Around 65% of primary immunodeficiencies are antibody deficiencies. Functional tests are useful tools to study B‐cell functions in vitro. However, no accepted guidelines for performing and evaluating ...functional tests have been issued yet. Here, we report our experience on the study of B‐cell functions in infancy and throughout childhood. We show that T‐independent stimulation with CpG measures proliferation and differentiation potential of memory B cells. Switched memory B cells respond better than IgM memory B cells. On the other hand, CD40L, a T‐dependent stimulus, does not induce plasma cell differentiation, but causes proliferation of naïve and memory B cells. During childhood, the production of plasmablasts in response to CpG increases with age mirroring the development of memory B cells. The response to CD40L does not change with age. In patients with selective IgA deficiency (SIgAD), we observed that switched memory B cells are reduced due to the absence of IgA memory B cells. In agreement, IgA plasma cells are not generated in response to CpG. Unexpectedly, B cells from SIgAD patients show a reduced proliferative response to CD40L. Our results demonstrate that functional tests are an important tool to assess the functions of the humoral immune system.
Immunological functional tests are useful tools to help the diagnostic workup of immunodeficiencies. We describe the response of B cells of children of different ages and adults to T‐independent and T‐dependent stimulation, and lay the groundwork to standardize tests to assess the functions of the humoral immune system in vitro.
Multi-stage tuberculosis (TB) vaccines composed of active- and dormancy-associated antigens are promising to trigger the immune protection against all TB stages. However, scientists are still in ...quest of the suitable vaccine candidates. In this study, we identified the potential targets for this vaccine in a high TB burden country, Thailand. Peptide microarray was applied to gauge IgA and IgG antibodies specific to 16,730 linear epitopes of 52 dormancy-associated Mycobacterium tuberculosis (M. tb) proteins in three study groups: active tuberculosis (ATB), latent tuberculosis infection (LTBI) and endemic healthy control (EHC). Preferential IgA recognition against epitopes of dormancy-associated proteins was identified in LTBI group. Validation of these findings revealed that LTBI subjects exhibited the greater levels of Rv2659c- and Rv1738-specific IgA than those of household contacts, but less than did ATB subjects. Frequencies of IFNγ-producing CD4
and CD8
T cells induced by proteins Rv2659c and Rv1738 were higher in LTBI than ATB individuals. The results indicated that LTBI group in a high TB burden country demonstrated cell-mediated immune response to proteins Rv2659c and Rv1738 stronger than those of ATB. These immune responses likely contribute to natural protection against dormant M. tb and might be potential targets for a multi-stage TB vaccine.
We conducted a randomized trial to evaluate whether melphalan-prednisone (MPH-P) treatment administered just after diagnosis improves survival of stage I multiple myeloma (MM). Between January 1987 ...and March 1993, 145 consecutive previously untreated patients with stage I MM were randomized between treatment with MPH-P (administered for 4 days every 6 weeks) just after diagnosis and treatment only at disease progression. Survival was not influenced by MPH-P treatment either administered just after diagnosis or at disease progression (64 vs 71 months respectively). Comparing the first with the second group the odds ratio of death is 1.17 (95% confidence interval 0.57-2.42; P = 0.64). Disease progression occurred within a year in about 50% of patients who were initially untreated. Response rate was similar in both groups, but duration of response was shorter in patients who were treated at disease progression (48 vs 79 months, P = 0.044). Patients actually treated at disease progression (34/70) survived shorter than those who had neither disease progression nor treatment (56 vs > 92 months; P = 0.005). Starting MPH-P just after diagnosis does not improve survival and response rate in stage I MM, with respect to deferring therapy until disease progression. However, patients with stage I MM randomized to have treatment delayed and who actually progressed and were treated had shorter survival than those with stable disease and no treatment. Biologic or other disease features could identify these subgroups of patients.
KRAS is a driver mutation for malignant transformation. It is found in 30% of all cancers and in 90% of pancreatic cancers. The identification of small molecules selectively inhibiting KRAS mutants ...has been challenging, yet mutant KRAS has recently been shown to be targeted by tumor-infiltrating lymphocyte (TIL)-derived T cells that confer tumor regression upon adoptive transfer. Furthermore, a human IgG1 monoclonal antibody interfering with mutant KRAS function inside the cell has been described to inhibit growth of KRAS-mutant xenografts in tumor-bearing mice. B cells have been described to infiltrate pancreatic cancer and may be associated with tertiary lymphoid structures associated with good prognosis, or, in contrast, promote tumor growth. However, their function, nor their antigen-specificity has been clearly defined. We discuss here the presence of tumor-infiltrating B cells (TIB) in patients with pancreatic cancer that produce KRAS-mutant specific IgG, underlining that intratumoral T and B cells may exclusively target mutant KRAS. KRAS-specific IgG may, therefore, serve as a readout of the activation of both arms of the anti-tumor adaptive immune armament although some B-cell populations may promote tumor progression.
