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Biomedical subjects

T R Cupps

Publications and source records attributed to T R Cupps.

At least 37 records · Page 2Linked to original sources

Anti-idiotype modulation of the in vitro immune response to hepatitis B surface antigen (HBsAg) following remote infection by hepatitis B virus in man.

An antigen-inhibitable Ab-2 that exhibits internal image activity will selectively stimulate the in vitro production of anti-HBs in individuals with remotely established immunity to hepatitis B virus. This response is seen (1) in the absence of a polyconal increase in total IgG, (2) with the F(ab')2 component of the Ab-2, (3) in cultures depleted of T-cells, and (4) in the absence of stimulation by antigen. This observation demonstrates that the Ab-2-mediated stimulation of specific IgG production may be an important regulatory function in man.

Adult↗

Suppression of B cell responses by natural killer cells is mediated through direct effects on T cells.

We examined the ability of human natural killer (NK) cells to modulate T cell-dependent mitogen-induced B cell responses. Highly purified NK cells inhibited the polyclonal antibody responses of autologous pokeweed mitogen (PWM)-stimulated unfractionated mononuclear cells in a reverse hemolytic plaque-forming cell (PFC) assay. Investigation of the possible mechanism(s) of the suppressor activity of NK cells revealed that lysis of mitogen-stimulated cells was unlikely. Chromium-51 release cytotoxicity assays of PWM-stimulated mononuclear cells did not demonstrate lysis by NK cells. Additionally, the monoclonal antibody 13.3, which abrogates NK cell cytolysis, did not reverse NK cell-dependent suppression of PFC formation. The putative lytic molecule elaborated by NK cells, NK cytotoxic factor, did not suppress B cell responses, further supporting a nonlytic inhibitory mechanism. That NK cell-derived lymphokines such as IFN-alpha, IFN-gamma, or IL-2 were uninvolved in the down-regulation of B cells was corroborated by the failure of antibodies to these mediators to reverse the suppression. NK cells did not suppress PFC formation when T cells were replaced by supernatants from PWM-stimulated T cells; additionally, NK cells had no effect on the generation of these necessary T cell factors. However, the coculture of T cells with NK cells resulted in the induction of suppressor activity within the T cell population suggesting that this was the mechanism of NK cell-mediated suppression of B cell responses.

Antibody Formation↗

An unusual case of central nervous system vasculitis.

A patient with CNS vasculitis limited to small vessels is described. Initial spinal cord involvement with paraparesis was followed by multifocal cerebral and cerebellar involvement, depicted by magnetic resonance imaging (MRI). She also had recurrent cerebral bleeding. A diagnosis of vasculitis was made by cerebral biopsy. Immunosuppressive therapy resulted in clinical improvement and resolution of the MRI abnormalities.

Biopsy↗

Sterile splenic abscesses in systemic Weber-Christian disease. Unique source of abdominal pain.

A patient with Weber-Christian disease and relapsing abdominal pain due to sterile splenic abscesses is presented. Histologically, acute and chronic inflammation with focal suppurative infiltrates of phagocytosed fat was detected in the absence of vascular or embolic disease, infection, or other apparent cause. Abdominal discomfort, an uncommon manifestation of Weber-Christian disease, usually is related to mesenteric panniculitis. Sterile splenic abscesses represent a previously undescribed complication of Weber-Christian disease, and another source of abdominal pain in this disorder. Although the precise pathophysiology of sterile splenic abscess formation in Weber-Christian disease is unknown, splenectomy is an effective means of alleviating pain.

Abdomen↗

Selective effects of cyclophosphamide therapy on activation, proliferation, and differentiation of human B cells.

The immune function of B lymphocytes from 12 patients with nonneoplastic immune-mediated diseases receiving chronic low-dose (2 mg/kg per d) cyclophosphamide (CY) was evaluated. There was a selective and differential suppressive effect of CY therapy on the various stages of the B cell cycle including activation, proliferation, and differentiation. The proliferative responses to Staphylococcus aureus Cowan strain I (SAC) and mitogenic concentrations of anti-mu were suppressed. In contrast, B cells that have been presumably activated in vivo proliferated with a normal pattern when exposed to B cell growth factor in vitro. Chronic low-dose CY therapy also suppressed B cell differentiation. Secretion of immunoglobulin by B cells following in vitro triggering with SAC and a T cell supernatant was suppressed in CY-treated patients. Moreover, differentiation of the large in vivo-activated B cells (which do not require an in vitro activation signal) in the presence of appropriate T lymphocyte supernatant was also suppressed. This selective suppression of B cell function at multiple points in the B cell cycle may be responsible for the efficacy of CY therapy in certain antibody and immune complex-mediated diseases.

