Mantle cell lymphoma (MCL) is a rare subtype of non-Hodgkin lymphoma (NHL) with high heterogeneity and a high recurrence rate. How heterogenous cell populations contribute to relapse remains to be elucidated.

We performed single cell RNA sequencing (scRNA-seq) on approximately 4,000 bone marrow cells sampled from one patient with multidrug resistant MCL. We identified 10 subpopulations comprising 4 malignant B cell subtypes, 3 T cell subtypes, 2 dendritic cell subtypes and 1 natural killer (NK) cell subtype. Subsequently, we identified cell markers, including a series of genes associated with immune escape and drug resistance. In addition, we explored the roles of these genes in the mechanism of immune escape and drug resistance, and we verified the expression imbalance and clinical prognostic potential by using GEO datasets including 211 MCL samples.

The major immune escape mechanisms of MCL included anti-perforin activity, decreased immunogenicity and direct inhibition of apoptosis and cell killing, as mediated by type Ⅰ and Ⅱ B cells. The drug resistance mechanisms of different cell clusters included drug metabolism, DNA damage repair, apoptosis and survival promotion. Type Ⅲ B cells closely communicate with other cells. The key genes involved in the resistance mechanisms showed dysregulated expression and may have significant clinical prognostic value.

This study investigated potential immune escape and drug resistance mechanisms in MCL. The results may guide individualized treatment and promote the development of therapeutic drugs.