Treatment of an Intramammary Bacterial Infection with 25-Hydroxyvitamin D3

Deficiency of serum levels of 25-hydroxyvitamin D3 has been correlated with increased risk of infectious diseases such as tuberculosis and influenza. A plausible reason for this association is that expression of genes encoding important antimicrobial proteins depends on concentrations of 1,25-dihydroxyvitamin D3 produced by activated immune cells at sites of infection, and that synthesis of 1,25-dihydroxyvitamin D3 is dependent on the availability of 25-hydroxyvitamin D3. Thus, increasing the availability of 25(OH)D3 for immune cell synthesis of 1,25-dihydroxyvitamin D3 at sites of infection has been hypothesized to aid in clearance of the infection. This report details the treatment of an acute intramammary infection with infusion of 25-hydroxyvitamin D3 to the site of infection. Ten lactating cows were infected with in one quarter of their mammary glands. Half of the animals were treated intramammary with 25-hydroxyvitamin D3. The 25-hydroxyvitamin D3 treated animal showed significantly lower bacterial counts in milk and showed reduced symptomatic affects of the mastitis. It is significant that treatment with 25-hydroxyvitamin D3 reduced the severity of an acute bacterial infection. This finding suggested a significant non-antibiotic complimentary role for 25-hydroxyvitamin D3 in the treatment of infections in compartments naturally low in 25-hydroxyvitamin D3 such as the mammary gland and by extension, possibly upper respiratory tract infections

The role of vitamin D in pulmonary disease: COPD, asthma, infection, and cancer

The role of vitamin D (VitD) in calcium and bone homeostasis is well described. In the last years, it has been recognized that in addition to this classical function, VitD modulates a variety of processes and regulatory systems including host defense, inflammation, immunity, and repair. VitD deficiency appears to be frequent in industrialized countries. Especially patients with lung diseases have often low VitD serum levels. Epidemiological data indicate that low levels of serum VitD is associated with impaired pulmonary function, increased incidence of inflammatory, infectious or neoplastic diseases. Several lung diseases, all inflammatory in nature, may be related to activities of VitD including asthma, COPD and cancer. The exact mechanisms underlying these data are unknown, however, VitD appears to impact on the function of inflammatory and structural cells, including dendritic cells, lymphocytes, monocytes, and epithelial cells. This review summarizes the knowledge on the classical and newly discovered functions of VitD, the molecular and cellular mechanism of action and the available data on the relationship between lung disease and VitD status

Regulation of Mycobacterium-Specific Mononuclear Cell Responses by 25-Hydroxyvitamin D3

The active vitamin D metabolite, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), has been shown to be an important regulator of innate and adaptive immune function. In addition, synthesis of 1,25(OH)2D3 from 25-hydroxyvitamin D3 (25(OH)D3) by the enzyme 1α-hydroxylase in monocytes upon activation by TLR signaling has been found to regulate innate immune responses of monocytes in an intracrine fashion. In this study we wanted to determine what cells expressed 1α-hydroxylase in stimulated peripheral blood mononuclear cell (PBMC) cultures and if conversion of 25(OH)D3 to 1,25(OH)2D3 in PBMC cultures regulated antigen-specific immune responses. Initially, we found that stimulation of PBMCs from animals vaccinated with Mycobacterium bovis (M. bovis) BCG with purified protein derivative of M. bovis (M. bovis PPD) induced 1α-hydroxylase gene expression and that treatment with a physiological concentration of 25(OH)D3 down-regulated IFN-γ and IL-17F gene expression. Next, we stimulated PBMCs from M. bovis BCG-vaccinated and non-vaccinated cattle with M. bovis PPD and sorted them by FACS according to surface markers for monocytes/macrophages (CD14), B cells (IgM), and T cells (CD3). Sorting the PBMCs revealed that 1α-hydroxylase expression was induced in the monocytes and B cells, but not in the T cells. Furthermore, treatment of stimulated PBMCs with 25(OH)D3 down-regulated antigen-specific IFN-γ and IL-17F responses in the T cells, even though 1α-hydroxylase expression was not induced in the T cells. Based on evidence of no T cell 1α-hydroxylase we hypothesize that activated monocytes and B cells synthesize 1,25(OH)2D3 and that 1,25(OH)2D3 down-regulates antigen-specific expression of IFN-γ and IL-17F in T cells in a paracrine fashion

1 alpha,25-Dihydroxyvitamin D3-binding macromolecules in human B lymphocytes: effects on immunoglobulin production.

Abstract Previous studies have indicated that upon in vitro activation with mitogenic lectins, human peripheral blood T lymphocytes express receptors for the steroid hormone 1 alpha, 25-dihydroxyvitamin D3(1,25(OH)2D3). Furthermore, the hormone can inhibit interleukin 2 production by the activated cells. In this investigation, we report that human peripheral B lymphocytes activated in vitro with the B lymphotropic Epstein-Barr virus (EBV) also express 1,25(OH)2D3 receptor-like macromolecules. These receptors are localized in the cell nucleus and exhibit properties similar to those found in classical target tissues for 1,25(OH)2D3. They sediment on sucrose gradients at 3.3 S, display a dissociation constant (Kd) of 4 X 10(-10) M, and can bind to DNA. In addition to the 1,25(OH)2D3 receptors, however, EBV-activated lymphocytes express a second class of 1,25(OH)2D3-binding proteins that appear to occur mainly in the cell cytosol and exhibit distinct biochemical properties from the receptor, including higher sedimentation coefficients (3.7 S to 4 S) and the lack of ability to bind to DNA. The addition of 1,25(OH)2D3 to cultures of EBV-infected cells inhibited the production of IgM and IgG by the B cells. The vitamin D3 analog 24,25(OH)2D3 did not inhibit Ig production, thus suggesting that the effect is probably mediated through the high affinity receptor macromolecule localized in the nucleus. Because the EBV-induced Ig production is independent of T cell participation, the data also suggest that the effects of 1,25(OH)2D3 are exerted directly on the B cell. The present results add to the evidence of the importance of 1,25(OH)2D3 as an immunoregulatory hormone.</jats:p

Interferon-gamma-induced IA expression in WEHI-3 cells is enhanced by the presence of 1,25-dihydroxyvitamin D3.

Abstract It has been suggested recently that 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] is involved in the regulation of the immune functions of lymphocytes and in the differentiation of monocytic cells. This report examined the possibility that 1,25(OH)2D3 influences immune functions mediated by monocytic cells by studying its effect on the murine myelomonocytic line WEHI-3. We found that WEHI-3 cells possess 3.3S receptor proteins with high affinity (Kd = 3.3 X 10(-10) M) for 1,25(OH)2D3 that are capable of binding to DNA. Also we found that 1,25(OH)2D3 enhances the interferon-gamma (IFN-gamma)-induced expression of the class II major histocompatibility complex antigens (Ia molecules), and such enhancement leads to increased capacity of the WEHI-3 cells to stimulate antigen-specific Ia-restricted T cell activation. Finally, 1,25(OH)2D3 inhibits the proliferation of WEHI-3 cells, and this inhibition is enhanced in the presence of IFN-gamma. The 1,25(OH)2D3 modulation of IFN-gamma induction of Ia antigens suggests that the hormone might promote monocytes to function more efficiently as antigen-presenting cells.</jats:p