Adolescent↗

Effects of in vitro corticosteroids on B cell activation, proliferation, and differentiation.

The present study demonstrates the graded effect of in vitro corticosteroids (CSs) on the different phases of B cell activation, proliferation, and differentiation. Early events such as activation and proliferation of high-dose anti-mu or Staphylococcus aureus-stimulated B cells are profoundly suppressed by the presence of in vitro CSs. The suppressed proliferative response may be mediated by a direct effect on B cells and/or modulation of accessory cell function. Later events in the B cell cycle such as the proliferative response to B cell growth factor after either in vivo or in vitro activation are less sensitive to the suppressive effects of in vitro CSs. The final events in the B cell cycle; namely, the differentiation to the immunoglobulin-producing state, is not suppressed by in vitro CSs. Indeed, depending on the systems employed, there is either no effect or enhancement of immunoglobulin secretion by the presence of in vitro CSs. The graded effect of in vitro CSs on the discrete phases of the B cell activation, proliferation, and differentiation cycle provide new insights into the complex nature of CS-induced modulation of human B cell responses.

Adult↗

Increased expression of HLA-DR antigens in hydrocortisone-treated monocytes.

Human peripheral blood monocytes incubated overnight with hydrocortisone had an increased expression of HLA-DR antigens. This change was noted as an increased proportion of DR-positive staining monocytes at greater fluorescence intensities as determined on a fluorescence-activated cell sorter. Hydrocortisone treatment of monocytes did not alter the expression of another Ia antigen on monocytes, HLA-DS. Neither did hydrocortisone treatment alter the expression of either Mac 120 antigen or monocyte .2 antigen on monocytes. Thus, the effect of hydrocortisone on monocyte DR antigens may be somewhat selective. Hydrocortisone also caused an increase in monocyte cell size after 3 to 4 days as compared to untreated controls.

Flow Cytometry↗

Hydrocortisone-mediated inhibition of monocyte antigen presentation: dissociation of inhibitory effect and expression of DR antigens.

The suppressive effects of hydrocortisone (HC) on the human immune system are well known. The mediation of the immunosuppressive effects of HC on lymphocyte responses via inhibition of monocyte function has been examined by monocyte-dependent, antigen-induced lymphocyte proliferation. Monocytes that were first treated with HC and then washed were unaffected in their subsequent ability to present antigen. However, there was a dramatic inhibition of lymphocyte proliferative responses if HC was present while monocytes were pulsed with antigen. This was directly related to the dose of HC present. HC-mediated inhibition of monocyte antigen presentation could not be overcome by the addition of interleukin-1 (IL-1) to cultures, and thus inhibition of monocyte IL-1 secretion cannot totally account for the inhibition of monocyte antigen presentation. Although HC inhibits monocyte antigen presentation, HC increases the expression of HLA-DR antigens on monocytes. Other monocyte stimulants, including lipopolysaccharide (LPS), lymphokine, and gamma interferon, were examined for their effect on monocyte DR expression and their effect on monocyte antigen presentation. No correlation was found between the ability to increase monocyte DR antigen expression and the effect on antigen presentation. While HC, lymphokine, and gamma interferon all increased the expression of DR antigens on monocytes, HC, LPS, and lymphokine, but not gamma interferon, inhibited monocyte antigen presentation. Although HC can exert profound immunosuppressive effects via monocytes, it is not the only mechanism of inhibition. HC added to cultures after monocytes had been pulsed with antigen was also inhibitory.

Antigens↗

Activation of human peripheral blood B cells following immunization with hepatitis B surface antigen vaccine.

