Cell-mediated immunity includes both the generation of cytotoxic cells and initiation of delayed-type hypersensitivity (DTH). The resting T-cell population, before stimulation by antigen, already contains cells of the Lyl subclass that are programmed to initiate DTH (and helper function) but not cytotoxic responses, as well as Ly23 cells which can generate killer activity (and suppressive funct...

We had previously shown that the local lymphocytic choriomeningitis virus-induced delayed-type hypersensitivity (DTH) reaction in mice consists of two well delineated phases that are mediated by CD8+ and CD4+ T lymphocytes, respectively. These findings have been confirmed and extended by showing that the first CD8+ cell-dependent part of the response was enhanced by either the presence of CD4+ ...

The objective of this study was to investigate the immunomodulatory efficacy of drugs (Praziquantel and Ivermectin) in Hymenolepis diminuta infected mice. The drugs were administrated to the infected mice on 13 , 14 and 15 post infection days. The immunomodulation due to test drugs was observed th th th on PCA and DTH response. PCA and DTH reactions were found to be directly proportional to the...

In four different systems it was shown that murine delayed-type hypersensitivity (DTH) responses at 18-48 h were preceded by early 2-h responses. CBA mice immunized with picryl chloride, BDF1 mice immunized with oxazolone, BALB/c mice immunized with dinitrofluorobenzene, and C57BL/6 mice immunized with L5178Y lymphoma cells, and challenged with the appropriate specific antigen, all gave rise to...

It is well established that females mount stronger immune responses than males, but only very little is understood about the underlying mechanisms. We have analyzed local cytokine differences among intact females, those that had been ovariectomized (OVX), those receiving estrogen replacement after OVX, and males, both before and after production of delayed-type hypersensitivity (DTH) responses....

The introduction of antigen into the anterior chamber (AC) of the eye induces the production of antigen-specific splenic CD8(+) regulatory T cells (AC-SPL cells) that suppress a delayed-type hypersensitivity (DTH) reaction in immunized mice. Because the generation of these regulatory T cells is also induced by exposure to transforming growth factor (TGF)-beta and antigen or F4/80(+) cells expos...

BACKGROUND Protection and recovery from visceral leishmaniasis (VL) have been associated with cell-mediated immune (CMI) responses, whereas no protective role has been attributed to humoral responses against specific parasitic antigens. In this report, we compared carefully selected groups of individuals with distinct responses to Leishmania chagasi to explore antigen-recognizing IgG present in...

The systemic injection of high doses of antigen into a preimmunized animal results in transient unresponsiveness of cell-mediated immune responses. This phenomenon is known as desensitization. Serum interleukin 2 (IL-2) activity was found transiently in desensitized mice at 3 h after the antigen challenge. These mice could not reveal antigen nonspecific delayed-type hypersensitivity (DTH) 1 d a...

BACKGROUND Delayed-type hypersensitivity (DTH) test responsiveness is associated with HIV disease progression; however it is unknown whether other immune markers, such as hepatitis B virus (HBV) vaccine seroresponse, also predict HIV outcomes. METHODS Eligible participants received HBV vaccine after HIV diagnosis, had non-anergic DTH testing at the time of last HBV vaccination, and available ...

Days to harvest (DTH) is the number of days a lamb is fed before reaching a target level of fatness. Although economically relevant, this trait has not been thoroughly evaluated in sheep. Most lambs harvested in the United Kingdom are crossbreds sired by purebred terminal sires, with Charollais, Suffolk, and Texel most commonly used. Sires from these breeds were selected on an index designed to...