| 1. |
- Hojjat-Farsangi, Mohammad, et al.
(författare)
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Spontaneous immunity against the receptor tyrosine kinase ROR1 in patients with chronic lymphocytic leukemia
- 2015
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Ingår i: PLOS One. - Stockholm : Karolinska Institutet, Dept of Oncology-Pathology. - 1932-6203.
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Tidskriftsartikel (refereegranskat)abstract
- Background: ROR1 is a receptor tyrosine kinase expressed in chronic lymphocytic leukemia (CLL) and several other malignancies but absent in most adult normal tissues. ROR1 is considered an onco-fetal antigen. In the present study we analysed spontaneous humoral and cellular immunity against ROR1 in CLL patients. Materials and Methods: Antibodies against ROR1 were analysed in 23 patients and 20 healthy donors by ELISA and Western blot. Purified serum IgG from patients was tested for cytotoxicity against CLL cells using the MTT viability assay. A cellular immune response against ROR1 derived HLA-A2 restricted 9 aa and 16 aa long peptides were analysed using peptide loaded dendritic cells co-cultured with autologous T cells from CLL patients (n = 9) and healthy donors (n = 6). IFN-γ, IL-5 and IL-17A-secreting T cells were assessed by ELISPOT and a proliferative response using a H3-thymidine incorporation assay. Results: The majority of CLL patients had antibodies against ROR1. Significantly higher titers of antiROR1 antibodies were noted in patients with non-progressive as compared to progressive disease. The extracellular membrane-close ROR1 KNG domain seemed to be an immunodominant epitope. Ten patients with high titers of anti-ROR1 binding antibodies were tested for cytotoxicity. Five of those had cytotoxic anti-ROR1 antibodies against CLL cells. ROR1-specific IFN-γ and IL-17A producing T cells could be detected in CLL patients, preferentially in non-progressive as compared to patients with progressive disease (p < 0.05). Conclusion: ROR1 seemed to spontaneously induce a humoral as well as a T cell response in CLL patients. The data support the notion that ROR1 might be a specific neo-antigen and may serve as a target for immunotherapy.
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| 2. |
- Hojjat-Farsangi, Mohammad, et al.
(författare)
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Frequency analysis of HLA class I alleles in Iranian patients with progressive and non-progressive chronic lymphocytic leukemia
- 2013
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Ingår i: Human Immunology. - Stockholm : Karolinska Institutet, Dept of Oncology-Pathology. - 1879-1166 .- 0198-8859.
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Tidskriftsartikel (refereegranskat)abstract
- Chronic lymphocytic leukemia (CLL) is a malignant disorder of B cell origin, with low incidence in Asian populations. In this study we investigated the HLA-class I A and B allele frequencies in 87 Iranian CLL patients and 64 healthy controls using sequence specific primer-polymerase chain reaction (SSP-PCR) technique. Our results showed increased frequencies of HLA-A11:01 (p=0.02) and HLA-B35:01 (p=0.002) alleles and HLA-A11:01/B35:01 haplotype (p=0.036) and decreased frequencies of HLA-A01:01 (p=0.02), HLA-A26:01 (p=0.03), HLA-B65:01 (p=0.03) and HLA-B53:01 (p<0.00001) alleles in CLL patients compared to the control group. Classification of the patients into non-progressive and progressive groups did not reveal significant differences for the frequency of any of the HLA-A and -B alleles or haplotypes between these two subtypes. Comparison between patients with immunoglobulin heavy chain variable region genes (IGHV) mutated (n=56) and unmutated (n=31) subtypes showed a significant increase in HLA-A32:01 (p=0.05) and HLA-A33:01 (p=0.05) alleles in IGHV unmutated patients compared to IGHV mutated patients. Similarly, a higher frequency of HLA-B52:01 (p=0.037) alleles was observed in CD38+ compared with CD38- patients. Our results obtained from an Iranian population indicate that CLL is associated with distinct HLA class I alleles and haplotypes some of which are linked to disease prognostic factors.
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| 3. |
- Hojjat-Farsangi, Mohammad, et al.
(författare)
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Immunophenotypic characterization of the leukemic B-cells from Iranian patients with chronic lymphocytic leukemia : association between CD38 expression and disease progression
- 2008
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Ingår i: Iranian Journal of Immunology. - Stockholm : Karolinska Institutet, Dept of Oncology-Pathology. - 1735-1383.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with B-cell chronic lymphocytic leukemia (B-CLL) have heterogeneous clinical courses, thus several biological parameters need to be added to the current clinical staging systems to predict disease outcome. Recent immunophenotypic studies performed mainly in Western populations have demonstrated the prognostic value of CD38 and ZAP-70 expression in B-CLL. Objectives: To investigate the expression pattern of a variety of membrane antigens on leukemic cells from Iranian patients with CLL and to find out if there are any differences in the expression of these markers between indolent and progressive groups. Methods: In the present study, peripheral blood samples from 87 Iranian patients with B-CLL were analysed by flow cytometry. Results: In all cases, the neoplastic cells displayed B-CLL phenotype (CD5+/CD19+/sIg+). The vast majority of the cases expressed CD23, but failed to stain for CD3 or CD14. The leukemic cells of most patients expressed CD27 (84/87, 95.4%) and CD45RO (74/87, 83.9%) molecules, suggesting a memory B-cell phenotype. Comparison between the indolent (n=42) and progressive (n=37) patients revealed significantly higher frequency and intensity of CD38 expression in progressive group (40.5%) compared to indolent (11.9%) patients (p<0.05). None of the other membrane antigens were differentially expressed in these two groups of patients. Conclusion: Our results obtained in an Asian ethnic population confirm and extend previous findings obtained from Western populations regarding the association of CD38 expression and disease progression in B-CLL.
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