To further evaluate the human immune response to hepatitis B surface antigen (HBsAg), we used an enzyme-linked immunosorbent assay to measure the in vitro production of antibody to HBsAg in normal individuals following booster immunization with the HBsAg vaccine. Following booster immunization, cells spontaneously secreting antibody to HBsAg were present in the peripheral blood. The specific antibody production was first detectable 4 days after booster immunization. The peak of specific antibody production was on Day 6, with resolution of the response by Day 9. The presence of these spontaneously secreting cells in the peripheral blood precedes the rise in serum antibody levels to HBsAg. The antibody secretion does not require the presence of accessory cells and is not enhanced by pokeweed mitogen, suggesting that these cells are quite advanced in the B-cell maturation sequence. The significance of these observations is discussed. Understanding the human immune response to HBsAg vaccine should provide insights into the immune regulatory abnormalities associated with disease states characterized by chronic hepatitis B antigenemia, including cryoglobulinemia, polyarteritis nodosa, and chronic hepatitis.

Adult↗

In vitro antigen-induced antibody responses to hepatitis B surface antigen in man. Kinetic and cellular requirements.

In this report we define the parameters of the human immune response after immunization with hepatitis B vaccine. 2 wk after booster immunization, there is significant spontaneous secretion of antibody to hepatitis B surface antigen (anti-HBs IgG), which is not further augmented by stimulation with antigen or pokeweed mitogen (PWM). By 4 wk there is little spontaneous secretion of specific antibody, and low doses of antigen or PWM produce significant increases in the amount of anti-HBs IgG produced. By 8 wk the peripheral blood mononuclear cells are refractory to stimulation by antigen, but anti-HBs IgG is produced in response to PWM. 0.5 yr or more after the last immunization, some individuals will manifest an antigen-induced specific antibody response. This induction of anti-HBs IgG by hepatitis B surface antigen (HBsAg) is monocyte- and T cell-dependent. Note that there is a dichotomy in the T cell response to HBsAg. The specific antibody response is clearly T cell dependent, but no in vitro T cell proliferative response to HBsAG could be demonstrated in the immunized individuals. Although the precise reason for the absent proliferative response to HBsAg despite well-established humoral immunity has not been determined, there was no evidence to suggest nonspecific suppression by HBsAg or the presence of an adherent suppressor cell population. The ability to evaluate antigen-induced, antigen-specific responses to HBsAg will be useful in defining the unique interaction between the human immune response and this clinically important viral agent.

Adult↗

Multiple mechanisms of B cell immunoregulation in man after administration of in vivo corticosteroids.

Despite the extensive clinical use of corticosteroids (CS) in the treatment of immune-mediated diseases, relatively little is known concerning the effects of CS on B cell function as measured by in vitro assays. The effects of single-dose vs several days of in vivo CS therapy on the spontaneous and mitogen-induced Ig production by human peripheral blood B cells are reported here. Spontaneous Ig production by individual B cells was enhanced by in vivo CS as measured by an in vitro plaque-forming cell (PFC) assay. The same increased response was also observed with a brief in vitro exposure of the B cells to CS, which suggests that a mere brief exposure to an active CS analogue is all that is required to produce the enhanced response. The immunoregulatory effects of in vivo CS on mitogen-induced Ig production are more complex. Pokeweed mitogen-induced PFC responses were suppressed 4 to 5 hr after a single in vivo pharmacologic dose of CS, with complete recovery by 24 hr. In contrast, after a 5-day course of CS, the suppressed PFC response did not recover until 60 hr after the last dose. Moreover, several mechanisms of suppression were operative. Ten hours after completing the 5-day course of CS, there was a relative enrichment in the peripheral blood compartment of lymphocytes bearing the OKT8 suppressor/cytotoxic T cell phenotype that coincided with a depressed PFC response. At 36 hr after the last dose, the T lymphocyte profile returned to normal while B cell function remained suppressed. The complex, multifaceted modulation of the immune response, resulting from redistribution of cell subsets as well as altered cell functions, vary with time-dose parameters of in vivo CS administration. These observations should provide additional insights into the heterogeneity of CS-induced therapeutic effects.

Adult↗

Neurological complications of vasculitis.

