Berno Heymer

Immunohistological Characterization of the Cellular Immune Response against Yersinia enterocolitica in Mice: Evidence for the Involvement of T Lymphocytes

Previous work from this laboratory has demonstrated that cloned T lymphocytes from spleens of Yersinia-infected mice can transfer immunity against Y. enterocolitica into naive animals. In this study, we investigated the cellular immune response to parenteral infection of Yersinia-resistant C57 BL/6 mice with the highly virulent Y. enterocolitica strain WA of serotype O:8 employing immunohistological methods. In the course of the infection the spleen and the liver were the organs most extensively affected. Histologically, three different patterns of inflammatory reactions could be observed: (i) small non-pyogenic granuloma-like lesions (in the liver only), (ii) microabscesses lacking a sharp outline, and (iii) larger abscesses disclosing a distinct cellular border (spleen and liver). Immunohistologically, Y. enterocolitica was detectable within abscesses but not in the small granuloma-like lesions present in the liver. CD11b/18 positive cells (= Mac-1-antigen expressed on macrophages, monocytes, granulocytes and NK-cells) could be shown in Yersinia-induced lesions. The number of these cells correlated with the extent of tissue alterations induced by Y. enterocolitica. More strikingly, we were able to demonstrate for the first time that both CD4 (helper) and CD8 (cytotoxic) T lymphocytes are present in Yersinia-induced lesions. In summary, we could demonstrate for the first time that granuloma-like lesions can be induced by Y. enterocolitica. Moreover, we supported our recent study suggesting that T lymphocytes are probably involved in the immune response against Y. enterocolitica in mice.

Fatal B-cell lymphoproliferative syndrome in allogeneic marrow graft recipients. A clinical, immunobiological and pathological study.

SummaryWe have studied four cases of fatal B-cell lymphoproliferative syndrome (LPS) developing among 333 patients (incidence 1.2%) treated with allogeneic bone marrow transplantion (BMT). All four patients had received a T-cell depleted graft. Onset of the first clinical symptoms (palpable lymph node enlargement in three and IgA-lambda paraproteinemia in two patients) occurred between 41 and 188 days post-BMT (median 76 days). The course of the LPS was rapidly progressive in all cases, leading to death in 2–5 weeks. The peripheral blood showed progressive pancytopenia with disproportionally high numbers of activated NK cells, apparently compensating for the T-cell deficiency. Post-mortem histological studies disclosed polymorphic B-cell proliferations, most pronounced in the lymph nodes, spleen, liver, lungs and kidneys. Lymphohemopoietic cells were of donor origin in three patients. In the fourth patient, graft failure suggested a host origin for the proliferating cells. Immunophenotyping and gene rearrangement analysis revealed polyclonal proliferation in one patient, monoclonal proliferation in another patient, and an oligoclonal pattern in the other two patients. The clinical behavior of the LPS was independent of clonality. Immunohistologically, the proliferating cells showed characteristics of relatively mature B-cells in three cases, and pre-B-cell features in one case. Epstein Barr virus (EBV) serology indicated seroconversion (primary infection) in one child, and chronic active EBV infection in both adults. EBV DNA as well as EBV nuclear antigen (EBNA) were detected in infiltrated tissues of all four patients. The labeling pattern on in situ hybridization suggested a replicative EBV infection comparable to that in lymphoblastoid cells lines. We conclude that EBV-associated LPS developing as a result of post-transplant immunodeficiency is a distinct clinicopathologic entity, differing from non-Hodgkin’s lymphoma (including Burkitt’s lymphoma) and infectious mononucleosis of the immunocompetent host.

Pathomorphology of humoral, cellular and combined primary immunodeficiencies.

