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K L Holmes

Publications and source records attributed to K L Holmes.

61 records · Page 4Linked to original sources
PubMed1984

Dissociation of severe lupus-like disease from polyclonal B cell activation and IL 2 deficiency in C3H-lpr/lpr mice.

The lymphoproliferation characteristic of all strains of mice homozygous for the gene lpr results from the expansion of an unusual subset of cells that express reduced levels of Ly-1 and Thy-1 antigens and high levels of Ly-5(B220), an antigen that is normally only detected on cells of the B lineage. In the present study, C3H-lpr mice were studied to determine when this population of cells first appears in lymph node (LN) and spleen and whether its appearance relates to the development of B cell activation and deficiencies in interleukin 2 (IL 2) production. The results showed that Ly-5(B220)+, sIg- cells were first detected in LN at 4 wk of age; thereafter their numbers increased exponentially until at 16 wk of age they represented more than 80% of LN cells. Two subpopulations of Ly-5(B220)+, sIg- cells were present in LN; one Ly-1+, Thy-1+ and the other Ly-1+, Thy-1-. Ly-5(B220)+, sIg- cells were not detected in C3H-lpr spleen until 6 to 10 wks after their appearance in LN, and their proportions never reached those in LN. Polyclonal B cell activation in C3H-lpr spleens was not observed until Ly-5(B220)+, sIg- cells were present, suggesting that this population may play a role in B cell stimulation. IL 2 production by C3H-lpr spleen and LN cells was normal up to 6 wk of age and was significantly impaired thereafter, with LN being more severely affected than spleen. The IL 2 defect could be significantly repaired by the addition of PMA to the cultures. Although defective IL 2 production coincided with the appearance of Ly-5(B220)+, sIg- cells in LN, it preceded the appearance of these cells in spleen. In spite of the impaired ability to produce IL 2 in vitro, CTL responses to alloantigens were normal. Although C3H-lpr mice share many of the lymphoid abnormalities observed in MRL-lpr mice, they do not develop severe, early-onset SLE-like disease characteristic of the latter strain. This suggests that factors other than defective IL 2 production and polyclonal B cell activation are required for the development of fulminant autoimmune disease.

Animals↗
PubMed1983

Transport of immune complexes from the subcapsular sinus to lymph node follicles on the surface of nonphagocytic cells, including cells with dendritic morphology.

The objective of the present study was to investigate the mechanism of antigen migration from the site of initial localization in the lymph node subcapsular sinus (SS) to regions of follicular retention in the cortex. The migration of horseradish peroxidase (HRP), used as a histochemically identifiable antigen, was followed by light and electron microscopy in C3H mouse popliteal lymph nodes obtained 1, 5, 15, and 30 min, and 5 and 24 hr after hindfoot pad injection of HRP. The observations showed that as early as 1 min after HRP injection, localization of antigen occurred at distinct sites in the SS and subjacent areas of the cortex on the afferent side. At these sites, between 1 min and 24 hr, the antigen formed light microscopically identifiable trails, which reached progressively deeper into the cortex with time toward individual follicular regions. By 24 hr this apparent migration of antigen was complete, and HRP was localized in follicles. This migration pattern did not occur on the efferent sides of lymph nodes, and it was dependent on the systemic presence of specific antibodies since it was observable only in passively immunized but not in nonimmune mice. Temporary retention of antigen by typical macrophages was also observed in the SS on the efferent side. This was minimal in nonimmune mice and was significantly enhanced in passively immunized mice. Electron microscopy indicated that the apparent migration of immune complexes was mediated by a group of cells observed in the migration path that had immune complexes sequestered on their surface or in plasma membrane infoldings. These antigen transporting cells (ATC) were relatively large nonphagocytic cells, with lobated or irregular euchromatic nuclei and cell processes of various complexity. ATC observed in or near the SS appeared to be less differentiated, were monocyte-like, and resembled non-Birbeck granule-containing Langerhans cell precursors or veiled cells. Others, located deeper in the cortex, appeared more differentiated, interdigitated with antigen-retaining dendritic cells, and shared morphologic characteristics with follicular dendritic cells (FDC). The results support the concepts that immune complexes are trapped in the SS and are transported by a group of non-phagocytic cells, other than lymphocytes, to follicular regions. The mechanism of transport may involve the migration of ATC with a concomitant maturation into FDC, or by a mechanism of ATC to FDC transport utilizing dendritic cell processes and membrane fluidity, or by a combination of the two mechanisms.

Animals↗
PubMed1982

Migration of chicken yolk sac cells to bursa of fabricius supernatants.

