand of CD161 is called lectin-like transcript 1(LLT1),which is
mainly expressed on activated monocytes and B cells, and interacts with
CD161 to inhibit the activation of NK cells, and inhibit cytotoxic
function and cytokine secretion mediated by NK
cells[9, 10].
At present, the few research of CD161 in pSS patients is limited to T
cells and the subsets of T cells[11, 12], and
there is no relevant study on the clinical relevance of CD161 expression
on NK cells in pSS patients.In this study,we detected the proportion of
CD161 in peripheral blood on CD56+NK cells of pSS patients by flow
cytometry, and analyzed the clinical correlation between the proportion
of CD161+CD56+NK cells and disease activity in pSS. This research aims
to provide new ideas and therapeutic targets for the diagnosis and
treatment of pSS.