Interaction of mouse splenocytes and macrophages with bacterial strains in vitro: the effect of age in the immune response.

Probiotics influence the immune system, both at the local and systemic level. Recent findings suggest the relation between microbiota and the immune system alters with age. Our objective was to address direct effects of six bacterial strains on immune cells from young and aged mice: Lactobacillus plantarum WCFS1, Lactobacillus casei BL23, Lactococcus lactis MG1363, Bifidobacterium breve ATCC15700, Bifidobacterium infantis ATCC15697, and Akkermansia muciniphila ATCC BAA-835. We used splenocytes and naïve or interferon-γ-stimulated bone marrow-derived macrophages (BMDM) as responder populations. All tested bacterial strains induced phenotypic and cytokine responses in splenocytes and BMDM. Based on magnitude of the cellular inflammatory response and cytokine profiles, two subgroups of bacteria were identified, i.e. L. plantarum and L. casei versus B. breve, B. infantis, and A. muciniphila. The latter group of bacteria induced high levels of cytokines produced under inflammatory conditions, including tumour necrosis factor (TNF), interleukin (IL)-6 and IL-10. Responses to L. lactis showed features of both subgroups. In addition, we compared responses by splenocytes and BMDM derived from young mice to those of aged mice, and found that splenocytes and BMDM derived from aged mice had an increased IL-10 production and dysregulated IL-6 and TNF production compared to young immune cells. Overall, our study shows differential inflammatory responses to distinct bacterial strains, and profound age-dependent effects. These findings, moreover, support the view that immune environment importantly influences bacterial immune effects.

Recent developments in basophil research: do basophils initiate and perpetuate type 2 T-helper cell responses?.

Basophils account for only 0.1-1% of all peripheral blood leukocytes. They were considered to be a redundant cell type for a long time. However, several findings show a non-redundant role for basophils in type 2 T-helper cell (Th2) immune responses in helminth infections, allergy and autoimmunity. Both immunoglobulin-E-dependent and -independent pathways have been described to contribute to basophil activation. In addition, several recent studies reported that basophils can function as antigen-presenting cells and are important in the initiation of Th2 immune responses. However, there are also conflicting studies that do not corroborate the importance of basophils in Th2 immune responses. This review discusses the role of basophils in Th2 immune responses in view of these recent findings.

Immunological characterization of non-Hodgkin's lymphoma: enrichment of neoplastic cells from lymphoid tissues and blood.

Cell suspensions prepared from lymph nodes, spleen or peripheral blood of patients with non-Hodgkin's lymphoma (NHL) often contain a high percentage of residual nonmalignant cellular elements. By E-rosette sedimentation, it was possible to enrich such suspensions from patients with various types of lymphoma for malignant cells. In patients with a B- or non-B/non-T-cell lymphoma, the neoplastic cells were found in the non-T fraction. The capacity to respond to stimulation by various stimuli was then confined to the T-cell fraction, which contained the residual normal T-cells. In patients with T-cell lymphomas, in which the malignant cells had retained the capacity to form E-rosettes, lymphoma cells were found in the T fraction. These cells usually did not respond to mitogenic stimuli. Using this separation method, small proportions of neoplastic cells could be identified in mixed cell populations. Thus, in the blood from nine out of 23 lymphoma patients without abnormalities in routine blood tests, a population of abnormal cells was detected after cell separation. This included a monoclonal B-cell population in the blood of four patients, a questionably monoclonal B-cell population in the blood of two patients and in increased non-B/non-T cell population in the blood of three patients.

Cryopreservation of cells for immunological typing of non-Hodgkin's lymphomas.

The influence of cryopreservation on markers and functions of cells from lymph node, spleen, and peripheral blood of patients with non-Hodgkin's lymphoma was investigated. For the markers and function tested, there were good correlations between the values obtained with fresh cells and those obtained with cryopreserved cells, proveded that cryopreserved cells were incubated for at least 3 hr at 37 degrees prior to testing.

Surface markers and functional properties of non-Hodgkin's lymphoma cells in relation to histology.

Cells from 32 adult patients with non-Hodgkin's lymphoma were studied with respect to surface markers and functional properties in short-term culture. Twenty-six lymphomas were of B-cell origin, including all nodular and diffuse lymphocytic lymphomas. Three tumors were of T-cell origin (one histiocytic lymphoma and two undifferentiated lymphomas). In the remaining three cases (histiocytic lymphomas) the immunological nature of the tumor cells could not be determined. All reactivity to mitogenic stimuli of cells from B-cell lymphomas was due to residual normal T cells. In follicular lymphocytic lymphomas more reactive T cells prevailed among the malignant B cells than in diffuse lymphocytic lymphomas. Heterogeneity among B-cell lymphomas was indicated by differences in intensity of fluorescence with anti-Ig reagents and in stimulatory capacity in mixed lymphocyte culture. T-cell lymphomas were characterized by high percentages of T cells together with impaired responses to stimuli. The results of immunological studies correlated well with the histological classifications of Rappaport, Lukes and Lennert.