Biomedical subjects
J Gossmann
Publications and source records attributed to J Gossmann.
Antiviral immune responses of fully allogeneic irradiation bone marrow mouse chimeras.
In (B10.BR----B10) chimeras infected with lymphocytic choriomeningitis (LCM) virus higher titers were attained in spleens and livers than in organs of the mice used for their construction, and the subsequent elimination was retarded, but eventually the virus was cleared. The numbers of LCM virus-specific CTL and their precursors as quantitated with chromium-release assay and limiting dilution method, respectively, were lower in chimeras than in B10.BR or C57BL/10J mice, and fewer were restricted for the haplotypes of the donors than of the recipients. The same was true with regard to antiviral effector cells, which were determined by adoptive immunization. The numbers of spleen cells releasing IgM and IgG antiviral antibodies were virtually as high in chimeras as they were in C57BL/10J and B10.BR mice. Transfer of immune splenocytes from either B10.BR or C57BL/10J mice resulted in incomplete virus elimination from the spleens of infected chimeras, whereas injection of a mixture of the two types of immune cells led to efficient clearance. We conclude that in the chimeras cells of both donor and recipient haplotypes participate in the infection, which is terminated by H-2k- and H-2b-restricted T lymphocytes that these animals are capable of generating. We conclude, furthermore, that clearance of the LCM virus from the tissues requires contact between effector and target cells.
Entry of antivirally active T lymphocytes into the thymus of virus-infected mice.
The thymus has long been regarded as an immunologically "privileged site" by being shielded against the entry of exogenous Ag as well as protective elements of the immune system. After i.p. infection of mice, the lymphocytic choriomeningitis virus multiplied in this organ. Viral Ag was found predominantly in the epithelial-reticular cells of the medulla and to a lesser extent in such cells of the cortex. Beginning on day 7 after infection, the virus disappeared, a process that could be blocked by depleting the mice of peripheral T lymphocytes or of CD8+ cytotoxic T lymphocytes. Viral clearance was accelerated by i.v. injection of splenocytes from mice, which themselves were just eliminating the virus. CD8+ cells from CD8-congenic donor mice, most with blast morphology, were detected immunocytochemically in the thymus, predominantly in the medulla. A few CD8+ T lymphocytes from donors not previously infected were also demonstrated in the thymic tissue of infected mice. Our findings indicate that the lymphocytic choriomeningitis virus has access to the thymus and suggest that it is cleared by the antiviral activity of circulating cytotoxic T lymphocytes. Thus, just as other organs, the thymus appears to be subject to immune surveillance by mature T lymphocytes that have their origin in secondary lymphoid tissues.
Virus-specific delayed-type hypersensitivity (DTH). Cells mediating lymphocytic choriomeningitis virus-specific DTH reaction in mice.
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+ cells or systemic treatment with IL-2 and that it developed in the absence of detectable numbers of mononuclear phagocytes, whereas the later CD4+ cell part required monocytes or related elements. Furthermore, in the DTH reaction that was elicited with noninfectious viral Ag in mice previously immunized by infection, only the CD4+ cells participated. Thus, the two phases of the lymphocytic choriomeningitis-viral DTH reaction are principally different, which has to be taken into account when trying to assess the relevance of DTH during this virus infection.
Mechanism of recovery from acute virus infection. IX. Clearance of lymphocytic choriomeningitis (LCM) virus from the feet of mice undergoing LCM virus-specific delayed-type hypersensitivity reaction.
As shown previously, after inoculation into the footpad of a mouse the lymphocytic choriomeningitis (LMC) virus multiplies locally. Beginning on day 6 or 7 after infection, the foot undergoes a delayed-type hypersensitivity (DTH) reaction which consists of two distinct phases that are mediated by CD8+ cells and CD4+ cells, respectively, and at about the same time the virus is eliminated. In general, for terminating infection of the mouse with LCM virus the CD8+ cytotoxic/suppressive T lymphocyte (CTL) is essential; we have now determined the cells that mediate control of the virus in a tissue undergoing a specific DTH reaction. Depletion, in infected mice, of all T lymphocytes by treatment with anti-Thy-1 monoclonal antibody prevented virus elimination from the foot, and the same was true when the CD8+ CTLs were removed. Depletion of the CD4+ helper/suppressor subset only marginally impaired the ability of the mice to rid themselves of the virus. The conclusion that here too the principal antiviral element is the CD8+ CTL was confirmed by experiments in which footpad-infected mice were adoptively immunized with virus-immune splenocytes from syngeneic mice selected for subclasses of T lymphocytes, or from mice differing in defined regions of the major histocompatibility complex (MHC), and also by experiments in which monocytes were virtually absent. However, CD8+ CTL alone or cells from MHC recombinant mice with identity in class I loci were never as antivirally active as unseparated splenocytes from syngeneic donor mice. Since the CD8+ cells' performance could be optimized by interleukin-2, we assume that the CD4+ T lymphocytes function as accessory cells; the same probably applies to monocytes.