99 research outputs found
Modulation of testicular macrophage activity by collagenase
Testicular macrophages (TMs) are located in the interstitial tissue of male gonad. These phagocytic cells take part in
forming the organ-specific functional blood-testis barrier and participate in the regulation of the local hormonal balance. In the present
study, we isolated TMs from testicular tissues using previously described methods - mechanical (M-TMs) or enzymatic, by treatment
with collagenase (E-TMs) and then we studied production by these cells of several cytokines and reactive oxygen intermediates
(ROI’s). Similarly treated oil-induced peritoneal macrophages (PMs) were used as control cells. PMs had a higher baseline level of
production of TNF-α, IL-6, IL-10 and IL-12 than M-TMs and collagenase treatment increased the production of these cytokines
(except IL-12) by both cell populations. This effect was significantly more expressed in TMs. In contrast to PMs, TMs produced
little ROI’s when stimulated by zymosan. We conclude that in the case of local inflammation in the testis, ROI-negative TMs do not
contribute to the tissue damage and instead may direct the local immune response into humoral pathway
Epicutaneous immunization with ovalbumin and CpG induces TH1/TH17 cytokines, which regulate IgE and IgG2a production
Background: Subcutaneous allergen-specific immunotherapy is
a standard route for the immunotherapy of allergic diseases. It
modulates the course of allergy and can generate long-term
remission. However, subcutaneous allergen-specific
immunotherapy can also induce anaphylaxis in some patients,
and therefore additional routes of administration should be
investigated to improve the safety and tolerability of
immunotherapy.
Objective: We sought to determine whether epicutaneous
treatment with antigen in the presence of a Toll-like receptor 9
agonist can suppress TH2-mediated responses in an antigenspecific manner.
Methods: Epicutaneous immunization was performed by
applying a skin patch soaked with ovalbumin (OVA) plus CpG,
and its suppressor activity was determined by using the mouse
model of atopic dermatitis. Finally, adoptive cell transfers were
implemented to characterize the regulatory cells that are
induced by epicutaneous immunization.
Results: Epicutaneous immunization with OVA and CpG
reduces the production of OVA-specific IgE and increases the
synthesis of OVA-specific IgG2a antibodies in an antigen-specific
manner. Moreover, eosinophil peroxidase activity in the skin
and production of IL-4, IL-5, IL-10, and IL-13 are suppressed.
The observed reduction of IgE synthesis is transferable with
T-cell receptor (TCR) ab1CD41CD252 cells, whereas IgG2a
production is dependent on both TCRab1 and TCRgd1 T cells.
Further experiments show that the described phenomenon is
myeloid differentiation primary response 88, IFN-g, and
IL-17A dependent. Finally, the results suggest that epicutaneous
immunization with OVA and CpG decreases the synthesis of
OVA-specific IgE and skin eosinophil peroxidase activity in mice
with ongoing skin allergy.
Conclusion: Epicutaneous application of protein antigen in
the presence of adjuvant could be an attractive needle-free and
self-administered immunotherapy for allergic diseases
THE INFLUENCE OF THE REPRODUCTIVE SYSTEM MICROBIOTA ON FEMALE AND MALE FERTILITY. THE ROLE OF LACTOBACILLUS BACTERIA
Neutrophil-derived myeloperoxidase facilitates both the induction and elicitation phases of contact hypersensitivity
Cutaneous Immunization Rapidly Activates Liver Invariant Vα14 NKT Cells Stimulating B-1 B Cells to Initiate T Cell Recruitment for Elicitation of Contact Sensitivity
T cell recruitment to elicit contact sensitivity (CS) requires a CS-initiating process mediated by B-1 cells that produce IgM, which activates complement to promote T cell passage into the tissues. We now show that Vα14i NKT cells induce B-1 cell activation likely by releasing IL-4 early postimmunization. The CS initiation process is absent in Jα18−/− and CD1d−/− NKT cell–deficient mice and is reconstituted by populations enriched for Vα14i NKT cells. Transfers are not effective if cells are derived from IL-4−/− mice. Staining with specific tetramers directly showed that hepatic Vα14i NKT cells increase by 30 min and nearly double by 2 h postimmunization. Transfer of immune B-1 cells also reconstitutes CS responses in NKT cell–deficient mice. The B-1 cells act downstream of the Vα14i NKT cells to restore CS initiation. In addition, IL-4 given systemically to Jα18−/− or CD1d−/− NKT cell–deficient mice reconstitutes elicitation of CS. Further, splenocytes from immune Jα18−/− mice produce less antigen (Ag)-specific IgM antibodies compared with sensitized WT mice. Together these findings indicate that very early after skin immunization Vα14i NKT cells are stimulated to produce IL-4, which activates B-1 cells to produce Ag-specific IgM, subsequently needed to recruit effector T cells for elicitation of CS responses
- …