The vasculitides are a group of disorders that include the polyarteritis nodosa group of systemic necrotizing vasculitides, hypersensitivity vasculitis, Wegener's granulomatosis, lymphomatoid granulomatosis, giant cell arteritis, Behçet's disease, and isolated angiitis of the central nervous system. Classification is based on clinical, angiographic, and histological features. The frequency and distribution of neurological involvement vary with the underlying disorder and may provide the initial symptoms. Polyarteritis nodosa and Wegener's granulomatosis may affect both the central and peripheral nervous systems, whereas isolated angiitis of the central nervous system and Behçet's disease affect the central nervous system alone. Neurological dysfunction occurs in 80% of patients with polyarteritis nodosa and fewer than 10% of patients with hypersensitivity vasculitis. The mechanism of neurological dysfunction in the vasculitides is tissue ischemia. The clinical effects of ischemia vary, and symptoms may be transient or prolonged. Mononeuritis multiplex, polyneuropathy, and stroke are frequent complications, but encephalopathies, cranial neuropathies, and brachial plexopathies are seen as well. The occurrence of symptoms late in the course of a disease suggests ischemia resulting from healed, scarred vessels as well as from those that are acutely inflamed; this is the case in Takayasu's arteritis and possibly also in polyarteritis nodosa. Treatment is based on identifying and removing the sensitizing agent when possible. Wegener's granulomatosis requires therapy with cyclophosphamide; temporal arteritis, with corticosteroids. In other vasculitides a balance must be reached between the progression of the disease and the side effects of immunosuppression.

Behcet Syndrome↗

Isolated angiitis of the central nervous system. Prospective diagnostic and therapeutic experience.

Isolated angiitis of the central nervous system is an uncommon clinicopathologic entity characterized by vasculitis restricted to the vessels of the central nervous system without other apparent systemic vasculitis. Experience with the diagnosis, treatment, and follow-up evaluation in four patients with this disease is presented. Early manifestations of disease include severe headaches, altered mental function, and focal neurologic deficits. The pattern of progression from headaches and altered mental status to multifocal neurologic deficits is particularly suggestive of the diagnosis of vasculitis of the central nervous system. Systemic symptoms such as fever, myalgia, arthralgia, and arthritis, which occur frequently in other vasculitic syndromes, are generally not present in patients with isolated angiitis of the central nervous system. No single laboratory study can firmly establish or completely exclude the diagnosis; consequently, tissue diagnosis with biopsy of the brain parenchyma and leptomeninges may be required. In two patients, recurrent disease developed despite treatment with corticosteroids alone. Sustained clinical remission was induced in all four patients with a regimen of daily cyclophosphamide and alternate-day prednisone therapy. Cyclophosphamide and alternate-day prednisone therapy are considered the treatment of choice in severe, progressive, or corticosteroid-resistant isolated angiitis of the central nervous system.

Adult↗

High-dose immunoglobulin replacement therapy by slow subcutaneous infusion during pregnancy.

The slow, subcutaneous infusion method of immune human serum globulin replacement was used during pregnancy in a woman with common common variable immunodeficiency and splenectomy. Since this method allows high doses of immune human serum globulin to be given with little pain or morbidity, as much as 20 mL/day of immune human serum globulin was tolerated, normal serum IgG levels, were maintained, and the patient was free from serious infection throughout her pregnancy. The infant also had a normal IgG level at birth and had no evidence of intrauterine infection. This may be a preferable route of immune human serum globulin administration, especially during pregnancy and in other situations where high-dose therapy is advantageous.

Adult↗

Chronic, recurrent small-vessel cutaneous vasculitis. Clinical experience in 13 patients.

The clinical experience in 13 patients with small-vessel cutaneous vasculitis limited to the skin is presented. Within the spectrum of what is referred to as "hypersensitivity vasculitis," this group of patients represents a distinctive clinical entity characterized by (1) clinical, laboratory, and histopathologic features of the hypersensitivity vasculitis group; (2) chronic and recurrent isolated cutaneous vasculitis eruptions; (3) absence of disease progression to systemic involvement during long-term follow-up; and (4) relative unresponsiveness to immunosuppressive therapy, including treatment with corticosteroids (prednisone) and cyclophosphamide. Because this disease remains limited to the skin, potentially toxic immunosuppressive regimens with prolonged daily corticosteroids or cytotoxic agents should be avoided. Treatment of local symptoms, particularly lower extremity pain, remains a difficult treatment problem in some patients.

Adolescent↗