Pancreatic cancer exhibits a poor prognosis and often presents with metastasis at diagnosis. Immunotherapeutic approaches targeting private cancer mutations (neoantigens) are a clinically viable ...option to improve clinical outcomes.
3/40 TIL lines (PanTT26, PanTT39, PanTT77) were more closely examined for neoantigen recognition. Whole-exome sequencing was performed to identify non-synonymous somatic mutations. Mutant peptides were synthesised and assessed for antigen-specific IFN-γ production and specific tumour killing in a standard Cr51 assay. TIL phenotype was tested by flow cytometry. Lymphocytes and HLA molecules in tumour tissue were visualised by immunohistochemistry.
PanTT26 and PanTT39 TILs recognised and killed the autologous tumour cells. PanTT26 TIL recognised the KRAS
mutation, while a PanTT39 CD4
TIL clone recognised the neoepitope (GLLRYWRTERLF) from an aquaporin 1-like protein (gene: K7N7A8). Repeated stimulation of TILs with the autologous tumour cells line lead to focused recognition of several mutated targets, based on IFN-γ production. TILs and corresponding PBMCs from PanTT77 showed shared as well as mutually exclusively tumour epitope recognition (TIL-responsive or PBMC-responsive).
This study provides methods to robustly screen T-cell targets for pancreatic cancer. Pancreatic cancer is immunogenic and immunotherapeutic approaches can be used to develop improved, targeted therapies.
Background. Human secretor-status is a strong susceptibility factor for norovirus infection in immunocompetent people. The predominant norovirus genotype GII.4 almost exclusively infects secretors ...and is also associated with more severe symptoms. However, it is not known to what extent this also applies to immunocompromised individuals. Our objective was to determine the importance of secretor-status and norovirus genotype for the susceptibility and/or the clinical course of norovirus infection in allogeneic hematopoietic stem cell transplant (HCT) patients. Methods: This was a retrospective study of 89 HCT patients diagnosed with norovirus infection. Secretor-status and norovirus genotype were determined using stored extracted DNA or blood (n = 89) and fecal samples (n = 22), respectively. Results: Seven of eighty-nine (8%) of the patients were secretor-negative, a small proportion compared to the expected rate of at least 20% non-secretors in the general Swedish population. Among the genotyped samples, norovirus genotype GII.4 was predominant (n = 12) and only detected in secretor-positive individuals. Patients with norovirus GII.4 had a median symptom duration of 36 (3–681) days compared to 15 (1–94) days in patients infected with other norovirus genotypes (n = 10, p = 0.1). Conclusions: The results suggest that secretor-status affects the susceptibility to norovirus infection even when the immune system is severely compromised. The norovirus genotype may also be a risk factor for chronic norovirus symptoms in immunocompromised patients.
Children with Down Syndrome (DS) suffer from immune deficiency with a severe reduction in switched memory B cells (MBCs) and poor response to vaccination. Chromosome 21 (HSA21) encodes two microRNAs ...(miRs), miR-125b, and miR-155, that regulate B-cell responses. We studied B- and T- cell subpopulations in tonsils of DS and age-matched healthy donors (HD) and found that the germinal center (GC) reaction was impaired in DS. GC size, numbers of GC B cells and Follicular Helper T cells (T
) expressing BCL6 cells were severely reduced. The expression of miR-155 and miR-125b was increased in tonsillar memory B cells and miR-125b was also higher than expected in plasma cells (PCs). Activation-induced cytidine deaminase (AID) protein, a miR-155 target, was significantly reduced in MBCs of DS patients. Increased expression of miR-155 was also observed
. MiR-155 was significantly overexpressed in PBMCs activated with CpG, whereas miR-125b was constitutively higher than normal. The increase of miR-155 and its functional consequences were blocked by antagomiRs
. Our data show that the expression of HSA21-encoded miR-155 and miR-125b is altered in B cells of DS individuals both
and
. Because of HSA21-encoded miRs may play a role also in DS-associated dementia and leukemia, our study suggests that antagomiRs may represent pharmacological tools useful for the treatment of DS.
The emergence of drug-resistant tuberculosis is challenging tuberculosis control worldwide. In the absence of an effective vaccine to prevent primary infection with Mycobacterium tuberculosis and ...tuberculosis disease, host-directed therapies may offer therapeutic options, particularly for patients with multidrug-resistant and extensively drug-resistant tuberculosis where prognosis is often limited. CD8+ and CD4+ T cells mediate antigen-specific adaptive cellular immune responses. Their use in precision immunotherapy in clinical conditions, especially in treating cancer as well as for prevention of life-threatening viral infections in allogeneic transplant recipients, demonstrated safety and clinical efficacy. We review key achievements in T-cell therapy, including the use of recombinant immune recognition molecules (eg, T-cell receptors and CD19 chimeric antigen receptors), and discuss its potential in the clinical management of patients with drug-resistant and refractory tuberculosis failing conventional therapy.
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