Investigators have suggested that a bursal chemotactic factor exists that selectively attracts hemopoietic stem cells. This theory was investigated by determining the ability of embryonic (10- through 14-day) bursal supernatants to cause migration of age-matched yolk sac cells using blind well chambers. Supernatants of 10, 11, 13 and 14-day bursae caused specific migration of yolk sac cells whereas 12-day bursal supernatants inhibited migration of 12-day yolk sac cells. Ten-day migrating cells consisted of pro- and basophilic erythroblasts and hemopoietic stem cells which formed erythroid colonies in a chorioallantoic membrane-colony forming unit (CAM-CFU) assay.

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PubMedDate not supplied

The effect of age on antigen retention in lymphoid follicles and in collagenous tissue of mice.

Our major objectives were to determine (1) when mice develop the cellular mechanisms necessary to trap and retain immune complexes in lymphoid follicles, (2) whether the ability to trap and retain immune complexes in lymphoid and collagenous tissues was maintained in old animals, and (3) whether the pattern of antigen localization in lymphoid follicles was altered as a consequence of ageing. Mice were passively immunized with a standardized amount of specific antibody and then challenged in the foot pads with radioactive antigen. The results indicated that newborn, and 1- and 2-week-old BALB/c mice lacked the cells or cellular mechanism necessary for trapping, localizing, and retaining immune complexes in lymphoid follicles. By 3 weeks, however, this ability to trap, retain, and localize antigen became apparent. The ability to trap and retain immune complexes on tendons and in lymphoid tissues was maintained as long as 27-30 months. A comparison of the quantity of antigen retained per mg of tissue in young-adult (6 months of age) and in old (27-30 months of age) mice indicated that old mice retained slightly more antigen in lymphoid tissues and substantially more on tendons. Antigen retained in spleens of both young-adult and old mice was localized in follicles by 24 h. However, the antigen retained in lymph nodes of old mice remained in the subcapsular sinus and adjacent superficial cortex and was not localized in follicles even after a full week. The cellular mechanisms necessary to trap and retain immune complexes in lymphoid tissue appear to develop in BALB/c mice a few weeks after birth and persist throughout life. However, localization of antigen in the lymphoid follicles of lymph nodes diminishes in old mice. The antigen trapping capability of collagenous tissues was not only maintained in old mice but was substantially increased.

Aging↗
PubMedDate not supplied

Induction of cytotoxic T-cell responses in vivo in the absence of CD4 helper cells.

Cytotoxic T lymphocytes (CTL) seem to provide the major line of defence against many viruses. CTL effector functions are mediated primarily by cells carrying the CD8 (Ly-2) antigen (CD8+ cells) and are triggered by interactions of the T-cell receptor with an antigenic complex, often termed 'self plus X', composed of viral determinants in association with class I molecules of the major histocompatibility complex (MHC). The mechanism(s) of induction of virus-specific CTL in vivo is poorly understood, but data from in vitro experiments suggest that their generation is strictly dependent on functions provided by CD4+ helper T cells (also referred to as L3T4+; or TH) that respond to antigens in the context of class II (Ia) MHC determinants. The prevailing opinion that induction of most functions of CD8+ cells requires help provided by CD4+ cells has recently been challenged by the observation that CD8+ cells alone can mediate a variety of responses to alloantigens in vitro and in vivo; however, the possibility that CTL to self plus X could be generated in vivo in the absence of TH cells has not been evaluated. We report here that C57BL/6J (B6) and AKR/J mice, when functionally depleted of CD4+ cells by in vivo treatment with the CD4+-specific rat monoclonal antibody GK1.5 (refs 8-14) responded to ectromelia virus infection by developing an optimal in vivo virus-specific CTL response, and subsequently recovered from the disease (mousepox) that was lethal for similarly infected nude mice (CD4-, CD8-).

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PubMedDate not supplied

Characteristics of a murine gammaherpesvirus infection immunocompromised mice.

BACKGROUND-MATERIALS: Mice with normal or impaired immune function were studied for responses to intranasal infection with MHV68, a gammaherpesvirus that acutely infects lung epithelial cells and establishes latency in B cells. Infection of normal mice induced a vigorous pulmonary inflammatory response composed of T, B, and NK cells and macrophages and stimulated activation and proliferation of T and B cells in spleen. METHODS-RESULTS-CONCLUSIONS: Resolution of the infection was associated with induction of MHV68-specific antibodies, but virus-specific cytotoxic T cells were not detected. Mice inoculated with retroviruses that induce severe immunodeficiency unexpectedly cleared MHV68 from lung in the same time-frame as controls and failed to develop latency as determined by infectious center tests of spleen cells. In contrast, control of MHV68 infection in spleen and/or lung was impaired in mice deficient in CD4+ or CD8+ T cells or both T cell subsets, B cells, IFN-gamma, or inducible nitric oxide synthase (iNOS). Infection was uniformly lethal in nude and iNOS-deficient mice and killed one-third of IFN-gamma-deficient mice. These results indicate that resistance to MHV68 is markedly influenced by expression of IFN-gamma from T cells leading to induction of iNOS and generation of nitric oxide.

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