Histologic, immunohistologic and electron microscopic findings in three children with primary immunodeficiencies are reported. Classical X-linked infantile agammaglobulinemia Bruton was present in case 1 (♂, aged 16 years), selective cellular immunodeficiency with thrombopenia in case 2 (♂, aged 2 1/2 years) and non-lymphopenic severe combined immunodeficiency in case 3 (♂, aged 1 3/4 years). At autopsy, all three cases exhibited unusual types of pneumonia. In case 2 a generalized cytomegalovirus infection was present. Case 3 disclosed panmyelopathia and chronic liver lesions due to severe GvH-reaction subsequent to bone marrow transplantation. A detailed morphologic study of the immune system revealed distinct alterations in the thymus, spleen, and lymph nodes and the lymphatic tissues of the gastrointestinal tract characteristic of an immunodeficiency state, either humoral (case 1), cellular (case 2) or combined (case 3).

The Cellular Immune Response Against Yersinia enterocolitica in Different Inbred Strains of Mice: Evidence for an Important Role of T Lymphocytes

Resistance of mice against infection with Yersinia enterocolitica has been shown to be related neither to the Ity locus coding for resistance against infection with Salmonella typhimurium and other pathogens nor to the H-2 locus. From other mouse infection models, e.g., murine leishmaniasis, there is evidence that a different T cell-dependent regulation of the host immune response in various inbred strains of mice determines the susceptibility to the infectious agent. However, until recently, little was known about the cellular immune response against Y. enterocolitica. Thus, in a first approach we used the highly virulent Y. enterocolitica strain WA of serotype O:8 and different inbred strains of mice (C57 BL/6, Balb/c and athymic T cell-deficient C57 BL/6 nude mice) to investigate the cell-mediated immunity against parenteral infection. Comparison of the median lethal dose and of the net-bacterial growth in the spleens of infected mice indicated that Balb/c mice could be considered as Yersinia-susceptible whereas C57 BL/6 mice were relatively resistant. However, in contrast to normal C57 BL/6, athymic T cell-deficient C57 BL/6 nude mice have proved to be highly susceptible to Yersinia infection suggesting that T cells are required for the elimination of the pathogen. This conclusion was supported by histomorphological and immunohistological results indicating that T lymphocytes were present in Yersinia-induced tissue lesions. Moreover, the adoptive transfer of Yersinia-specific T cell lines and clones into naive animals mediated significant protection against the pathogen in both Yersinia-resistant C57 BL/6 and in Yersinia-susceptible Balb/c mice. These findings emphasize an important role of T lymphocytes in the host response against Y. enterocolitica infection.

Pathomorphologic Findings in Severe Combined Immunodeficiency and Reticular Dysgenesia

Pathomorphologic findings in an 11 month old boy with severe combined immunodeficiency (case 1) and in a 4 month old boy with reticular dysgenesia (case 2) are reported. Case 1: The bone marrow exhibited regular granule-, erythro- and thrombopoiesis. The hypoplastic thymus consisted exclusively of epithelial reticulum cells. The spleen and lymph nodes showed considerable depletion of lymphocytes in both the T- and B-cell areas. There was a complete lack of all lymphatic structures in the gastrointestinal tract and aplasia of the tonsils. Death resulted from Candida sepsis in conjunction with giant cell pneumonia closely resembling Hechts pneumonia in measles. Case 2: The bone marrow showed a total lack of granulopoiesis. The strongly dysplastic thymus weighed only 1 g. The spleen, the lymph nodes and the gastrointestinal tract exhibited a very strange histologie structure resulting from a complete absence of lymphocytes and plasma cells. The tonsils were aplastic, the parathyroid glands as well as the other endocrine glands were normally developed. The cause of death was Klebsiella sepsis and Pneumocystis pneumonia, the latter without the characteristic interstitial plasma cell infiltration. The importance of the immune system for activation of the nonspecific mechanisms of defense is discussed with respect to the two types of immunodeficiency states described here.

Immunoadjuvant Effects of the Synthetic Muramyl-Dipeptide (MDP) N-Acetylmuramyl-L-Alanyl-D-Isoglutamine

The adjuvant activity of the synthetic muramyl-dipeptide (MDP) N-acetyl-muramyl-L-alanyl-D-isoglutamine upon immunization of mice with BSA or SRBC was studied. MDP was found to significantly increase BSA-antibody formation and to favour the induction of anaphylactic reactions to BSA. In contrast, under the conditions employed, MDP only weakly stimulated the immune response to SRBC.

Induction of granulomatous hepatitis in mice infected with group A streptococci and treated with penicillin

Mice intravenously infected with group A streptococci and simultaneously treated with penicillin developed a granulomatous hepatitis closely resembling lesions induced by intravenous injection of heat killed streptococci. In these two experimental groups, only the initial phase of granuloma induction differed: in addition to macrophages and lymphocytes, polymorphonuclear granulocytes participated in granulomata elicited by live streptococci. The number and size of liver granulomata in both instances were correlated to the amount of streptococcal material present in the liver as detected by immunofluorescence and electron microscopic techniques. There was no evidence to suggest that penicillin treatment accelerated the elimination of streptococcal components from tissues. The analogy of these experimental liver lesions to “non-specific granulomatous hepatitis” in humans is discussed.

Vergleichende elektronenoptische und biochemische Untersuchungen über die Wirkung einerStreptomyces albus Endo-N-Acetyl-Muramidase auf die Streptokokkenzellwand

This paper describes the lysis of the cell walls of living group A streptococci by an endo-N-acetyl-muramidase fromStreptomyces albus (SA). The enzymatic action was studied by biochemical methods and electron microscopy over a period of 18 hr under isotonic and hypertonic conditions. The muralytic processes observed are discussed in connection with current knowledge of the structure of the streptococcal cell wall and with pertinent investigations by other authors.ZusammenfassungIn der vorliegenden Arbeit wird über die Muralyse lebender Gruppe A-Streptokokken durchStreptomyces albus (SA) Endo-N-Acetyl-Muramidase berichtet. Die enzymatische Zerstörung der Streptokokkenzellwand wurde sowohl unter isotonen als auch unter hypertonen Versuchsbedingungen über einen Zeitraum von 18 Std mit elektronenmikroskopischen und biochemischen Methoden verfolgt. Die beobachteten muralytischen Prozesse werden in bezug auf die heutigen Vorstellungen von der Struktur der Streptokokkenzellwand und in bezug auf vergleichbare Untersuchungen anderer Autoren diskutiert.

Reticuloendothelial system cells modifying bacterial antigen specificity

Natural infection with A-variant streptococci does not occur in man and is rarely seen in scientists working with these organisms [10], despite the fact tha t many individuals possess humoral antibodies against A-variant antigens [3,5]. In contrast, infections with group A streptococci are extremely common in man and are the antecedents of serious diseases such as rheumatic fever and glomerulonephritis [I0]. Streptococcal group-specificity has been based on solid grounds since clarification of the chemical [9] and antigenic [6] structure of the cell-wall C-carbohydrates. The group A-specific determinant is represented by a terminal fl-N-acctylglucosaminide residue at tached to trirhamnose side chains of the C-carbohydrate backbone, whereas the group A-variant determinant, lacking N-acetylglucosamine in the terminal position, is primarily constituted of rhamnose oligosaccharide [6]. Interestingly, C-carbohydrates possessing A-variant specificity have been detected in tissue extracts of mice injected with streptococcal cell-walls of group A [11, 12].

The cervical lymph nodes inStreptococcus pyogenes, group A, type 50, infection in mice

Streptococcus pyogenes, group A, type 50, one of the few group A streptococcal types naturally occuring in mice, proved highly virulent in this species after experimental infection. Intranasal infection of 96 mice (Swiss albino, NMRI, and CBA) with this microorganism induced profound reactions in the cervical lymph nodes of 69% of the animals. Histologically, two different forms of reaction were distinguishable. In 61 mice, the lymph nodes exhibited follicular and lymphoplasmacellular hyperplasia and in 9 animals suppurative lymphadenitis was present. The ability of type 50 streptococci to persist in the pharynx of mice, and the similarity of the morphological changes induced by this organism appear to make intranasal murine group A, type 50, streptococcal infection a suitable model for human streptococcal pharyngitis.